Service Manual XGA COLOR MONITOR Model : L500B1 DAEWOO ELECTRONICS CO., LTD. http : //svc.dwe.co.
CONTENTS SAFETY PRECAUTIONS 1 GENERAL SAFETY INFORMATION 2 SERVICING PRECAUTIONS 3 TECHNICAL INFORMATION 6 GENERAL INFORMATION 7 PIN CONNECTOR 8 CAUTIONS FOR ADJUSTMENT AND REPAIR 8 OPERATION & ADJUSTMENT 9 ALIGNMENT PROCEDURE 14 TROUBLESHOOTING HINTS 15 BLOCK DIAGRAM 22 PCB LAYOUT 23 SCHEMATIC DIAGRAM 27 EXPLODED VIEW & MECHANICAL PARTS LIST 28 INFORMATION OF PART DESCRIPTION 29 ELECTRICAL PARTS LIST 30
SAFETY PRECAUTIONS CAUTION: No modifications of any circuits should be attempted. Service work should be performed only after you are thoroughly familiar with all of the following safety checks and servicing guidelines. ◆ Safety Check Care should be taken while servicing this analog color display because of the high voltages used in the deflection circuits. These voltages are exposed in such areas as the associated flyback and yoke circuits.
GENERAL SAFETY INFORMATION ◆ Terms in the manual CAUTION Statements identify conditions or practices that could result in damage to the equipment or other property. WARNING Statements identify conditions or practices that could result in personal injury or loss of life. ◆ Terms as marked on equipment CAUTION Statements indicate a personal injury hazard not immediately accessible as one reads the marking or a hazard which is properly included on the equipment itself.
SERVICING PRECAUTIONS CAUTION: Before servicing instruments covered by this service manual, its supplements, and addendum, please read and follow the SAFETY PRECAUTIONS of this manual. NOTE: If unforeseen circumstances create conflict between the following servicing precautions and any of the safety precautions on page 1 of this manual, always follow the safety precautions. Remember: Safety First. ◆ General Servicing Precautions 1. Always unplug the AC power cord from the AC power source before: a.
◆ Electrostatically Sensitive (ES) Devices Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components are commonly called Electrostatically Sensitive (ES) Devices. The typical examples of ES devices are integrated circuits, some field-effect transistors, and semiconductor “chip” components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity. 1.
FIGURE 1. USE SOLDERING IRON TO PRY LEADS ◆ IC Removal/Replacement Some utilized chassis circuit boards have slotted (oblong) holes through which the IC leads are inserted and then bent flat against the circuit foil. When holes are slotted, the following technique should be used to remove and replace the IC. When working with boards using the familiar round hole, use the standard technique as outlined in paragraphs 5 on the page under the title of general soldering guidelines. ◆ Removal 1.
◆ Diode Removal/Replacement 1. Remove defective diode by clipping its leads as close as possible to diode body. 2. Bend the two remaining leads perpendicularly to the circuit board. 3. Observing diode polarity, wrap each lead out of the new diode around the corresponding lead on the circuit board. 4. Securely crimp each connection and solder it. 5. Inspect the solder joints of the two “original” leads on the circuit board copper side.
GENERAL INFORMATION This TFT LCD monitor automatically scans all horizontal frequencies from 30KHz to 62KHz, and all vertical frequencies from 50Hz to 85Hz. This TFT LCD monitor supports IBM PC, PC/XT, PC/AT, personal System/2 (PS/2), Apple Macintosh, and compatible users crisp text and vivid color graphics display when using the following graphics adapters : (VGA, Super VGA, VESA and XGA and Apple Macintosh Video Card).
PIN CONNECTOR Pin Signal 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Red Green Blue GND GND GND - Red GND - Green GND - Blue +5Vdc GND - H.Sync GND - V.Sync Bi-directional Data (SDA) Horizontal Sync Vertical Sync (VCLK) Data Clock (SCL) 1 6 10 15 Arrangement of 15-pin D-sub connector CAUTIONS FOR ADJUSTMENT AND REPAIR • Degaussing is always required when adjusting purity or convergence. • The white balance adjustment has been done by a color analyzer in factroy.
OPERATION & ADJUSTMENT Control Panel AUTO AUTO EXIT MENU BRIGHTNESS BRIGHTNESS EXIT MENU BRIGHTNESS • The AUTO button launches the AUTO TRACKING function directly. • • The EXIT button turns the OSD (On-Screen Display) window off. • • The MENU button turns the OSD window on. • • The button moves cursor to the left or high window in the OSD window. • • The button moves cursor to the right or low window in the OSD window. This button moves from sub menu to top menu in the OSD window.
