Chosen Solution
I have a 21.5 A1311 EMC:2428 iMac. I found it dead no power up, no fans. Tried PMC reset, remove replace Ram and checked power cable (good) and nothing worked. I got a new power supply (614-0445) from you put it all back together twice and nothing. Plugged it in and checked LEDs and I get 1 when plugged in but nothing changes when I press power button. Is this beyond my ability to fix? Could I have a bad power button? Is there a decent write up on how to start without using power button for my specific model? Any help would be greatly appreciated.
I believe that you have a logic board problem. I do not know of a DIY procedure to verify or identify what that is. I would have Apple do an estimate, or, if you pull the board you could send it off someplace (e-bay) for diagnosis. Jump starting a damaged logic board could cause more damage. If this answer is acceptable please remember to return and mark it.
