Service manual

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SERVICE MANUAL

MODEL: MFC8420/8820D/8820DN

DCP8020/8025D/8025DN

Read this manual thoroughly before maintenance work.

Keep this manual in a convenient place for quick and easy reference at all times.

Summary of content (353 pages)

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SERVICE MANUAL MODEL: MFC8420/8820D/8820DN DCP8020/8025D/8025DN Read this manual thoroughly before maintenance work. Keep this manual in a convenient place for quick and easy reference at all times.
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© Copyright Brother Industries, Ltd. 2003 All rights reserved. No part of this publication may be reproduced in any form or by any means without permission in writing from the publisher. Specifications are subject to change without notice. Trademarks: The brother logo is a registered trademark of Brother Industries, Ltd. Apple, the Apple Logo, and Macintosh are trademarks, registered in the United States and other countries, and TrueType is a trademark of Apple computer, Inc.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL PREFACE This publication is a Service Manual covering the specifications, construction, theory of operation, and maintenance of the Brother machine. It includes information required for field troubleshooting and repair--disassembly, reassembly, and lubrication--so that service personnel will be able to understand machine function, to rapidly repair the machine and order any necessary spare parts.
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TABLE OF CONTENTS TABLE OF CONTENTS REGULATION ............................................................................................ viii SAFETY INFORMATION .............................................................................. x CHAPTER 1 GENERAL........................................................................... 1-1 1. OVERVIEW ............................................................................................................ 1-1 2. SPECIFICATIONS .......................
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.2.2 For Parallel Interface Cable Users ® (For Windows 95/98/98SE/Me/2000 Professional/XP) ...................................................2-13 ® 3.2.3 For Windows NT Workstation Version 4.0 Users ............................................................2-18 3.2.4 For Network Interface Cable Users ® (For Windows 95/98/98SE/Me/NT/2000 Professional/XP) ..............................................2-20 ® 3.2.
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TABLE OF CONTENTS 2.4.9 Rear cover sensor .............................................................................................................3-21 2.4.10 HP sensor .........................................................................................................................3-21 2.5 Drum Unit ....................................................................................................................... 3-22 2.5.1 2.5.2 2.5.3 2.5.4 2.6 2.7 Photosensitive drum..................
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.28 3.29 3.30 3.31 3.32 3.33 Paper Feeder.................................................................................................................. 4-71 Frame L / Drive Unit ....................................................................................................... 7-78 Reversing Release Solenoid (MFC-8820D/8820DN, DCP-8025D/8025DN only).......... 4-82 Thermistor ASSY...........................................................
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TABLE OF CONTENTS 3.4 Paper Feeding Problems................................................................................................ 6-18 4. SOFTWARE SETTING PROBLEMS .................................................................... 6-20 5. MALFUNCTIONS.................................................................................................. 6-23 6. TROUBLESHOOTING OF THE CONTROL PANEL ............................................. 6-28 7. TROUBLESHOOTING OF FAX FUNCTIONS .......
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 Fine Adjustment of Scan Start/End Positions (Maintenance mode 54).......................... 7-18 CCD Scanner Area Setting (Maintenance mode 55) ..................................................... 7-20 EEPROM Customizing (Maintenance mode 74) ............................................................ 7-21 Printing out of Machine Log Information (Maintenance mode 77)..................................
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REGULATION REGULATION LASER SAFETY (110 - 120V MODEL ONLY) This printer is certified as a Class I laser product under the US Department of Health and Human Services (DHHS) Radiation Performance Standard according to the Radiation Control for Health and Safety Act of 1968. This means that the printer does not produce hazardous laser radiation. Since radiation emitted inside the printer is completely confined within the protective housing and external covers.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL IEC 825 (220-240V MODEL ONLY) This printer is a Class I laser product as defined in IEC 825 specifications. The label shown below is attached in countries where required. CLASS 1LASERP RODUCT APPAREIL Å LASER DE CLASSE 1 LASER KLASSE 1 PRODUKT This printer has a laser diode which emits invisible laser radiation in the Laser Unit.
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SAFETY INFORMATION SAFETY INFORMATION CAUTION FOR LASER PRODUCT (WARNHINWEIS FUR LASER DRUCKER) CAUTION: When the machine during servicing is operated with the cover open, the regulations of VBG 93 and the performance instructions for VBG 93 are valid. CAUTION: In case of any trouble with the laser unit, replace the laser unit itself. To prevent direct exposure to the laser beam, do not try to open the enclosure of the laser unit.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL DEFINITIONS OF WARNINGS, CAUTIONS AND NOTES The following conventions are used in this service manual: WARNING Indicates warnings that must be observed to prevent possible personal injury. ! CAUTION: Indicates cautions that must be observed to service the printer properly or prevent damage to the printer. NOTE: Indicates notes and useful tips to remember when servicing the printer.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL CHAPTER 1 1. GENERAL OVERVIEW ADF document support extension Automatic document feeder (ADF) Control panel ADF document output support flap Face-down output tray support flap Document cover Front cover release button Manual feed tray (MFC-8420, DCP-8020) Multi-purpose tray (MP tray) (MFC-8820D/8820DN, DCP-8025D/8025DN) Power switch Front cover Paper tray (Tray #1) Fig.
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CHAPTER 1 GENERAL Document cover White film Scanner lock lever Glass strip Document guidelines Scanner glass Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2. 2.1 2.
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CHAPTER 1 GENERAL 2.3 Print Media Paper Input • Paper type: Plain paper, recycled paper and transparencies, envelopes (Manual Feed/Multi-purpose Tray) • Paper size: A4, Letter, Legal, B5 (ISO), B5 (JIS), Executive, A5, A6, B6 (ISO) 2 Weight: 16 - 28 lb (60 - 105 g/m ) (Paper Tray) For more details, see Paper specifications for each paper tray on page 1-10. • Maximum paper tray capacity: 2 Approx.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.5 Fax Compatibility ITU-T Group 3 Coding System MH/MR/MMR/JBIG Modem Speed 33600-2400 bps Automatic Fallback Original Size ADF Width: 5.8" to 8.5" (148 mm to 216 mm) ADF Height: 5.8" to 14.0" (148 mm to 356 mm) Scanner Width: Max. 8.48" (212 mm) Scanner Height: Max. 14.0" (356 mm) Scanning Width 8.2 inches (208 mm) Printing Width 8.
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CHAPTER 1 GENERAL 2.6 Scanner Color/Monochrome Color/Monochrome TWAIN Compliant Yes (Windows 95/98/98SE/Me/2000 Professional and Windows ® NT Workstation Version 4.0) WIA Compliant Yes (Windows XP) Resolution Up to 9,600 x 9,600 dpi (interpolated)* Up to 600 x 2,400 dpi (optical) ® * Maximum 1200 x 1200 dpi scanning with Windows XP (resolution up to 9600 x 9600 dpi can be selected by using the Brother scanner utility) Document Size ADF Width: 5.8" to 8.5" (148 mm to 216 mm) ADF Height: 5.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.8 Interfaces Interface Recommended Cable Parallel A bi-directional shielded parallel cable that is IEEE 1284 compliant and not longer than 6 feet (2 m). USB A Hi-Speed USB 2.0 cable that is not longer than 6 feet (2 m). NOTE: • Please make sure that you use a Hi-Speed USB 2.0 certified cable if your computer uses a Hi-Speed USB 2.0 interface. • Even if your computer has a USB 1.1 interface you can connect the MFC.
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CHAPTER 1 GENERAL 2.11 Computer Requirements Minimum System Requirements Computer Platform & Operating System Version ® Windows Operating System Processor Minimum Speed Minimum RAM Recommended RAM 95, 98, 98SE Pentium 75MHz 24 MB 32 MB Me Pentium 150MHz 32 MB 64 MB ® NT Workstation 4.0 Pentium 75MHz 2000 Professional Pentium 133MHz XP Pentium 233MHz ® Mac OS X 10.1/10.2.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.12 Paper 2.12.1 Type and size of paper The machine loads paper from the installed paper tray, manual feed tray, multi-purpose tray or optional lower tray. Tray type Model name Paper tray (Tray #1) MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN Manual feed tray MFC-8420, DCP-8020 Multi-purpose tray (MP tray) MFC-8820D/8820DN, DCP-8025D/8025DN Optional lower tray (Tray #2) Option for MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN 2.12.
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CHAPTER 1 GENERAL 2.12.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL ! CAUTION: When you are choosing print media, be sure to follow the information given below to prevent any paper jams, print quality problems or machine damage; • It is recommended to use long-grained paper for the best print quality. If short-grained paper is being used, it might be the cause of paper jams. • Use neutral paper. Do not use acid paper to avoid any damage to the drum unit. • Avoid using coated paper such as vinyl coated paper.
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CHAPTER 1 GENERAL The table below shows the printable areas when printing on Portrait for each paper size. Size Letter Legal Folio Executive A4 A5 A6 B 5 (JIS) B 5 (ISO) B 6 (ISO) COM10 MONARCH C5 DL A 215.9 mm 8.5” (2,550 dots) 215.9 mm 8.5” (2,550 dots) 215.9 mm 8.5” (2,550 dots) 184.15 mm 7.25” (2,175 dots) 210.0 mm 8.27” (2,480 dots) 148.5 mm 5.85” (1,754 dots) 105.0 mm 4.13” (1,240 dots) 182.0 mm 7.1” (2,130 dots) 176.0 mm 6.93” (2,078 dots) 125.0 mm 4.92” (1,476 dots) 104.78 mm 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Landscape F G E E G G G Physical page Printable area Logical page D B F C A 1-13 B D F Physical page length Maximum logical page length Distance from edge of physical page to edge of logical page
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CHAPTER 1 GENERAL The table below shows the printable areas when printing on Landscape for each paper size. Size Letter Legal Folio Executive A4 A5 A6 B 5 (JIS) B 5 (ISO) B 6 (ISO) COM10 MONARCH C5 DL A 279.4 mm 11.0” (3,300 dots) 355.6 mm 14.0” (4,200 dots) 330.2mm 13.0” (3,900 dots) 266.7 mm 10.5” (3,150 dots) 297.0 mm 11.69” (3,507 dots) 210.0 mm 8.27” (2,480 dots) 148.5 mm 5.85” (1,754 dots) 257.0 mm 10.11” (3,033 dots) 250.0 mm 9.84” (2,952 dots) 176.0 mm 6.93” (2,078 dots) 241.3 mm 9.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.14 Print Speeds with Various Settings Print speed of the machine is up to 16/17 ppm when loading A4 or Letter size paper from the paper tray in the plain paper mode. Actual print speed varies depending on the media type or paper size as shown in the tables below; Media type setting All models Transparencies Up to 16/17 ppm Thin Paper Up to 16/17 ppm Plain paper, Env.
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CHAPTER 1 GENERAL 3. SERIAL NO.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (4) Toner cartridge: Imprinted on the aluminum bag 3A30 J YEAR MONTH DATE FACTORY ID NO. Printed on the bar code label attached on the toner cartridge CARTRIDGE PRODUCTION INFO. M39A000199A MONTH YEAR SERIAL NO. TONER VOLUME FACTORY ID NO. PRODUCT LINE NO. (5) Laser unit: On the laser unit 2 8 0 0 1 PRODUCTION LOT NO. LASER UNIT NO. 8: LJ7516001 Laser Unit ZL2 FACTORY ID NO.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL CHAPTER 2 1. 1.1 INSTALLATION AND BASIC OPERATION CONDITIONS REQUIRED FOR INSTALLATION Power Supply • The source voltage must stay within ±10% of the rated voltage shown on the rating plate. • The power cord, including extensions, should not exceed 5 meters (16.5 feet). • Do no share the same power circuit with other high-power appliances, particularly an air conditioner, copier or shredder.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION 2. UNPACKING When unpacking the machine, check to see that all of the following components are included in the carton. 8 MFC 1 7 Quick Setup Guide 2 3 6 5 4 1. Control Panel 4. Paper Tray 2. Face-down Output Tray 5. Front Cover Support Flap (Support Flap) 6. Power Switch 3. Manual Feed Tray 7. Document Cover (For MFC-8420, DCP-8020) 8.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3. INSTALL THE MACHINE You need to implement hardware setup and driver installation to use the machine. ® ® Firstly, identify the Operating System on your computer. (Windows 95/98/Me, Windows NT ® 4.0, Windows 2000/XP and Macintosh)Then, purchase the appropriate interface cable (Parallel, USB or Network) for your computer.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION 3.1.1 Install the Automatic Document Feed (ADF) support (1) Open the ADF cover. ADF cover Fig. 2-2 Fig. 2-3 (2) Slide ADF support into the groove on ADF. Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (3) Close the ADF cover. Fig. 2-5 3.1.2 Install the drum unit assembly (1) Open the front cover by pressing the front cover release button. (2) Unpack the drum unit assembly. Remove the protective part. (3) Rock it from side to side several times to distribute the toner evenly inside the assembly. Fig. 2-6 (4) Push the drum unit assembly into the machine (until it snaps into place). Fig. 2-7 (5) Close the front cover of the machine.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION 3.1.3 Load paper into the paper tray (1) Pull the paper tray completely out of the machine. (2) While pressing the paper guide release lever, slide the adjusters to fit the paper size. Check that the guides are firmly in the slots on the tray. Paper guide release lever Universal guide release button Fig. 2-8 NOTE: For Legal size paper, press the universal guide release button and pull out the back of the paper tray.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.1.4 Release the scanner lock (1) Push the lever up to unlock the scanner. (Refer to Fig.2-11.) Scanner lock lever Fig.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION 3.2 Installing the Driver & Software 3.2.1 For USB Interface Cable Users (For Windows 98/98SE/Me/2000 Professional/XP) ® (1) Switch off and unplug the machine from the AC outlet and disconnect it from your computer, if you already connected an interface cable. (2) Turn on your computer. ® (For Windows 2000 Professional/XP, you must be logged on as the administrator.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (13) When the Brother MFL-Pro Suite Installation window appears, click Next. NOTE: • If an error message appears during the installation process, or if you have previously installed the MFL-Pro Suite, you will first have to uninstall it. • From the Start menu, select Programs, Brother, Brother MFL-Pro Suite, Uninstall, and then follow the instructions on the screen. (14) When the Brother Software License Agreement window appears, click Yes.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION ® < For Windows 2000 Professional Users Only > Make sure that you followed the instructions in (1) to (16) on pages 2-8 to 2-9. (17) When this screen appears, connect the USB interface cable to your PC, and then connect it to the machine. Turn on the machine by plugging in the power cord. Turn the power switch on. It will take a few seconds for the installation screen to appear. The installation of the Brother drivers will automatically start.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (28) Make sure X:\W2K\Addprt is displayed in the window and click OK (X:\ is the drive letter of your CD-ROM). (29) Highlight the model you are installing from the list of machines and click Next. (30) The model you are installing will be listed in the window. Select Yes or No if you want this driver to be your default printer. (31) Select Do not share this printer and Next. (32) Select Yes and Next to print a test page.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION Brother Native driver Installation (20) (21) Click Start and select Printers and Faxes. Click on Add a printer and the Add Printer Wizard will start. When this screen appears, click Next. Un-check the Automatically detect and install my Plug and Play printer selection and then click Next. (22) Select USBXXX from the pull down window for the Printer Port Selection and then click Next. (23) Click on Have Disk. (24) Browse the CD-ROM for the WXP folder.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.2.2 ® For Parallel Interface Cable Users (For Windows 95/98/98SE/Me/2000 Professional/XP) (1) Switch off and unplug the machine from the AC outlet and disconnect it from your computer, if you already connected an interface cable. (2) Turn on your computer. ® (For Windows 2000 Professional/XP, you must be logged on as the administrator.) (3) Insert the supplied CD-ROM for the operating system you are using into your CD-ROM drive.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION (14) When the Brother Software License Agreement window appears, click Yes. (15) Select Local Interface, and then click Next. (16) Select Standard, and then click Next. The application files will be copied to your computer. ® < For Windows 95/98/98SE/Me Users Only > Make sure that you followed the instructions in (1) to (16) on pages 2-13 to 2-14. (17) When this screen appears, connect the parallel interface cable to your PC, and then connect it to the machine.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (20) Click Finish to restart your computer. (21) After the computer restarts, the installation of the Brother drivers will automatically start. Follow the instructions on the screen. (22) If the Digital Signature Not Found dialog boxes appear, click Yes to install the driver. ® (23) Click Yes to have the Control Center loaded each time Windows is started. The Control Center will appear as an icon in the task tray.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION NOTE: • There will be two Brother printer drivers listed in the Printers selection. • The driver with "Printer" after the model name (ex. Brother MFC-8820D Printer) is the Brother Native Driver. OK: The Brother Native Drivers have been installed and the installation is now complete. ® < For Windows XP Users Only > Make sure that you followed the instructions in (1) to (16) on pages 2-13 to 2-14.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (27) Highlight the model you are installing from the list of machines and click Next. (28) The model you are installing will be listed in the window. Select Yes or No if you want this driver to be your default printer. (29) Select Do not share this printer and Next. (30) Select Yes and Next to print a test page. (31) When this screen appears, click Finish. (32) When the Windows Logo testing screen appears, click Continue Anyway.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION 3.2.3 ® For Windows NT Workstation Version 4.0 Users (1) Turn on your computer. You must be logged on as the Administrator. (2) Connect the parallel interface cable to your computer, and then connect it to the machine. (3) Make sure you turn on the machine by plugging in the power cord, and turning the power switch on. (4) Insert the Supplied CD-ROM for the operating system you are using into your CD-ROM drive.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (15) When the Brother Software License Agreement window appears, click Yes. If you agree to it and go to next screen. (16) Select Local Interface, and then click Next. (17) When the Setup Type window appears, select Standard, and then click Next. (18) The README.WRI file will be displayed. Please read this file for troubleshooting information and then close the file to continue installation. (19) Click Finish restart your computer.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION 3.2.4 ® For Network Interface Cable Users (For Windows 95/98/98SE/Me/NT/2000 Professional/XP) (1) Connect the network cable to the machine, and then connect it to a free port on your hub. Turn on the machine by plugging in the power cord. Turn the power switch on. (2) Turn on your computer. ® (For Windows 2000 Professional/XP, you must be logged on as the administrator.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (14) When the Brother Software License Agreement window appears, click Yes. (15) Select Network Interface, and then click Next. (16) Select Standard, and then click Next. The application files will be copied to your computer. (17) Select Search from a list of available devices, and then click Next. NOTE: If you see the following screen, click OK.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION (25) After the computer restarts, click Yes to have the Control Center load each time ® Windows is started. The Control Center will appear as an icon in the task tray. If you click No the Scan keys on the machine will be disabled. NOTE: Even if you select NO, later you will be able to launch the Brother Control Center to use the Scan to key by double clicking the Smart UI icon on the desktop. This loads the Brother Control Center to the task tray.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.2.5 ® For USB Interface Cable Users (For Mac OS 8.6 to 9.2 Users) (1) Switch off and unplug the machine from the AC outlet and disconnect it from your Macintosh if you already connected an interface cable. (2) Turn on your Macintosh . (3) Insert the supplied CD-ROM for the operating system you are using into your CD-ROM drive. (4) Double-click the Start Here! icon to install the printer, scanner and PC-FAX Send drivers.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION 3.2.6 ® For USB Interface Cable Users (For Mac OS X 10.1/10.2.1 or greater Users) (1) Switch off and unplug the machine from the AC outlet and disconnect it from your Macintosh if you already connected an interface cable. (2) Turn on your Macintosh . (3) Insert the supplied CD-ROM for the operating system you are using into your CD-ROM drive.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.2.7 ® For Network Interface Cable Users (For Mac OS 8.6 to 9.2 Users) (1) Switch off and unplug the machine from the AC outlet and disconnect it from your Macintosh if you already connected an interface cable. (2) Turn on your Macintosh . (3) Insert the supplied CD-ROM for the operating system you are using into your CD-ROM drive. (4) Double-click the Start Here! icon to install the printer, scanner and PC-FAX Send drivers.
