Possible GPU failure

[peacockharris]

So a bit of a weird one. My late 2013 iMac has been slowing down the last few weeks, so I've been expecting something to fail. Last night I woke it from sleep only to get a blank screen entirely unresponsive. I had to manually turn it off and when I then tried to boot it, I was met with the usual apple loading bar, but with green pixel glitches in it. Sometimes the green was on one end of the loading bar, other times it was all over the screen. I didn't take photos of all variations but below is an example.
New item by Rhodri Harris

It also didn't boot. Just froze and sometimes crashed back to the start again.

Long story short, I tried everything to get it to boot (safe mode, recovery mode, nothing worked) I tried booting into a disk image of an osx install so I could run disk utility but it didn't show up as an option in the boot menu (holding down alt/option)

Then suddenly it booted without me having actually changed anything. It took ages, but I was finally back in. But performing any action at all, whether it's opening a program, switching window, or even moving the mouse a bit too quickly, risks the screen going crazy with RGB pixel glitches. Initially my mouse pointer remains with everything else frozen, but in a few moments the mouse pointer freezes too, with the computer either crashing and restarting, or needing to be manually turned off.

Example of this below:
New video by Rhodri Harris

Tried running diagnostics (D key on boot) but it finds no issues.

This strikes me as a possible GPU issue, but am just wondering if anyone has any other ideas. Also would like to know if it's worth fixing/replacing or if I should just look for a new computer.

Appreciate any insight you can give!

Edit: Also, I already did the steps to reset NVRAM and SMC at boot.

 

[Raz0rEdge]

Yup, that looks like a GPU failure. With the iMac, that would mean a logicboard replacement and for a 9+ year old machine I wouldn't recommend it. Take that money and put it against a new Mac.

 

[gnarlybole]

So a bit of a weird one. My late 2013 iMac has been slowing down the last few weeks, so I've been expecting something to fail. Last night I woke it from sleep only to get a blank screen entirely unresponsive. I had to manually turn it off and when I then tried to boot it, I was met with the usual apple loading bar, but with green pixel glitches in it. Sometimes the green was on one end of the loading bar, other times it was all over the screen. I didn't take photos of all variations but below is an example.
New item by Rhodri Harris

It also didn't boot. Just froze and sometimes crashed back to the start again.

Long story short, I tried everything to get it to boot (safe mode, recovery mode, nothing worked) I tried booting into a disk image of an osx install so I could run disk utility but it didn't show up as an option in the boot menu (holding down alt/option)

Then suddenly it booted without me having actually changed anything. It took ages, but I was finally back in. But performing any action at all, whether it's opening a program, switching window, or even moving the mouse a bit too quickly, risks the screen going crazy with RGB pixel glitches. Initially my mouse pointer remains with everything else frozen, but in a few moments the mouse pointer freezes too, with the computer either crashing and restarting, or needing to be manually turned off.

Example of this below:
New video by Rhodri Harris

Tried running diagnostics (D key on boot) but it finds no issues.

This strikes me as a possible GPU issue, but am just wondering if anyone has any other ideas. Also would like to know if it's worth fixing/replacing or if I should just look for a new computer.

Appreciate any insight you can give!

Edit: Also, I already did the steps to reset NVRAM and SMC at boot.

Hi Rhodri
I'm running a 27-inch late-2009 iMac that encountered similar issues a couple of years ago. Fortunately, I discovered JDW on YouTube. He has posted a series of videos showing how to open up the iMac, remove the GPU and, astonishingly, bake it in an oven before repasting it. It sounds crazy, but two years on my old iMac is still working. For how long is another matter, but I'm planning to replace it in the coming months – assuming Apple ever get round to releasing an M2 Mini. I would encourage you to take a look at JDW's videos. The process does appear a bit daunting, especially if you've never performed a teardown of an iMac, but if I can do it I reckon anyone can. This second video might be a good place to start.

Good luck!

 

[peacockharris]

Yup, that looks like a GPU failure. With the iMac, that would mean a logicboard replacement and for a 9+ year old machine I wouldn't recommend it. Take that money and put it against a new Mac.

Thanks for the reply. Yeah, that's what I feared, so I've gone and ordered a 2018 Mac Mini.

I do hear there's a way to 'reflow' these GPUs by baking them in the oven, so I may try that as a last ditch effort. If it gets a bit more life out of my iMac, that'll at least allow me to use it in target display mode so I don't have to buy another monitor for my setup.

 

[peacockharris]

Hi Rhodri
I'm running a 27-inch late-2009 iMac that encountered similar issues a couple of years ago. Fortunately, I discovered JDW on YouTube. He has posted a series of videos showing how to open up the iMac, remove the GPU and, astonishingly, bake it in an oven before repasting it. It sounds crazy, but two years on my old iMac is still working. For how long is another matter, but I'm planning to replace it in the coming months – assuming Apple ever get round to releasing an M2 Mini. I would encourage you to take a look at JDW's videos. The process does appear a bit daunting, especially if you've never performed a teardown of an iMac, but if I can do it I reckon anyone can. This second video might be a good place to start.

