iMac does not power ON
I have a Power issue with my mid 2011 iMac.
I've already opened it up. I have experience with repairing electronics, etc. But now i'm stuck. On the logic board ( Main board) :
- Diagnostic LED 1 goes ON, this seems a power-OK led to me, I measure 12v on the supply.
- If I press the power button nothing happens.
- I detached all peripherals, sdcardreader, camera, audio, hdd, speakers, etc. Still nothing.
- I checked the power button, the button and cables are OK.
- I can also measure 12v on the logic board.
- What can keep it from powering on, what does it need?
- Does it need memory in the banks to power on, ( LED #2) ?
- Could it be a faulty CPU or GPU, does it need that to power on?
- Do all the sensors have to be connected?
- Could I detach the video card an test power without it?
The thing is I don't feel like replacing the logic board, its to expensive, I just wondered if there is any information about the "logic" which turns on the power, could I override it, so I can see where the smoke comes from ? :)..