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CHAPTER 2 INSTALLATION AND BASIC OPERATION 3.2.8 ® For Network Interface Cable Users (For Mac OS X 10.1/10.2.1 or greater Users) (1) Switch off and unplug the machine from the AC outlet and disconnect it from your Macintosh if you already connected an interface cable. ® (2) Turn on your Macintosh . (3) Insert the supplied CD-ROM for the operating system you are using into your CD-ROM drive. (4) Double-click the Start Here OS X folder to install the printer driver and Remote Setup program.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL CHAPTER 3 1. 1.1 THEORY OF OPERATION ELECTRONICS General Block Diagram Fig. 3-1 shows a general block diagram.
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CHAPTER 3 THEORY OF OPERATION 1.2 Main PCB Block Diagram Fig. 3-2 shows the block diagram of the main PCB. A S I C CPU Core (SPARClite 133MHz) Reset Circuit BUS Oscillator 66.6MHz INT Address Decoder DRAM Control Program + Font ROM 1MB, 4MB, 8MB Timer Network Program (1.5 MB) FIFO STRAGE (0.5 MB) RAM 4MB, 8MB, 16MB CDCC Parallel I/O USB I/O RAM (DIMM) (max.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 1.3 Main PCB For the entire circuit diagram of the main PCB, see APPENDIX 4.1 to 4.6 ‘MAIN PCB CIRCUIT DIAGRAM’ in this manual. 1.3.1 CPU A Fujitsu 32bit RISC CPU, SPARClite is built in the ASIC. While the CPU is driven with a clock frequency of 66.66 MHz in the user logic block, it itself runs at 133.33 MHz, which is generated by multiplying the source clock by two.
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CHAPTER 3 THEORY OF OPERATION 1.3.3 IEEE1284 Stores the data received from the PC into DRAM as controlled by the DMA controller. It is applicable to both normal receiving and bi-directional communication (nibble mode, byte mode, ECP mode). 74LVX161284, 3.3V 5.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 1.3.5 Flash ROM A 16Mbit flash ROM (x 16bit) is fitted. Fig. 3-7 1.3.6 SDRAM Fig.
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CHAPTER 3 THEORY OF OPERATION 1.3.7 Optional RAM A 32bit (100 pin) DIMM can be fitted as optional RAM. The main PCB has one slot and the capacity of DIMM can be from 16MB to 128MB.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 1.3.8 EEPROM The EEPROM is BR24126 type of two-wire method with a 8192 x 8bit configuration. U15 Aurora Fig. 3-10 1.3.9 Reset circuit The reset IC is a R3112N281C. The reset voltage is 2.8V (typ.) and the LOW period of reset is 22.4ms (typ.) VDD3 C71 5 C103 C103 U5 C75 CD VCC 2 4 TP310 NC TP4 3 0V GND VOUT C77 R84 1 0V 68 R3112N281C C101 Fig. 3-11 1.3.
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CHAPTER 3 THEORY OF OPERATION 1.3.12 Video I/O The video signal output from the ASIC is reversed through a transistor and output after being corrected by the buffer IC. VDD3 VDD3 VDD5 U2 A Y 0V VDD5 C3735 E R16 680 TP234 R10 R13 0 100 0V 1D TP232 R12 C20 BDN ENBN0 CN1 R8 1k 4 TC7SH08FU B 680 C21 C103 0V 0 2D 0V 0V Fig. 3-14 1.3.13 Scanner control Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 1.3.14 Power supply +5V is generated by the 3-pin regulator from astable 7V supplied from the LVPS. +5V is used for the IEEE1284 interface, the LD PCB and the engine PCB. In addition, +1.9V is generated by the 3-pin regulator from 3.3V supplied from the LVPS. +1.9V is used for the CPU within the ASIC and the logic circuit. VDD3 + C138 6.3V 6V C220 C137 D1 RB751V-40 Q5 C104 VCC VDD1.
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CHAPTER 3 THEORY OF OPERATION 1.4 Engine PCB The gate array which transforms the serial signal from the main PCB into the parallel signal is mounted on the engine PCB.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 1.5 Power Supply 1.5.1 Low-voltage power supply The power supply uses a switching regulation system to generate the regulated DC power (+3.3V, +8V [non regulated] and +24V), which are converted from the AC line. The regulated output is listed below; Regulated Output +3.3V / 1.5A +8V / 0.4A +24V / 2.2A For the circuit diagram of the low-voltage power supply PCB, see APPENDIX 4.15 or 4.
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CHAPTER 3 THEORY OF OPERATION 1.5.2 High-voltage power supply The high-voltage power supply generates and outputs the voltages and currents for the charging, development and transfer functions. For the circuit diagram of the high-voltage power supply PCB, see APPENDIX 4.17 or 4.18 ‘HIGH-VOLTAGE POWER SUPPLY PCB CIRCUIT DIAGRAM’ in this manual.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2. 2.
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CHAPTER 3 THEORY OF OPERATION 2.2 Scanner Mechanism LF roller 1 ASSY PF roller holder ASSY Front sensor actuator ASSY LF roller 2 ASSY Eject roller ASSY ADF cover Guide shaft Top cover HP sensor Pulley ASSY CCD module Scanner base Belt Fig. 3-20 This scanner mechanism supports a dual scanning system.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.3 Paper Transfer 2.3.1 Paper supply The paper pick-up roller picks up one sheet of paper from the paper tray every time it is rotated and feeds it to the paper feed roller. First feed roller First feed pinch roller Paper feed pinch roller Paper feed roller Regist front actuator Paper pick-up roller Separation pad Pressure plate Fig.
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CHAPTER 3 THEORY OF OPERATION 2.3.3 Paper eject After the printing image on the photosensitive drum is transferred onto the paper, the paper is fed to the fixing unit to fix unfixed toner onto the paper. Afterwards, the paper is ejected from the fixing unit by the first eject roller in the fixing unit. The paper eject actuator detects whether the paper is ejected correctly or not.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.4 Sensors 2.4.1 Cover sensors Detect opening and closing of the front cover. Front cover sensor Fig. 3-24 2.4.2 Toner sensors Detects if there is toner in the toner cartridge. The toner sensor at the left side emits light through the window on the left side of the toner cartridge, then the toner sensor at the right side receives it when the toner is low. They also detect whether or not the drum unit is installed.
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CHAPTER 3 THEORY OF OPERATION 2.4.3 Cassette sensor / Paper empty sensor Detect if the paper tray is installed. They also detect if there is paper in the paper tray . Paper empty sensor Cassette sensor PCB ASSY Cassette sensor Fig. 3-26 2.4.4 Paper eject sensor Detects if paper is ejected from the fixing unit. Fixing unit Eject sensor PCB ASSY Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.4.5 MP-PE sensor Detects if there is paper in the MP tray. MP-PE sensor PCB ASSY Feed MP unit Fig. 3-28 2.4.6 Document cover sensor Document cover sensor Fig.
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CHAPTER 3 THEORY OF OPERATION 2.4.7 Document front sensor /Document rear sensor Document front sensor Document rear sensor Fig. 3-30 2.4.8 DX-sensor PCB ASSY DX-sensor PCB ASSY Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.4.9 Rear cover sensor Rear cover sensor Fig. 3-32 2.4.10 HP sensor HP sensor Fig.
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CHAPTER 3 THEORY OF OPERATION 2.5 Drum Unit 2.5.1 Photosensitive drum Generates the latent electrostatic image and develops the image on the drum surface. 2.5.2 Primary charger Forms a uniform charge on the drum surface. (1) Corona wire Generates the ion charge on the drum. (2) Grid Spreads the ion charge evenly over the drum surface. 2.5.3 Transfer roller Transfers the toner image to the paper from the drum surface. 2.5.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.7.2 Exposure stage After the drum is positively charged, it is exposed to the light emitted from the laser unit. Drum Laser beam Paper Laser beam f θ lens Laser detector Polygon mirror Laser diode Motor Lens Fig. 3-35 The area exposed to the laser beam is the image to be printed. The surface potential of the exposed area is reduced, forming the electrostatic image to be printed.
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CHAPTER 3 THEORY OF OPERATION 2.7.3 Developing Developing causes the toner to be attracted to the electrostatic image on the drum so as to transform it into a visible image. The developer consists of a non-magnetic toner. The development roller is made of conductive rubber and the supply roller (which is also made of conductive sponge) rotate against each other. The toner is charged and carried from the supply roller to the development roller.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.7.5 Fixing stage The image transferred to the paper by static electricity is fixed by heat and pressure when passing through the heat roller and the pressure roller in the fixing unit. The thermistor keeps the surface temperature of the heat roller constant by detecting the surface temperature of the heat roller and turning on or off the halogen heater lamp. Thermistor First eject roller Heat roller Pressure roller Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL CHAPTER 4 1. DISASSEMBLY AND RE-ASSEMBLY SAFETY PRECAUTIONS To avoid creating secondary problems by mishandling, follow the warnings and precautions below during maintenance work. WARNING (1) Always turn off the power switch and unplug the power cord from the power outlet before accessing any parts inside the printer. (2) Some parts inside the printer are extremely hot immediately after the printer is used.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 2. DISASSEMBLY FLOW 14 1 16 SIDE COVER L/R AC CORD FRONT COVER ASSY (MFC-8420, DCP-8020 only) 2 15 17 DRUM UNIT JOINT COVER 3 PAPER TRAY MP UNIT (MFC-8820D/8820DN, DCP-8025D/8025DN only) 18 REAR COVER SENSOR 4 21 DX FEED ASSY (MFC-8820D/8820DN, DCP-8025D/8025DN only) LASER UNIT 5 23 ACCESS COVER/BATTERY BASE PLATE / LV INSULATION SHEET 22 6 DRIVER PCB ACCESS COVER 24 MAIN PCB DX-SENSOR PCB ASSY (3.5 (1) and (2) are contained.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3. 3.1 DISASSEMBLY PROCEDURE AC Cord (1) Disconnect the AC cord from the machine. Machine AC cord Fig. 4-1 3.2 Drum Unit (1) Open the front cover and remove the drum unit. Drum unit Front cover Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.3 Paper Tray (1) Close the front cover and pull out the paper tray. (2) Remove the paper from the paper tray. Front cover 1 Paper tray 2 Fig. 4-3 (3) Remove the pad holder and the separation pad spring from the paper tray. Pad holder Separation pad spring Paper tray Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL NOTE: When replacing/re-assembling the pad holder ZL2 ASSY, remove the old grease and apply a suitable amount of grease referring to the figure below; Paper pick-up roller Paper tray Grease: Molykote PG-662 (4 mm dia.ball) Fig. 4-5 (4) Remove the four bind B M4x12 Taptite screws, and then remove the paper tray front cover. Taptite, bind B M4x12 Paper tray Hook Taptite, bind B M4x12 Paper tray front cover Hook Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (5) Remove the two cup B M3x10 Taptite screws, and then remove the paper tray cover. Paper tray Taptite, cup B M3x10 Paper tray cover Taptite, cup B M3x10 Fig. 4-7 (6) Remove the pressure roller holder. Pressure roller holder Paper tray Flat screwdriver Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (7) Remove the pressure roller collar. (8) Remove the pressure roller shaft. Pressure roller shaft Pressure roller collar 2 1 Pressure roller holder ASSY Fig. 4-9 (9) Remove the scratch spongy holder ASSY from the pressure roller holder. (10) Remove the two scratch spongy springs. (11) Remove the scratch spongy from the scratch spongy holder ASSY.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (12) Remove the two cup M2.6x5 Taptite screws. (13) Release the lock lever, and then unhook the catches of the two side guide racks. Taptite, cup M2.6x5 Side guide L Taptite, cup M2.6x5 2 Side guide rack 2 1 Catches Lock lever Paper tray Side guide rack Side guide L Fig. 4-11 (14) Remove the side guides right and left from the paper tray. Side guide L Side guide R 2 2 1 1 Paper tray Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (15) Unhook the two catches (A) of the pressure plate while pulling the plastic frame outwards, then unhook the other two catches (B) of the plate while pulling the plastic frame outwards to remove the pressure plate ASSY. Catches (A) Pressure plate ASSY Paper tray Catch (B) Plastic frame Fig. 4-13 (16) Unhook the pressure plate spring from the plastic hook to remove the two pressure plate springs.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY NOTE: When re-assembling the pressure plate ASSY, ensure that the paper indicator arm is under the pressure plate. ! CAUTION: When unhooking the catches to remove the pressure plate, do not bend the pressure plate, gently ease the plastic cover. If the pressure plate is deformed, paper feeding problems may occur. (17) Remove the herical extension spring. (18) Remove the lock lever.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (19) Remove the cup B M3x8 Taptite screw, and then remove the side guide gear and the friction spring. (20) Remove the two side guide racks. Taptite, cup B M3x8 2 Side guide gear Side guide rack Friction spring 1 1 Side guide rack Fig. 4-16 (21) Remove the paper indicator. Paper tray Paper indicator Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY NOTE: • When re-assembling the side guide racks, they should both be aligned so that the wide end of the racks are in line with the inside edge of the paper guide release slots in the tray before refitting the spring and gear. • When replacing/re-assembling the paper cassette, remove the old grease and apply a suitable amount of grease onto both sides of the paper tray referring to the figure below; Grease: Molykote PG-662 (2 mm dia.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (24) Remove the paper rear guide. Paper tray 1 Paper rear guide 1 2 Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.4 DX Feed ASSY (MFC-8820D/8820DN, DCP-8025D/8025DN only) (1) Remove the DX feed ASSY. DX feed ASSY Fig. 4-21 (2) Remove the four bind B M3x8 Taptite screws, and then remove the DX roller holder and three pressure rollers. (3) Remove the three pressure roller springs. Pressure roller springs Taptite, bind B M3x8 Taptite, bind B M3x8 Pressure roller spring DX roller holder Pressure rollers Pressure roller Tray feed ZL2 Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL NOTE: Set pressure roller, and assemble pressure roller spring after assembling DX roller holder. Pressure roller spring Pressure roller Tray feed ZL2 Fig. 4-23 (4) Remove the two bind B M3x8 Taptite screws, and then remove the guide plate stopper. (5) Remove the two left guide spring 2.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (6) Remove the side regist guide. (7) Remove the left guide plate ASSY and DX paper switch pull arm. 2 Side regist guide 3 Left guide plate ASSY DX paper switch pull arm 1 Hooks Tray feed ZL2 Fig. 4-25 (8) Remove the DX feed roller, drive gear 14, two side regist rollers, T-belt (S) and ground wire. (9) Remove the guide actuator and T-belt (L).
