Apple quadra.lc 630.performa 640 Service Manual

 

 Troubleshooting

Symptom Charts/Video - 8

 

Screen is completely 

dark, fan is not 

running and LED is 

not lit

1 Check all external power connections.

2 Computer powers on exclusively through softpower on 

keyboard.      Verify that power-on connections of keyboard 

are functioning by testing with known-good keyboard.

3 Reseat logic board.  

4 Unplug 4.5 battery, wait 20 seconds, plug in battery, and 

restart computer.

5 Verify that monitor has power. 

6 Remove expansion card, if present.

7 Remove peripherals.

8 Replace power supply.

9 Replace logic board.  Retain customer’s  SIMMs.