Key Process MENU MENU MENU EXIT EXIT EXIT OSD OFF 10
Adjustment Procedure Yes Is the mode 1024x768? No Adjust the FIT SCREEN. No Is the H.Size proper? Adjust the CLOCK control. Yes Perform the AUTO Is the noise displayed on the screen? POSITION. No Yes Perform the AUTO TRACKING. Is the noise displayed on the screen yet? No Yes Adjust the CLOCK FINE until the screen is cleared.
OSD Functions ICON CONTROL FUNCTIONS LANGUAGE Select language for OSD (5 languages). CLOCK Adjust the width (horizontal size) of the screen image. CLOCK FINE Sharpen the focus by aligning the illuminated pixels and adjust until the screen image looks focused, crisp and sharp. Adjusting the CLOCK FINE after the CLOCK adjustment will produce a clear screen. COLOR TEMP Choose different preset color temperatures or set your own customized color parameters. R RED CONTROL Adjust the red color.
Self Diagnosis When the monitor doesn’t display, if you press any key, Self Diagnosis screen is displayed. Self Diagnosis function checks if the status of the monitor is No Signal or Out of range. No Signal screen is displayed when the D-Sub signal connector is not connected or the status of the monitor is on DPMS mode. Out of Range screen is displayed when the applied frequency is under or over normal range.
ALIGNMENT PROCEDURE Standard Check point 1. Power source : 100 - 240Vac, 50/60Hz. 2. Aging : Take at least 20 minutes warm-up time. 3. Signal Video input : Analog 0.7Vpp 75Ω terminal positive polarity Synchronizing : acceptable negative or positive at TTL level Resolution Horizontal : 1024 max. Vertical : 768 max. Frequency Horizontal : 30KHz - 62KHz Vertical : 50Hz - 85Hz (available only non interlace mode) Adjustment 1. Smart scaling set to 69%. 2. Contrast set to 100% 3. Brightness set to 50% 4.
TROUBLESHOOTING HINTS 1. Abnormal mode detect Abnormal mode detect Yes Is a input H-sync of ADC correct? No Trouble in the H-sync input circuit. No Trouble in ADC. Yes Is waveform of pin 84 of ADC correct? Yes Trouble in Scalier.
2. Trouble in Power on Is Power LED on or off? Off Refer to No video or No raster. No Trouble in the adapter. No Trouble in U3 & Q1 and its ambient circuit. No Trouble in SQ1 and its ambient circuit. On Check the output voltage of adapter. Yes Is the pulse of pin 7 of -com.
3. No Raster Check the output of Q6 or pin 3 of CN2. < 2.5 Trouble in Q6 or pin 3 of -com. > 2.5 Is 12V plugged in pin 1 of CN2? No Check 12V line of CN3. Yes Is the output of inverter correct? No Yes Replace a LCD panal. 17 Replace the inverter.
4. One color is missing One color is missing Yes No Is the OSD color normal? Check the output signal of Scalier. Yes Is the input signal normal? No Check the video signal cable or R,G,B con-ass’y. Yes Are the R,G,B Digital values (every eight bits) correct on ADC output stage? Yes Trouble in the soldering of R,G,B data lines from output of ADC to pin 41 wafer. 18 No Check the ambient circuit of ADC.
5. No Video Has display image only white? No Next page. Yes Is pin 41 cable of CN6 well connected? No Connection trouble. Yes Is pin 1 of Q16 3.3V? No Yes Check the output of scalier (pin 70, 99, 100, 101) and soldering of CN6. 19 Check Q16, its ambient circuit and pin 26 of -com.
5-1. No Video Black Yes Is OSD normal? No (3) No raster or Check SDRAM. No Set the contrast up to Max. Yes Is the contrast at its maximum? Yes Is the output of ADC correct? No Is the input of ADC correct? Yes Yes Next Page. No Check the video input signal. Replace the main board (or replace ADC). Yes Is the output of Scalier correct? Is the input of Scalier correct? No No Yes Yes Replace the main board (or replace ADC). Check the LCD panel or pin 41 wafer and con-ass’y.
