Chosen Solution
I found the appropriate iFixGuide to replace the GPU on my iMac. However, iFixIt is out of stock for the replacement part. I also tried looking at their suggested vendor, and they are also out of stock. I’ve found several sellers on eBay, but I’m not sure whether these are direct replacement parts. How do I know if I’ve got the correct replacement or equivalent? My iMac: iMac “Core i3” 3.06 21.5-Inch (Mid-2010) Specs (Mid-2010, MC508LL/A, iMac11,2, A1311, 2389) The GPU is a 256MB Radeon HD 4670 GDDR3 memory From what I can see, I could also replace it with a 5670 with 512 MB. My iMac has crashed, so I’m just trying to get it up and working. I’m not too concerned about upgrading, but, if the 5670 is available, I might as well.
The two GPU boards your system supports are: ATI Radeon HD 4670 (256 MB) - Apple P/N 661-5539ATI Radeon HD 5670 (512 MB) - Apple P/N 661-5546 I often find looking up the Apple part number will more likely get you the correct part. In any case the firmware chip will have an Apple logo label on it. Thats the most important thing as some people will try to see you the Dell board which won’t work. Here’s a few ones I found but they go quickly! You may need to call them. ATI Radeon HD 4670: PowerBookMedic USATheBookYard UK ATI Radeon HD 5670: PowerBookMedic USATheBookYard UK
