Service manual

Service Manual
Part 4 - Fault diagnosis 4-1
Test equipment required 4-1
Checking a 'dead' computer 4-2
Functional testing 4-4
General test procedure 4-4
Preparing to run the tests 4-5
Creating a CMOS test data file 4-6
Completing the tests 4-6
Main PCB functional test suite 4-7
Individual tests 4-15
Part 5 - Main PCB fault diagnosis 5-1
Test equipment you will need 5-1
Integral test software overview 5-1
Power-on self-test (POST) 5-1
Using the test link 5-3
Using the display adapter 5-4
Using the external diagnostic interface 5-9
Probe SWIs 5-17
Repairing a 'dead' computer 5-23
Test ROMs 5-23
Repairs following functional testing 5-27
Keyboard and mouse 5-28
Expansion cards 5-28
Part 6 - Parts lists 6-1
Main PCB assembly parts list 6-1
4MB RAM card (optional upgrade) 6-6
Backplane adaptor 6-6
ARM3 (PGA) Daughter card 6-7
Keyboard adaptor PCB (membrane keyboard) 6-7
Keyboard adaptor PCB (cont.) (membrane keyboard) 6-8
Keyboard assembly (keyswitch keyboard) 6-8
Ethernet I 6-8
Ethernet II 6-9
SCSI interface card (issue 2+) 6-10
iv Issue 2, June 1991 Contents