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.5 Access Cover / Battery (1) Remove the access cover. (2) Loosen the two access plate screws. (3) Remove the access plate. Access plate screw Access cover Hooks Hooks Access plate screw Access plate Hooks Hooks Fig. 4-27 (4) Disconnect the connector, and then remove the battery. (MFC-8420/8820D/8820DN only) Main PCB Battery Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.6 Driver PCB Access Cover (1) Remove the bind B M4x12 Taptite screw, and then remove the driver PCB access cover. Driver PCB access cover Taptite, bind B M4x12 Fig.
PAGE 100
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.7 ADF Unit (1) Remove the document tray ASSY. Hooks Document tray ASSY 1 2 Hooks Fig. 4-30 (2) Disconnect the three connectors. (3) Remove the cup B M3x10 Taptite screw, and then remove the ground wire. Driver PCB ASSY Connector Taptite, cup B M3x10 Ground wire Connector Connector Main PCB Fig.
PAGE 101
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (4) Remove the two bind B M4x12 Taptite screws, and then remove the document cover. 2 Taptite, bind B M4x12 Document cover 1 Fig. 4-32 (5) Remove the hinge base R. (6) Remove the three cup B M3x10 Taptite screws, and then remove the hinge arm R. (7) Remove the three cup B M3x10 Taptite screws, and then remove the hinge ASSY L. Hinge base R Taptite, cup B M3x10 Taptite, cup B M3x10 Hinge arm R Hinge ASSY L Document cover LGL Hinge base R Hinge arm R Fig.
PAGE 102
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (8) Remove the document hold ASSY and document hold spring. (9) Remove the two cup B M3x10 Taptite screws, and then remove the rear sensor cover. Taptite, cup B M3x10 Hooks Hooks Document hold ASSY Document hold spring Document hold spring Rear sensor cover 2 4 1 Hooks Document hold ASSY 3 Hook Fig. 4-34 (10) Remove the ADF cover. ADF cover 2 1 Document cover LGL Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (11) Remove the document ejection tray. Document ejection tray Document cover LGL Fig. 4-36 (12) Remove the cup B M3x10 Taptite screw, and then remove the side cover F. (13) Remove the cup B M3x10 Taptite screw, and then remove the side cover R. Hook Side cover R 4 Taptite, cup B M3x10 Hook 3 Hook 2 1 Side cover F Hook Taptite, cup B M3x10 Document cover LGL Fig.
PAGE 104
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (14) Disconnect the four connectors. (15) Remove the cup S M3x6 Taptite screw, and then remove the ground wire. (16) Remove the four cup B M3x10 Taptite screws, and then remove the ADF chute ASSY. Taptite, cup B M3x10 ADF motor ADF chute ASSY Connector ADF relay PCB ASSY Taptite, cup B M3x10 Connector Ground wire Taptite, cup S M3x6 Document cover LGL Fig. 4-38 (17) Remove the conductive bushing, and then remove the PF roller holder ASSY.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (19) Remove the cup S M3x6 Taptite screw, and then remove the ADF relay PCB ASSY. (20) Remove the three cup S M3x6 Taptite screws, and then remove the motor frame ASSY. (21) Remove the two pan (S/P washer) M3x8 screws, and then remove the ADF motor. Taptite, cup S M3x6 Taptite, cup S M3x6 Pan (S/P washer) M3x8 ADF relay PCB ASSY Motor frame ASSY ADF chute ASSY ADF motor Taptite, cup S M3x6 Fig.
PAGE 106
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (23) Remove the ADF film. (24) Remove the B M3x6 Taptite screw, and then remove the spring plate ADF front A ASSY. (25) Remove the separation rubber, rubber holder and compression spring. (26) Remove the two pressure rollers and pressure roller shaft S.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (28) Remove the conductive bushing, and then remove the LF roller 2 ASSY. (29) Remove the conductive bushing, and then remove the ejection roller ASSY. Ejection roller ASSY LF roller 2 ASSY Conductive bushing 1 2 1 PF roller holder Conductive bushing Fig. 4-44 (30) Remove the two pressure rollers and pressure roller shaft S. (31) Remove the two cup S M3x10 Taptite screws, and then remove the two LF springs.
PAGE 108
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (33) Remove the film. (34) Remove the document rear sensor, and then disconnect the connector. (35) Remove the document cover sensor. Document rear sensor Connector Film 1 2 Document cover sensor Document cover LGL Connector Document rear sensor Fig.
PAGE 109
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.8 Document Scanner NOTE: The disassembly job of the scanner unit should be done in a clean room to prevent dust or dirt from getting into the scanner unit. (1) Disconnect the FFC cable. (2) Remove the two cup B M3x10 Taptite screws, and then remove the driver PCB shield. (3) Disconnect the two connectors.
PAGE 110
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (5) Remove the six cup B M4x12 Taptite screws, and then remove the top cover ASSY. Taptite, cup B M4x12 Top cover ASSY Taptite, cup B M4x12 Taptite, cup B M4x12 Taptite, cup B M4x12 Scanner base ASSY Fig. 4-49 (6) Remove the cup B M3x6 Taptite screw, and then remove the lock lever B. (7) Remove the two cup B M3x6 Taptite screws, and then remove the lock lever ASSY.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (8) Remove the guide shaft from the CCD module. (9) Release the belt from the pulley ASSY. (10) Remove the belt support rubber, and then remove the belt from the CCD module. (11) Disconnect the FFC cable from the CCD module. (12) Remove the CCD module from the scanner base. CCD module Belt support rubber 6 Belt 3 7 CCD module Belt Belt Guide shaft 2 5 4 1 Scanner base Fig.
PAGE 112
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (13) Remove the cup B M3x8 Taptite screw, and then remove the FFC plate. (14) Remove the sponge and FFC cable ASSY. FFC plate Taptite, cup B M3x8 Hook Sponge FFC cable ASSY Pin Scanner base Fig. 4-52 (15) Remove the cup S M3x6 Taptite screw, and then remove the ground wire. (16) Remove the four pan B M3x8 Taptite screws, and then remove the drive plate ASSY. (17) Remove the HP sensor, and then disconnect the connector.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (18) Remove the two pan (S/P washer) M3x6 screws, and then remove the scanning motor FB. Scanning motor FB Drive plate ASSY Pan (S/P washer) M3x6 Fig. 4-54 (19) Remove the B M3x6 Taptite screw, and then remove the pulley ASSY and pulley spring. Taptite, B M3x6 Pulley ASSY Pulley spring Scanner base Fig.
PAGE 114
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.9 Panel Unit (1) Remove the four cup B M4x12 Taptite screws, and then remove the connector and panel unit. Taptite, cup B M4x12 Panel unit 2 Taptite, cup B M4x12 1 Panel PCB harness Fig. 4-56 (2) Remove the six cup B M3x8 Taptite screws, and then remove the panel rear cover. Taptite, cup B M3x8 Panel rear cover Taptite, cup B M3x8 Hook Panel cover Hooks Fig.
PAGE 115
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (3) Disconnect the three cables. Lock Cable 2 1 Cables Panel cover 1 2 Lock Fig. 4-58 (4) Remove the two cup B M3x8 Taptite screws, and then remove panel PCB ASSY. Taptite, cup B M3x8 Panel PCB ASSY Panel cover Hooks Fig.
PAGE 116
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (5) Remove the backlight holder and the deffusion film. Backlight holder Panel cover Deffusion film Fig. 4-60 (6) Remove the LCD. LCD Panel cover Hooks 1 Hook Hook LCD LCD 2 4 3 Hooks Fig.
PAGE 117
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.10 Rear Cover C (MFC-8420, DCP-8020 only) (1) Remove the bind B M4x12 Taptite screw, and then remove the rear cover C. Rear cover C Taptite, bind B M4x12 Fig.
PAGE 118
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.11 Outer Chute (MFC-8420, DCP-8020 only) (1) Remove the outer chute. Hook Outer Chute Fig. 4-63 (2) Remove the outer chute tray. Outer Chute Outer chute tray Fig.
PAGE 119
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.12 Rear Cover MP ASSY / Outer Chute MP ASSY (MFC-8820D/8820DN, DCP-8025D/8025DN only) (1) Remove the rear cover MP ASSY. Hook Rear cover MP ASSY Fig. 4-65 (2) Remove the outer chute MP ASSY. Hook Outer chute MP ASSY Fig.
PAGE 120
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (3) Remove the rear cover MP tray. Rear cover MP ASSY Rear cover MP tray Fig. 4-67 3.13 Rear Cover L/R (1) Remove the two bind B M4x12 Taptite screws, and then remove the rear cover L. (2) Remove the two bind B M4x12 Taptite screws, and then remove the rear cover R. Taptite, bind B M4x12 Rear cover R Taptite, bind B M4x12 Hook Taptite, bind B M4x12 Hook Fig.
PAGE 121
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.14 Side Cover L/R (1) Remove the three bind B M4x12 Taptite screws, and then remove the side cover R. Side cover R Taptite, bind B M4x12 Taptite, bind B M4x12 Taptite, bind B M4x12 Taptite, bind B M4x12 Fig. 4-69 (2) Remove the four bind B M4x12 Taptite screws, and then remove the side cover L. Side cover L Taptite, bind B M4x12 Fig.
PAGE 122
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.15 Joint Cover (1) Disconnect the three connectors. Joint cover Driver PCB ASSY Speaker harness Driver PCB harness Panel PCB harness Main PCB Fig. 4-71 (2) Remove the four bind B M4x12 Taptite screws, and then remove the joint cover. Hook Joint cover Taptite, bind B M4x12 Hooks Taptite, bind B M4x12 Taptite, bind B M4x12 Hook Hook Hook Taptite, bind B M4x12 Fig.
PAGE 123
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (3) Remove the speaker hold spring and the speaker. Speaker Speaker hold spring Hook 2 1 Fig. 4-73 (4) Remove the four bind B M4x12 Taptite screws, and then remove the inner chute. Inner chute Taptite, bind B M4x12 Taptite, bind B M4x12 Hooks Taptite, bind B M4x12 Joint cover Hook Fig.
PAGE 124
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (5) Remove the two bind B M4x12 Taptite screws, and then remove the joint cover front L. (6) Remove the two bind B M4x12 Taptite screws, and then remove the joint cover front R. Joint cover Taptite, bind B M4x12 Taptite, bind B M4x12 Joint cover front R Hooks Joint cover front L Fig. 4-75 (7) Remove the cup B M3x10 Taptite screw, and then remove the driver PCB ASSY. Driver PCB ASSY Taptite, cup B M3x10 Driver PCB harness Joint cover Fig.
PAGE 125
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (8) Remove the support flap and the support flap S. Support flap Support flap S Fig.
PAGE 126
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.16 Front Cover ASSY (MFC-8420, DCP-8020 only) (1) Release the link. (2) Remove the front cover ASSY. Frame Front cover ASSY Link Fig.
PAGE 127
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.17 MP Unit (MFC-8820D/8820DN, DCP-8025D/8025DN only) (1) Disconnect the two connectors. (2) Remove the MP ground spring. (3) Remove the bind B M3x8 Taptite screw and cup S M3x6 Taptite screw. (4) Remove the MP solenoid holder unit. MP ground spring MP solenoid holder unit Engine PCB connector Taptite, bind B M3x8 MP sensor harness Taptite, cup S M3x6 Fig. 4-79 (5) Remove the cup S M3x6 Taptite screw, and then open the MP chute ASSY cover.
PAGE 128
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (7) While pushing the MP pressure plate, remove the separation plate ASSY. Separation plate ASSY MP chute ASSY MP pressure plate Fig. 4-81 NOTE: When replacing with the new separation plate ASSY, attach it after peeling the cover paper of double-faced tape. Double faced tape Separation plate ASSY Fig.
PAGE 129
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (8) Remove the shaft of the MP front cover ASSY from the drive release link, and then remove the MP front cover ASSY from the MP chute ASSY. MP chute ASSY Drive release link Shaft MP front cover ASSY Shaft Fig. 4-83 (9) Remove the bosses from the guide at 2 spots in the MP tray ASSY, and then remove the MP paper guide ASSY. MP chute ASSY MP tray ASSY MP paper guide ASSY Fig.
PAGE 130
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (10) Remove the MP tray ASSY. MP chute ASSY MP tray ASSY Fig. 4-85 (11) Remove the MP tray support flap 2 and the MP tray support flap 3 from the MP tray ASSY. MP tray support flap 3 MP tray support flap 2 MP tray ASSY Fig.
