27-inch / 27" iMac Random Shut down

Hi cvdave,

how's your iMac doing now? I have the same problem for some time now. I bought 4x8GB Samsung RAM to replace the original 2x4GB from Hynix, but no difference 😟

Unfortunately I had the same professional apple Support every body is getting... And I can't send it in again since I need the computer for work.

Hey guys,

My iMac shut down randomly was temporary solvedsince Jul 2015.
The past six months are at peace with using it, perhaps it might because of the ram cleaning software.

But it shut down without warning was happened again last nightunfortunately.

Every things seem didn't help, it drive me crazy and depressed extremely...😕😢😟😠😟

What can I do??????????????????????????????????????????????

Crazy that it's still going! Thanks for the update Berry with an A

same problem, random shut down despite the "pulling out the plug for fifteen seconds" solution done 3x.

PROCESSOR 065-C2LC 3.5GHz QC i5 Turboboost 3.9GHz

MEMORY 065-C2LT 16GB 1600MHz DDR3 SDRAM-2x8GB

HARD DRIVE 065-C2M0 3TB Fusion Dr (3TB+128GBFlash)

GRAPHIC 065-C2LH AMD Radeon R9 M290X 2GB GDDR5

I am bringing it in to the Apple Center if this shuts down again. I added the steps of taking out all USB connections and the power cord totally now after reading Resetting the System Management Controller (SMC) on your Mac - Apple Support and If your Mac won't turn on - Apple Support. I have even played around the extension cord and power slots where my other 2009 iMac and Time Capsule is plugged into and they are experiencing zero problems unlike this 2015 iMac.

There seems to be many threads on the same topic here in Apple and MacRumors. They should really be fixing this issue once and for all!

It took me almost FOUR MONTHS of hassling with Apple Store and Apple Care to get this resolved....

FINALLY I think they got tired of my complaining every day ( I was senting 3 or 4 emails PER DAY about this),

They ultimately replace both the power supply and the logic board, and other that reboots that I have initiated myself.... it has now been running 24x7 for a few months now.

But be persistent. DO NOT LET THEM TELL YOU THIS IS A RARE OCCURANCE (heck this topic itself proves that it is notO

I have the same machine as you have Late 2012 27'' iMac. And I am experiencing exactly the same thing. I was eligible for a 3TB hard disk replacement so I thought it is because of the hard disk. Maybe it was because before I got the hard disk replaced it made an infamous "click" sound and iMac shut itself down instantly. Now it just shuts itself down and won't turn on if I won't unplug the cord and wait for like 10 mins. (2-3 mins waiting does not work). Interestingly even when the computer was properly shut, it sometimes won't turn on the next time unless I pull the plug and wait.

Apple told me the same thing on the phone. To reinstall the software. But before they made me try to set up a new user. It interetingly ran fine for 2 days with this test account. I'll try to reinstall OSX and see if it'll help

I AM SO DONE WITH THIS. It has been a week since we received the i5 iMac and it keep shutting down in the middle of editing, uploading. Can't work at all. I am taking it in on Sunday.

Add me to the list of the Late 2012 27" imac random shutdowns. My problems with this imac started about a year after purchase. I had one of apples nature desktop images on my screen for the first year. One day I turned that image to a solid gray background, much to my horror there were fingerprint like cloudy dark spots coming out of the lower left corner of the display, and some on the right corner. I had an applecare plan and knew they would rectify the problem but I wasn't in a hurry to bring it in because as a graphic designer this machine is my livelihood. Over the next month or so it kept getting worse so I made the appointment and they replaced my display... in 9 hours! (Praise be to Apple!).

6-8 months later the stains came back, in different designs and configurations, but they were back and steadily got worse.... then one night while I was working in photoshop... POOF! black screen, no power, machine dead. Could not reboot, no power, nothing. I unplugged the machine and all of the peripherals waited 20 minutes plugged it back in and everything was back to normal (except the stained display). The next day same thing, unplugged for an hour and I was back in business, for about 40 minutes, then 10 minutes, then it was appointment time again and back to apple the imac went.

