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

• Case Number **** from July 26 (reset SMC & PRAM)
• Case Number **** from July 29 (Genius Bar Appt - no hardware problems were found and issue did not replicate itself)
• Issue did not reappear for a few weeks.
• Case Number **** from August 19th - Talked with Senior Steve N. - reinstalled OSX (without a full disk erase). Emailed him back on August 20th to say the problem was not resolved, no answer. Emailed again on August 27th, no answer. Left voicemail on August 27th no call back.
• Case Number **** from August 30th - Talked to senior Pete H. Removed all apps that were automatically loading at startup.
• Case Number **** from August 30 - Talked to senior Jonathan B. Reinstalled OSX (twice) after a complete disk erase. Set up as a new computer with no transfer of old files. Got stuck in "setting up mac" both times.
• Case Number **** from August 31 - Talked to senior Brandon D. who told me to hard restart without reinstalling. System booted up fully. Still experienced a random shutdown within 15 minutes of working in Safari and Photos. Brandon told me that it has to be a hardware issue and to make another appointment at the genius bar. Case number ****: September 2 - Genius Bar Appointment. Replaced PowerSupply. Ready for pick up on September 7th.
• Issue did not reappear for 4 months. Now starting on January 9 (exactly 4 months after power supply was replaced) it has happened 3 times in the last week. Genius bar repair set for January 16th. Will Update after I see what they say.

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Thanks Anne for your summary. I read that you had only the power supply changed, and once.

I also read that you spent a long time before going toward the hardware track, hence even more frustration.

As per this change fixed the computer for 4 months, and given this is the only thing that was replaced, it really seems to point to this component being the culprit.

Good luck with the Genius bar meeting, I'll have to do the same on my side (convincing my dad first it worth trying).

On a separate note, I can not help noticing the irony that the host of this discussion keeps editing some of the posts (legitimate reasons I am sure) but on the other side, Apple have not yet put any comment on the forum nor seems to acknowledge the existence of this issue, still, one of them is reading ;-)

1] My case number goes back to March 2015: *** *** *** Same late 2012/2013 27" Core i7 iMac. Three times to Genius Bar for ineffective repairs, now on my third AppleCare Senior Adviser. Brought it back for the fourth time to Apple Store in Short Hills NJ, this time with a print of all fifteen pages of this thread.

2] The AppleCare Warranty issued in 2013 reads, in part, as follows: 3. What is Covered? 3.1 Hardware Service. If during the Coverage Period, you submit a valid claim by notifying Apple that (i ) a defect in materials and workmanship has arisen in the Covered Equipment, or (ii ) the capacity of a covered iPod battery etc. . . , Apple will either (a) repair the defect at no charge, using new or refurbished parts that are equivalent to new in performance and reliability, or (b) exchange the Covered Equipment with a replacement product that is new or equivalent to new, in performance and reliability, and is a least functionally equivalent to the original product. . . "

3] If Apple, in the case of these defective 27" iMacs, replaces the power unit with another unit which subsequently fails, as seems to be the case with many of the contributors to this thread, has Apple honored its Warranty? i.e. it has replaced one defective part with another similarly defective part.

4] Is there a limit to the number of trips to the Genius Bar and the same recitation of ineffective solutions: remove programs, reformat disk, remove plug ins etc?

5] At what point will it be concluded that the defect has not been repaired, and the exchange of the Covered Equipment be honored? To what extent, if any, can the Warranty be extended if a "repair" was executed within the Warranty period, yet after an lapse of three months, for example, the defect reappears? Does the Consumer have any right to Warranty repair if the repair is ineffective?

6] Based upon a review of all these threads, one may realistically conclude that there is no repair which meets Apple's criteria of "using new or refurbished parts that are the equivalent to new in performance and reliability".

7] To reiterate an earlier suggestion of mine: you can always use the machine in Safe Boot. You will lose audio and flash, but the computer will still operate.