6. Broke graph Is clock of SDRAM pin 35 correct? No Check Scalier pin 135. Yes Is 3.3V plugged in VCC pin of SDRAM? No Yes After checking the soldering between SDRAM and Scalier, if O.K., replace the SDRAM. 21 Check 3.3V line.
H/V sync Main Borad RGB signal Mx88LC284FC PRE-AMP Data line/Address line/contorl line SDRAM (16Mbit*2) 15pin DSUB -Connector panel TDA8752 MIU RED (8) ADC Buffer 74ACT14 Green(8) Odd/ Even MUX Red(6) Green(6) Blue(6) Hs,Vs,DE,LCLK Panel S,G Driver Back light Dithering Scaling Blue(8) Offset/Corse 630VAC/ 62khz 22 clk OSD Mux Dot clk Hs,Vs Controller PLL DC-AC Inverter CPU I/F -Clock timing& phase -Current &resistance address/data line I2C Micom DDC I2C Dimming 12V/ On-Off 12V
PCB LAYOUT Main PCB Component Side 23
Main PCB Solder Side 24
Control PCB Component Side Control PCB Solder Side 25
D-sub PCB Component Side D-sub PCB Solder Side 26
SCHEMATIC DIAGRAM 27
EXPLODED VIEW & MECHANICAL PARTS LIST 28
INFORMATION OF PART DESCRIPTION Important Safety Notice Components identified with the International Symbol have special characteristics important for safety. When replacing any components, use only manufacturer’s specified parts. Abbreviation of Description RESISTOR Description Tolerance F ± 1% J ± 5% K ± 10% M ± 20% G ± 2% Example: Fig & Index Part No Description Resistors RD-4Z820J Carbon : 82J HRFS472JBA Chip 4.7K OHM J R101 R30 CAPACITOR Description C D F J K P Z Tolerance ± 0.25pF ± 0.
ELECTRICAL PARTS LIST The components identified by mark have special characteristics important for safety and x-ray radiation. These should be replaced only with the types specified in the parts list. LOC PART-CODE PART-NAME PART-DESC LOC PART-CODE PART-NAME PART-DESC 00030 9970800035 CABLE SIGNAL AS 15P+15P/DDC=1.5M(GY275A) C28 HCFK104ZBA C CHIP CERA 50V Y5V 0.1MF Z 1608 00040 W1112B831- CORD POWER CML-100 1.8M BK(AME) C29 HCFK104ZBA C CHIP CERA 50V Y5V 0.
LOC PART-CODE PART-NAME PART-DESC LOC PART-CODE PART-NAME PART-DESC C71 HCBK103KBA C CHIP CERA 50V X7R 0.01MF K 1608 L1 HFFTB2601B COIL CHIP BEAD TB321611Z260 C72 HCBK223KBA C CHIP CERA 50V X7R 0.022MF K 1608 L10 HFFTB2601B COIL CHIP BEAD TB321611Z260 C73 HCBK103KBA C CHIP CERA 50V X7R 0.01MF K 1608 L11 HFFTB2601B COIL CHIP BEAD TB321611Z260 C74 HCBK223KBA C CHIP CERA 50V X7R 0.
LOC PART-CODE PART-NAME PART-DESC LOC PART-CODE PART-NAME PART-DESC R28 HRFS105JBA R CHIP 1/16 1M OHM J 1608 R9 HRFS101JBA R CHIP 1/16 100 OHM J 1608 R29 HRFS472JBA R CHIP 1/16 4.7K OHM J 1608 RP1 HFFH4H300E COIL CHIP BEAD HB-4H3216-300JT R3 HRFS000JBA R CHIP 1/16 0 OHM J 1608 RP10 HFFH4M121E COIL CHIP BEAD HB-4M3216-121JT R30 HRFS472JBA R CHIP 1/16 4.7K OHM J 1608 RP11 HFFH4M121E COIL CHIP BEAD HB-4M3216-121JT R31 HRFS472JBA R CHIP 1/16 4.
LOC PART-CODE PART-NAME PART-DESC LOC PART-CODE PART-NAME PART-DESC SU1 1LM2596S33 IC SD REGULATOR LM2596S3.3 U3A 9979300501 SOCKET IC SDIF-42T(1.
DAEWOO ELECTRONICS CO., LTD 686, AHYEON-DONG MAPO-GU SEOUL, KOREA C.P.O. BOX 8003 SEOUL, KOREA TELEX : DWELEC K28177-8 CABLE : "DAEWOOELEC" E-mail : G7F00E@web.dwe.co.
