Jeremy Liu

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

My iMac has been randomly restarting itself (about once a day) when it is idle.  Has anyone else experienced the same problem?  I found a YouTube video and it is exactly what happened to my iMac:  https://www.youtube.com/watch?v=ka7lUIeiH5E

 

I witnessed it once -- the computer was on (not sleeping) with the display off, nothing CPU/GPU intensive running.  I suddenly heard a chime and saw that the computer restarted itself.  I logged in.  There was no pop-up window.  I launched Console and did not see anything unusual before the restart.

 

More information:

 

  1. The computer is idle when restart happens.  Nothing on the computer indicates it overheats.  Display is off (due to inactivity) and fan is quiet.
  2. There is no trace of software shutdown, kernel panic or crash.  System log shows normal activities and then a sudden BOOT_TIME entry, as if someone yanks the power cord.
  3. It is not a power failure because the computer should be off if it is really a power failure.  "Start up automatically after a power failure" is not checked.
  4. It started to happen after I came back from a trip and upgraded my iMac to the latest Mac OS X five days ago.  This computer was purchased last October and I had never seen something like this until a few days ago.

 

The comments on the YouTube video suggest a total replacement, but I'm reluctant to do so if it turns out to be a software/firmware problem that can be fixed. -- The computer is heavy and the nearest Apple Store is not very close, not to mention the backup/restore efforts.

 

Thanks

iMac with Retina 5K display, OS X El Capitan (10.11.4), Retina 5K, 27-inch, Late 2015

Posted on Apr 7, 2016 6:45 PM

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

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  • by Emptynet,

    Emptynet Emptynet Aug 17, 2016 3:25 PM in response to Emptynet
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    Aug 17, 2016 3:25 PM in response to Emptynet

    Well, irony of ironies, I got another while on Web Chat with Apple Support. Thanks to Kimberly, Destiny and Aaron from the Senior Support team, who reinstated my faith in humanity or at least the humanity of the Apple Support folks. I'm back to the Genius Bar next week, and will be getting a callback from the UK organisation tomorrow. Fingers crossed.

  • by Emptynet,

    Emptynet Emptynet Aug 20, 2016 4:48 PM in response to Emptynet
    Level 1 (4 points)
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    Aug 20, 2016 4:48 PM in response to Emptynet

    If anyone is still following this thread, I shot a video of the freeze and restart while my machine was unattended. Hopefully this will convince the Geniuses that I'm not making this stuff up...

     

    Please forgive the quality of the video - it's an old webcam and the lighting isn't great.

     

    https://www.youtube.com/watch?v=NnGr4GQi_DE

  • by mrdgvb1,

    mrdgvb1 mrdgvb1 Aug 20, 2016 6:44 PM in response to Emptynet
    Level 1 (16 points)
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    Aug 20, 2016 6:44 PM in response to Emptynet

    Nice video - was always trying to capture the restarts myself. Exactly what would happen to my machine. Clock freeze and everything. Had my Logic Board Replaced on July 26th - no random restarts since. Also upgraded the RAM last week and stable as can be.

     

    The guy who swapped out my logic board says it is a bad BIOS. Only solution is replacing the logic board with a newer version. Send this video to the Supervisor you are assigned to - proof positive that it is a Logic Board issue like all of us. So far everyone who has had the logic board replaced has stated that it has fixed the issue.

  • by Mateys,

    Mateys Mateys Aug 20, 2016 10:42 PM in response to Jeremy Liu
    Level 1 (4 points)
    Aug 20, 2016 10:42 PM in response to Jeremy Liu

    I have the same issue and it gets worse and worse. Now it takes a few seconds after login to freeze. And the worse part of it is that I am in Romania and I could expect anything from the authorised services here... Hope they will fix it. I'll phone them on monday

  • by andrewfromashton,

    andrewfromashton andrewfromashton Aug 23, 2016 6:39 PM in response to mrdgvb1
    Level 1 (8 points)
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    Aug 23, 2016 6:39 PM in response to mrdgvb1

    I'm absolutely amazed, and a bit jealous , you were able to have a tech come out.  I've spoken to 5 senior Applecare techs and 2 on-site reps. to come out to a client's small business who has the exact same problem.  Apparently there are no on-site techs available in all of the Washington D.C. / Baltimore area. 

  • by Kylomoo,

    Kylomoo Kylomoo Aug 24, 2016 12:49 AM in response to mrdgvb1
    Level 1 (4 points)
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    Aug 24, 2016 12:49 AM in response to mrdgvb1

    So it's been a while since I last posted.

    In that time I had my imac collected after refusing to take it in myself (why should I?)

    It was then collected from my house , taken away for two weeks (this being the second time) and had the logic board replaced. I got it back yesterday    had it on for 15mins    boom   restarts again even after a logic board change.

    I had provided multiple video evidence of the restarts plus the logs  which got them to chnage the board

    But unfortunately it's not worked for me....

    My imac also came back with a different serial number ???

     

    So after phoning them straight away to tell them thier fix had not worked   it's now being collected again from my house.

     

    So now after being opened three times its going back to be opened again! I've thus paid full price for a now refurbished Imac, and I'm not willing to accept that.

     

    I will post as to what happens next when I speak to the advisor today.

     

    #product recall.

