2008 Aluminium iMac graphics flickering/freezing problem.

[Luke7610]

Hey all,

I'm having issues with my iMac, I'm guessing something to do with the graphics card maybe? Problem only started up today, can't think of any reason why.

Screen flickers with the black half flashing on black, then I get small flickers all over the screen, then it just freezes. Will try and get a photo up if I can.



Mac is out of warranty. If anyone has any suggestions, or info on what I'd need repair wise or a rough idea on how much, it would be much appreciated.

Thanks for your time.

Luke.

 

[Hellhammer]

Try SMC and PRAM reset.

 

[MikeMaximus]

I had the exact same problem occur with my 2008 iMac last night. According to what i've read on a few forums it's the graphics card, I've got the Nvidia 8800 GS in mine. It froze while playing Left 4 Dead 2 and now i get garbage and a freeze nearly everytime I boot, pictures below. A few times it will actually boot cleanly into OSX, then 5 minutes later it looks like Space Invaders are eating the screen or exactly like Luke's image in the opening post. In addition to this, sometimes when booting it just gets stuck in an endless "bong" loop and the screen never powers up.


My plan today is to try and get it into OSX, then SMCFanControl and turn the fans on max to see how long it will run so i can maybe get some data off without ripping it apart for the HD.

As for a permanent fix I don't know exactly yet, but judging by what I read the part is worth and factoring in the labour cost of the local Apple repair shop, at least 400 dollars, probably more. I googled and found a guy who done a DIY fix, but it basically requires tearing the entire thing apart and putting it back together again, which didn't look pretty.