2013 27 iMac blackouts under load

[SergueiTemp]

I own a 2013 iMac with GeForce GT 755 1 GB.

The issue is that once you use enough apps that load GPU (like watching Youtube video while being connected to remote Parsec session) - the screen goes black and then, after 10-15 seconds, computer powers up again and continues playing whatever was playing etc. Sometimes, probably when I plug it into bad outlet, it can even result in kernel panic, but if it's a good outlet - just blackouts.

I suspect the culprit of the issue is faulty PSU or some capacitor on a logic board, which supplies power to the GPU. Because I've had much worse but similar issue with 2010 MacBook, where it would kernel attack when switching to discrete GPU. And I've fixed it by re-soldering the capacitor (thanks to Louis Rossman for providing solution!)

I've had this issue for years, but lately it's become really annoying since I can't multitask freely and do graphic stuff. Also in the past I had USB ports randomly turn on/off.

Has anyone encountered similar issue and was able to fix it? I really love my iMac and want it to keep going. Thanks.

 

[Fishrrman]

You've got to realize that one gets only "so many years" out of a Mac (or any other computer).

You're at "ten" now.

Might be time to start thinking, "replacement"...

 

[Jumpthesnark]

I own a 2013 iMac with GeForce GT 755 1 GB.

The issue is that once you use enough apps that load GPU (like watching Youtube video while being connected to remote Parsec session) - the screen goes black and then, after 10-15 seconds, computer powers up again and continues playing whatever was playing etc. Sometimes, probably when I plug it into bad outlet, it can even result in kernel panic, but if it's a good outlet - just blackouts.

I suspect the culprit of the issue is faulty PSU or some capacitor on a logic board, which supplies power to the GPU. Because I've had much worse but similar issue with 2010 MacBook, where it would kernel attack when switching to discrete GPU. And I've fixed it by re-soldering the capacitor (thanks to Louis Rossman for providing solution!)

I've had this issue for years, but lately it's become really annoying since I can't multitask freely and do graphic stuff. Also in the past I had USB ports randomly turn on/off.

Has anyone encountered similar issue and was able to fix it? I really love my iMac and want it to keep going. Thanks.

I have the same issue (late 2014 Retina 27" 4GHz i7, Radeon R9 M295X 4GB) that also blacks out, occasionally, under graphics load. It only happens under gaming (which I do pretty rarely) and work (generally with a complex set of files in Adobe Lightroom Classic or multiple large layers in Photoshop, which is why I need it to not black out). I've taken to keeping my music turned off while working, so I can keep my ear tuned to the fan noise, and I've installed Macs Fan Control to monitor the GPU temp.

When I hear the fans ramp up I pause my work for a couple moments, then I make sure my work is saved before moving on.

Like you, I very occasionally have a kernel panic as well. I have not yet found a solution, and it's frustrating.

 

[Nguyen Duc Hieu]

I have the same issue (late 2014 Retina 27" 4GHz i7, Radeon R9 M295X 4GB) that also blacks out, occasionally, under graphics load. It only happens under gaming (which I do pretty rarely) and work (generally with a complex set of files in Adobe Lightroom Classic or multiple large layers in Photoshop, which is why I need it to not black out). I've taken to keeping my music turned off while working, so I can keep my ear tuned to the fan noise, and I've installed Macs Fan Control to monitor the GPU temp.

When I hear the fans ramp up I pause my work for a couple moments, then I make sure my work is saved before moving on.

Like you, I very occasionally have a kernel panic as well. I have not yet found a solution, and it's frustrating.

Normally, if it's only GPU overheating issue on an old computer, I would just simply have it cleaned-up inside out, and thermal paste/pads reapplied. Since the shops where I live charge me quite modestly on this service (30~40$), I do that every 3 years.

 

[Jumpthesnark]

Normally, if it's only GPU overheating issue on an old computer, I would just simply have it cleaned-up inside out, and thermal paste/pads reapplied. Since the shops where I live charge me quite modestly on this service (30~40$), I do that every 3 years.

Thanks, but I don't think there's a reputable shop that would do that service on a late 2014 iMac for that price range. I've taken my iMac apart before (for cleaning, and to swap out the fusion drive for an SSD), and it's a time consuming process that also requires the removal and replacement of adhesive strips. Those alone are half the cost that you just quoted. Add the cost of materials to the time it would take and a shop will charge much more.

 

[Nguyen Duc Hieu]

Thanks, but I don't think there's a reputable shop that would do that service on a late 2014 iMac for that price range. I've taken my iMac apart before (for cleaning, and to swap out the fusion drive for an SSD), and it's a time consuming process that also requires the removal and replacement of adhesive strips. Those alone are half the cost that you just quoted. Add the cost of materials to the time it would take and a shop will charge much more.

Yeah, we live in very different parts of the world.

 

[tagriesti]

I had a similar issue with my previous iMac except it would just randomly shut itself down. At first I thought it was an overheating issue and it was the preventative shutdown to prevent itself from overheating, but I took it to an authorized repair center and it was determined to be one of the capacitors on the PSU. Replacing the PSU solved the issue, but while they had the iMac open I had them redo the thermals on the CPU and GPU and clean out the fans, etc. as it was almost 4 years old at that point. So, my guess is it's either thermal paste or the PSU.