  • by Mateys,

    Mateys Mateys Aug 24, 2016 1:25 AM in response to andrewfromashton
    Level 1 (4 points)
    Aug 24, 2016 1:25 AM in response to andrewfromashton

    In Romania, I am lucky to have a service in my city!!!

  • by Mateys,

    Mateys Mateys Aug 24, 2016 1:27 AM in response to Kylomoo
    Level 1 (4 points)
    Aug 24, 2016 1:27 AM in response to Kylomoo

    Latest Apple products are kind of faulty... hope the new macbooks pro are better since they have been working on them for 2 years

     

    I have friends with Macbook Air problems and I just read an article about iPhone 6 problems

  • by wyowoman,

    wyowoman wyowoman Aug 24, 2016 6:39 AM in response to Kylomoo
    Level 1 (4 points)
    Aug 24, 2016 6:39 AM in response to Kylomoo

    Anyone who has had a logic board replaced: Are you ever going to update your iMac again? Or are you afraid like I am that something catastrophic will happen again like after the 10.11.4/10.11.5 updates? Do you think the new logic board doesn't have the same fault that led to the random shutdowns like before?

  • by bendean,

    bendean bendean Aug 24, 2016 7:00 AM in response to wyowoman
    Level 1 (4 points)
    Aug 24, 2016 7:00 AM in response to wyowoman

    I am totally leery of updating my iMac 5k. Way back in the late years of OS9 and early days of OSX (now Mac OS), every once in awhile an update would carry some form of problem, but it was usually a software issue, not a systematic hardware failure.

     

    What bothers me about this is that Apple has now designed their OS and their iOS (where you cannot turn off notifications) to constantly prompt users to upgrade, all while knowing there's a possibility those updates could brick a machine/device.

     

    At this stage, the iMac 5k for me is a work (not a surfing the internet) machine, so it will stay where it is until I am forced to upgrade or my Adobe software offers an upgrade worth taking a chance on.

  • by mrdgvb1,

    mrdgvb1 mrdgvb1 Aug 24, 2016 7:05 PM in response to andrewfromashton
    Level 1 (16 points)
    Desktops
    Aug 24, 2016 7:05 PM in response to andrewfromashton

    There are probably non-Apple techs available like mine. He just worked at a local computer store but was certified to fix Apple computers - he had 19 years of experience - probably more than most at the "Genius Bar."  I find it hard to believe that they don't have anyone to send in the D.C. area...

     

    I just send my Supervisor a simple e-mail "Can I have someone come out to my house and replace my Logic Board?"

    He responded a few hours later with, "Yes. I will need your address."

     

    It was pretty cool. My opinion of Apple did a 180 from that point. I love Apple now They are the Best 1984

     

    No random restarts since new Logic Board, been over 30 days now. I feel I am out of the woods now.

     

    I am afraid to update my Mac OS,  so 10.11.5 is where it will stay.

  • by Emptynet,

    Emptynet Emptynet Aug 25, 2016 11:41 AM in response to mrdgvb1
    Level 1 (4 points)
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    Aug 25, 2016 11:41 AM in response to mrdgvb1

    Well, the latest trip to the Genius Bar has resulted in a hardware repair - finally!

     

    But to my disappointment they have decreed that a power supply replacement is called for... not the logic board. And it's not a part they have in stock. Anti climax.

     

    I fear I'm likely to be on this thread for another round, but fingers crossed I guess. If this doesn't fix it, I'll be abandoning the Apple Warranty and taking the Consumer Rights Act 2015 approach instead.

     

    It's been four months, two Genius Bar "vacations", and more calls than I care to remember already. I think I've done more than a reasonable amount of trying to replicate the problem, providing video evidence, log extracts, rebuilding the machine from scratch.

  • by Mateys,

    Mateys Mateys Aug 25, 2016 11:43 AM in response to Emptynet
    Level 1 (4 points)
    Aug 25, 2016 11:43 AM in response to Emptynet

    It seems that I get the logic board replacement. No questions asked, they know by now.

  • by Emptynet,

    Emptynet Emptynet Aug 28, 2016 8:34 AM in response to Mateys
    Level 1 (4 points)
    Desktops
    Aug 28, 2016 8:34 AM in response to Mateys

    Oh Happy Day! The Apple Store rang, and after replacing the power supply, some other anomalies were noticed with the graphics elements of the main logic board, so now they are, FINALLY, going to replace the MLB - and I should have my machine back sometime next week.

    It's been a long road, but I hope I'll also be able to put this problem to bed once and for all, as with most of you on this thread - thanks for all the support and encouragement!

    Good luck to those still negotiating with Apple on this issue...

  • by TJ-Alex,

    TJ-Alex TJ-Alex Aug 30, 2016 12:32 AM in response to Jeremy Liu
    Level 1 (8 points)
    Desktops
    Aug 30, 2016 12:32 AM in response to Jeremy Liu

    I have been having that annoying random Freeze and restart no matter what application I'm using since March. I also bought my iMac Retina 5k, 27inch, late 2015) 3.3 GHz Intel Core i5, Memory: 8 GB 1867 MHz DDR3, Graphics: AMD Radeon R9 M395 2048 MB at Best Buy. I already tried all the solution by apple support. I even erased my hard drive and clean install OS X 2 times and still happens after a few hours or days. Today I'm seeing the Genius Bar. Wish me luck guys. I'm so frustrated with this problem for a long time.

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