Level 1

20 points

iMac keeps shutting down randomly

Hi,

I have a late 2015, 27" iMac Retina 5K, running OS X El Capitan Version 10.11.6.

Recently I've been experiencing random, unexpected shut downs. I'm not putting the machine through anything strenuous, just listening to music, web browsing and looking at photos. It shuts off completely with no warnings. The iMac doesn't feel hot.

This has been happening a lot in the last couple of weeks. Although I've noticed the machine has been restarting alot while asleep. When I go to wake it I'm greeted with a message telling me the iMac restarted unexpectedly. To be honest it didn't occur to me that something could be wrong and I ignored it (I thought it could have restarted after updates etc) but the recent complete shut downs have me concerned. When it goes off it won't allow me to turn it back on unless the power cord has been pulled out for a while.

I left it unplugged overnight and removed both external hard drives and USBs. I have been on it most of the day and it's been behaving as normal but just shut down again completely unexpectedly.

I've owned this machine since new and have not had any issues with it unlike my previous late 2009 iMac which gave me continuous grief for 6 years. I have Applecare and spoke to someone on Wednesday about the shutdown issue. She was nice enough on the phone but didn't really help and wouldn't acknowledge the issue even though I was aware this had been happening to other owners, after I did a quick Google search on the issue. I did all the usual resets but still it keeps happening.

She suggested if the problem persisted to upgrade to the latest OS but I'm wary about doing this as I have a lot of third party applications that I'm not sure will be compatible as yet. Also I can't see it being an OS issue as the machine is 2 years old and has been running El Capitan since day 1.

I've read numerous causes from power supply's to poor fan control and overheating but the machine isn't hot, is well ventilated and hasn't been overworked.

Hopefully someone can help. I still have another year of Applecare but I've seen from other owners that unless the shutdown occurs when they are looking/testing it, they won't acknowledge it as an issue. I'm hoping to avoid sending it off at this stage as my previous machine spent more time with Apple repair than it did on my desk.

If anyone knows of a fix I'd be grateful.

Thanks,

Phil

iMac (Retina 5K, 27-inch, Late 2015), iOS 10.1.1

Posted on Oct 14, 2017 10:11 AM

23 replies

Rahsten

Level 1

4 points

Mar 20, 2018 6:03 PM in response to ScottSieg

I am having this exact same issue. I went away on vacation for 10 days, prior to that everything was running fine. Now, back from vacation I turn on my iMac and it keeps randomly shutting down and I can't power it back on un;ess I unplug it and plug it back in. I have tried all of the suggested trouble shooting (Updates (weren't any), First Aid, SMC, PRAM, swapped out memory, tried alternate power cord, etc.) I've also turned off screensaver and set display to never sleep just to make sure if going into those modes was triggering the shutdown... they are not. It just randomly shuts down minutes after booting.

cvdave

Level 1

4 points

Apr 2, 2018 3:38 PM in response to Rahsten

I have a 27" 2012 iMac that has had this problem since 2014 (it is now 2018). Apple has replaced the logic board twice, the power-supply once, the hard-drive, all of the RAM, and reimaged the OS 3x ..... and it has shutdown 10 more times in the last week. I have send console logs to the AppleCare techs (I have one on speed-dial, not that he is doing a whole lot)..... but all they have really done is thrown parts at is while screaming "Hail Mary!".... one one hand is hasn't cost me out of pocket. but it has cost me tons of frustration, and having to save my work every two minutes "just in case"..... hard to be productive when you keep waiting for the other shoe to drop.

Apple has out-right refused to replace the machine, or to even give me a "discount" on a new one.

"Don't worry, we will get this fixed for you..." Yeah? its taken 4 years, and you have replace almost everything inside, and we are exactly how much closer to solving this? Right,

mgkock

Level 1

7 points

Apr 25, 2018 9:00 AM in response to dellphillius

I have a 1 week old iMac Pro end 2017, 3.2 Ghz intel Xeon - 32 GB ram.

It's been shutting down when in sleep mode for the last 3 days.

Since there's no Apple store where I'm from it's difficult to ship it back.

SeaPapp

Level 7

26,492 points

Oct 15, 2017 12:54 PM in response to dellphillius

Running and posting an EtreCheck report might help.

dellphillius Author

Level 1

20 points

Oct 15, 2017 11:06 AM in response to SeaPapp

Thanks Mike, I'll get that done and posted in the morning.

SeaPapp

Level 7

26,492 points

Oct 16, 2017 4:27 PM in response to dellphillius

I would try uninstalling, per the developers instructions, Little Snitch and the Intego backup assistant. You also have some bad fonts installed, you might try opening Font Book and resolving those.

dellphillius Author

Level 1

20 points

Oct 18, 2017 7:28 AM in response to SeaPapp

Thanks Mike, i'll give it a go.

Best,

Phil

Dec 3, 2017 5:26 AM in response to SeaPapp

Thank you. I appreciate the help. The report now states 'excellent'

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iMac keeps shutting down randomly