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Azrael9

macrumors 68020
Original poster
Apr 4, 2020
2,287
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Dear Mac Users,

I have an iMac 2012 27 inch iMac 8gigs of ram, 680 MX, quad core i7.

It won't boot.

I've done the obvious:

PVRAM clear. (I got the chime chord back...then it hangs.)
Tried remote installing of Mac Os (it hangs...)
Safe mode. Gets 5/6 of the way there. Hangs.

The Hardware check comes back clear.

Terminal command line check.

Says I can boot. But it still hangs.



PC BOOT CAMP.

WILL load in safe mode. Clear of green fleck artefact.
In normal mode. Had Green fleck artefacts. (I did try to install a new NV driver on the PC side. Not the best move.)

Of all the times for my Mac to go down.


Yes. 7.3 years old. But it had been fine. Only time I've 'pushed' it is playing an old game in boot camp over the last year. Fried my GPU?

I do have an external drive and that won't Boot either.

I don't have any install discs or Thumnail drives big enough to download the installs to use Utilities. (The boot sequence or remote OS installation won't let me get far enough to use Disk utilities...this is where not have CD boot discs incurs my agitation. Should have seen this day coming and prepared with a thumn nail back up.

My external drive as has a back up of key date.


The Terminal command line says my hard drive on my Mac is fine. As does the health diagnostic (apple check) logic board. Hard drive. Memory. All came back clear.

Disturbing this puzzle is.

Any help in this hour of need?

Would be much appreciated.

Azrael.

PS. I wonder if the old game I was playing hacked at or changed my gl drivers on both sides. The PC side says I no longer have GL. The Mac side. Can't get that far to check.

I have data on my primary drive so reluctant to do a wipe and install just yet. But I've been trying remote install the OS I shipped with, close or new (none have worked so far...) as I have the option to preserve data. This data is about 95% backed up on my external hard drive.

So I could nuke the primary drive and take the data hit. But not until I can confirm my external drive still works with a newer Mac.


PPS. Yes, 'buy a new one.' But I was hoping to hang on until Apple released a new iMac this year. The current ones are pretty old, 6 core vs AMD's upto 16 cores. And they're not cheap to be behind the curve. eg. 8 gigs of ram still. That's how much ram my iMac shipped with in early 2013 (by the time mine was shipped...)

I know this is 7.3 years old. But it's been well looked after. The only tell tale signs was slower boot progress bar. I presumed this was due to the ssd 128 gig drive filling up and the spinning 7200 rpm drive taking over those chores. Maybe the SSD finally gave out? I wonder if PC boots off the 7200 rpm as it boots slower.
 
Thankyou for replay, Herrdude.

My external hard drive has it.

My main hard drive doesn't appear to have it. (That a hang over from having Moutain Lion originally?)

The 'recovery' on High Sierra on my external drive doesn't work either. Hangs half way. So neither internal or external drives will boot. Hang half way. Recovery on my external doesn't work.

Regards,

Azrael.
 
Thankyou for replay, Herrdude.

My external hard drive has it.

My main hard drive doesn't appear to have it. (That a hang over from having Moutain Lion originally?)

The 'recovery' on High Sierra on my external drive doesn't work either. Hangs half way. So neither internal or external drives will boot. Hang half way. Recovery on my external doesn't work.

Regards,

Azrael.
I mean: turn off your computer and use internet recovery to reinstall your operating system using the key combination in my previous post.
 
Ty for the reply.

I turned off my computer, tried internet recovery to reinstall my OS using the key combination.

It still hangs on the progress bar just over half way.

Azrael.
 
Boot the iMac in Target Disk Mode and copy the drive to another Mac?
 
Stuck loading bar and green artifacts = GPU is dead.

IMG_4363.jpg
 
Joevt.

Thankyou for the suggestion, however, I don't have a spare Mac.

I was hoping to hang on until the next iMac release. The diagnostic hardware test says the mainboard, hard drive and memory are fine.

Herrdude.

I can't say 100% the hard drive is 'fine.' But the diagnostic test says it is.
Stuck loading bar and green artifacts = GPU is dead.

View attachment 903808

You may be correct. But I haven't confirmed this. But I am getting that pattern. Not in Boot Camp Safe mode...but in standard PC mode, yes.

I can't access the Mac 'safe mode...' yet.

I've caught a video on youtube that allows you to disable the mac gpu in the command line.