Good luck!

Lol, I hadn't seen you'd responded with this very solution when I wrote my response above. Great minds, eh?

Definitely going to try it.

 

[Raz0rEdge]

You've got nothing to lose by doing the reflow hack. If it works and makes that machine operational, you have an extra.

 

[peacockharris]

Well colour me confused about the possibility of reflowing the GPU. Despite the fact my searches of the issue (specifically with this model) were bringing up results related to this fix, I'm unable to find anyone having done it specifically on a late 2013 model (I'm only finding it done with 2009 and 2011 iMacs)

As pointed out by another poster, the GPU in the late 2013 model is integrated with the logic board. Does that mean I can't even attempt it? Feeling pretty bummed, especially as it turns out I ideally need to access the computer so that I can update the OS to Mojave, and the file system to APFS. My newly purchased Mac Mini won't play ball with my Time Machine backups otherwise.

 

[pigoo3]

Trying to reflow a GPU is a very very very very risky venture. When you reflow the GPU...you're basically melting the solder that connects the GPU to the board it's mounted on...hoping that the broken solder connection related to the GPU is restored/repaired during the reflow process.

Of course the solder connections to the GPU are not the only solder connections that are melted on the board...every solder connection on the board is melted/liquified...thus a great chance something else could suffer an issue in the reflow process.

Trying something like this should be the absolutely last thing you try (after you've tried every other troubleshooting possibility)...since you may ruin the board. If ruined...you won't even be able to sell it for parts.

Nick

 

[gnarlybole]

Apologies. I'd completely forgotten that, by 2013, Apple had integrated the GPU into the logic board. I certainly don't think it would be advisable to stick the whole board into an oven! As for Time Machine backups: you should be able to reinstall data from them even if your disk is HFS+ formatted and your new Mini is running Catalina. I suppose once your Mini is up and running you could reformat your old backup to APFS, but I'd be tempted to buy a new one (more expense I'm afraid) and keep the data on the old one... just in case.

 

[pigoo3]

It is more risky putting the whole logic board into the oven...but folks that have reflowed the GPU on portable computers (laptop computers) do it...they put the whole portable computer logic board into the oven (since many times even dedicated GPU's on a portable computer are not on a separate board).

Trying a DIY reflow in an oven is definitely very risky...and if someone does it (especially for the 1st time)...you might as well go into it with the idea that it's going to fail (since there's a high probability it will).

The professional method of reflowing a GPU is much much more controlled & precise...using professional equipment that costs thousands of dollars.

If the DIY oven method does happen to come out as a success...then it's time to buy a lottery ticket!

Nick

 

[pigoo3]

Feeling pretty bummed, especially as it turns out I ideally need to access the computer so that I can update the OS to Mojave, and the file system to APFS. My newly purchased Mac Mini won't play ball with my Time Machine backups otherwise.

If this 2013 iMac feels like it's about to fail (GPU failure)...accessing it in order to upgrade the macOS to Mojave is really not important. There's really no point of being concerned what macOS the iMac is running if it has a serious hardware problem.

If the computer finally ends up dying...it won't really matter what macOS it's running.

On the positive side (in case it was not known)...Late 2013 iMac's originally came with a "spinner" hard drive or a blade SSD. Either of these can be removed...and placed in an external case to be used for other purposes...or to access what's on them (in case the 2013 iMac does completely fail).

Nick

 

[pigoo3]

By the way...two important troubleshooting steps were not mentioned:

* Connect an external display to the 2013 iMac to see what is seen on the external display.
* Try to boot 2013 iMac from an external drive with the macOS installed on it.

Nick

 

[pigoo3]

...so I've gone and ordered a 2018 Mac Mini.

Just curious...was this a brand new 2018 Mac-Mini...or a used one?

The reason I ask is...if it was a new 2018 Mac-Mini...you would have been MUCH better off purchasing a new or used 2020 M1 Mac-Mini!!!

Nick

 

[gnarlybole]

It is more risky putting the whole logic board into the oven...but folks that have reflowed the GPU on portable computers (laptop computers) do it...they put the whole portable computer logic board into the oven (since many times even dedicated GPU's on a portable computer are not on a separate board).

Trying a DIY reflow in an oven is definitely very risky...and if someone does it (especially for the 1st time)...you might as well go into it with the idea that it's going to fail (since there's a high probability it will).

The professional method of reflowing a GPU is much much more controlled & precise...using professional equipment that costs thousands of dollars.

If the DIY oven method does happen to come out as a success...then it's time to buy a lottery ticket!