8] As for dealing with the AppleCare Senior Advisers, while some may fail expectations, others do try to be helpful under what must be very stressful conditions. I certainly would not last 30 minutes dealing with any Customer over the telephone. Their performance is constantly scrutinized by their own Senior Staff. It must be nerve-racking. As Customers we should be meticulous in keeping records of contact with Apple Support, as well as be aware that just because we may have had a bad day, we should not unload on the Advisers. I am guilty of this as much as anyone, and my apologies to Messers. C. and K.

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I have been having the same issue and spent almost a year with Apple trying to get the issue resolved. Eventually they replaced my unit with a new 2015 iMac. The Apple store was never able to replicate the problem, but the genius at the store did go through the system logs and find the sleep failure and shutdown codes and then spent about 30 minutes on the phone with a senior advisor to get approval for a replacement unit.

I really wish I knew what was going on with this. It's one of the few computer issues I've not been able to solve on my own.

Hi all,

I am still waiting feedback from Genius Bar. They called me three days ago and they were not able to replicate the crash, I gave them some guidelines to try to mimic the problem, still waiting since then.

According with the term and condition of this forum I cannot perform polls or petitions, so I have rewriten my post deleted some hours ago.

I am very interested in:

to Robert Van Dogen: can you share your experience after receiving the first repair with only the new motherboard?

to Robert Van Dogen: is the part number of the new power unit different to the original one?

to sjkmd: can you share your experience using safe mode?

I have not seen in this forum anything about only graphic cards replacement or upgraded with the original motherboard to solve the problem.

finally, muting hyper threading or turbo boost is something to investigate as they are related to power consumption, and the graphic card will remain operative.

Kind regards,

HI all,

Feedback from Apple, they are not able to replicate the problem, solution proposed: OsX reinstallation which of course I have already done more than 5 times from clean. They will keep working to mimic the problem. But I have gathered some important information, all the Apple Store are anti static areas and works with usb keyboard. Maybe this is something to think about. Any of you have had the problem using anti static devices or usb keyboard?

kind regards,

Ok, so I've just picked up my iMac after being with Amsys - a UK based Apple repairer who had my iMac for 2 weeks. The repair report simply stated that there were intermittent shutdowns due to a faulty logic board which has been replaced and OSX El Capitan reinstalled. So here's waiting to see if the problem arises again.

I've had the iMac in for 2 hardware repair/checkups and 2 AppleCare Warranty sessions on software related issues in an attempt to eradicate the problem.

I'm hoping it won't return fingers crossed) :-)

This is an update from my original post on this thread dated 1-8-16 at 10:48pm concerning my 27" late 2012 model imac. As a result of the latest issue, all major components within the iMac are replaced.

1-10-16

11:20am: a portable G-Drive (portable hard drive) was attached directly to the rear USB port in an attempt to perform a time machine backup. 15 minutes into the back-up, the iMac crashed.

12:45pm the G-drive was disconnected from the USB port and iMac manually powered on. Log in successful. At this time a time machine back-up was again attempted. One thing that was noted is that it took at least 10 minutes for the "preparing backup" step to complete and another 10 minutes for "calculating time remaining" to transition into the back-up actually performing. A back-up had been completed a month prior to this attempt that was much shorter in duration. No significant usage changes had been made to the iMac in the past 30 days.

1:09pm the imac crashes with "6 hours remaining" on the back-up when in previous times the backup had been performed in 10 minutes or less.

1-11-16 the area MacMan store is again contacted and the iMac brought in for observation. Hard drive tested as being in a "failing state".

1-14-16 while at the store under observation of an Apple certified-technician, the shut-down problem is replicated. At this point it is thought that the power supply is the most likely issue with the logic board also considered as a problem.

1-14-16 The following parts are replaced: main logic board (with graphics card), main power supply, and 1TB hard drive

1-19-16 The iMac service is completed and the iMac brought home. At 2:05pm the iMac with the restored parts is booted up and in good working condition. At this point a close observation will be followed and this thread updated every 2-3 weeks with updates on performance.

One omission on the last post: The power cord was also replaced

Important: everyone who experiences shutdown issues like the ones posted in this thread should contact Apple to report the problem, even if you don't have Apple Care and they can't help finance the repairs. Their main number is 1-800-275-2273. By calling, you can have your iMac's serial number registered as having the problem. Apple can then better verify the number of people experiencing the problem with this late 2012 model.