Maybe then I can boot in safe mode...and access my files?

Azrael.
 
I don't want to insult you, but are you SURE that you booted to INTERNET recovery, and NOT to "the recovery partition" ??

Recovery partition = Command-R at boot.

Internet recovery = Command-OPTION-R at boot.

You should be able to boot to internet recovery regardless of the condition of the hard drive inside.

BUT... if you still can't get running using internet recovery... could be a problem with graphics hardware inside.

Looks like you're not going to be able "to wait" until a new iMac is released.
Remember the old saying:
"If you NEED now, BUY now."

Well, how does this apply to YOU...?
 
Hello Fishrrman,

No insult taken. We have to check and double check these things.

You're quite right on the INTERNET recovery. There isn't any 'Internet Recovery' my main hard drive. Odd. (I guess my iMac late 2012 with Mountain Lion was the 1st to ship without system discs? Though I did buy a DVD 'super' drive.)

So, I guess I was pressing = Command=R at boot...in vain.

Again. I have a 2nd external hard drive and that won't boot either. That's running High Sierra. It DOES have a System Recovery option. I tried that. It didn't do anything other than 'hang.' It won't boot. The recovery doesn't appear to work either.

If it is GPU related, I did try the command line tutorial off YouTube to 'unhook' the Nvidia 6800MX gpu. To try to get the iMac to run in 'safe' mode. No luck. It hangs. Still.

I've done the 'apple diagnostic.' Says everything is 'fine.'

One thing I was running on both the PC side and the Mac side was an old game that runs on Open GL. I looked this up on the Internet and found that unregistered developers that 'hack' at the Open GL or make DL changes can bork the system. On the PC side (where I have the green static) it says I don't have Open GL and that's where I 1st encountered the trouble. I made the mistake of trying to run newer Nvida drivers for my 680 MX. I wonder if running the same thing on the Mac (this 'old game' is available for the mac as well...) has borked the GL drivers on the Mac side and this is why the OS can't boot because it's 'borked.' That said. The Mac side of the game worked fine then started crashing. Then 'vector' triangles and three SERIOUS system crashes...and that was that. No more booting.

I ran a command line diagnostic on the Hard Drive and it says it's fine.

Though 'some' say you can get a false positive.

I don't have the Utilties (or can't access them because it won't boot that far...) Disk Help to reinstall, diagnose etc....and no external or access to a friend's Mac to access that avenue of capability.

I've done PRAM and SMC checks. (I got the chime back...)

On the boot camp partition...i CAN(!) access 'safe mode' in windows (oh the bitter irony...) and there is NO green static. But in 'standard' windows. Green static. No static on the Mac 'boot attempts.'

Safe Mode on Mac? The loader gets to 5/6 way there and stuck!

I've tried doing the remote install of Mac OS. Original. Most close to. And even the latest one. All of them? Still hang.

One thing I have done is...to buy a Mountain Lion OS Thumn Nail drive off Amazon. I ordered it last night. With a delivery date (in current circumstances...) of around 5 days. I'm hoping I can at least access a software safe mode on the main drive to get my files off and get access to my external drive as well. I don't mind running it in 'crippled' on board gpu mode until a new iMac ships. I don't mind jittery scrolling if this iMac has 'onboard' gpu (not sure if it has?) There's no noises inside the iMac. No high temperatures. (It was blowing abit when I was running the game, perhaps the most intensive thing I've done in the last year over the last 7.3 years. But the game was very old. 2004 but the fans did work up a bit. Maybe that's the way iMacs are with a limited thermal enclosure.)

It's, again, with deep irony, that I'm typing this on the Bootcamp PC partition...running FireFox. Meh. Complete with magenta static. The ignominy.

I see. So Internet Recovery should run even if the hard drive is borked (which it doesn't appear it is?) That said, the boot times were getting longer and the start up bar longer. I just took this as a sign the SSD was full (128 gig fusion drive...) witha 750 Hard drive spinner picking up the slack...slowly. So my boot times haven't been fast for a quite a while now. SSDs that are full or nearly full also degrade in speed?

Re: Buy now. I remember saying I'd wait for the Retina iMac. I bought the model just before they went Retina. Annoying. The resolution on 'this thing' has really pulled my eyes about. Even the 24 inch iMac I had before it was kinder on the eyes. Buyer's remorse. 'A little.'

