Apple macintosh iisi Service Manual

Troubleshooting

Symptom Charts/Miscellaneous - 12

Miscellaneous

Clicking, chirping,

or thumping

1 Replace power supply.

2 Disconnect hard drive. If noise disappears, replace drive.

3 Replace logic board. Retain customer’s SIMMs.

System shuts down

intermittently

1 Check that air vents on the back and top of the case are

unobstructed. (Thermal protection circuitry may shut down

the system. After 30 to 40 minutes, the system should run.)

2 Replace power cord.

3 Replace power supply.

4 Replace logic board. Retain customer’s SIMMs.