Original post by: mayer ,
This model had a recall on it for a while on the GPU. https://9to5mac.com/2013/08/16/apple-opens-graphics-card-replacement-program-for-some-mid-2011-imacs/ I have one on my bench right now that I’ll have back together hopefully by Monday. I tried reflowing the GPU. This has worked for me about 70% of the time. I’m also pursuing GPU replacement alternatives as the high demand for the replacement card has pushed prices up.