Chosen Solution
Dear all, A picture says more than a 1000 words, so I edited some graphics to explain the situation Suppose this is the image on the screen how it’s supposed to be Than I see this I think this is a problem with the backlight, because I see also some other signs that refer to this. I’m quite positive it has nothing to do with the GPU. Is there a way to fix this? Regards, Michael
I haven’t seen a shadow masking issue like you have here (all the way around). Most of the time it’s a lamp issue or the inverter has gone. I’m wondering if the foil tape adhesive has broken down or someone sprayed a contact cleaner which has oil which has managed to migrate onto the defuser sheets. I think the best solution here is to replace the display unit. Here is the part you’ll need: iMac Intel 20" (EMC No. 2210 or 2133) LCD Assembly - Apple P/N 661-4434. Here’s the IFIXIT guide you’ll need to follow: iMac Intel 20" EMC 2133 and 2210 Display Panel Replacement
