RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START For Authorized Service Personnel Only: AM-990 SBC Service Manual RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START RIGHT. FROM THE START DSS-10524-00, Rev.
ALPHA MICROSYSTEMS FCC Notice This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment.
AM-990 SBC Computer Service Manual Page i TABLE OF CONTENTS INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ACCESSING YOUR COMPUTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Opening the Front Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Opening the Top Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AM-990 SBC Computer Service Manual Page 1 INTRODUCTION This document contains instructions which are intended only for authorized service personnel. The AM-990 computer contains a high-output power supply, which produces current levels high enough to make it unsafe for unauthorized persons to perform work inside the chassis. The following procedures are discussed: Accessing your computer. Electronic equipment handling precautions. Peripheral installation. AM-140 and AM-145 CPU board configuration.
Page 2 AM-990 SBC Computer Service Manual Opening the Top Cover In order to remove the side panel, you must first remove the computer’s top cover. The procedure for removing the top cover is as follows: 1.Swing the front door open to expose the screws that hold the top cover in place. 2.Using a phillips-head screwdriver, remove the two screws that connect the top cover to the chassis as shown in the illustration. 3.Don’t worry about the display panel, it is not attached to the top cover.
AM-990 SBC Computer Service Manual Page 3 LOCKING TABS ER V TOP CO LE FT SI DE PA N MAC4 4 2 EL TO REMOVE THE TOP COVER, REMOVE THESE TWO SCREWS. TO REMOVE THE SIDE PANEL, REMOVE THESE FOUR SCREWS. Removable Top Cover and Side Panel DSS-10524-00, Rev.
Page 4 AM-990 SBC Computer Service Manual Electronic Equipment Handling Precautions With the AC power cord unplugged and the sheet metal removed, the components inside your computer are vulnerable to damage caused by static discharge. Your body and clothing are capable of storing an electrical charge that can damage or destroy unprotected electronic components. Prior to handling any computer hardware, make sure your work area is properly protected against static discharge.
AM-990 SBC Computer Service Manual Page 5 Inside Your Computer Once you have removed the side panel, you will be able to gain access to the equipment inside your computer.
Page 6 AM-990 SBC Computer Service Manual Reinstalling the Top Cover and Side Panel If you removed the top cover and side panel as described in the two previous sections, you probably noticed the panels are a snug fit. The snug fit helps the computer meet FCC requirements. Use the following instructions when reinstalling the side panel and top cover: Side Panel 1.Install the side panel before you install the top cover. The side panel has twelve small tabs and four screws that hold it in place.
AM-990 SBC Computer Service Manual Page 7 INSTALLING PERIPHERALS Mounting peripheral devices in your computer is simply a matter of attaching plastic rails to the side of the peripheral and sliding the device into its mounting position. The AM-990 chassis has mounting locations for 12 half-height (or six full-height) 5-1/4" peripherals. The front door on the AM-990 chassis has a cutout which allows access to peripheral devices using removable media.
Page 8 AM-990 SBC Computer Service Manual The first hard disk drive is mounted in slot 12, or slots 11 and 12 if it is a full-height device. A second hard disk drive would be mounted in the next available slot above the first disk drive. The hard disk drives are mounted in the lower part of the chassis for two reasons: to make sure the weight in the chassis is properly distributed and to provide easy access for both power and interface cables.
AM-990 SBC Computer Service Manual Page 9 DWF-20652-00 MOUNTING RAIL HALF-HIGH 5-1/4" PERIPHERAL MAC4 7 1 Attaching Mounting Rails to Peripheral Additional Documentation Each peripheral device sold by Alpha Micro is covered by its own set of installation instructions. The installation instructions include information on jumper settings, termination, and cabling. Before installing a peripheral, make sure you read the documentation pertaining to the device.
Page 10 AM-990 SBC Computer Service Manual SBC AM-140 CPU BOARD The AM-140 is a 50Mhz main logic board available for the SBC. Most of the AM-140 specifications are covered in Appendix A (in the SBC owner’s manual); however, the following list highlights some of the key features on the AM-140 board: Memory expansion up to 64 megabytes. I/O expansion up to 66 serial ports. On-board intelligent ESDI controller. 68030 Processor chip.
AM-990 SBC Computer Service Manual Page 11 If you are going to mix 4MB and 16MB memory boards in your SBC, make sure you install the 16MB boards first followed by the 4MB memory boards. SBC Expansion I/O There are two 60-pin connectors on the SBC CPU board, each capable of supporting 32 serial ports. The first 32 ports are controlled by connector J7 and the second 32 ports are controlled by connector J8.
Page 12 AM-990 SBC Computer Service Manual PARITY STATUS 1 FRONT PANEL DISPLAY 1 J17 J16 60-PIN ESDI CONNECTOR J15 J14 J13 J12 MEMORY EXPANSION W88 CPU W15 U144 J10 LOW BYTE FLOATING POINT CO-PROCESSOR SOCKET U131 U130 BOOT PROMS HIGH BYTE 36-PIN FLOPPY CONNECTOR 1 50-PIN SCSI CONNECTOR U97 W14 W13 1 J19 POWER CONNECTOR PAL W8 SSD SOCKET J20 W12 NTSC W12 REMOTE RESET JUMPER IN = ENABLED JUMPER OUT = DISABLED J18 60-PIN I/O CONNECTORS 1 J8 U32 W9 W10 BATTERY LINK TERMINAT
AM-990 SBC Computer Service Manual Page 13 SBC AM-145 CPU BOARD The AM-145 is a 33Mhz main logic board available for the SBC. Most of the AM-145 specifications are covered in Appendix A in the owner’s manual; however, the following list highlights some of the key features on the AM-145 board: Memory expansion up to 16 megabytes. I/O expansion up to 34 serial ports. On-board floppy controller. 68020 Processor chip.
Page 14 AM-990 SBC Computer Service Manual If your computer includes an AM-522 ESDI controller board, the maximum memory capacity is reduced to 12 megabytes. The AM-522 board requires one of the memory expansion slots for installation. SBC Expansion I/O The AM-145 board has one 60-pin connector, located at J9, designed to support a maximum of 32 serial ports. These ports are in addition to the two standard AM-145 serial I/O ports (0 and 1) shown in the illustration.
AM-990 SBC Computer Service Manual Page 15 W18 REMOTE RESET JUMPER IN = ENABLED JUMPER OUT = DISABLED FRONT PANEL DISPLAY 1 J8 BATTERY W18 J7 J6 W11 J5 On B. Revison artwork and earlier W100 is hard-wired.