PAGE 131
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (12) Open the MP chute ASSY cover. (13) Remove the MP-PE actuator. MP-PE actuator MP chute ASSY Fig. 4-87 (14) Remove the four bind B M4x12 Taptite screws, and then remove the MP chute ASSY. Taptite, bind B M4x12 MP chute ASSY Taptite, bind B M4x12 Fig.
PAGE 132
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (15) Remove the cup S M3x6 Tite screws, and then remove the MP gear cover. (16) Remove the MP roller cover. (17) Remove the MP-PE sensor PCB ASSY. MP-PE sensor PCB ASSY Hook Hook (pin) Hook Hook MP roller cover MP chute ASSY Hook (pin) Hooks Tite, cup S M3x6 MP gear cover Fig. 4-89 3.18 Rear Cover Sensor (1) Disconnect the connector, and then remove the rear cover sensor. Connector Rear cover sensor Fig.
PAGE 133
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.19 NCU (MFC-8420/8820D/8820DN only) (1) Disconnect the connector. (2) Remove the two cup S M3x6 Taptite screws, and then remove the NCU unit. Hook NCU harness NCU unit Taptite, cup S M3x6 Hook Fig. 4-91 (3) Remove the cup S M3x6 Taptite screw, and then remove the NCU shield cover. (4) Remove the two cup S M3x6 Taptite screws, and then disconnect the connector. (5) Remove the NCU.
PAGE 134
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.20 Fixing Unit (1) Disconnect the heater harness and thermistor harness. (2) Remove the bind B M4x12 Taptite screw and the shoulder screw, and then remove the fixing unit. Fixing unit Shoulder screw Heater harness Taptite, bind B M4x12 Thermistor harness Fig. 4-93 (3) Remove the three cup B M3x10 Taptite screws, and then remove the FU paper guide. Pin Fixing unit Pins Taptite, cup B M3x10 FU paper guide Fig.
PAGE 135
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (4) Remove the three cup B M3x10 Taptite screws, and then remove the star wheel holder. Fixing unit Pin Pins Taptite, cup B M3x10 Star wheel holder Fig. 4-95 (5) Remove the cup B M3x12 Taptite screw. (6) Release the thermistor ASSY harness from the hooks. (7) Remove the thermistor ASSY. Fixing unit Thermistor ASSY Hooks Hook Thermistor relay PCB ASSY Thermistor ASSY harness Thermistor relay PCB ASSY Fig.
PAGE 136
MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL NOTE: When re-assembling the thermistor to the FU frame upper, ensure the direction of the thermistor is correct referring to the figure below; FU frame upper Thermistor Thermistor Taptite, cup B M3x12 Fig. 4-97 (8) Remove the two cup B M3x20 Taptite screws. (9) Remove the FU frame upper from the FU frame lower. Hook Pin FU frame lower Hook Taptite, cup B M3x20 Hook Pin FU frame upper Hook Taptite, cup B M3x20 Fig.
PAGE 137
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (10) Remove the two pan (washer) M2.6x6 Taptite screws. (11) Remove the heat roller 25. (12) Remove the halogen lamp. Heat roller 25 Screw, pan (washer) M2.6x6 Halogen lamp Screw, pan (washer) M2.6x6 Colored side 115V:Orange 230V:Black Halogen lamp connector plate FU frame upper Heat roller 25 Halogen lamp Fig. 4-99 NOTE: When re-assembling the halogen heater lamp, ensure that the direction of the halogen heater lamp is correct referring to the figure above.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (13) Remove the HR bearing 25. (14) Remove the HR gear 34. (15) Remove the HR retaining ring 25. (16) Remove the heat roller washer 25. (17) Remove the HR bearing 25. HR bearing 25 HR bearing 25 Heat roller 25 Heat roller washer 25 HR retaining ring 25 HR gear 34 Fig. 4-101 ! CAUTION: Never touch the surface of the heat roller.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY • When re-assembling the heat roller 25 to the FU frame upper, ensure you do not damage the heat roller 25 with the four separate claw ASSY on the FU frame upper. Heat roller 25 Separate claw ASSY Separate claw ASSY FU frame upper Fig. 4-103 (18) Remove the pressure roller 25. Pressure roller 25 3 2 FU frame lower 1 FU jam remove cover Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (19) Remove the three cleaner spring S. (20) Remove the three cleaner pinch roller ASSY S. (21) Remove the cleaner spring L. (22) Remove the cleaner pinch roller ASSY L. Cleaner spring S Cleaner spring L Cleaner pinch roller ASSY S Cleaner spring S Cleaner pinch roller ASSY L Cleaner pinch roller ASSY S FU frame lower Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (23) Disconnect the connector for the eject sensor harness from the thermistor relay PCB ASSY. (24) Release the eject sensor harness from the three hooks. (25) Remove the bind B M3x10 Taptite screw, and then remove the eject sensor PCB ASSY. (26) Remove the bind B M3x10 Taptite screw, and then remove the thermistor relay PCB ASSY.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL NOTE: When re-assembling the paper eject actuator and the eject actuator spring to the FU frame lower, ensure the paper eject actuator is seated correctly in the locating channel referring to the figure below; FU frame lower Eject actuator spring Paper eject actuator Fig. 4-109 (28) Disconnect the heater harness. (29) Remove the four cup B M3x6 Taptite screws. (30) Remove the four claw holder plate. (31) Remove the four separate claw ASSY.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.21 Laser Unit (1) Remove the filter, and then remove the cup S M3x8 Taptite screw and the air duct. Hook Filter Air duct Taptite, cup S M3x8 Hook Fig. 4-111 (2) Disconnect the LD harness 5P from the laser unit. (3) Disconnect the polygon motor harness and remove the spongy from the laser unit. (4) Remove the six cup S M3x8 Taptite screws, and then remove the laser unit.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (5) Remove the shutter arm C. Shutter arm C Frame L Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.22 Main PCB (1) Disconnect the LD harness 5P. (2) Disconnect the four connectors. Thermistor connector LD harness 5P Main PCB ASSY LVPS connector Engine connector LVPS connector Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (3) Remove the three pan M3x6 screws. (4) Remove the five cup S M3x6 Taptite screws, and then remove the main PCB ASSY. Screw, pan M3x6 Taptite, cup S M3x6 Main PCB ASSY Taptite, cup S M3x6 Fig. 4-115 NOTE: After replacing the Main PCB, please perform the following operations. • APPENDIX 1 EEPROM CUSTOMIZING CODES (Refer to A-1.) • APPENDIX 2.1 INSTALING THE UPDATE DATA TO THE MACHINE (Refer to A-3.) • APPENDIX 2.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.23 Base Plate / LV Insulation Sheet (1) Remove the eight bind B M4x12 Taptite screws. (2) Remove the four cup S M3x6 Taptite screws. (3) Remove the pan (washer) M3.5x6 Taptite screw, and then remove the ground wire. (4) Remove the base plate. Taptite, bind B M4x12 Taptite, cup S M3x6 Taptite, bind B M4x12 Taptite, bind B M4x12 Taptite, cup S M3x6 Base plate Ground wire Screw, pan (washer) M3.5x6 Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.24 DX-Sensor PCB ASSY (MFC-8820D/8820DN, DCP-8025D/8025DN only) (1) Disconnect the connector. (2) Remove the bind B M3x10 Taptite screws, and then remove the DX-sensor PCB ASSY. Taptite, bind B M3x10 DX-sensor PCB ASSY Engine PCB ASSY Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.25 Engine PCB (1) Disconnect the connectors.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.26 High-voltage PS PCB ASSY (1) Remove the bind B M4x12 Taptite screw, and then remove the high-voltage PS PCB ASSY. (2) Disconnect the flat cable from the high-voltage PS PCB ASSY. Taptite, bind B M4x12 High-voltage PS PCB ASSY Flat cable Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.27 Low-voltage PS PCB ASSY (1) Remove the bind B M4x12 Taptite screw. (2) Disconnect the three connectors from the low-voltage PS PCB, and then remove the lowvoltage PS PCB. Low-voltage PS PCB Taptite, bind B M4x12 Heater Connector Main PCB/Engine PCB Connector Main PCB connector Fig. 4-122 (3) Remove the two bind B M4x12 Taptite screws, and then remove the inlet holder. (4) Remove the bind B M4x12 Taptite screw, and then remove the SW holder.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.28 Paper Feeder (1) Remove the bearing R. (2) Remove the paper pick-up roller ASSY. (3) Remove the two roller collars from the paper pick-up roller ASSY. Roller collar Paper pick-up roller ASSY Roller collar Bearing R 1 2 Fig. 4-124 (4) Remove the bind B M3x10 Taptite screw, and then remove the PE sensor cover. (5) Remove the cassette sensor PCB ASSY. Taptite, bind B M3x10 PE sensor cover Cassette sensor PCB ASSY Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (6) Remove the PE actuator and the CA actuator. CA actuator PE actuator Frame Fig. 4-126 (7) Remove the spring, extension P/R from the gear 63P/R. (8) Remove the gear 63P/R. (9) Remove the ground spring from the conductor bearing. Hooks Conductor Bearing Gear 63P/R Hooks Ground spring Spring, extension P/R Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (10) Remove the bearing L from the P/R shaft. (11) Remove the P/R shaft. P/R shaft Bearing L 1 2 Fig. 4-128 (12) Remove the idle gear 22. (13) Remove the middle roller gear. (14) Remove the bind B M3x10 taptite screw and the conductor bearing. (15) Remove the 1st F/R shaft. Hook Idle gear 22 1st F/R shaft Middle roller gear Conductor bearing Taptite bind B M3x10 Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (16) Remove the two cup S M3x6 Taptite screws and the four bind B M4x12 Taptite screws. (17) Remove the front chute ASSY. Taptite, bind B M4x12 Front chute ASSY Taptite, cup S M3x6 Taptite, bind B M4x12 Taptite, cup S M3x6 Fig. 4-130 (18) Remove the feed roller gear. (19) Remove the bearing F/R. (20) Remove the feed roller gear shaft. Bearing F/R Hook Feed roller gear shaft Bearing F/R Frame Feed roller gear Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (21) Remove the hook of the bearing 5, and then slide the feed roller ASSY in the direction of the arrow. (22) Remove the feed roller ASSY. (23) Remove the joint 5 and the bearing 5 from the feed roller ASSY. Bearing 5 Feed roller ASSY 5 4 Joint 5 2 3 1 Hook Bearing 5 Fig. 4-132 NOTE: Be careful that the different direction installation causes jam when you install joint 5. Joint 5 Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (24) Remove the chute cover. Chute cover Hook Hook Fig. 4-134 (25) Remove the regist front actuator and regist front actuator spring. (26) Remove the regist rear actuator and regist rear actuator spring. Regist front actuator Regist front actuator spring Regist rear actuator Regist rear actuator spring Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL NOTE: When assembling the regist front actuator and the regist rear actuator, set the spring as shown in the figure. Regist rear actuator spring Regist rear actuator Hole Regist front actuator Hole Regist front actuator spring Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.29 Frame L / Drive Unit (1) Remove the main PCB sheet from the frame L. (2) Remove the four bind B M4x12 Taptite screws. (3) Remove the two bind B M3x10 Taptite screws, and then remove the frame L. Frame L Under bar Taptite, bind B M4x12 Main PCB sheet Taptite, bind B M3x10 Under bar Taptite, bind B M4x12 Taptite, bind B M3x10 Fig. 4-137 (4) Remove the back up plate ground spring. (DCP-8020/MFC-8420 only) Drive unit Frame L Back up plate ground spring Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (5) Remove the cup S M3x6 Taptite screw. (6) Remove the ground wire. (7) Remove the six bind B M4x12 Taptite screws. (8) Remove the cup S M3x10 Taptite screw. (9) Remove the cup S M3x6 Taptite screw, and then remove the sub gear plate. (10) Remove the LD harness 5P from the drive unit. (11) Remove the drive unit. (12) Disconnect the connector for the main motor harness from the main motor ASSY.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY (13) Remove the four cup S M3x6 Taptite screws, and then remove the main motor ASSY. Taptite, cup S M3x6 Main motor ASSY Taptite, cup S M3x6 Drive unit Fig. 4-140 (14) Remove the bind B M3x10 Taptite screw. (15) Remove the P/R solenoid ASSY, the P/R solenoid lever and the solenoid release spring P/R. (16) Remove the bind B M3x10 Taptite screw. (17) Remove the F/R solenoid ASSY and solenoid release spring F/ R.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (18) Disconnect the connector from the front cover sensor. (19) Remove the bind B M3x10 Taptite screw. (20) Remove the toner LED PCB unit ASSY. (21) Remove the sensor clip. (22) Remove the front cover sensor from the frame L. Front cover sensor Frame L Connector Sensor clip Toner LED PCB unit ASSY Front cover sensor Taptite, bind B M3x10 Sensor clip Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.30 Reversing Release Solenoid (MFC-8820D/8820DN, DCP-8025D/8025DN only) (1) Remove the two bind B M4x12 Taptite screws, and then remove the PCP case. (2) Remove the two bind B M4x12 Taptite screws, and then remove the eject gear frame unit. Gear A Gear B Eject gear frame unit Frame L Taptite, bind B M4x12 PCP case Taptite, bind B M4x12 Fig. 4-143 (3) Remove the switch arm return spring and sector gear spring. (4) Remove the idle gear and switch arm ASSY.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.31 Thermistor ASSY (1) Remove the thermistor ASSY. Frame L Thermistor ASSY Fig. 4-145 3.32 Fan Motor 60 Unit LV / Fan Motor 60 Unit (1) Remove the fan motor 60 unit LV and the fan motor 60 unit. Main frame R Fan motor 60 unit Fan motor 60 unit LV Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 3.33 Frame R (1) Remove the four bind B M4x12 Taptite screws. (2) Remove the cup S M3x16 Taptite screw. (3) Remove the two cup S M3x6 Taptite screws. (4) Remove the main frame R unit. Main frame R unit Taptite, bind B M4x12 Under bar Taptite, cup S M3x6 Taptite, bind B M4x12 Taptite, cup S M3x16 Under bar Taptite, bind B M4x12 Taptite, cup S M3x6 Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (5) Remove the two bind B M4x12 Taptite screws. (6) Remove the cup S M3x6 Taptite screw. (7) Remove the drum spring R. (8) Remove the FG plate. Main frame R Taptite, cup S M3x6 FG plate Taptite, bind B M4x12 Drum spring R Taptite, bind B M4x12 Fig. 4-148 (9) Remove the toner sensor PCB unit (Light reception). Main frame R Pin Toner sensor PCB unit (Light reception) Fig.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 4. PACKING AC power cord Telephone line cord Pad ADF support Carton Carton Drum unit Pad Carton Machine Pad Carton Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 5. GUIDELINES FOR LEAD FREE SOLDER Information on Manually Repairing PCB Soldered with Lead-Free Solder This document provides information on how to correctly make manual repairs to a printed circuit board (PCB) soldered with lead-free solder. 1. Characteristics of lead-free solder Melting point higher than that of conventional tin-lead solder (Lead-free solder: approx. 220'C, Conventional tin-lead solder: approx.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 5. Precautions for hand soldering operations 1) Soldering operations using lead-free solder are basically the same as those using tinlead solder, however, due to the lead-free solder's characteristics of being difficult to melt, wet, and spread, as well as being hard, a soldering iron needs to be applied for a longer period of time than when soldering with conventional tin-lead solder.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 6. Soldering irons When soldering is performed manually using lead-free solder, a soldering iron that has little reduction in its temperature needs to be used. This refers to a soldering iron that has a smaller degree of decrease in the temperature at the soldering iron's tip, such as when the soldering iron is applied to the base metal or solder is supplied, and the temperature is soon returned to the specified temperature.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 6. 1. SCREW TORQUE LIST Main Body No. Parts code Parts name 1 087320-616 Taptite, cup S M3x6 2 2. No. 1 087320-616 Location Pcs. Tightening torque N⋅m (Kgf⋅cm) NCU PCB ASSY 2 NCU shield cover 1 NCU shield plate 2 Taptite, cup S M3x6 Main PCB ASSY 5 Parts name Location Pcs. Tightening torque N⋅m (Kgf⋅cm) Inner chute 4 Joint cover front L 2 Joint cover front R 2 0.686 ±0.098 (7 ±1) 0.686 ±0.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 4. No. ADF Unit Parts code Parts name 087311-016 Taptite, cup B M3x10 0A4300-605 3 4 1 2 5 Location Pcs. Tightening torque N⋅m (Kgf⋅cm) LF spring 2 Hinge arm R 3 Rew, pan (S/P washer) M3 ADF motor 2 0.686 ±0.098 (7 ±1) 087320-616 Taptite, cup S M3x6 Motor frame 3 0.686 ±0.098 (7 ±1) 087311-016 Taptite, cup B M3x10 Paper feed chute 4 0.686 ±0.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 7. LUBRICATION Flame L PG4 PG4 Gear 20 center F/R PG4 Idle gear 16A Gear 17 planetary Shaft idle gear 16 Gear 45 arm F/R PG4 PG4 PG4 Shaft idle gear 16 PG4 PG4 Gear, 40/54Y PG4 PG4 Idle gear 16A PG4 Pendulum gear 22 Drive unit Pendulum gear 22 PG4 Gear 58/88 PG4 Gear 58/88 * PG4: Grease PG662 4 mm dia.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Tray feed ZL2 Side regist roller ZL2 Side regist roller ZL2 EM3 DX feed roller EM3 * EM3: Grease EM-D110 3 mm dia.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY Separation plate ASSY SK4 * SK4: Grease SK-623 4 mm dia. ball PG2 Rubber holder Paper feed chute * PG2: Grease PG-662 2 mm dia.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 8.
