iMac G5 (20-inch iSight) Troubleshooting — Symptom Charts 151
Turn the computer on by pressing the power button on the rear of the case. Go to the next 8.
step.
Does the computer start up normally after pressing the power button? 9.
Yes:
Press and hold the power button until the computer powers o.
Unplug the power cord from the iMac, and replace the front bezel.
Return the computer to the upright position and connect the power cord.
Press the power button to turn on the computer.
Make sure the computer starts up properly. Attach applicable external peripherals removed
in step 4, and verify that the system remains operational. If OK, return the system to the
customer.
No:
When pressing the power button to start up the computer, does LED 2 come on
momentarily, or does LED 2 not come on at all?
Momentarily: The logic board has detected 12V, but the power supply cannot maintain it.
Replace the DC-DC board.
Not at all: The DC-DC board is unable to power up. Replace the DC-DC board.
If replacing the DC-DC board doesn’t correct the problem, replace the logic board..