Chosen Solution
Hi guys! I received an iMac 27" Late 2009, but it has some problems. The biggest one is that the GPU card is dead and I have to change it, of course. So, the real problem is that this iMac has an ATI Radeon HD 4850m, which is not produced anymore and it’s very difficult to find. Now, I live in Italy and I found some 4850m but they’re in the USA and shipments are very expensive for me. I read somewhere on the Web that I can replace the 4850 with a compatible one, for example with the 6970m (I’m not sure of this information, let me know if you tried!). But I found a 6970m on eBay (from UK) which was in an Alienware m17x (link: http://www.ebay.it/itm/Alienware-m17x-R2… ). The question is: can I use it with my iMac? It totally looks-alike the 4850m (I mean, the connectors) but I’m not sure that it’s compatible with the iMac. Thank you for the help!
Sadly, you can’t use this GPU. You are limited to the ones that Apple used and have the required firmware. The two GPU cards this system came with are: ATI Radeon HD 4670 256 GB - 661-5314ATI Radeon HD 4850 512 GB - 661-5315 You might be able to fit a newer iMac systems GPU card in yours but you may have to swap out the heat sink unit.
About 70% of the time (I’ve done about a dozen) a reflow of the GPU with a hot air workstation gun does the trick.
