27 iMac (2012) crashes and requires smc reset to turn on

Is it just me or is there a clue in the number of units which seem to be failing in a very close time frame post manufacture?

I was wondering if there is an NVRAM power supply on the logic board.

I also have the same problem with also a late 2012 27" iMac 13,2 3.4 GHz i7, 16 Gb RAM, NVIDIA GeForce GTX 680MX 2048 Mo.

Reading several posts on this subject, I see that it happened on other iMac models, although much more often/reported on the late-2012 27" iMac.

It would be interesting to really compare our configurations.... so far I have seen only one mentioning i5 CPU.

There is another thread on the same topic here : Why is my imac shutting down by itself?

The first symptoms started for me beginning of July 2015, e.g. 2.25 years after purchase.

Things I did:

- brought it to a Mac repair: they didn't find anything, said it was a software issue, reinstalled OS X. It worked 2 weeks before starting again, and more and more frequently as reported by others.

- Downloaded and installed MacFan : http://www.crystalidea.com/macs-fan-control

to "force" the fan cooling better the inside

- Purchased and installed a physical power switch between the electrical cord and the plug: as reported in the other thread above, that seems to be the only thing that works: each time I switch off the iMac from the Apple Menu and the iMac powers off, I then physically switch off the plug. This is like resetting the SMC each time you switch the computer on. So far (2 days) symptoms have stopped.

Hey guys I do not want to jinx it but I may have found a way to fixing this random shutdown problem of iMac. As mentioned before in my post, I have a late 2012 27inch iMac and it's been randomly shutting down for the past year or so. One short term solution that I've found was to leave the iMac unplugged from power for a couple of days then reconnect. There seems to be a relationship between the longer the period of unplugged time, the longer it will stay up before crashing. A few days ago I decided to factory reset my iMac. I've backed up using Time Machine just right before it. Surprisingly, the iMac hasn't crashed since yet. I do not know if anyone has attempted this method yet but hopefully this solves the issue. I've also installed CUDA when smithy_dave posted that it might solve the issue. But anyways, let me know if anyone's iMac show the same result after factory resetting! Good Luck! 🙂

I'm almost certain its graphics card related, the CUDA installation, coupled with making sure all apps are upto date seems to have significantly reduced the number of crashes / random shut downs. this is true for the two machines I have access too, I have however experienced one shut down in the last 14 days or so, however this is more bearable then the several a day I was getting and could be unrelated. it would be great to see if anyone else noticed this improvement with CUDA install.

Count one more. Same same. Last week got my iMac back from the Apple Store with a new hard drive installed as part of the iMac (27-inch) 3TB hd replacement program they've offered for computers sold between December 2012 and September 2013. I was hoping it would solve my sudden shutdown issue that began to occur sparingly last April and became more frequent. They gave the new hd a stress test before releasing it to me after finding nothing wrong. It worked fine for a week, then yesterday I experienced several "intermittent shutdowns" as they termed it. The nightmare continues.

We bought 3 similar computers at the same time for work, mine is the only one with this issue. Thank you all who have replied here offering solutions that have worked or not worked for you. Small comfort to have company in this situation but helpful to read of your similar experiences and attempts at eliminating the problem.

I'm absolutely gutted to say that after 4 weeks of relative calm since installing CUDA, I'm back at square one, for no reason at all multiple shut downs within a couple of hours. Honestly thought I was close to a solution. 😟

Update - but not convinced. Having ( for 10 days in a row ) unplugged the Imac at close of play until it wakes itself at 7am for routine backups - no failures, the machine has now been running for a further 7 days without the unplug routine and SMC reset without any crashes. Not so sure it is a hardware issue.

I've been having the same problems. started a few months back. been at the apple store twice. had the fusion drive replaced and then a full system wipe. every time its around 2 weeks later the random shut downs start. Apple store blamed software last time, which is odd since it will shutdown without loading any apps. usually struggles to stay on for more then a minute once it happens.

not really sure how to sort this either. massively affecting my work since its my main work computer.

will be following this thread closely

late 2012 imac 27''

3.4ghz i7

16gb crucial mem

3TB Fusion Drive

NVIDIA GeForce GTX 680MX 2GB GDDR5

How long can you run before it turns off again? I've been having the same issue. It's no problem for me to unplug my computer at night but I need 8 hours of uninterrupted work time during the day. I used to put it in sleep mode at night but that seemed to speed up the crashes.

