Failing GPU in iMac 27" (Late 2012)

[Sankel]

Hi Guys,

Since last week my iMac is constanley failing. And my best guess is a GPU-faillure. Also my MacbookPro (late 2011) failed a few months ago, same problem, GPU-faillure.

Now with my MacbookPro, I tried to use ArchLinux to configure the EFI and so, to set up a boot without the GPU, but only the Intel Iris GPU.

I only see Macbook-related topics with GPU-faillures and the solution with ArchLinux.

Is there anybody who has experience or knows what to do with a faillure of the GPU in the iMac? I really would like to disable the GPU, so I can use my computer for browsing and maybe some other stuff.

 

[Juicy Box]

I'm curious, what are the symptoms?

 

[Sankel]

I'm curious, what are the symptoms?

Boots up, shows Apple Logo, progress bar starts to load, at ~50% it stops and all kinds of glitches fills the screens, wait a few moments and it boots up again. Those glitches always look different.

I'm pretty sure it's the GPU

 

[Icy1007]

Boots up, shows Apple Logo, progress bar starts to load, at ~50% it stops and all kinds of glitches fills the screens, wait a few moments and it boots up again. Those glitches always look different.

I'm pretty sure it's the GPU

Are they words that you are seeing as "glitches". Does it look like a Windows Blue Screen, but on top of the screen with the Apple logo?

 

[Sankel]

Are they words that you are seeing as "glitches". Does it look like a Windows Blue Screen, but on top of the screen with the Apple logo?

https://imgur.com/a/K7RsE5R

Sometimes it looks different, but mostly the same.

 

[stillcrazyman]

https://imgur.com/a/K7RsE5R

Sometimes it looks different, but mostly the same.

That certainly looks like GPU failing. Those artifacts appear when VRAM is having errors. If you have added ram to it, maybe try a reseat of the sticks to see if that alleviates the problem. I also have a Late 2012 27" iMac, and as far as I recall, the GPU is not a separate card on the MLB. It's going to get expensive to repair if it has failed.

 

[Fried Chicken]

That certainly looks like GPU failing. Those artifacts appear when VRAM is having errors. If you have added ram to it, maybe try a reseat of the sticks to see if that alleviates the problem. I also have a Late 2012 27" iMac, and as far as I recall, the GPU is not a separate card on the MLB. It's going to get expensive to repair if it has failed.

I can confirm it's not. This has me worried. I've pushed my GPU very hard in the span of my ownership.

OP, which GPU do you have?

 

[Sankel]

I can confirm it's not. This has me worried. I've pushed my GPU very hard in the span of my ownership.

OP, which GPU do you have?

The glitches that I see looks very familiar to the glitches my Macbook Pro shows. Why do you think it not?

My iMac had the Nvidia Geforce 680MX

 

[Fried Chicken]

The glitches that I see looks very familiar to the glitches my Macbook Pro shows. Why do you think it not?

My iMac had the Nvidia Geforce 680MX

NOOOOOOOOOOO I have the same one -_-

I can confirm it's not a separate card... the whole logic board will need replacing.

 

[Binarymix]

Have you tried reinstalling the OS, it seems to be glitching at the point where kexts are loaded, perhaps the graphics kexts have become corrupted. Try internet recovery, and see if it glitches out there also.

 

[Sankel]

Have you tried reinstalling the OS, it seems to be glitching at the point where kexts are loaded, perhaps the graphics kexts have become corrupted. Try internet recovery, and see if it glitches out there also.

Yes it glitches out there too. Also tried Apple Hardware Test, where it also crashed