Chosen Solution
Hey guys! So I just picked up a 2011 21.5” imac. Previous owner said it wouldn’t turn in, put in a replacement powersupply, and still wouldn’t turn on. Upon further inspection, only the 4th LED lights up (technically LED #1) and nothing else lights up. I tried using the spare PSU I was given, and a 27” PSU I had laying around. Still nothing, so I assumed it’s a logic board issue. I don’t see any damage or corrosion on the board at all, is there a common failure point in these boards I could attempt to pinpoint and fix? I really don’t want to spend money on a logic board.
The most common issue is the MXM GPU board fails. If the system had been sitting awhile unplugged you likely need a fresh PRAM battery as well.