Well, my office wakes up at. 7am and the computers do an auto backup (CCC) and are generally not switched off again until 6pm earliest - often much later according to studio work load. As I said in my last post, I am not convinced but we have had no crashes at all after continuously unplugging overnight over a period of about 10 days and since then we have not needed to unplug at all.

Same issue for me.

I have this iMac:

late 2012 imac 27''

3.4ghz i7

32gb Ram

3TB Fusion Drive

NVIDIA GeForce GTX 680MX 2GB GDDR5

I have notice that the last two time when the pc shuts down were during the pass from Bootcamp to Mac.

In particular from Bootcamp and Windows when I press "restart". In this case instead to restart the system on OSX, the iMac shuts down. So I had to remove the plug and wait some minutes...

In my case, the 95% of the times the iMac shuts down was during the use of Windows (on Bootcamp). 5% of the time during the use of OSX.

I don't know if it may help...

I've had the same issue with my late 2012 27" 3.4 GHz i7 750 SSD 32GB imac, running 10.10.5. (NVIDIA GeForce GTX 680MX 2048 MB)

It's definitely a graphics card issue. I was dealing with debilitating shutdowns. I wiped my drive and did a complete system reinstall (did not install any NiViDA/CUDA drivers). My imac runs like a beast now. I worked on a 4k project in After Effects (Creative Cloud 2015 version) this past week and haven't had any shutdowns. Trust me, I pushed it hard. I worked on the project for 10 hrs straight yesterday. I don't know what I'm going to do when I have to render it out.. I can't use GPU without the Nivida Cuda drivers.

This is on Apple.. They put a graphics card inside these imacs that are faulty. I can't belive they haven't recalled the machines for this issue.

First of all imac isn't meant to be used under severe usage like hours of rendering. Ventilation isn't enough for that usage. Despite that, it worked 3 years. It's not bad at all for low profile slim computer.

Hello,

I have come across this problem in the last 2 weeks now. I am a freelance Editor/Asst. Editor working on a:

27" Late 2012

Yosemite 10.10.5

3.2 GHz Intel Core i5

8 GB 1600 MHz DDR3

NVIDIA GeForce GTX 675MX 1024 MB

I purchased this in June 2013 and have had no issues up until this month. I am guessing I should have purchased the extra apple care service? Or is there is a solution as to why my computer crashes every hour or so? I originally thought it was Adobe Premiere with their new updates but after reinstalling that, verify/repairing permissions with no problems, doing the opt + cmd + P + R at boot thing, and now have been trying to Time Machine back up but my machine won't even stay on long enough without crashing for it to complete a back up. At this point there are only a few programs I would need to somehow get back but want to see what I should do before reformatting.

I keep reading about similar issues regarding the power supply, the graphics card, or the logic board but is there a way to tell without spending a lot of money? What are some more steps I can do to fix/test/figure out this issue? I need this for work and is quite embarrassing to have it crashing while having a group edit session. Please let me know if more information is needed.

Add me to the list too.

27" late 2012 iMac

Yosemite 10.10.4

3.4 GHz Intel Core i7

32 GB 1600 MHz DDR3

NVIDIA GeForce GTX 680MX 2048 MB

Just had the fusion drive replaced last week under the HD replacement program - Started shutting down again this morning. This most often happens when using Adobe Premiere but can happen at other times too.

Clearly something is failing or not operating properly - probably graphics or power related. I have CUDA running and I'm using the latest Nvidia Web drivers but none of these things have helped.

Apple, I am a poor professional who spent every penny on this computer 2 1/2 years ago hoping it would last for 5. This is not good enough. Please may we have an official response on this issue which is clearly not isolated judging by quantity of posts on this issue.