Apple quadra.lc 630.performa 640 Service Manual

 

 Troubleshooting

Symptom Charts/Video - 9

 

Vertical lines, 

horizontal lines, or 

snow appears on 

screen, or screen is 

completely dark; 

startup  tone is 

normal

1 Perform monitor adjustments.

2 Replace monitor.

3 Replace logic board.  Retain customer’s  SIMMs.

4 Replace power supply.

Unable to tune in some 

UHF channels.

Replace Rev. A video-in card, part number 661-0159, with Rev. 

B video-in card, part number 661-1073.