Technical information

Troubleshooting Symptom/Cure Tables: System Problems After Startup - 36
Intermittent Shut Down or Sleep
An iMac with a sticking power button can generate unpredictable behavior. The iMac
randomly shuts itself off or puts itself to sleep. The iMac will not start up from either
the front power button or the keyboard.
Possible Cause Possible Fix
Improperly aligned front
power-on button
-If the front power-on LED is not centered properly
within the inner button hole, the power button can
become stuck between the LED and the inner bezel
resulting in a no power, intermittent shut down, or
sleep situation. Refer the LED Alignment procedure in
the Adjustments chapter or to Kbase/TIL article
58622 for steps to resolve the LED alignment issue.