Opened my 21.5" iMac Yesterday, Christmas Day. I had read this & other Posts about the issue weeks ago, so of course I used the Test & Yes, mine has Yellow Tint, Bottom Left part of Screen. I probably would have never noticed, had I not done the test. It's that slight. No flickering. No Screen Noise. BTW, mine was made week 45 & has the NVidea Graphics Card. But I have to tell you, this is the best Computer I have ever used. Fast, Stable, Quiet, & Beautiful. I started to think about going through the entire hassle of exchanging it, but I decided I'm keeping it. I hear there are a lot of horror stories & from what I read, I think the newer bunch have the same & other issues. Yes , I'm disappointed that Apple did not notice this from the Get Go. But I love this thing & cannot part with it.The only thing I can hope, that over time, The slight Yellow Tint, does not become a severe & noticeable Yellow Tint. I welcome opinions & knowledge from others.
Welcome to the club. I have this same machine and love it. I really contemplated switching it out for the next model with ATI graphics, but I have not found a single reason to do so yet.