Mac Pro 5,1 random shutdown

Discussion in 'Mac Pro' started by w8ing4intelmacs, Jun 10, 2015.

  1. w8ing4intelmacs macrumors 6502a

    Joined:
    Feb 22, 2006
    Location:
    East Coast, US
    #1
    Hi,

    My Mac Pro (2010, single 2.8) has randomly shutdown on me a couple of times. When I reboot, there wasn't a dialog box saying that the computer shutdown unexpectedly, nor was there's a dialog to ask if I want to reopen applications or send a report to Apple. I can't figure out what's causing it. I've been a Mac enthusiast for awhile but am pretty new to Mac Pros, so I'm not sure what to check.

    As always, help is greatly appreciated :)
     
  2. JesterJJZ macrumors 68020

    JesterJJZ

    Joined:
    Jul 21, 2004
    #2
    This has happened to me recently. My 2012 MP would just randomly reboot. Screen would just turn black and restart after a few seconds. This usually happened when using an intensive program like Adobe Premiere or RedcineX or other video things. Thought it was my graphics card and so did everyone else, even Apple. But in the end it was my logic board and I needed to get that replaced. It was about a $350 repair with Apple.
     
  3. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #3
    1) Did you update any hardware on your own?

    2) Do you have a reliable power source?

    3) Is the shutdown "purely random"? Or related to something else? e.g. high workload, any particular software.

    4) Do you have another partition to boot the machine for stability test? Or you may just boot the machine to recovery partition. If that's a hardware problem, it may self reboot even in the recovery partition.

    5) You may run the Apple Hardware Test to check if there is any hardware failure (not 100% accurate especially if there is any 3rd party hardware installed).
     
  4. w8ing4intelmacs thread starter macrumors 6502a

    Joined:
    Feb 22, 2006
    Location:
    East Coast, US
    #4
    Great stuff! I'm really hoping it's not a logic board issue :)

    I haven't been able to get Apple Hardware Test to run, which I'm assuming is because of my wireless keyboard (I don't have the original discs). Is there an alternative for AHT?

    No hardware mods (yet!) other than ram. It's a stock 2.8 single with 16GB 1066 DDR3.

    Power seems fine but it is an older home that I'm renting.

    It has only happened twice as far as I know in the last two weeks, but it's so abrupt that it has me a little worried.

    I haven't tried an alternate boot partition yet. I'd have to set it up.

     
  5. Moonshot macrumors member

    Moonshot

    Joined:
    May 24, 2015
    Location:
    Planet Earth
    #5
    Are you running 4 x 4GB DIMMS? Can you swap out your RAM? You could possibly have a bad chip in there that's causing your cold reboots. A bad logic board can do the same, but I like to start with the small stuff first.
     
  6. w8ing4intelmacs thread starter macrumors 6502a

    Joined:
    Feb 22, 2006
    Location:
    East Coast, US
    #6
    Yeah. I have to check that out. Just ordered my wired keyboard (I haven't been able to get AHT to work with my wireless keyboard.

     
  7. w8ing4intelmacs thread starter macrumors 6502a

    Joined:
    Feb 22, 2006
    Location:
    East Coast, US
    #7
    The machine ransomed shut off again. I haven't been able to detect a pattern since it seems like it happens (at this point) only every couple days.

    Anyway, this machine came with 16GB (4x4GB) installed but I just recently noticed that the chips are not the same.

    Sorry if these seems like a newbie questions, but:
    1. How can I tell if they are registered or unregistered?
    2. Could using 1333 memory speeds be the culprit in my random shutoffs? (or mixing 1066 and 1333 memory?) - two of the chips are PC3-8500 and two are PC3-10666. I'm trying the system with just the two PC3-8500 chips and see how stable it is.
    3. Would upgrading to a Westmere CPU potentially change this?

    and out of curiosity
    4. why is PC3-8500 = 1066 speed? what's the point of the 8500 designation? why not just call it DDR3 PC3-1066 instead of DDR3 1066 PC3-8500)
     
  8. Inutopia, Jun 15, 2015
    Last edited: Jun 17, 2015

    Inutopia macrumors 6502

    Inutopia

    Joined:
    Apr 8, 2009
    Location:
    South of Heaven
    #8
    Hey there,

    1. Usually the registered ram is designated with an R at the end, ie. PC3-8500R - look on the stickers on the side of the ram. I think System profiler may have this info too.
    2. Highly doubt it. The 1333 will just run at the slower speed. Easier on the higher rated ram if anything.
    3. Not if you have mixed RAM, it will still run at the speed of the lowest common denominator.

    4. No idea. Its been this way for ages though.

    EDIT: Test your ram with Memtest.
     
  9. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
  10. w8ing4intelmacs thread starter macrumors 6502a

    Joined:
    Feb 22, 2006
    Location:
    East Coast, US
    #10
    Aahh. That makes sense. I tried memtest on all my memory and they passed fine. I'm away for the next couple of days but I have a keyboard now to do the AHT. I'll update with the findings.
     
  11. registudio macrumors member

    registudio

    Joined:
    Aug 8, 2013
    Location:
    Montreal, QC
    #11

    It happened to me some time ago, and luckily it wasn't the logic board, but the energy saver settings with OS X 10.8.5
    In fact, I had to reset to default factory, shut it down and clear the smc.
    After restart, tested few days, no more shut down by surprise, then I put again my own settings in the energy saver.
    Hope that can help.

    Cheers
    Regis
     

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