Chosen Solution
Dear friends, my iMac 27 “A1312 2011 has just stopped working and isn’t showing any image. I turn it on, It chimes but the 3rd LED indicating the video is communicating with the logic board doesn’t turn on. Initially, I thought it could be the video card but I tested it on my friend’s iMac, and it was working flawlessly. Everything seems to be working fine, but the video doesn’t appear. I tried to reset the VRAM and SMC unsuccessfully. The %#*@ LED doesn’t light up. Can anyone give me a tip on how to work this out? This iMac never let me down. I’d appreciate any contribution that can be made.
First hook up an external monitor to verify that the GPU is working in your machine.
MOST likely the connection of the GPU to the Motherboard
This repair guide may help. https://tim.id.au/laptops/apple/imac/ima…