They had the machine for days (wherein i lose money for days) and they tested it top to bottom and stated they found no problems with the machine. So they replaced the power supply and put yet another display in the machine (this is now the 3rd display in it's 2.5 year existence). So I'm disgruntled but happy to be up and running again and thanking my lucky stars I had the applecare plan. (on a brief sidenote here, I have been an apple guy for 25 years, I've had a powermac 6100, a quadra tower, A beige G3, The first imac 15" flat panel, Powermac g4 MDD, a Powermac G5, a G5 Intel, and lastly this i7 27" imac, and I NEVER had an applecare plan, and NEVER had the issues I am having now.)

Apple replaced the power supply and display 2 months before my applecare plan was ready to expire, I expressed my concern about this happening again and they assured me since it was a running issue they would honor a repair if it happens again. Well here I am 2 months after the applecare has expired, the 3rd monitor is staining in the exact same spots, and in the last 48 hours the machine has shutdown 5 times requiring it to be unplugged for 20 minutes or so to get it to boot back up. Called applecare and since there is a running record of this issue they will repair it at no charge to me.... but what will the solution be? Probably a new logic board, but from reading about everyone with the same issue the logic board replacement doesn't fix the issue, and it now needs a 4th display. There's something rotten in Denmark... or Cupertino California.

I have the same shutdown issue--how can we get the attention of Apple or the class action lawyer vultures?

Frank I just got mine back from apple yesterday, they had it for 5 days. They replaced the display (this is the 4th one), the power supply (this is the 3rd one), the logic board, and the computer housing..... the only thing they didn't replace was the hard drive and the ram. Let's see how long it lasts this time, they felt pretty confident it would fix the issue this time, I'm thankful they did the work under applecare but I'm skeptical that it took care of the issue.

I have the same problem:

iMac (27-inch, Late 2012)

3,4 GHz Intel Core i7

8 GB DDR3 a 1600 MHz

Fusion drive 1T + 128ssd

NVIDIA GeForce GTX 675MX 1024 MB

Sudden random shutdown

I have tu unplug it for 30 seconds, allowing to discharge the capacitor of power supply

and only in this mode i can turn it on.

I read that Apple haven't a solution

to change logico board, hard disk, power supply and others don't solve the matter.

near 4000$ in the WC....

This is my 3th Apple PC that has BIG problem

Macbook pro 17 (mainboard)

iMAC 2010 (graphic card)

iMAC 2012 (????)

My next PC will be windows based!!!!!

Hello everyone,

Same as everybody, my iMac 27 late 2012 has started random shutoffs a week ago. My LCD was replaced last year and my PSU was replaced in february 2016. Seem that this piece of **** of a computer (golden **** should I say, because the price) can no longer be usefull. The only thing that could be usefull would be throwing it in the bin, build a windows PC tower, and NEVER, NEVER buy an Apple computer anymore.

so we can resume that replacing:

LCD,

HD,

Power supply,

Logic Board

Graphic card

RAM

don't solve the problem?

What remains? CPU?

Was To somewone replaced CPU?

If they don't change the processor with the logic board then there is that and the wiring itself may the only other culprit.

My extensive tests showed that in my situation (late 2012 27'' i7, 680MX) it only happens while the machine is doing something. I created a new user on OSX went for a vacation for 4 days and it was still on when I got back. But on the usual user which I use since I got the machine or on the Windows partition it dies on me.

My honest opinion is though, it is Power Supply's fault. Because anyone who got it changed gets some mileage before it breaks again (if it breaks) I think even some of the newer replacement power supplies they put in may be faulty. Now I live in Turkey and I'll take the machine back and specifically ask for a power supply change. I'll report back when I get it swapped with a new one