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

Very good suggestion. There was an issue with an early IBook which was addressed by the consumer rights associaton in Denmark some years ago. It related to a soldering manufacture error on the power control chip. I believe a successful case was brought against Apple in Denmark which resulted in units being replaced. It remained a massive problem for owners of that particular model outside Denmark however.

http://www.macworld.com/article/1057719/denmark.html

Also adding my computer to this list.

Incredibly frustrating but glad to know I'm not the only one with this problem.

OSX El Capitan 10.11

late 2012 imac 27''

2.9ghz i5

24gb Ram

1TB Fusion Drive

NVIDIA GeForce GTX 660M 512MB

Problem started occuring several months ago. Have to unplug the computer for 30+ seconds until I can power it back on. I took it to the Apple store back in July but they couldn't replicate the problem. I've been so busy that I haven't had the chance to revisit the store, but after reading this thread, it seems pointless to try to replace the power supply / logic board.

I had a suspicion it might be graphics related because mine seems to crash whenever I'm watching a video on YouTube or flash... It crashes a lot whenever I'm using a web browser (Safari / Chrome) but generally seems tied to videos. For example, even being on Facebook crashes my computer frequently but being on a forum with no videos doesn't seem to have the same issue (although I can't really verify this).

I upgraded from Mountain Lion to El Capitan but it was a fruitless effort.

Has anyone tried replacing their GFX card?

I have been scanning through these posts on the nine pages of listing thus far and my heart just sank. I have had my late 2012 iMac in to the Apple Store Genius Bar five times since August 27 with exactly the same problem as indicated in most of these posts. I have worked with Apple chat staff, and a couple of engineers in the Apple support community who have helped me engage in some very in-depth problem-solving to try to come to a resolution. I have not even gone to the point of replacing the power supply and logic board, or graphics card. After reading all these posts I am not going even to attempt to do that. It seems apparent to me that there is a serious unit problem/flaw and it also seems clear that there should be a recall with all of the people affected by this problem. If that does not happen, then it seems a class-action suit might be in order for reparations. I spent over $2800 on my late 2012 iMac back in July 2013 which ran fine up until August of this year. Now it has been an unending nightmare with no resolution in sight and the prospect of having to just eat the cost I paid two years ago and go on to a different computer. I'm very frustrated and disappointed about this given that I have had Macs that have worked flawlessly for over 10 years until this. I'm even considering going to a PC model as a result of this. Thanks to all of you for your posts which have helped to confirm both the severity and pervasiveness of this problem.

Yours worked ok from July 2013 to August 2015. Mine from December 2012 to January 2015.

How long until it started to fail for the rest of you? The 2 year period is a common thread?

Earlier today, I posted at the end of this thread about my current issue with random shutdowns on my 27 inch late 2012 iMac. I spent $2800 to purchase my unit in July 2013. It worked fine until August of this year when it begin to shut down for no apparent reason. I have had it into the Apple store Genius Bar five times within the last three months and they have not been able to identify or fix the problem. First they thought it was a defective fusion drive and replaced that for free, then they looked at software and then they looked at extensive hardware stress testing the next three times and ended up with no indication of what the problem was. I have bought a new UPS surge protector battery backup system, put the computer on a different outlet in a different part of the house, run antivirus screens and malware screens, reinstalled the operating system, deleted third-party software that would compete with the Mac fan control, spoke with Apple chat technicians, had communications with Apple support community engineers and with all this no solution to the problem. Since you're the first one to start this post, I'm wondering if you have since found a permanent solution or if we are truly looking at a deep defect within this model that should require a recall from Apple. It appears to me as though there are a large number of people that have had the exact same problem and are still struggling to find the answer. Thank you for your post.

I've been heavily using the iMac since late 2013. The shutdowns surfaced only a couple of months ago.

Bought mine very end of 2012. I got about 2 1/2 years out of mine before the shutdowns started this July.

I sent an email to Tim Cook today detailing this problem and the trouble we have all had trying to get it resolved. I read that he sometimes reads emails from customers. I thought it was worth a shot.

<Edited by host>

I learned a few more things about this issue that some might want to know.

Looking through this thread, there are quite a few different hardware problems listed. They include logic board and graphic board failures, power supply problems, and a few things that aren't even related to the subject. But the underlying problem with the plurality of users is that some unknown hardware fault that is causing random shutdowns and/or screen anomalies.

There's no "silver bullet" yet, though some have had success with a BGA re-ball - a specialized and pricey procedure. It's not a DIY fix.

The most recent solution for some has been to simply swap out the RAM. Mac RAM can be notoriously finicky. If the computer problem started happening after an update - even if it's from a solid vendor - perfectly functional RAM may have become unstable for some reason. You don't notice this issue much with Apple RAM, but third-party RAM is another issue. (This "fix" isn't relevant if your RAM is soldered in.) If you have old RAM that worked before, you might want to test it out - and post your results here.

After sending in an activity report Apple informed me the problem was isolated to either the RAM or the video card. The RAM is third party (four 8 gig units by Crucial) and I no longer have the original so I'm testing each unit individually to see if I can replicate the issues. Will post the results over the course of the week.

Thank you for testing this out Red, my RAM and video card are original equip so it will be interesting to see if this brings a full resolution. Like the Apple tech said to me at the Genius Bar on my second trip there: "It would be nice to get a win on this issue."

Ok guys,

so I'm now about to join the predicament you are all having!

I have a late iMac (27inch, late 2012)

3.4Ghz i7

32GB (4x 8Gb Crucial) RAM

NVIDIA GeForce GTX 680MX 2048MB

1TB Fusion Drive

OS X El Capitan 10.11.1

Mine has just started today with about 10 shutdowns. This can be after 30mins or within a few seconds of logging into my account.

It's random and not associated with any particular piece of software running. I've unplugged all peripherals which made no difference.

I have to do a SMC reset in order to get the iMac to startup again.

I've already tried a number of solutions inc turning bluetooth off, installing CUDA 7.5.21, using a wired keyboard & mouse but no solution.

I've also ran TechTool Pro 8 from and external Thunderbolt drive and no (hardware) errors are reported.

I've unplugged the RAM and reinstalled it trying one slot at a time, but again it still shut's down.

I've also used DiskWarrior 5 and Onyx, but again no solution.

I bought the iMac in Feb 2013 and I've had no problems with it until today :-(

I suppose my next step is to contact Apple, but I'm non too hopeful after reading the previous 9 pages, but here goes!

Will update you if any solution is found.

I hope you can find the solution.

I am having the same issue as well. I hope apple really take care of this. This obviously is a firmware mistake.

I really think we need to start getting organized. Gather computer details, purchase dates, put all data together and measure how many of us are affected.

I don't know if a Google Spreadsheet is the best approach (I'm concerned about privacy).

I spent 3hrs yesterday with AppleCare staff trying to sort the problem. Their analysis being a software issue.

I reformatted the fusion drive and did an internet recovery install of Mountain Lion in the hope of it ruling out El Capitan. This went well for the next 24hrs with no shutdowns and so I then upgraded to El Capitan tonight.

I re-installed Office,Photoshop etc and all went well. Then I added 3 user accounts and it went bad after the third user account, with the all too familiar shutdown.

I deleted the third account to see if that would isolate the problem but it shutdown again after 5 mins.

I'm now typing after a SMC restart with the iMac running for 10mins now.

Back to Apple(Care) I think tomorrow. This is the weirdest issue I've ever come across :-(.