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CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY 8 9 Speaker 10 FFC / HP sensor / Scanning motor FB Panel PCB Panel FFC Speaker HP sensor Scanning motor FB Driver PCB ASSY Driver PCB ASSY Main PCB Main PCB 11 12 Rear cover sensor Main PCB Main PCB Rear cover sensor 13 Main PCB ADF motor / ADF relay PCB ASSY ADF motor ADF relay PCB ASSY ADF Engine PCB Low-voltage PS PCB ASSY Driver PCB ASSY Main PCB Engine PCB 4-96
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL CHAPTER 5 PERIODIC MAINTENANCE To avoid creating secondary problems by mishandling, follow the warnings below during maintenance work. WARNING (1) Always turn off the power switch and unplug the power cord from the power outlet before accessing any parts inside the machine. (2) Some parts inside the machine are extremely hot immediately after the machine is used.
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CHAPTER 5 PERIODIC MAINTENANCE If the LCD shows the message below, it means the drum unit is near the end of its life. We recommend that you replace the drum unit with a new one before there is a noticeable deterioration in the print quality. Change Drum Soon Fig.5-1 ! CAUTION: While removing the drum unit, handle it carefully because it may contain toner. (1) Press the cover release button and then open the front cover of the machine.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (4) Unpack the new drum unit. (5) Put the toner cartridge in the new drum unit until you hear it lock into place with a click. When the toner cartridge is installed correctly, the blue lock lever is lifted automatically. Make sure you fit the toner cartridge properly, or it may separate from the drum unit when you pick up the drum unit assembly. Fig. 5-4 (6) Put the drum unit assembly in the machine.
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CHAPTER 5 PERIODIC MAINTENANCE When the toner cartridge is running low, the LCD shows Toner Low. Toner Low Fig.5-5 If the LCD shows this message, the toner cartridge has nearly run out of toner. Buy a new toner cartridge and have it ready before you get a Toner Empty message. Toner Empty Open cover, then replace new t Fig.5-6 (1) Press the cover release button and then open the front cover. (2) Pull out the drum unit assembly.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (3) Push down the blue lock lever and take the toner cartridge out of the drum unit assembly. (4) Unpack the new toner cartridge. Hold the cartridge level with both hands and gently rock it from side to side five or six times to spread the toner evenly inside the cartridge. Fig. 5-8 (5) Remove the protective cover. Fig. 5-9 (6) Put the new toner cartridge firmly into the drum unit until you hear it lock into place.
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CHAPTER 5 PERIODIC MAINTENANCE ! CAUTION: • Handle the drum unit and toner cartridge carefully. If toner scatters on your hands or clothes, wipe or wash it off with cold water immediately. • Be sure to seal the toner cartridge tightly so that toner powder does not spill out of the cartridge. • Dispose of the used toner cartridge in accordance with local plastic waste regulations. • Only unpack a toner cartridge immediately before you need to install it into the machine.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2. PERIODICAL REPLACEMENT PARTS Periodical replacement parts are the parts to be replaced periodically to maintain product quality. These parts would affect the product quality greatly if they lost their function even if they do not appear to be damaged or there is no change in their appearance.) The periodical replacement parts listed below should be replaced at the service center referring to the service life.
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CHAPTER 5 PERIODIC MAINTENANCE 2.1 Fixing Unit 1) Disconnect the AC cord from the machine. Machine AC cord Fig.5-12 2) Close the front cover and pull out the paper tray. Front cover Paper Tray Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3) Remove the DX feed ASSY. DX feed ASSY Fig.5-14 4) Remove the rear cover MP ASSY. Hook Rear cover MP ASSY Fig.
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CHAPTER 5 PERIODIC MAINTENANCE 5) Remove the outer chute MP ASSY. Hook Outer chute MP ASSY Fig.5-16 6) Remove the two bind B M4x12 Taptite screws, and then remove the rear cover L. 7) Remove the two bind B M4x12 Taptite screws, and then remove the rear cover R. Taptite, bind B M4x12 Rear cover R Taptite, bind B M4x12 Hook Taptite, bind B M4x12 Hook Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 8) Remove the two cup S M3x6 Taptite screws, and then remove the NCU unit. NCU unit Taptite, cup S M3x6 Fig.5-18 9) Disconnect the heater harness and thermistor harness. 10) Remove the bind B M4x12 Taptite screw and the shoulder screw, and then remove the fixing unit. Fixing unit Shoulder screw Heater harness Taptite, bind B M4x12 Thermistor harness Fig.
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CHAPTER 5 PERIODIC MAINTENANCE 2.2 Paper Feeding Kit 1) Disconnect the AC cord from the machine. Machine AC cord Fig.5-20 2) Close the front cover and pull out the paper tray. Front cover Paper tray Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3) Remove the pad holder and the separation pad spring from the paper tray. Pad holder Separation pad spring Fig.5-22 4) Remove the bearing R. 5) Remove the paper pick-up roller ASSY. 6) Remove the two roller collars from the paper pick-up roller ASSY. Roller collar Paper pick-up roller ASSY Roller collar Bearing R 1 2 Fig.
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CHAPTER 5 PERIODIC MAINTENANCE 3. PERIODICAL CLEANING Clean the following parts periodically to avoid any machine problems or print image defects. ! CAUTION: While drum unit and scanner window cleaning basically can be implemented by the end user, the electrical terminals inside the machine and on the drum unit should be cleaned by a service technician. Instruct the users not to touch those terminals. WARNING There are high voltage electrodes inside the machine.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL White film Fig.5-25 3.3 Cleaning the Printer ! CAUTION: • Do not use isopropyl alcohol to remove dirt from the control panel. It many crack the panel. • Do not use isopropyl alcohol to clean the scanner window or toner sensor. • Do not touch the scanner window with you finger. • The drum unit contains toner, so handle it carefully. If toner scatters and you hands or cloths get dirty, immediately wipe or wash it off with cold water.
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CHAPTER 5 PERIODIC MAINTENANCE 3.4 Cleaning the Drum Unit When replacing the drum unit or toner cartridge with a new one, be sure to clean the drum unit. 1) Turn off the power switch and unplug the power cord. 2) Press the cover release button, and then open the front cover. 3) Pull out the drum unit assembly. ! CAUTION: It is recommended to place the drum unit assembly on a piece of disposable paper or cloth in case you accidentally spill or scatter toner.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 4) Gently wipe the scanner window with a soft dry cloth. Fig. 5-28 5) Re-install the drum unit assembly into the machine. Close the front cover. 6) Plug in the power cord, and then turn on the power switch. ! CAUTION: • Handle the drum unit carefully since it contains toner. If toner scatters and your hands or cloths get dirty, immediately wipe or wash it off with cold water. • Do not touch the scanner window with your fingers.
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CHAPTER 5 PERIODIC MAINTENANCE 4. MTBF / MTTR The meantime between failure (MTBF) and the meantime to repair (MTTR) for this machine are as follows; MTBF: Up to 4,000 hours MTTR: Average 30 minutes except the periodical maintenance parts (the Paper Feeding Kit) and the machine control boards whose MTTR is average 10 minutes.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL CHAPTER 6 TROUBLESHOOTING 1. INTRODUCTION 1.1 Initial Check (1) Operating environment Check if: • The source voltage stays within ±10% from the rated voltage shown on the rating plate. • The machine is installed on a solid, level surface. • The room temperature is maintained between 10°C and 32.5°C. The relative humidity is maintained between 20% and 80%. • The machine is not located in a dusty place.
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CHAPTER 6 TROUBLESHOOTING (4) Others Condensation: When the machine is moved from a cold room into a warm room in cold weather, condensation may occur inside the machine, causing various problems as listed below: • Condensation on the optical surfaces such as the scanning mirror, lenses, the reflection mirror and the protection glass may cause the print image to be light.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 1.3 Identify the Problem If you encounter any machine error or problem, first identify it referring to the chart below, then see the appropriate section. NOTE: The following troubleshooting sections contain both the actions which users should take or check and the ones which service technicians should perform. The machine does not print. The machine does not work. The machine does not load paper. 3.
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CHAPTER 6 TROUBLESHOOTING 2. 2.1 ERROR MESSAGE Error Message on the LCD If a machine error occurs, the machine emits an audible alarm (continuous beeping) for approximately 4 seconds and shows the error message on the LCD. For the error message, see below. Error Message Change Drum Soon Cause Action The drum unit is near the end of its life. Use the drum unit until you have a print quality problem; then replace the drum unit with a new one. The drum counter was not reset. 1.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Error Message Cause Action DX Lever Error The paper adjustment lever for duplex printing is not correctly set for the paper size. Set the duplex lever to the correct position. Fuser Open The fuser cover is open. Please close the jam clear cover. (See Paper Jam on page 6-13.) Machine Error XX Machine has a mechanical problem. Refer to ‘2.2 Error Codes Shown in the “MACHINE ERROR X X” message’.
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CHAPTER 6 TROUBLESHOOTING Error Message Cause Action No DX Tray You tried to make duplex printing with duplex cover open. Install the duplex tray correctly. (See Paper is jammed in the duplex tray (For MFC-8820D/8820DN, DCP-8025D/8025DN) on page 6-16.) Paper Jam The paper is jammed in the machine. See Paper Jam on page 6-13 or Paper is jammed in the Duplex Tray (For MFC8820D/8820DN, DCP-8025D/8025DN) on page 6-16. Toner Empty Toner cartridge is not installed.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2.2 Error Codes Shown in the “MACHINE ERROR X X” message. If the LCD shows the "PLS OPEN COVER" message, you can display the detailed error code following the MACHINE ERROR, by using the maintenance-mode function code 82 described in Chapter 7, Section 3.16. NOTE: • When checking a PCB as instructed in the "Check:" column, check its harness also. • To check sensors, use the maintenance-mode function code 32 described in Chapter 7, Section 3.
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CHAPTER 6 TROUBLESHOOTING Error Code (Hex) Error factor Check: Drum unit is not mounted. • Toner sensor • Drum unit Toner empty. • Toner sensor • Toner cartridge In-casing temperature error. • Thermistor ASSY Heater harness disconnected or broken. • Thermistor ASSY • Halogen lamp 78 Heater thermistor harness disconnected or broken. • Thermistor ASSY 79 In-casing temperature sensor harness disconnected or broken. 7A Main motor does not synchronize with the reference clock.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Error Code (Hex) A2 Error factor Check: Document too long to scan. Document not detected by the document rear sensor. A3 AA The document cover is not closed. • • • • • • Document front sensor Document rear sensor Document sensor PCB Document feed roller ADF motor Main PCB Remove the document and close the document cover. The CCD HP sensor will not go OFF. • • • • B0 Reading motor half inserted.
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CHAPTER 6 TROUBLESHOOTING Error Code (Hex) Error factor Check: Internal software error. • Replace the main PCB if this error occurs frequently. PC interface error. • Interface cable • Main PCB FA Reading motor error detected. • Reading motor FF Memory management error. • Replace the main PCB if this error occurs frequently.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3. 3.1 PAPER PROBLEMS Paper Loading Problems First, make sure that you are using paper that meets Brother recommended paper specifications. See 2.12 Paper in Chapter 1. Problem Remedy The machine does not feed paper. • If there is paper in the paper tray, make sure it is straight. If the paper is curled, you should straighten it before printing. Sometimes it is helpful to remove the paper, turn the stack over and put it back in the paper tray.
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CHAPTER 6 TROUBLESHOOTING 3.2 Original Jams Based upon where the original or printed sheet is jammed, follow the appropriate set of instructions to remove it. 3.2.1 Original is jammed in the top of the ADF unit (1) Take out any paper from the ADF that is not jammed. (2) Lift the ADF cover. (3) Pull the jammed original out to the right. (4) Close the ADF cover. (5) Press Stop/Exit button. Fig. 6-1 3.2.2 Original is jammed inside the ADF unit (1) Take out any paper from the ADF that is not jammed.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.3 Paper Jams 3.3.1 Clearing jammed paper Clear the jammed paper following the procedures below; (1) Pull the paper tray completely out of the machine. (2) Pull the jammed paper up and out of the machine. Fig. 6-4 (3) Press the cover release button and then open the front cover. (4) Pull out the drum unit assembly. Pull the jammed paper up and out of the machine.
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CHAPTER 6 TROUBLESHOOTING ! CAUTION: To prevent damage to the machine caused by static electricity, do not touch the electrodes shown in Figure 6-6. Fig. 6-6 (5) Open the back output tray. Pull the jammed paper out of the fuser unit. If the paper jam can be cleared, go to Step 7. Fig. 6-7 NOTE: If you have to pull the paper toward the back of the machine, the fuser may get dirty with toner powder and it may scatter on the next printouts.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (6) Open the jam clear cover. Pull the jammed paper out of the fuser unit. Fig. 6-9 (7) Close the jam clear cover. Close the back output tray. (8) Push the lock lever down and take the toner cartridge out of the drum unit assembly. Take out the jammed paper if there is any inside the drum unit. Fig. 6-10 (9) Put the drum unit assembly back in the machine. (10)Put the paper tray in the machine. (11)Close the front cover.
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CHAPTER 6 TROUBLESHOOTING 3.3.2 Paper is jammed in the Duplex Tray (For MFC-8820D/8820DN, DCP-8025D/8025DN) (1) Pull the Duplex Tray and paper tray out of the machine. Fig. 6-11 (2) Pull the jammed paper out of the machine. Fig. 6-12 (3) Pull the Duplex Tray and paper tray back into the machine. Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.3.3 Causes & countermeasures The causes for paper jam problems vary depending on the location of the paper jam. When a paper jam occurs inside the machine, you have to find the location of the paper jam first, remove the jammed paper and then take the appropriate countermeasure referring to the table below; Problem Type of Jam Cause Remedy Jam when the machine is turned on.