I'm invested in the Apple Eco-System. But I've increasingly made sure any software I buy is cross platform. The debacles over the Mac Pro 'Can' and the uBer Price 'New' Mac Pro-er and the design stagnation and value equation of the iMac have given me pause. (I did wait for ten years to buy my 2008 iMac...then only 4 years later to buy my 2012 late iMac. So late it shipped in Jan' 2013.)

And given rising iMac prices for medicore specs, hell will freeze over before I hand over about £2,000 for an i5 with six cores when PC systems with 8 cores and 12 cores can be had for the same price or far less, 8 gigs of ram (7.3 years ago my iMac shipped with 8 gigs of ram...c'mon, Apple...) and a low end gpu...and a crummy Fusion Drive with less SSD room than the one mine shipped with. With all due respect, Apple can get bent on the current value equation. Not to mention that we're probably on the cusp of an iMac refresh...and, 'maybe' a design refresh with better specs or SSD as standard (SSD drives are no longer expensive.) So, yes. I get the 'buy now if you need' advice. I really do.

This situation has made me think more broadly about my 'single system' approach being flawed. ie. Don't game on your mission critical computer. Not even on Bootcamp. Maybe it pushed it over the edge. Either a hard ware failure or a hack that has torpedoed the OS so it needs a rescuse and reinstall. (My pants were caught down for having no physical OS back up to diagnose or reinstall.)

I have thought about getting a Mac Mini 512 gig SSD with a Sonnet eGPU (to do the heavy lifting) and external monitor and having this as a back up system. It's taught me a lesson re: back ups, back ups, back ups. Having the external Mac boot drive was not enough. :/ And also that I might even try to have an additional PC/Hackintosh tower rig as well as the new iMac when it ships. 3 computers? Sound extreme..?

Not if you're going to be serious about running a business. Having a back up rig makes more sense now. And going cross platform to a degree. I always had the idea of the PC doing heavy 3d lifting and general production work on the Mac. It seems if you push the iMac even moderately hard the inside starts to cook. I've had two of them now. And both of them can get hot to the touch. I'm more a natural tower buyer (My 1997 PPC was...) But Apple have priced mainstream creative tower buyers out the market with no down to earth monitor options either. With the iMac ...if the GPU cooks, you can't just pull it out and replace. *Shrugs.

Thank you for your help and advice. I've double and triple checked everything. But you're right on the recovery thing on my main drive. It doesn't have that option at all.

I wonder, can I do a factory restore setting? ie back to the setting it shipped with? I'd probably lose my data. I won't attempt that until I've tried the Thumn Nail drive with Mountain Lion OS & Utilities Tools.

In the mean time, I'll try the Internet Recovery advice again. (Hey, when we're flappin' and our systems have gone down we don't always think or act clearly. You never know...)

Regards,

Azrael.
 
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If you can't boot any of the recovery tools, or in safe mode, you're not going to be able to boot a Mountain Lion thumb drive. Safe mode in Windows will work because it uses a bog standard VGA driver, with a very limited resolution - which often allows faulty GPUs to boot.

If you're getting artefacts on the boot loader, it's going to be the graphics card. It's not what you want to hear, but that's the only thing that would cause that. You have 2 real options: source a new graphics card, or buy a new machine.
 
Maybe then I can boot in safe mode...and access my files?

Azrael.

Once again: when GPU is dead, there is no chance to get to recovery mode. No chance! This is because each gui Mac Os menu needs GPU to display. Even worse: recovery mode works but You can't see anything. It's like computer without monitor. Make short test: boot in recovery mode; when load bar stuck, do not touch anything but wait. After few moments you'll hear voice command prompting to choose language, but there will be still halfloaded bar on the screen.


If this is just GPU failure, your data is safe on main drive. I suck all my data using target mode with other Mac. I'm so lucky to have tb->firewire cable and old firewire Macbook Pro. I could even use dead iMac as startup drive using target mode.
 
Once again: when GPU is dead, there is no chance to get to recovery mode. No chance! This is because each gui Mac Os menu needs GPU to display. Even worse: recovery mode works but You can't see anything. It's like computer without monitor. Make short test: boot in recovery mode; when load bar stuck, do not touch anything but wait. After few moments you'll hear voice command prompting to choose language, but there will be still halfloaded bar on the screen.