I'm following along with this thread because I'm experiencing the same exact issue as everyone here, and I just noticed at the top of the thread, it says "Branched to a new discussion."

When I click the link, it says I'm unauthorized to access the content. What is this link about? Is there a new thread we should be following/posting on instead?

Alright, took a few hours reading this thread from the top really hoping a solution would be somewhere.

27" 2012 (thin) iMac, purchased January 2013

Nvidia 680MX 2GB Cache

I've had the instant shutdown problem for about 6 months, I've contacted Apple Support but only to have them reference me to a store for inspection. Unfortunately for me I do not have the time to travel hours to a certified repair location only to have them discover the same issues you all have found ( or more like to have them discover nothing).

I can only speculate that unplugging our machines extending their run time is the number one clue into their problems. Wether or not the problem is directly a result of the power supply or not can not be determined as the shutdown looks to occur mostly during high graphical load. That is to say, perhaps a faulty power supply sends improper power (or just faulty electricity to be general in physics terms) to the graphics chip. Resulting in an SMC "lifesaver" shutdown to prevent damage that may or may not occur otherwise.

I've run through so many situations in my head, brainstorming a fix.

I read the earliest posts about this issue 6 months ago and thought perhaps my RAM was to blame, I had installed an additional 8 GB that came OEM in my dad's iMac, he upgraded to 32 GB when he bought his machine. Interestingly the brand of my RAM and his RAM are not the same, however the specifications are. I have no way of knowing which set truly belong to my computer anymore but I have run them separately, both resulting in sudden switch offs. The two brands are;

"ELPIDA": made in Taiwan, 4GB 2Rx8 PC3 12800S - 11 - 10 - F3, EBJ41UF8BDU5-GN F 1251GK052093 (I don't think these are serial numbers, they are the same for each stick of the same brand.)

"hynix": made in China, 4GB 2Rx8 PC3 12800S - 11 - 11 - F3, HMT351S6CFR8C-PB NA AA 1240

The only notable difference is in the SPD revisions (the number after the 11) but 10 and 11 seem to run at the same latency and with the same "math" (not an expert here). The RAM "Chips" are not identical across the two brands, that is, they are not rebranded, they are different upon visual inspection of specific molding designs and serial/product numbering. Again though, I've had crashes while running both and one or the other sets.

This is a good time to point out that my dad's computer has not had this problem, though my iMac has likely seen a 4,5,6 or so thousand more hours of use and his model is the base version purchased in spring time, 2013.

The crash occurs or has occurred in Mountain Lion, Yosemite, El Caption, Windows 7, and Windows 10 (Bootcamp)

I thought running my computer from a non-grounded outlet (old house) could be causing problematic surges so I plugged the computer into a grounded outlet (I know it's grounded, I installed it), no fix. (Additionally this has occurred in two houses from different "grids".)

I've done everything possible save removing the screen to get a look inside the machine and clean it, no avail and not hardly any dust either.

I'm definitely preaching to the choir when I say no computer should ever behave this way, even an old computer should have mechanical failures long before issues like these come up, and much later in life too, nothing close to 2-2.5 years. This error is most definitely recall worthy, I'd just like to hear from Apple that "Yes, we are aware of a possibly power related issue impacting owners of our late 2012 iMac and are studying defective models to learn the exact cause of the problem. Apple will work to rectify all models effected by means of component or model replacement and issue refunds for services previously aimed to fix the issue." Ahh, wouldn't that be nice.

I'm at the end of the thread from the end of the rope, if I can't get this fixed within the next few months, I'll likely never buy an Apple computer again.

Edit: Perhaps I shouldn't sound too grim, I've learned a lot from this thread and will be putting to use many of the techniques from contributors.

Same problem here, but I have a little bit more info that might help diagnose this issue.

I've read this whole thread for hours, so I'll try not to expand too much on my own nightmare story with unsuccessful Apple customer service since it's very similar to everyone.

