Chosen Solution
Hello, I’ve got an problem with my Mid-2010 27" iMac (A1312, EMC 2390, 3.6 GHZ, 12 GB of RAM, HD 5750 1GB). When I press the power button it starts normally but the display stays powered off. I tried to check with a light if it was a backlight failure but it’s not. The display displays nothing at all. I also tried to plug in an external display using a Mini Display Port to VGA adapter and I’ve got no signal too. So I opened it yesterday and everything seems okay inside (I cleaned it too and now it’s clean as a brand new inside). So I checked the diagnostics LEDs: the #1 is normal, the #2 is on when the iMac is started and #3 and #4 never shine.
So I’ve got several questions: 1 - Is my GPU totally broken? 2 - How to be sure it is worth the pain to buy a new GPU? Could the logic board be broken too? Some pictures of the iMac:
Attempt a reflow of the GPU before spending any money. Here’s how: https://www.youtube.com/watch?v=hoxR_TVE…
If reheating the GPU chip doesn’t solve the problem you’ll need to replace the GPU board. Finding a good working GPU card is getting harder in this series and they tend to be expensive as many people want to hang onto them. When I get home tonight I’ll plug in the possible GPU boards your system will support here.