If this is just GPU failure, your data is safe on main drive. I suck all my data using target mode with other Mac. I'm so lucky to have tb->firewire cable and old firewire Macbook Pro. I could even use dead iMac as startup drive using target mode.

Hello Citd,

Thank you for you explanation as to the boot differences between the Mac and PC. Ergo why the PC is still usable (well, for light browsing and not much else...) with a green static and the Mac is not. It would also explain why recovery mode also goes into a black screen after a while of being stuck on the half way grey screen/apple logo/progress bar.

Just a matter of getting the data off. So, I'll need another Mac, a Thunderbolt cable(?) and put this 'He's dead, Jim,' iMac to pasture.

This 2012 iMac can output to another Mac? As a monitor? So if I bought a Mac Mini...I could still hook this up to the iMac and it will serve as a monitor? ie. I'd get some use out of it? Mind you. I never did like the top resolution on this thing. 'Pulled my eyes.' But I could save it for use as a start up drive using target mode 'break glass in case of emergency.'

Thanks again for the insight.

Regards,

Azrael.
 
This 2012 iMac can output to another Mac? As a monitor? So if I bought a Mac Mini...I could still hook this up to the iMac and it will serve as a monitor? ie. I'd get some use out of it? Mind you. I never did like the top resolution on this thing. 'Pulled my eyes.' But I could save it for use as a start up drive using target mode 'break glass in case of emergency.'
Target Display Mode of an iMac requires the iMac to be booted into macOS where the Target Display Mode software is located (it's not in EFI firmware like Target Disk Mode is).
 
Hmm. I had a thought as may have been hinted at in this thread...

You have 2 real options: source a new graphics card, or buy a new machine.

If I connected a Sonnet and Radeon 580 eGPU set up to my iMac, would it boot? (I'm still presuming my gpu is down from the advice in this thread as a given.)

Being late 2012, I have Thunderbolt 1? So would Mac Os support eGPU anyhow? If I could source a cheap UK Mac repairer it may be an option to buy me sometime until WWDC or whenever Apple released a new iMac.

Thoughts?

Azrael.
 
Hmm. I had a thought as may have been hinted at in this thread...

If I connected a Sonnet and Radeon 580 eGPU set up to my iMac, would it boot? (I'm still presuming my gpu is down from the advice in this thread as a given.)

Being late 2012, I have Thunderbolt 1? So would Mac Os support eGPU anyhow? If I could source a cheap UK Mac repairer it may be an option to buy me sometime until WWDC or whenever Apple released a new iMac.
Go to the egpu.io website and look for builds that include your Mac or similarly old Thunderbolt 1 or Thunderbolt 2 Macs to see how it's done. Decide if you want to use macOS or Windows.
Search for "Mac TB[12]" (it accepts regular expressions separated by spaces)
Here's a few:
 
You can potentially disable your 680MX and use the integrated chip instead. See if this thread helps : https://discussions.apple.com/thread/7781774
I have done something similar in a MBP and it helped me isolate the problem at the least. Once you have isolated the issue you can decide whether to replace your GPU or use an external one.

I do have a 27" 2012 iMac which had power related issues and got it resolved by replacing the power supply module myself, Apple support asked me to recycle my iMac, smh.
 
You can potentially disable your 680MX and use the integrated chip instead. See if this thread helps : https://discussions.apple.com/thread/7781774
I have done something similar in a MBP and it helped me isolate the problem at the least. Once you have isolated the issue you can decide whether to replace your GPU or use an external one.

I do have a 27" 2012 iMac which had power related issues and got it resolved by replacing the power supply module myself, Apple support asked me to recycle my iMac, smh.

Hello Roshan,

Aha. Now. If that would work...I'd be a happy(er) camper.

Yeah...Apple 'support.' 1 trillion and counting. 'Recycle' your iMac? The gaul of them. Only Apple could expect something for nothing in return whilst charging you through the nose for support, repairs or new rigs with out of date specs.

'Money isn't everything.' Steve Jobs.

Thank you for your advice, Roshan. I'll give this a try and report back to you.

If it works it just buys me more time to either get an external Sonnnet/580 eGPU or new rig set up.

I just get the feeling we're 'inbetween' real updates for Mac at the moment and awaiting the next big shift. Looks like I'm not the only 2012 iMac owner waiting for the 'next big' iMac release.

Regards,

Azrael.
 
This happened me over the weekend.

I was hoping to hang on till end of year for the facelift too.

