iMac (21.5" late 2009) won't power on. Have tried several fixes...
iMac 21.5” late 2009 EMC 2308
A couple days ago I discovered the machine was off and would not power on. Don’t think we had a power surge or anything like that - nothing else in my home was affected. So far have tried several fixes.
- Swapped the AC power cable. Nothing.
So I opened up the machine and…
- Checked the Diagnostic LED’s. Light #1 comes on when the machine is connected to AC power. Light #2 does not come on when the power button is pressed.
- Checked the logic board test pins:
- Pin 4 (Standby Power) - 12V OK!
- Pin 11 (Run-Mode Power) - Nothing
- Pin 12 (Power On Request) - Nothing
- Checked the power button by testing for continuity between the two pins on the power button cable. Seems to be working properly (infinite resistance when not pressed, zero resistance when pressed).
- Swapped the power supply - Nothing
- Swapped the DC-In cable - Nothing
Is the only remaining step to replace the logic board?
So far the parts and attempted fixes have been pretty cheap. I’m not sure I’ll want to buy a new logic board.
Is there anything else I should try?
I can’t find any other recommended fixes or troubleshooting steps.
Check the power button itself. It's a bear to get to but you can check it by shorting where it plugs into the power source.
由 Dekinekind 完成的