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CHAPTER 6 TROUBLESHOOTING 3.4 Paper Feeding Problems Even if the paper is printed and ejected without any problems such as paper jams, paper feeding problems below may appear. Users can clear these problems by following the ‘User Check’ items for each problem. Even if the same problem occurs again, follow the procedures in the table below. F-1 Double feeding User Check Check the paper used meets the recommended paper specifications.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL F-4 Curl or Wave User Check (1) Check the paper used meets the recommended paper specifications. Both high temperature and humidity will cause paper to curl. (2) If the machine is used infrequently, the paper may have sat for too long in the paper tray . Turn over the stack of paper in the paper tray . Also, try rotating the paper 180° in the paper tray . (3) Try printing using the straight-through output path.
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CHAPTER 6 TROUBLESHOOTING 4. SOFTWARE SETTING PROBLEMS The machine may not print the data correctly if there are incorrect software settings. S-1 “There was an error writing to LPT1: (or BRUSB) for the machine” error message appears. User Check (1) Check that the printer cable is not damaged or broken. Check also that the cable is connected to the correct interface connectors of both the machine and PC. (2) Check that the correct machine is selected if you have an interface switching device.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL S-3 Although the USB driver is installed, it is unable to find the BRUSB: port. (Windows98/Me only) User Check (1) Re-install, according to the instruction of the subsection 3.2 in Chapter 2. (2) Try to connect the machine directly to the computer if it is connected through a USB hub. Possible cause Step Check Result Remedy Computer Operating System 1 Windows 95 or Windows NT4.0? Yes Not supported.
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CHAPTER 6 TROUBLESHOOTING S-4 This machine does not appear in Chooser with iMac and Power Macintosh G3 with USB. User Check (1) Check the machine is turned on. (2) Check the USB interface cable is connected correctly. (3) Check the printer driver is installed correctly. Possible cause Machine connection Step Check Result 1 Select ‘Apple System Profiler’ in Apple Menu.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 5. MALFUNCTIONS When taking countermeasures for malfunctions as described in this section, check connectors for contact failure before measuring the voltage at the specified connector pins. M-1 No AC power supplied Possible cause Step Check Result Remedy Supply voltage 1 Is the correct voltage present at the outlet? No Inform the user that the correct voltage is not supplied at the outlet.
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CHAPTER 6 TROUBLESHOOTING WARNING If you analyze malfunctions with the power plug inserted into the power outlet, special caution should be exercised even if the power switch is OFF because it is a single pole switch. M-3 Possible cause Main motor failure Step Check Result Failure of connector 1 Is the connection of connector CN9 on the engine PCB correct? No Reconnect the connector. Main motor 2 Is the problem solved by replacing the main motor? Yes Replace the main motor.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL M-5 Insufficient output from high-voltage power supply unit Possible cause Step Check Result High-voltage contact 1 Do any of the terminals on the high-voltage contacts have dirt or contact burns? Yes Clean the terminals. High-voltage power supply PCB 2 Check the connections of the connector between the highvoltage power supply and the engine PCB are secured correctly.
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CHAPTER 6 TROUBLESHOOTING M-9 Fixing Unit failure Possible cause Step Check Result Remedy Poor thermistor harness contact 1 Is the contact of connector CN7 on the engine PCB good? No Reconnect the connector. Blown thermal fuse 2 Remove the fixing unit and measure the resistance between the input connectors. Is it open circuit? Yes Replace the fixing unit. Thermistor failure 3 Is the thermistor installed properly? Yes Replace the fixing unit. No Reinstall the thermistor properly.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL M-12 Engine PCB error Possible cause Fixing unit ground wire connection Harness connection failure Step 1 2 Engine PCB 3 Main PCB 4 M-14 Result No Check Result No Remedy Secure the ground wire correctly with the shoulder screw. Reconnect the connectors securely. Yes Replace the engine PCB. Yes Replace the main PCB.
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CHAPTER 6 TROUBLESHOOTING 6. TROUBLESHOOTING OF THE CONTROL PANEL L-1 Nothing is displayed on the LCD. User Check (1) Verify if the power switch is turned off. Possible cause Step Connection between main PCB, relay PCB, and control panel PCB 1 Check Main PCB and control panel PCB are properly connected. Result No Remedy Fix the connector properly. Harness between main PCB, relay PCB, and control panel PCB 2 Harness wire is damaged. Yes Replace the harness with a normal part.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL L-2 The control panel does not work. User Check (1) No Possible cause Step Check Any key on control panel is stuck. Result Yes Remedy Clean up the panel cover, or remove the burrs from panel cover and panel keys. Fix the connection properly. Key sticking 1 Connection between main PCB, relay PCB, and control panel PCB 2 Main PCB, relay PCB, and control panel PCB are properly connected.
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CHAPTER 6 TROUBLESHOOTING 7. TROUBLESHOOTING OF FAX FUNCTIONS F-1 FAX can't send it. User Check (1) Verify that the telephone cord is securely inserted. Possible cause Step Check Dialing signal (PB or DP) comes out normally in each mode. (Use telephone line emulator.) Result Yes Remedy Check the dialing mode setting at customer's again. Check the telephone line cord between machine and socket. Fix the connection properly.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL F-2 Speed dialing and One-touch dialing can't be used. Possible cause Step Check Result Remedy Speed dialing, One-touch dialing 1 A fax transmission can be made using the key, ten? Yes Replace the main PCB. Dialing mode setting 2 Dialing signal (PB or DP) comes out normally in each mode. (Use telephone line emulator.) Yes Connection between main PCB and NCU PCB 3 Main PCB and NCU PCB are properly connected.
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CHAPTER 6 TROUBLESHOOTING F-4 No bell ring. Possible cause Step Ring delay 1 Check Ring delay is set to "0". Ring volume 2 Ring volume is set to "OFF". Yes Connection between main PCB, relay PCB, and scanner unit 3 Main PCB, relay PCB, and scanner unit are properly connected. No Harness between main PCB, relay PCB, and scanner unit 4 Harness wire is damaged. Yes Replace the harness with a normal part.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL F-5 Speaker is silent during on-hook dialing. Possible cause Step Result No Remedy Fix the connection properly. Replacement of speaker solves the problem. Main PCB and NCU PCB are properly connected. Yes Replace the speaker with a normal part. Fix the connection properly. 4 Harness wire is damaged. Yes Replace the harness with a normal part.
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CHAPTER 6 TROUBLESHOOTING 8. 8.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 8.3 Troubleshooting Image Defect Several types of the image defects can be cleared by end users. For those defects, instruct the user to check the ‘User Check’ items described in each table. Even if the same image defect appears, the following procedures should be followed in the event of specific image defects. See also subsection 8.4 ‘Location of Ground Contacts’ in this Chapter for information about the location of the grounding contacts.
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CHAPTER 6 TROUBLESHOOTING I-2 Dark User Check (1) Check the paper used meets the recommended paper specifications. (2) Check the machine’s environment. High temperature and high humidity conditions can increase the amount of background shading. (3) Clean the corona wire with the wire cleaner. (4) Try installing a new toner cartridge or drum unit.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL I-3 Completely blank User Check (1) Check for the setting of originals. Possible cause Step Check Result Developing bias contact failure 1 Are the developing bias contacts between the machine body and drum unit dirty? Yes Drum unit 2 Are the drum shaft and drum electrode of the machine connected correctly? Yes No Remedy Clean the electrodes at both sides. (4) Clean the shaft and the electrode.
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CHAPTER 6 TROUBLESHOOTING I-4 All black User Check (1) Clean the corona wire of the drum unit. (2) The drum unit may be damaged. Install a new drum unit. Possible cause Corona failure Step Check Result Remedy Ground contacts (2) 1 Is the corona wire dirty? Yes Clean the corona wire with the wire cleaner. 2 Is the corona wire broken? Yes Replace the drum unit. 3 Are the charge electrodes between the machine and the drum unit dirty? Yes Clean both electrodes.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL I-5 Dirt on the back of paper Possible cause Fixing unit dirty Step 1 Check Result Is the pressure roller dirty? Yes Clean the pressure roller referring to the following procedure. Yes Replace the drum unit No Replace the high-voltage power supply PCB.
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CHAPTER 6 TROUBLESHOOTING I-6 Black and blurred vertical streaks User Check (1) Clean the corona wire in the drum unit. (2) Check that the corona wire cleaner is at the home position. (3) Check that the toner cartridge is not empty. (4) The drum unit may be damaged. Install a new drum unit. (5) The toner cartridge may be damaged. Install a new toner cartridge. Possible cause Step Check Result Remedy Dirt on the scanner glass. 1 Is there any dirt on that? Yes Clean the scanner glass.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL I-7 Black and blurred horizontal stripes User Check (1) The drum unit may be damaged. Install a new drum unit. (2) Check the paper used meets the recommended paper specifications. (3) Clean the machine interior and the corona wire in the drum unit. Possible cause Step Check Result Remedy Scratch on the drum 1 Are the horizontal stripes at 94mm (photosensitive drum) intervals? Yes The photosensitive drum was scratched.
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CHAPTER 6 TROUBLESHOOTING I-9 White vertical streaks User Check (1) Try to wipe the scanner window with a soft cloth. (2) The toner cartridge may be damaged. Install a new toner cartridge. (3) Check the machine’s environment. High temperature and high humidity conditions can cause this problem. (4) Damp (wet) paper might be used. Try to change to freshly unpacked paper. Possible cause Step Dirt on the CCD. 1 Is there any dirt on that? Yes Replace the CCD.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL I-11 Faulty registration Possible cause Step Excessive paper load 1 Is the paper loaded in the paper tray more than 27mm high? Yes Instruct the user to keep paper loads below 27mm in depth. Print paper 2 Is the specified weight of the recommended paper being used? No Recommend to use the specified types of paper.
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CHAPTER 6 TROUBLESHOOTING I-13 Image distortion Possible cause Step Check Result Remedy Laser unit installation 1 Is the laser unit secured to the frame incorrectly? (Check if there is any play.) Yes Secure the unit correctly and tighten the screws. Laser scanner LD emission failure 2 Is the laser diode or the scanner motor defective? Yes Replace the laser unit. 3 Is the scanner harness connected properly? (Check if it is coming loose.) No Connect the harness correctly.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL I-15 White spots User Check (1) If the problem is not solved after printing a few pages, the drum unit may have glue from label stock on the photosensitive drum surface. Refer to Step 1 in the table below and NOTE in the next page. (2) The drum unit may be damaged. Install a new drum unit.
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CHAPTER 6 TROUBLESHOOTING NOTE: Clean the drum unit as follows: (1) Remove the toner cartridge from the drum unit. Place the printing samples in front of the drum unit, and find the exact position of the image defect. Drum unit Position of smudge on the drum 94mm interval Printing sample Fig. 6-15 (2) Turn the drum gear by hand while looking at the surface of the photosensitive drum. Photosensitive drum Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL I-16 Black spots User Check (1) If the problem is not solved after printing a few pages, the drum unit may have glue from label stock on the photosensitive drum surface. Refer to Step 1 in the table below and NOTE in the previous page. (2) The drum unit may be damaged. Install a new drum unit. Possible cause Step Check Result Remedy Drum unit 1 Are the spots at 94mm intervals? (The problem is not solved after printing a few pages.
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CHAPTER 6 TROUBLESHOOTING I-17 Black band Possible cause Corona failure Corona failure Ground contacts Step Check Result Remedy 1 Is the wire cleaner at its home position? No Return the wire cleaner to its home position. (2) Is the corona wire dirty? Yes 1) Clean the corona wire. 2) If the problem still appears after cleaning, replace the drum unit.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL I-18 Gray background Possible cause Print paper Step 1 Check Result Does the paper being used meet the paper specification (weight, etc.)? Remedy No Recommend to use the specified types of paper. Yes Recommend to change to freshly unpacked paper.
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CHAPTER 6 TROUBLESHOOTING I-19 Hollow print User Check (1) Check the paper used meets the recommended paper specifications. (2) Select the ‘Thick paper mode’ in the printer driver, or use thinner paper than you are currently using. (3) Check the machine’s environment, conditions such as high humidity may cause this situation to occur.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL I-21 Horizontal lines Possible cause Step Paper feed roller 1 Check Are the feed roller shaft and the ground contact connected correctly? Result Remedy No Check the connection between the shaft and the ground contact. Ground contacts Also check the ground contact on the back of the feed roller. Paper tray contacts I-22 2 Are the ground contacts on the back side of the paper tray connecting correctly? No Clean the contacts.
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CHAPTER 6 TROUBLESHOOTING I-23 Ghost User Check (1) Check the paper used meets the recommended paper specifications. Damp paper, thick media or rough surfaced paper can cause the problem. (2) Check the machine’s environment. High temperature and high humidity conditions can cause the problem. (3) Check that the appropriate media type is selected in the printer driver. (4) Try installing a new drum unit.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 8.4 Location of Grounding Contacts 8.4.1 Drum unit (2) Wire cleaner Drum Unit (5) Grid (8) Cleaner (4) Development roller (3) Charge (1) Photosensitive drum (6) Transfer roller Fig. 6-18 8.4.2 Machine body & Paper tray (3) Charge (5) Grid (8) Cleaner (4) Development roller (1) Photosensitive drum (6) Transfer roller (7) Ground Paper Tray Fig.
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CHAPTER 6 TROUBLESHOOTING 9. INCORRECT PRINTOUT When the data is not printed correctly as it is seen on the PC screen, follow the procedures below in the event of a specific error. P-1 The machine prints unexpectedly or it prints garbage. User Check (1) Check if the printer cable is not too long. It is recommended to use a parallel cable of less than 2 meters (6.6 feet) in length. (2) Check that the printer cable is not damaged or broken.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL P-2 Unable to print full pages of a document with the “MEMORY FULL” message. User Check (1) Menu and 2,5,4 are pushed, and the data accumulated by a memory are output. (2) Reduce the complexity of your document or reduce the machine resolution. (3) Expand the printer memory by adding a commercially available DIMM. NOTE: This problem may appear if the data is too complex.
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CHAPTER 6 TROUBLESHOOTING 10. NETWORK PROBLEM If the error related to network occurs, refer to the following sections; 10.1 Installation Problem If you cannot print over the network, check the following: (1) Make sure that the machine is powered on, is on-line and ready to print. Verify that the machine and the configuration are good by printing the machine settings page.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (3) If you cannot make any of the connections in step (2), check the following: a) Make sure the machine is powered on and on-line. b) Check the cabling, network connection, and print out a configuration page in the Network STATISTICS information to see if bytes are being transmitted and received. c) Check to see if there is any LED activity. The NC-9100h print/fax server has two LEDs on the back panel of the machine.
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CHAPTER 6 TROUBLESHOOTING 10.3 TCP/IP Troubleshooting If you are using TCP/IP and cannot print to the print server and you have checked the hardware and network as described in the previous steps, then check the following: NOTE: It is always a good idea to try the following in order to eliminate the possibility of setup errors. • Turning off the machine and then on again, • Deleting and recreating the print/fax server and creating a new print queue in order to eliminate the possibility of setup errors.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (7) If PostScript jobs fail to print or are run together, try setting the service (remote machine) with EOT set to string number 3 (control-D). For example: SET SERVICE BRN_xxxxxx_P1 EOT 3 (8) If the lines of a text file are staggered, make sure that you have specified a remote printer (rp) name of TEXT in your /etc/printcap file. (9) If you are using Sun Solaris V2.
