Apple performa 400 series 서비스 매뉴얼
Troubleshooting
Symptom Charts/Built-in Video - 5
Vertical lines,
horizontal lines, or
snow appears on
screen, or screen is
completely dark;
startup tone is
normal
1 Replace video cable.
2 Replace monitor.
3 Replace VRAM SIMM. Refer to Hardware/Memory
4 Replace logic board. Retain customer’s SIMMs.
5 Replace power supply.