iMac (Retina 5K, 27-inch, Late 2015) Randomly Restarts Without Errors

Hi everyone,

I'm so relieved to have found this thread - I have the exact same situation happening with my 5K Retina 27 inch iMac (bought new December 2015) - The freezes started about a month ago, first when using Spotify, and now it seems just randomly (twice this week while editing on Final Cut Pro X). The screen freezes, the mouse cursor won't move, and eventually the whole system restarts without incident. It happens anywhere between once every 15 minutes to once every 6 hours, but it always happens.

Anyone able to figure out what's happened? I updated my OS, and still getting issues.

Yes, same think was happening to mine. It has now been on for 7 days straight without restarting. It too restarted with random Apps running, while it was Sleeping and whenever it felt like it.

I updated to 10.11.5 but I also had removed the Apple factory memory before the update. The Apple Engineers after reading the log said it was a RAM issue. So with the RAM I purchased online the restarting issue seems to be cured... I once went 4 days without restarting but I wasn't using the machine much during that time. But usually it would restart at least twice a day and always at night when it was in Sleep Mode.

My hunch is that something in the Factory RAM does not sit well with any update after 10.11.3 - my machine ran perfectly before the update.

If you want to try swapping out your RAM here is what I ordered on Amazon -

Adamanta 16GB (2x8GB) Apple Memory Upgrade for Late 2015 iMac 27" DDR3 1867Mhz PC3-14900 SODIMM 2Rx8 CL13 1.35v RAM

If it starts restarting again I will update you but so far with 10.11.5 and the above RAM it is running fine. And I am doing a lot on the computer including running Parallels.

After 7 days it just restarted. Log says AirplayerXPChelper about 100 times before restart. Very strange how it worked so long without restarting.

Just another "Me Too" here.

Bought the bugger about a month ago, rebooted same day I set it up, and kept doing this every day. I initially suspected Fusion being the culprit, but even after uninstalling Fusion and removeing every trace of it, the machine would still do the same. Turned my eyes to the many "what to do when mac freezes"-guides on the net, reinstalled OS X twice and finally downloaded memtest86 - both the current version and the 7.0 beta. Created USB sticks with these, and they both found a large amount of errors on the factory installed memory.

Looong story short; contacted the dealership, asked if they could replace the computer, but due to the strict Apple DOA rules they could not. Sent my machine in for service and have been without since.

Today I stumble across this info after my MBP13 retina has started showing the same symptoms. This is seriously the worst bug I've experienced with Apple computers since I started using them professionally about 15 years ago. I really hope they get their act together and sort this quicker than quick. 🙂

-KJ

I've used 3 different RAM modules in my machine to no avail. The Supervisor says we can probably rule out any RAM issue. Sent the engineers a second set of logs 5 days ago. Still no word on a possible solution. Apple is also trying to push this problem under the table by not entering it in their "known problem" internal log. I had the supervisor check and he says no one has reported this issue to Apple - when I know from this thread and others that many have.

I am beginning to think they just don't know what is causing the issue. This is all new territory for Apple. More like a common unreliable PC issue so maybe they should get on the horn with HP or Microsoft 😉.

Never owned an Apple since 1990 - owned only PC's. I should have known it was a fatal moment when the sales person said Apple never has a crash issue and they are so reliable that it is part of their reputation. Darn...

Sorry to hear about your troubles guys.

I've not had a solution yet, did the same contacted about a replacement and was denied ( which i doubt would of solved the issue ) so Imac is at a service center , dropped it off on Monday and haven't heard a thing since.

I can see this being drawn out , granted they might repair it but if they are gonna replace this bit and that bit to sort it , at the end of the day we are gonna end up with refurbished I mac's... I didn't pay for a refurbished Imac so I don't think I'm gonna be happy accepting one that's been messed about with and rebooted who knows how many times.... anyone feel the same?

Will post an update when I hear back from them....

Upon taking it in they had no interest in even looking at this post...?

I took my iMac to the Apple Store in Greensboro NC and dropped it off yesterday. The genius ran the usual hardware tests and everything checked out. No one at the store would admit to there being a problem. I had to leave the iMac so they could see if they could duplicate the error. So now I have spent over $3000 on a computer I cannot use and no one will admit there is anything wrong with it. *****.

For some reason the two Supervisors I am working with have not suggested I take the computer in yet. I asked them both in two separate conversations and both said not to yet. My guess is that they don't yet know what is wrong. Some other thread mentioned it is the OS in conflict with the hardware which would be hard to fix unless they can isolate the software glitch. And once updated to 10.11.4 it cannot be reversed by restoring it to 10.11.3. I think as this thread grows, and grows big enough Apple will put more resources into this problem. And the thread is growing. My machine is unusable for what I purchased it for - the random restarts is something that renders it into $2000 prop. It looks great sitting on my desk...