Nick

I'm still not convinced by the idea of reflowing. Ten minutes in a conventional oven isn't going to melt solder and remake dry joints. It might have some effect on the chemical composition of the processor itself, but even that seems unlikely. I suspect that whatever brought my 2009 iMac back to life had more to do with the repasting of the GPU. But, like most people on this forum, I was more interested in the result than the science behind it.

However, as it worked for me, I will definitely be stumping up for a Euromillions ticket.

 

[pigoo3]

Yes the DIY oven-bake method of reflowing a GPU is definitely not very precise...and is full of risk. The main thing is getting the time & temperature correct (hot enough to liquify the solder...but not too hot to damage anything)...and long enough time-wise to do the same.

As said...also not going to get the best solder joints. Anyone that knows anything about soldering knows...for a good solder joint...you need to start with clean surfaces to be soldered...and need both solder & flux for a strong joint. With the DIY oven method...the solder is only being melted...then cooled. No actual cleaning or new flux being added. The joints that result will probably be very weak/brittle...and the joints may not even fully form like they would be when new.

The other critical part is the board being "baked"...needs to be as perfectly level as possible...otherwise when the solder melts...the hot liquid solder will run in all sorts of directions.

I've seen videos of how a professional piece of reflowing equipment operates...very very different & much more precise than the DIY method.

Don't get me wrong...lots of folks out there claim they've been able to successfully reflow GPU's & logic boards via the over-bake method. What they don't tell you is how many boards they destroyed learning how to do it right...or what their success rate is/was.

Definitely a learning-curve...and not a 100% success rate. Definitely not as simple as adding air to a flat automobile tire/tyre...and back on the road again!

Nick

 

[peacockharris]

Just to clarify for those saying it doesn't matter which OS the old or new machine are running, or suggesting I should have bought an M1 Mac instead, it needs to be an intel mac, running Mojave at the latest due to the software I use (I still have projects in Final Cut Pro 7 that haven't been migrated over to FCP X). I probably should have mentioned that before.

The new unit is a Brand New 2018 Mac Mini I got for quite a good price on eBay. This is why it's imperative I find a way to make my existing Time Machine backup compatible with it as that was the entire point of buying this particular era Mini! So seeing as reflowing the GPU is probably out of the question now, and I can't get into the system long enough to do what I need before it crashes/pixelates, my next step will be:

1. Borrowing a pre-Mojave Mac from a family member,
2. Restoring my TM backup to it.
3. Updating it to Mojave (which also fixes the file system compatibility issue)
4. Doing a fresh TM backup.
5. Finally using that new TM backup to restore to my new Mac Mini.

This all seems such ridiculous lengths to go to in order to keep my projects usable. Had I known about this lack of compatibility with Sierra/HFS I'd have updated long ago as a precaution. Sierra is the last OS to officially support FCP7. There are hacks around that mean you can use it on Mojave these days, but nothing after.

Hope that explains my predicament.... Kill me.

EDIT: I know I could technically drag files needed over from my HFS backup as opposed to doing a full system restore from it, but that seems laborious, and from experience in the past doing fresh installs, some niche software and plugins have stopped working and i'd have to go through troubleshooting all over again that won't necessarily be successful this time as I've long forgotten what I did.

 

[peacockharris]

By the way...two important troubleshooting steps were not mentioned:

* Connect an external display to the 2013 iMac to see what is seen on the external display.
* Try to boot 2013 iMac from an external drive with the macOS installed on it.

Nick

I've always had a 2 monitor setup, so I'm afraid this has already been confirmed. Same issues on both screens (if I'm able to get into the system at all before it crashes)

I've tried multiple boot options - a Windows partition (which oddly had less glitches but still crashed before being able to boot) and also a Linux distro on a USB stick.

There's no reason or rhyme to whether I can boot fully into the OS or not. It's more likely when the PC has cooled off for a while, but mostly it's just pot luck whether green pixelation populates the screen before I can even log in. I could try 50 attempts, get in once, but then it starts glitching just as I'm trying to do the thing I wanted to do. (Performing my final TM backup was fun!)

 

[MacInWin]

not going to get the best solder joints.

Actually, it might. Most of the issues that the EasyBake Oven approach fixes are cracked solder joints. The solder is properly flowed to both contacts, but has a crack in the solder itself. So an oven reflow melts the solder, the crack is repaired and the connection restored.

But as you have said, it's really tricky to do in a standard kitchen oven.

 

[pigoo3]

Just to clarify for those saying it doesn't matter which OS the old or new machine are running, or suggesting I should have bought an M1 Mac instead, it needs to be an intel mac, running Mojave at the latest due to the software I use (I still have projects in Final Cut Pro 7 that haven't been migrated over to FCP X). I probably should have mentioned that before.

Good deal...that makes sense...not an uncommon situation.

Nick

 

[ferrarr]

My newly purchased Mac Mini won't play ball with my Time Machine backups otherwise.

How are you attempting this?
What macOS is the 2018 Mini running?
What macOS was the dead Mac running?