Are there replacement gpu cards available for a machine this old?
 
If your iMac is the 2012 slim design, then the GPU is soldered onto the motherboard. The motherboard itself will then have to be replaced.

If it is the Nvidia GPU HW fail (excluding any SW/driver issue) you have perhaps the following options:
- get a replacement/refurbished motherboard and replace your old
- get your iMac to a skilled repair shop that may offer soldering repairs on motherboards, replacing your GPU (if they have a salvaged GPU available, otherwise MoBo replacement)
- try to disable the Nvidia GPU and use the onboard integrated Intel hd graphics 4000 instead (if possible)
- recover your files from your internal discs (target disc mode e.g) if important and not backed up elsewhere.

If your MB is beyond saving and no other options are worth going for, there are some tutorials on the web/youtube how to gut the iMac and convert it to a very good monitor.
 
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Green artifacts on boot is a bad sign. Sounds like your graphics card is toast. Motherboards on Fleabay for your model are $175 plus. Now you have to ask yourself if the potential expense is worth a vintage 2012 machine? If so, your best option is have the MB replaced. If not, you could probably find a late 2013 27" iMac (faster bus, USB3) for about the same cost. What I would do: Purchase the best iMac (2017+) you can afford. Make sure your new iMac comes with an SSD. No fusion drives.
 
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If your iMac is the 2012 slim design, then the GPU is soldered onto the motherboard. The motherboard itself will then have to be replaced.

If it is the Nvidia GPU HW fail (excluding any SW/driver issue) you have perhaps the following options:
- get a replacement/refurbished motherboard and replace your old
- get your iMac to a skilled repair shop that may offer soldering repairs on motherboards, replacing your GPU (if they have a salvaged GPU available, otherwise MoBo replacement)
- try to disable the Nvidia GPU and use the onboard integrated Intel hd graphics 4000 instead (if possible)
- recover your files from your internal discs (target disc mode e.g) if important and not backed up elsewhere.

If your MB is beyond saving and no other options are worth going for, there are some tutorials on the web/youtube how to gut the iMac and convert it to a very good monitor.

Mine is the slim type. I took it to a repair shop today, they told me the cost of repair would exceed the value of a vintage machine.
Green artifacts on boot is a bad sign. Sounds like your graphics card is toast. Motherboards on Fleabay for your model are $175 plus. Now you have to ask yourself if the potential expense is worth a vintage 2012 machine? If so, your best option is have the MB replaced. If not, you could probably find a late 2013 27" iMac (faster bus, USB3) for about the same cost. What I would do: Purchase the best iMac (2017+) you can afford. Make sure your new iMac comes with an SSD. No fusion drives.
I have the green flecks in Bootcamp mode.

Oh well, it served me well over the past 8 years. It has the SSD also.
 
This happened me over the weekend.

I was hoping to hang on till end of year for the facelift too.

Are there replacement gpu cards available for a machine this old?

You got the same fate as me, Aiden? *shame.

I was hoping to hang on until this fall. When planets and stars align.

It's 2nd hand Mac (expensive), refurb Mac (expensive), PC Hack'tosh build (doable...) or buy the new iNtel iMac paper weight (shipping July? Sep? Oct?) or wait for iMac ARM 24 inch end of year or early 2021?

Azrael.
[automerge]1594047914[/automerge]
Mine is the slim type. I took it to a repair shop today, they told me the cost of repair would exceed the value of a vintage machine.

I have the green flecks in Bootcamp mode.

Oh well, it served me well over the past 8 years. It has the SSD also.

I have the 'green flecks' in Boot camp. Basically my iMac got too hot playing a 2004 very old game. It couldn't cope. So the gpu cooked/friend. Great cooling, Apple.

The 1 year out of 7 I pushed it moderately hard and it fried. *Shrugs.

Now? The waiting game.

See post above.

Yep. You try to get that repaired? It will be a chunk of money to go towards a new one, the AS iMac or a PC Hack'tosh build or...2nd hand...or refurb...

Decisions...decisions...the wait goes on.

Azrael.
[automerge]1594048236[/automerge]

I've checked the price of 2017 iMacs out. Pricey.

May as well get a new iMac 2019 for some of those 'hopeful' prices.

The reality of the AS ARM move hasn't sunk it yet. But it will when consumer models with ARM in them drop.

Or build a Hack'tosh far cheaper.

Azrael.
 
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