My computer:

-iMac (27-inch) late 2012

-Intel Core i7-3770 CPU @ 3.40GHz

-16gb RAM

-Nvidia GTX 680mx

Had crashes for 6 months too.

My Apple Care is ending soon but it should be fine since I've reported the problem before the end of warranty.

Computer had excellent results both times when tested at the Genius Bar in the past 4 months.

Didn't had any parts replaced.

My iMac is almost only used for Bootcamp on Windows, so that is where I've seen the problem the most. (both on Win7 and Win10)

On Windows, after a crash if I go into the Event Viewer > Windows Logs > System Logs and search around the time of shutdown I can find a Critical Error from Kernel-Power, ID 41 saying "The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly."

I want to add that my computer mostly crashes when I'm playing video games or working on 3D graphic tools like Unreal Engine and Blender. I've been using those applications for years and they're essential for my job as a 3D artist.

Since my problem only happened on Windows so far, Apple blamed Windows....

So I made tests on OS Yosemite. Note that I had nothing but default applications on there since they formatted my pc when I went to the genius bar the second time. (immediately installed Win7 on it and still had the crashes so I tried Win10 and it didn't fix anything)

I installed Steam on Mac, and also installed whatever Mac compatible games I had there: Witcher 2 and Metro: Last Light.

As you can guess it crashed.

Called Apple again saying it crashes on their OS too. Apple blamed the applications.....

So I looked deeper into the issue found a similar Kernel error on Yosemite I had on Windows 10.

Here is the interesting part:

I found an error pretty much saying the application I was using was about to burn the CPU and the computer had to shutdown to prevent a nuclear explosion.

Seriously, here is the error:

"kernel: process MetroLL [366] thread 3771 caught burning CPU!; EXC_RESOURCE suppressed due to audio playback."

So I invite everyone having the issue to open the Console and search at the time of the crash if you have a similar error.

Gotta say I've lost confidence in Apple, I've been using iMac since the G3 model at the beginning of the millennium, but now I just can't accept I paid $2500 for a computer that dies after 3 years while the 2006 model lasted 7 years. On top of that, Apple just throwing the blame at other companies, or even worse blaming me because I use the computer to intensively or install "non-apple" applications on it.

So now either Apple fix this problem, or they replace my computer with a new model so I can sell it and buy myself a real PC actually worth the money.

-sigh-

Feel free to ask me any precision or more info, I got a lot more details to share if needed.

I really wish all of us to get rid of this very frustrating issue. :/

Same problem here!

iMac 27 late 2012

3.4 GHz i7

32 GB 1600 DDR3

NVIDIA GeForce GTX 680MX 2048 MB

The random shutdowns have been happening since Jan '15.

Took it to the Apple Store two times - in May 2015 & in July 2015. They were not able to "replicate" the issue, in spite of me leaving the computer for two weeks the Second time I took it to the store. After doing extensive tests they did not come up with any issues at all with the computer. They suggested replacing the logic board and power supply but did not guarantee to fix my problem! And now the issue is aggravating. My system keeps shutting down more frequently - almost every hour or so.......!!!

Reading through this discussion, it's very clear that thIs is a bad batch of iMac's! Waited for over 2 months to receive it when they came out in 2012.

Hope Apple lives up to the reputation and solve this situation.

Have the exact sam problem with my late 2012 iMac. Randomly dies, but i think it has to do with the heating. Its like every time i do something heavy like word with highres pictures i PS or something similar it dies.

Hi everybody,

I have the same problem everybody has here, same iMac 27 late 2012 shipped in February 2013. Out of the blue it started to shut down randomly about 20 days ago.

Here is what I've tried:

change the cord

change the outlet/plug

put fan at max speed

hardware test with apple tool

read the crash log

Every time it shuts down I need to unplug for about 1 minute otherwise it wont startup again.

Interestingly I've noticed that turning on "startup after automatically after power failure" make the iMac startup automatically after I unplug it for 1 minute hence the problem would be a power failure, but what's the part involved?

I really hope Apple takes some action on this shameful problem and fix it for free, it's ridiculous that a 2400 euros machine it's already broken after less than 3 years.