Apple Mac 8600 - Manual (Page 74)

Troubleshooting Symptom Charts/Video - 11
Video
Screen is black, boot
tone is present, drive
operates, fan is
running, and LED is
lit
1 Adjust brightness on monitor.
2 Clear parameter RAM. Hold down
during startup but before "Welcome to Macintosh"
appears.
3 Reset Cuda chip. (Refer to The Cuda Chip in Basics.)
4 Reset logic board. (Refer to Resetting the Logic Board in
Basics.)
5 Replace monitor cable.
6 Remove all DRAM DIMMs and try replacing them one at a
time to test. Replace any bad DIMMs.
7 Test with known-good monitor. Replace monitor if
necessary. Refer to appropriate monitor manual to
troubleshoot defective monitor.
8 Replace video PCI card.
9 Replace processor card.
10 Replace logic board. Retain customer's DIMMs.