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CHAPTER 6 TROUBLESHOOTING 10.8 Windows® 95/98/Me/2000/XP/NT 4.0 Peer to Peer Print (NetBIOS) Troubleshooting ® If you are having trouble printing on a Windows 95/98/Me/2000/XP/NT 4.0 (or later) Peer to Peer network (NetBIOS), check the following: (1) Make sure that the Brother NetBIOS Port driver is securely installed and configured ® according to the Windows 95/98/Me/2000/XP/NT 4.0 Peer to Peer (NetBIOS) chapters.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 10.11 Novell Netware Troubleshooting If you cannot print from NetWare and you have checked the hardware and network as described in the previous steps, first verify that the Brother print/fax server is attached to the server queue by going to PCONSOLE, selecting PRINT QUEUE INFORMATION, and then CURRENTLY ATTACHED SERVERS.
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CHAPTER 6 TROUBLESHOOTING 10.12 AppleTalk Troubleshooting In case of using Postscript driver, if you cannot print from an AppleTalk for Macintosh computer and you have checked the hardware and network as described in the previous steps, then check the following: (1) Make sure that you are running Phase 2 AppleTalk and that you have selected the correct network interface from the Apple Talk Control Panel on the Macintosh. (2) Make sure that the AppleTalk protocol of the print/fax server is enabled.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 10.15 Internet Fax Troubleshooting (1) If there is a mail delivery error while sending an Internet Fax, the mail server will send an error message back to the machine and the error message will be printed. If there is an error while receiving mail, an error message is printed (Ex. The message being sent to the machine was not in a TIFF-F format.) All documents transmitted to the machine via email must be in a TIFF-F format.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL CHAPTER 7 1. MAINTENANCE MODE ENTRY INTO THE MAINTENANCE MODE To make the machine enter the maintenance mode, press the Menu button, *, 2, 8, 6, and 4 keys in this order. Within 2 seconds " on the The machine beeps for approx. one second and displays " LCD, indicating that it is placed in the initial stage of the maintenance mode, a mode in which the machine is ready to accept entry from the keys.
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CHAPTER 7 MAINTENANCE MODE 2. LIST OF MAINTENANCE–MODE FUNCTIONS Maintenance-mode Functions Function Code 01 Reference Subsection (Page) Function EEPROM Parameter Initialization 3.1 (7-4) 05 Printout of Scanning Compensation Data 3.2 (7-5) 06 Placement of CCD Unit in Position for Transportation 3.3 (7-7) 08 ADF* Performance Test 3.4 (7-7) 09 Test Pattern 1 3.5 (7-8) 10 Firmware Switch Setting 3.6.1 (7-9) 11 Printout of Firmware Switch Data 3.6.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL < IMPORTANT> Basically, the maintenance-mode functions listed on the previous page should be accessed by service personnel only. However, you may allow end users to access some of these under the guidance of service personnel (e.g., by telephone). The user-accessible functions (codes 06, 10, 11, 12, 54, 80, 82, 87 and 91) are shaded in the table given on the previous page.
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CHAPTER 7 MAINTENANCE MODE 3. 3.1 DETAILED DESCRIPTION OF MAINTENANCE-MODE FUNCTIONS EEPROM Parameter Initialization (Maintenance mode 01/91) < Function > The machine initializes the parameters, user switches, and firmware switches registered in the EEPROM, to the initial values. Entering the function code 01 initializes all of the EEPROM areas, but entering 91 does not initialize some areas, as listed below.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.2 Printout of Scanning Compensation Data (Maintenance mode 05) < Function > The equipment prints out the white and black level data for scanning compensation. < Operating Procedure > Do not start this function merely after powering on the equipment but start it after carrying out a sequence of scanning operation. Unless the equipment has carried out any scanning operation, this function cannot print out correct scanning compensation data.
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CHAPTER 7 MAINTENANCE MODE a) b) c) d) e) f) g) h) i) j) k) l) m) Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.3 Placement of CCD Unit in Position for Transportation (Maintenance mode 06) < Function > This function is to move the CCD unit in position for transportation located at the right end. When you fix the FAX equipment and check its operation, you need to perform this function right before packing and shipping it.
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CHAPTER 7 MAINTENANCE MODE 3.5 Test Pattern 1 (Maintenance mode 09) < Function > This function, much like the copying function, prints out test pattern 1 to allow the service personnel to check for record data missing or print quality. < Operating Procedure > Press the 0 and 9 keys in this order in the initial stage of the maintenance mode. The figure below shows test pattern 1. Fig.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.6 Firmware Switch Setting and Printout 3.6.1 Firmware switch setting (Maintenance mode 10) < Function > The machine incorporates the following firmware switch functions which may be activated with the procedures using the control panel keys and buttons. The firmware switches have been set at the factory in conformity to the communications standards and codes of each country. Do not disturb them unless necessary.
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CHAPTER 7 MAINTENANCE MODE WSW No. WSW35 WSW36 WSW37 WSW38 WSW39 WSW40 WSW41 WSW42 WSW43 WSW44 WSW45 WSW46 WSW47 WSW48 WSW49 WSW50 Function Function setting 13 Function setting 14 Function setting 15 Function setting 16 Function setting 17 Function setting 18 Function setting 19 Function setting 20 Function setting 21 Speeding up scanning-1 Speeding up scanning-2 Monitor of PC ON/OFF state Function setting 22 Function setting 23 Function setting 24 Not used.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.6.2 Printout of firmware switch data (Maintenance mode 11) < Function > The machine prints out the setting items and contents specified by the firmware switches. < Operating Procedure > (1) Press the 1 key twice in the initial stage of the maintenance mode. The "PRINTING" will appear on the LCD. (2) The machine prints out the configuration list as shown in the figure below.
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CHAPTER 7 MAINTENANCE MODE 3.7 Operation Check of LCD (Maintenance mode 12) < Function > This function allows you to check whether the LCD on the control panel works normally. < Operating Procedure > (1) Press the 1 and 2 keys in this order in the initial stage of the maintenance mode. The LCD shows. (2) Press the Start button. Each time you press the Start button, the LCD cycles through the displays shown at right.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.8 Operational Check of Control Panel PCB (Maintenance mode 13) < Function > This function allows you to check the control panel PCB for normal operation. < Operating Procedure > (1) Press the 1 and 3 keys in this order in the initial stage of the maintenance mode. The "00 " will appear on the LCD. (2) Press the keys and buttons in the order designated in the illustration shown below.
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CHAPTER 7 MAINTENANCE MODE 3.9 Sensor Operational Check (Maintenance mode 32) < Function > This function allows you to check whether the 13 sensors--document front sensor, document rear sensor, cover sensor, registration sensor, toner sensor, paper ejection sensor, CCD HP sensor, manual insertion sensor, cassette sensor, jam sensor, document tray open sensor, 2nd registration sensor*, and 2nd cassette sensor*--operate correctly. (* These sensors are provided for models supporting a 2nd paper cassette.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (2) Change the detecting conditions to check that the indication on the LCD changes according to the sensor states. For instance, insert paper through the document front (or rear) sensor or the registration sensor (s), open the front cover or the document cover, remove the toner cartridge, jam paper at the paper outlet, insert paper from the manual feeder, and load a recording paper tray, etc. (3) Press the Stop button.
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CHAPTER 7 MAINTENANCE MODE 3.10 Received Data Transfer Function (Maintenance mode 53) (MFC-8420/8820D/8820DN only) < Function > This function is to transfer received data to another FAX equipment when the machine fails to print out the data because of a recording system failure. NOTE: • The maximum number of files to be transferred at a time is 99. If there are 100 files or more, you need to perform this function more than once.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Example of the cover page ===FAX TRANSFER COVER PAGE=== JOB NO. TOTAL PAGE[S] NAME FAX TEL TIME :001 :001 :BROTHER :052 824 2330 :052 824 2846 :2002/03/04 14:11 Job No. of the transfer setting Total number of pages to be transferred Sender's name registered in the sender's FAX machine Sender's FAX number Sender's phone number Start time Model code Boot ROM information 8X5-653 B0108251119 U0203122124 VER.
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CHAPTER 7 MAINTENANCE MODE 3.11 Fine Adjustment of Scan Start/End Positions (Maintenance mode 54) < Function > This function is to adjust the scan start/end positions. < Operating Procedure > (1) Press the 5 and 4 keys in this order in the initial stage of the maintenance mode. The “SCAN START ADJ.” will appear on the LCD. (2) The “1. ADF 2. FB” will appear. Select one of them that you want to adjust the start position.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL MAINTENANCE 5 and 4 keys SCAN START ADJ. 2 second later 1. ADF 2. FB 1 or 2 keys Set button Left arrow key + MAINTENANCE - + - Stop button Right arrow key - + MAINTENANCE Stop button Set button ACCEPTED 1 second later Fig.7-13 Left arrow key Right arrow key Fig.
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CHAPTER 7 MAINTENANCE MODE 3.12 CCD Scanner Area Setting (Maintenance mode 55) < Function > The machine sets the CCD scanner area and stores it into the EEPROM. < Operating Procedure > (1) Press the 5 key twice in the initial stage of the maintenance mode. The "SCANNER AREA SET” will appear on the LCD. (2) When setting of the scanner area is completed, a 4-digit number will appear on the LCD. (e.g.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.13 EEPROM Customizing (Maintenance mode 74) < Function > This function allows you to customize the EEPROM according to language, function settings, and firmware switch settings. The customizing codes list is given in Appendix 1. NOTE: If you replace the main PCB, be sure to carry out this procedure. < Operating Procedure > (1) Press the 7 and 4 keys in this order in the initial stage of the maintenance mode. The current customizing code (e.g.
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CHAPTER 7 MAINTENANCE MODE 3.14 Printing out of Machine Log Information (Maintenance mode 77) < Function > This function is to print out log information. < Operating Procedure > (1) Press the 7 key twice in the initial stage of the maintenance mode. The “MAINTENANCE 77” will appear on the LCD. (2) The machine prints out a list of log information. The example of the log information is shown below.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL (1) Loader version (2) Program version and checksum (3) RTC check result and RTC backup check result (4) WHQL serial number (5) Reading process information (6) Presence or absence of maintenance upon process inspection (7) Drum counter (8) Average black coverage (9) Total number of pages printed (10) Number of pages picked up from each tray (11) Number of pages picked up according to the paper size (12) Total number of paper
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CHAPTER 7 MAINTENANCE MODE 3.15 Display of the Equipment’s Log Information (Maintenance mode 80) < Function > The equipment may display its log information on the LCD. < Operating Procedure > (1) Press the 8 and 0 keys in this order in the initial stage of the maintenance mode. The USB serial number appears on the LCD. (2) Press the Start button. Each time the Start button is pressed, one of the following log information items appears on the LCD in the order given below.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL USB: USB Serial No.
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CHAPTER 7 MAINTENANCE MODE 3.16 Machine Error Code Indication (Maintenance mode 82) < Function > This function displays an error code of the last error on the LCD. < Operating Procedure > 3.17 (1) Press the 8 and 2 keys in this order in the initial stage of the maintenance mode. The LCD shows the "MACHINE ERROR X X." (2) Press the Stop button. Return to the initial stage of the maintenance mode.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 3.18 Cancellation of the Memory Security Mode (Not applicable to the Japanese version) < Function > This procedure can cancel the memory security mode. Use this procedure if the user forgets his/her password entered when setting the memory security mode so as not to exit from the memory security mode. NOTE: Carrying out this procedure will lose passwords previously entered but retain FAX messages received in the memory security mode.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL APPENDIX 1 EEPROM CUSTOMIZING CODES This function allows you to customize the EEPROM according to language, function settings, and firmware switch settings. < Operating Procedure > (1) To make the machine enter the maintenance mode, press the Menu button, *, 2, 8, 6, and 4 keys in this order. Within 2 seconds " The machine beeps for approx.
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APPENDIX 1 EEPROM CUSTOMIZING CODES < EEPROM Customizing Codes List > Models Versions DCP8020 DCP8025D DCP8025DN MFC8420 MFC8820D MFC8820DN U.S.A.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL APPENDIX 2 1. INSTALLING THE UPDATE DATA INSTALLING THE UPDATE DATA TO THE MACHINE If you want to update the current program stored in the flash ROM of the main PCB to the newer version or after you replace the main PCB, install the update program onto the flash ROM. The program installation requires a PC/AT-compatible computer (which is capable of running MS-DOS or its compatible OS). 1.1 1.
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APPENDIX 2 INSTALLING THE UPDATE DATA 1.3 Installing the Update Data onto the Flash ROM of the Machine < On a PC running Windows 95 > (1) Copy the update data and transfer utility onto the desired same directory of the hard disk. e.g., C:\UPDATE (2) Click the Start button, point to Programs, and then click MS-DOS Prompt to open an MS-DOS window. (3) Type the drive letter where the update data and transfer utility are located.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL 2. SETTING ID CODES TO MACHINES Brother driver machines are assigned unique ID codes (character strings) at the factory. If you replace the main PCB of the machine, the machine will lose its assigned ID code so that it will not be identified by the connected PC*. You need to assign a unique ID code (character string) to the machine according to the procedure given here.