(repeating my post in this other thread: Retina iMac Freezing and Restarting)

Just chiming in with my similar woes. Purchased my new iMac (Retina 5K, 27-inch, Late 2015, 4 GHz Intel Core i7) in February and noticed immediately that it was sluggish and glitchy compared to my older late 2012 27-inch iMac:


1. Random and erratic behaviour from the start
2. Spinning Beach Ball Of Doom doing the most menial tasks
3. Bluetooth keyboard disconnects for seconds at a time, numerous times an hour - so frustrating writing emails
4. All progs & system eventually grind to a halt
5. Audio randomly glitchy and then grinds to a static-y halt - half the time I thought it was the music I was listening to
6. Screen refresh very buggy on occasions - major pixilation, artefacts, weird sections of the screen flickering
7. Black screen at startup - I'd be waiting for it to display and realise that the computer is somehow on, with no chime, but the display is black - no way to get in other than force reboot
8. Error messages regarding iTunes Store nearly always
9. Mail giving me disconnected accounts messages, randomly offline
10. Unable to have many Tabs open in Chrome, etc, etc, etc

To name just a few. I brought it back to the store after 3-4 weeks and they graciously gave me a new computer.

Most of the problems still exist but do seem a little infrequent.

The iTunes error messages have stopped, though I occasionally get iCloud error messages. My computer just randomly rebooted straight into the User Login Screen (like, the screen just went blank for a second and I thought it was a powercut, but a second later I was presented with the unfamiliar User login Screen - normally it just boots straight into my account) just a few minutes ago (hence this search for similar stories) and it is beginning to seriously **** me off that my old machine (which my wife now claims) is so much more stable and 'usable' than this state-of-the-art glitch-fest.

Have moved from Sydney to the country so no way can I just 'drop-in' and get it checked. There is obviously some flaw in the design of these retina macs and simply replacing them doesn't solve the issue. There is no way I would recommend the retina iMacs to anyone who needs to get work done on their computer. Too much work has been lost and time wasted trying to 'fix' things.

My old mac looks like a dream machine but my missus is guarding it like it's our baby!

Anyway, just my 2 cents. I needed to rant after that horror reboot

SAME PROBLEM!!!

Mouse freezes, restarts in about 30 seconds, boots back up with chime, volume is turned all the way up for some reason, also gives me the option to log into mac as guest which is weird too.

Happens no matter what I'm doing, chrome, safari, photoshop, illustrator, youtube, Facebook, craigslist, you name it.

Never happened until the El captain 11.10.4 update!

I lugged this POS to apple store, and they said nothing was wrong with it, kept it for a few days, said they fixed it...

Took it home and in less than 30 minutes, BOOM, restart...

Unacceptable. Horrible bullsh*t and even more frustrating is how they say nothing is wrong with it.

I need this iMac for work, and it can't even function without restarting!

Apple better take care of this problem, **** sure I didn't spent 2k for a piece of **** computer that restarts every other hour or so.

Ive got exactly the same problem as everybody else on here. Bought a 27" iMac late 2015 model brand new 2 weeks ago. System shipped with 8 GB of RAM but I upgraded it with an additional 8 GB Crucial RAM - upgrade was done by Apple store. I initially thought that the the freezing and reboots was due to additional RAM but I have ruled that out now. Upgraded 10.11.5 and that made absolutely no difference whatsoever.

There is nothing in the any log file/console that seems to indicate the root cause of the behaviour.

I have also done things such as disabling putting computer to sleep which initially seemed to improve the interval between reboots quite a lot.

Really at a loss but from what I can gather on this and other threads this does seem to be a post 10.11.4 issue.

I got mine back from service today, and they had downgraded it to 10.11.3 for me. In a few days I will know if this helped.

-KJ

Ok please do let us know if the downgrade to 10.11.3 solves your issues. I understood that a downgrade is not possible?

A direct downgrade is not possible. They had to repartition the harddrive and reinstall the whole system from scratch using terminal commands to repartition the hard drive.

For me the choice was pretty simple; daily restarts without warning versus reinstalling the whole system.I will report later today or tomorrow if this sorted things.

-KJ

I just got off the phone with Apple and I stated that after 50 plus random restarts I believe no matter what they do the machine is compromised. I asked for a refund of my $2,000 but they said they will do everything to "fix" the issue. Apple does not refund. The problem is if the issue does get fixed my machine has suffered and I fear long term damage - which means a short life span. They said they would swap out any parts in that case - I said I didn't pay $2,000 for a refurbished machine - If I wanted a refurbished machine I would have purchased one at less cost.

There have been over 1000 views on this thread so I hope more of you post your issue. Just log in with your Apple ID and post here. Apparently they don't give a d@mn at Apple. This version of the iMac is a lemon. I am filing a claim with the Department of Consumer Affairs to get on their *****.