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APPENDIX 2 INSTALLING THE UPDATE DATA 2.3 Running the Setup Utility (1) On your PC, run the ID/head property setup utility (BRUSBSN.EXE). The following window will appear. (2) On the Model menu, click MFC 2. In Port, make sure that the HFC/DCP ports connected are shown. When not select, please click button and select the USB port of MFC-8820 or MFC8420 or DCP-8025 or DCP-8020. In the Serial No = 000 box, type the 9-digit serial number (e.g.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL APPENDIX 3 WSW No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW01 (Dial pulse setting) Selector No. Function Setting and Specifications Dial pulse generation mode No. 1 0 0 1 1 2 0 1 0 1 : : : : N N+1 10-N N Break time length in pulse dialing No. 3 0 0 1 1 4 0 1 0 1 : : : : 60 ms 67 ms 40 ms (for 16 PPS) 64 ms (at 106-ms intervals) Inter-digit pause No.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL l Selector 7: Switching between pulse (DP) and tone (PB) dialing, by the function switch This selector determines whether or not the dialing mode may be switched between the pulse (DP) and tone (PB) dialing by using the function switch. l Selector 8: Default dialing mode, pulse (DP) or tone (PB) dialing This selector sets the default dialing mode (pulse dialing or tone dialing) which may be changed by the function switch.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW03 (PABX* mode setting) Selector No. Function Setting and Specifications 1 CNG detection when sharing a modular wall socket with a telephone 2 | 4 Not used. 5 CNG detection when sharing a modular wall socket with a telephone 6 | 8 Not used. 0: A 1: B 0: A 1: B * PABX: Private automatic branch exchange NOTE: Selectors 2 through 4, 6 and 7 are not applicable where no PABX is installed.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW05 (1st dial tone and busy tone detection) Selector No. Function Setting and Specifications No. 1 0 0 0 0 1 1 1 1 1 | 3 1st dial tone detection 4 Max. pause time allowable for remote ID code detection 5 6 7 Busy tone detection in automatic receiving mode 8 Not used. 3 0 1 0 1 0 1 0 1 : : : : : : : : 0 : 2 seconds No. 5 0 0 1 1 Busy tone detection in automatic sending mode 2 0 0 1 1 0 0 1 1 6 0 1 0 1 : : : : 3.5 sec. WAIT 7.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) l Selectors 5 and 6: Busy tone detection in automatic sending mode These selectors determine whether or not the machine automatically disconnects a line upon detection of a busy tone in automatic sending mode. Setting selector 6 to "0" ignores a busy tone so that the machine does not disconnect the line. Setting selectors 5 and 6 to "0" and "1," respectively, makes the machine detect a busy tone only after dialing and disconnect the line.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL l Selectors 1 through 3: Pause button setting and 2nd dial tone detection Selectors 1 2 3 l 0 0 0 No WAIT is inserted even if the Pause button is pressed. 0 0 0 1 0 1 1 0 1 0 1 0 If you press the Pause button during dialing, the machine will insert WAIT as defined in the above table. If the Pause button is pressed repeatedly, the machine inserts the specified WAIT multiplied by the number of depressions.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW07 (Dial tone setting 1) Selector No. Function Setting and Specifications No. 1 2 1 Frequency band range 2 3 0 0 : Narrows by 10 Hz 0 1 : Initial value 1 X : Widens by 10 Hz Not used. No. 4 5 6 4 | 6 2nd dial tone detection level (Z = 600 Ω) 7 1st dial tone interrupt detecting time 8 Not used.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW08 (Dial tone setting 2) Selector No. 1 | 3 4 5 6 | 8 Function Setting and Specifications 1st dial tone detection time length Time-out length for 1st and 2nd dial tone detection Detection level of 1st dial tone and busy tone before dialing No. 1 0 0 0 0 1 1 1 1 2 0 0 1 1 0 0 1 1 3 0 1 0 1 0 1 0 1 No. 4 0 0 1 1 5 0 1 0 1 : 10 sec. : 20 sec. : 15 sec. : 30 sec. No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW09 (Protocol definition 1) Selector No. Function Setting and Specifications 1 Frame length selection 0: 256 octets 1: 64 octets 2 Use of non-standard commands 0: Allowed 1: Prohibited No. 3 0 0 1 1 3 No. of retries 4 4 0 1 0 1 : : : : 4 times 3 times 2 times 1 time 5 T5 timer 0: 300 sec. 1: 60 sec. 6 T1 timer 0: 35 sec. 1: 40 sec. 7 8 Elapsed time for time-out control for no response from the called station in automatic sending mode No.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW10 (Protocol definition 2) Selector No. Function Setting and Specifications 1 Not used. 2 Time length from transmission of the last dial digit to CML ON 0: 100 ms 1: 50 ms 3 Time length from CML ON to CNG transmission 0: 2 sec. 1: 4 sec. 4 Time length from CML ON to CED transmission (except for facsimileto-telephone switching) 0: 0.5 sec. 1: 2 sec. No. 5 6 7 8 l Selector 2: No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW11 (Busy tone setting) Selector No. Function Setting and Specifications No.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW12 (Signal detection condition setting) Selector No. 1 2 3 4 Function Setting and Specifications Min. OFF time length of calling signal (Ci) No. 1 0 0 1 1 2 0 1 0 1 : : : : 1500 ms 500 ms 700 ms 900 ms Max. OFF time length of calling signal (Ci) No. 3 0 0 1 1 4 0 1 0 1 : : : : 6 sec. 7 sec. 9 sec. 11 sec. Detecting time setting No. 5 0 0 1 1 6 0 1 0 1 : : : : 800 ms 200 ms 250 ms 150 ms 5 6 l 7 Not used. 8 Not used.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW13 (Modem setting) Selector No. 1 2 3 4 5 | 8 Function Setting and Specifications Cable equalizer No. 1 0 0 1 1 2 0 1 0 1 : : : : 0 km 1.8 km 3.6 km 5.6 km Reception level No. 3 0 0 1 1 4 0 1 0 1 : : : : -43 dBm -47 dBm -49 dBm -51 dBm 0: 0: 0: 0: Modem attenuator 0 dB 0 dB 0 dB 0 dB 1: 1: 1: 1: 8 dB 4 dB 2 dB 1 dB The modem should be adjusted according to the user's line conditions.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW14 (AUTO ANS facility setting) Selector No. Function Setting and Specifications No. 1 2 Frequency band selection (Lower limit) No. 3 4 Frequency band selection (Upper limit) No. 5 | 8 l No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW15 (REDIAL facility setting) Selector No. Function Setting and Specifications 1 Selection of redial interval 2 3 | 6 No. of redialings No. 1 0 0 1 1 2 0 1 0 1 : : : : 5 minutes 1 minute 2 minutes 3 minutes No.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW16 (Function setting 1) Selector No. l Function Setting and Specifications 1 Not used. 2 CCITT superfine recommendation 3 | 6 Not used. 7 8 Selector 2: 0: OFF 1: ON Max. document length limitation 0: 400 cm 1: 90 cm Stop button pressed during reception 0: Not functional 1: Functional CCITT superfine recommendation If this selector is set to "1," the machine communicates in CCITT recommended superfine mode (15.4 lines/mm).
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW17 (Function setting 2) Selector No. Function Setting and Specifications No. 1 0 0 1 1 2 l Off-hook alarm 3 4 Not used. 5 Calendar clock type 6 Not used. 7 Non-ring reception 8 Not used. 2 0 1 X : : : No alarm Always valid Valid except when 'call reservation' is selected. 0: U.S.A.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW18 (Function setting 3) Selector No. 1 2 3 4 5 6 Function Setting and Specifications Not used. Detection enabled time for CNG and no tone No. 2 0 0 1 1 3 0 1 0 1 : : : : Not used. Registration of station ID 0: 7 Permitted No. 7 0 1 8 X 0 : : 1 1 : Tone sound monitoring 8 l 40 sec. 0 sec. (No detection) 5 sec. 80 sec.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW19 (Transmission speed setting) Selector No. Function Setting and Specifications No. 1 No. 4 0 0 0 0 1 1 1 1 2 5 0 0 1 1 0 0 1 1 3 6 0 1 0 1 0 1 0 1 1 | 3 First transmission speed choice for fallback 4 | 6 Last transmission speed choice for fallback 7 V. 34 mode 0: Permitted 1: Prohibited 8 V. 17 mode 0: Permitted 1: Prohibited : : : : : : : : 2,400 bps 4,800 bps 7,200 bps 9,600 bps 12,000 bps 14,400 bps NOTE: For the transmission speed setting in V.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW20 (Overseas communications mode setting) Selector No. Function Setting and Specifications 1 EP* tone prefix 0: OFF 1: ON 2 Overseas communications mode (Reception) 0: 2100 Hz 1: 1100 Hz 3 Overseas communications mode (Transmission) 0: OFF 1: Ignores DIS once. 4 5 Min. time length from reception of CFR to start of transmission of video signals No. No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW21 (TAD setting 1) Selector No. l Function Setting and Specifications 1 | 7 Not used. 8 Erasure of message stored in the memory after the message transfer Selector 8: 0: Yes 1: No Erasure of message Setting this selector to "0" will erase the message recorded in the memory after the document retrieval feature transfers the message. WSW22 (ECM setting) Selector No.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW23 (Communications setting) Selector No. 1 Function Setting and Specifications Starting point of training check (TCF) 0: From the head of a series of zeros 1: From any arbitrary point No. 2 Allowable training error rate 3 No. 4 5 Decoding error rate for transmission of RTN 6 7 Not used. 8 Limitation of attenuation level 2 0 0 1 1 3 0 1 0 1 : : : : 0% 0.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW24 (TAD setting 2) Selector No. 1 2 Function Setting and Specifications Not used. No. 3 4 5 | 8 l Time length from CML ON to start of pseudo ring backtone transmission 3 0 0 1 1 4 0 1 0 1 : : : : 4 sec. 3 sec. 2 sec. 1 sec. Not used. Selectors 3 and 4: Time length from CML ON to start of pseudo ring backtone transmission These selectors set the length of time from CML-ON up to the start of pseudo ring backtone transmission.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW26 (Function setting 4) Selector No. Function Setting and Specifications 1 2 Not used. 3 Dialing during document reading into the temporary memory in inmemory message transmission 4 5 6 7 8 0: Disabled 1: Enabled No. of CNG cycles to be detected (when the line is connected via the external telephone except in the external TAD mode) No. 4 0 0 1 1 5 0 1 0 1 : : : : 0.5 1 1.5 2 (A) (B) (C) (D) No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW27 (Function setting 5) Selector No. 1 Function Setting and Specifications Not used. 2 Ringer OFF setting 3 Not used. 4 Detection of distinctive ringing pattern 5 | 7 Not used. 8 Not used. 0: Yes 1: No 0: No 1: Yes 0: Yes 1: No NOTE: l • Selector 1 takes effect only in models/versions having a TEL key. • Selector 4 is applicable only to the U.S.A. versions.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW28 (Function setting 6) Selector No. Function Setting and Specifications 1 | Transmission level of DTMF highband frequency signal 3 l 4 | 6 Transmission level of DTMF low-band frequency signal 7 8 Not used. Selectors 1 through 6: No. 1 0 0 0 0 1 1 1 1 2 0 0 1 1 0 0 1 1 3 0 1 0 1 0 1 0 1 : : : : : : : : 0 dB +1 dB +2 dB +3 dB 0 dB -1 dB -2 dB -3 dB No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW29 (Function setting 7) Selector No. 1 | 8 Function Setting and Specifications Not used. WSW30 (Function setting 8) Selector No. Function Setting and Specifications 1 | 3 Not used. 4 Duty cycle control of pulsed current for the heat-fixing unit 0: OFF 1: ON 5 Drum cleaning prompt settings 0: ON 1: OFF 6 | 8 Not used. NOTE: Selector 4 is applicable to the European version only.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW31 (Function setting 9) Selector No. l Function Setting and Specifications 1 Not used. 2 Default reduction rate for failure of automatic reduction during recording 3 4 Not used. 5 Minimum short-OFF duration in distinctive ringing 6 7 Not used.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW32 (Function setting 10) Selector No. 1 | 4 Function Setting and Specifications Not used. Default resolution No. 5 0 0 1 1 6 0 1 0 1 : : : : Standard Fine Super fine Photo Default contrast No. 7 0 1 1 8 X 0 1 : : : Automatic Super light Super dark 5 6 7 8 l Selectors 5 and 6: Default resolution These selectors set the default resolution which applies when the machine is powered up or completes a transaction.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW34 (Function setting 12) Selector No. 1 | 3 4 Function Setting and Specifications Not used. Not used. 5 7 Number of DTMF tone signals for inhibiting the detection of CNG during external TAD operation 8 Not used. 6 No. 6 0 0 1 1 7 0 1 0 1 : : : : 3 2 1 OFF NOTE: Selectors 4 and 5 are not applicable to the American version.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW36 (Function setting 14) Selector No. Function Setting and Specifications 1 ECP* mode 0: ON 1: OFF 2 Recovery from inactive PC interface 0: Disabled 1: Enabled 3 PC power-off recognition time 0: Normal 1: Long 4 Not used. 5 Escape from phase C 0: Yes 1: No 6 | 8 Lower limit of frequency to be ignored after detection of calling signals (Ci) No.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW37 (Function setting 15) l Selector No. Function 1 Printout of the stored image data of an unsent document onto the error report 0: No 1: Yes 2 Erasure of the stored image data of an unsent document at the time of the subsequent in-memory message transmission 0: No 1: Yes 3 | 8 Not used.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW38 (Function setting 16) Selector No. Function Setting and Specifications No. 1 0 1 1 2 X 0 1 Automatic Fixed to 4 points Fixed to 16 points 1 2 Setting of the equalizer 3 Sending level of guard tone at phase 2 0: Normal - 7 db 1: 4 Stepping down the transmission speed at fallback each 0: 2400 bps 4800 bps 5 6 : : No.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW39 (Function setting 17) Selector No. Function Setting and Specifications 1 | 4 First transmission speed choice for fallback 5 | 8 Last transmission speed choice for fallback No. 1 No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW40 (Function setting 18) Selector No. Function 1 Not used. 2 Not used. Setting and Specifications Not masking Masking 3 | 8 No. 3 No. 4 No. 5 No. 6 No. 7 No. 8 Masking of symbol rate(s) 0 0 0 0 0 1 1 1 1 1 3429 symbols/sec 3200 symbols/sec 3000 symbols/sec 2800 symbols/sec Not used. 2400 symbols/sec NOTE: l • WSW40 takes effect only in the V. 34 mode. • Selector 2 is applicable only to models equipped with a flat-bed scanner.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW41 (Function setting 19) Selector No. 1 | 3 4 5 | 8 Function Setting and Specifications ON-duration of the fluorescent lamp built in the CCD unit Broadcast report via e-mail No. 1 0 0 0 0 1 1 1 1 2 0 0 1 1 0 0 1 1 3 0 1 0 1 0 1 0 1 : : : : : : : : 16 hours 24 hours 12 hours 8 hours 4 hours 2 hours 10 minutes 0 minute 0: ON No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW42 (Function setting 20) Selector No.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW43 (Function setting 21) Selector No. 1 2 3 4 Function Setting and Specifications Addition of a header (station ID) to FAX images to be sent to PCs having e-mail addresses Wait time for PCFax reception (Class 2) and FPTS command transmission Detection time of 2100 Hz CED or ANSam 5 0: Yes 1: No. 2 0 0 1 1 3 0 1 0 1 : : : : 50 ms 100 ms 150 ms 0 ms No. 4 0 0 1 1 5 0 1 0 1 : : : : 200 ms 300 ms 400 ms 500 ms No 6 Not used.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW44 (Speeding up scanning-1) Selector No. 1 | 5 Function Setting and Specifications Not used. No. 6 7 8 0 0 0 : 6 | 8 Effective time length of the white level compensation data obtained beforehand 0 0 0 1 1 1 1 0 1 1 0 0 1 1 1 0 1 0 1 0 1 : : : : : : : Obtained compensation data ineffective 1 min. 3 min. 5 min. 10 min. 15 min. 20 min. 30 min. NOTE: WSW44 is applicable only to models equipped with a flat-bed scanner.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW45 (Speeding up scanning-2) Selector No. 1 | 3 Function Setting and Specifications Delay time from when documents are set until the ADF starts drawing them in No. 1 0 0 0 0 1 1 1 1 2 0 0 1 1 0 0 1 1 3 0 1 0 1 0 1 0 1 : : : : : : : : No.
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APPENDIX 3 FIRMWARE SWITCHS (WSW) WSW46 (Monitor of PC ON/OFF state) Selector No. Function Setting and Specifications No. 1 0 0 1 1 2 0 1 0 1 : : : : Disabled Monitor SELECT IN Monitor STROBE Monitor both SELECT IN and STROBE 1 2 Monitoring the PC ON/OFF state 3 Parallel port output pins kept at high level 0: Enabled 1: Disabled 4 Scanned garbage correction processing 0: ON 1: OFF 5 | 8 Not used. NOTE: l • Selector 3 is applicable only to models equipped with a parallel interface.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL WSW48 (Function setting 23) Selector No. 1 2 3 | 5 Function Setting and Specifications Not used. Number of pieces of (scan) key information registered according to application (i.e., Number of PCs that can be registered via Net) - PC registration using the Network TWAIN 6 | 8 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 : : : : : : : : 25 pcs. 50 pcs. 75 pcs. 100 pcs. 125 pcs. 150 pcs. 175 pcs. 200 pcs.
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APPENDIX 4 CIRCUIT DIAGRAMS Appendix 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Appendix 4.
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APPENDIX 4 CIRCUIT DIAGRAMS Appendix 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Appendix 4.
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APPENDIX 4 CIRCUIT DIAGRAMS Appendix 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Appendix 4.
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APPENDIX 4 CIRCUIT DIAGRAMS Appendix 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Appendix 4.
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APPENDIX 4 CIRCUIT DIAGRAMS Appendix 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Appendix 4.10 NCU PCB Circuit Diagram (U.S.A.
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APPENDIX 4 CIRCUIT DIAGRAMS Appendix 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Appendix 4.
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APPENDIX 4 CIRCUIT DIAGRAMS Appendix 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Appendix 4.
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APPENDIX 4 CIRCUIT DIAGRAMS Appendix 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Appendix 4.
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APPENDIX 4 CIRCUIT DIAGRAMS Appendix 4.
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MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN SERVICE MANUAL Appendix 4.
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April.