wclimenh

Q: Sudden restarts while using bootable USB installer (mid-2011 iMac) - evidence of hardware problem?

Greetings:

 

For a couple of years I've been suffering from an issue reported in many threads:  seemingly random shutdowns and restarts of my mid-2011 iMac.  These can happen several times a day, or there can be a gap of weeks between occurences.  I've searched the web and discussions.apple.com endlessly, and tried every conceivable solution.  I've observed no consistent pre-restart pattern in Console.  I've tried removing all unnecessary extensions and start-up programs.  Fixed permissions, repaired HDD, many of the diagnostic procedures described by LINC (superuser on this forum).  I would sometimes get temporary relief from periodic restart loops, by unplugging the computer and resetting PRAM, but this would not last long. I couldn't discern whether it is a software/conflict issue, or a hardware issue.  Have run AHT in extended looping mode, several times, and found nothing wrong.  Which caused me to keep thinking it must be a software issue.  The last thing I've tried is a clean install of Yosemite, with full HDD erase, from bootable USB.

 

I did this successfully, restored files from Time Machine...but then a few hours later, a series of sudden restarts began, with 4 or 5 within a couple of hours. I decided to shutdown and restart using the bootable USB installer again, and run Disk Utility from it to check the HDD for errors.

 

But then, while booted up from the USB (and after running Disk Utility with a normal result):  the computer suddenly turned off and restarted!  And then it rebooted again into installer mode (i.e. running off the bootable USB), and I ran Disk Utility again and ...it happened again!

 

So what does this tell me?  I am asking all of you for confirmation please.  I am thinking this is a strong indication that whatever the issue is causing the restarts, it is hardware based, as the system was running off the bootable USB at the time, NOT using installed operating system or software.  AND this reminded me of one other instance where the system had rebooted randomly, while I was in SAFE mode.

 

Would you agree that this is likely now pointing to a hardware issue?  Is power supply the likely culprit?  Or??  (and recalling that repeated AHT have showed nothing...).  Is it worth trying to fix (out of warranty)?

 

thanks for any insights,

Warren

iMac, OS X Yosemite (10.10.2), mid-2011, 2.7 GHz, 8 GB RAM

Posted on Apr 6, 2015 6:45 PM

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Q: Sudden restarts while using bootable USB installer (mid-2011 iMac) - evidence of hardware problem?

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  • by Linc Davis,

    Linc Davis Linc Davis Apr 6, 2015 7:17 PM in response to wclimenh
    Level 10 (208,000 points)
    Applications
    Apr 6, 2015 7:17 PM in response to wclimenh
  • by wclimenh,

    wclimenh wclimenh Apr 6, 2015 7:22 PM in response to Linc Davis
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    Apr 6, 2015 7:22 PM in response to Linc Davis

    Thanks Linc - but I should have specified: it is a 21.5 inch, with Radeon 6770M, so not addressed by that replacement program.  Any other ideas?

  • by Linc Davis,

    Linc Davis Linc Davis Apr 6, 2015 7:33 PM in response to wclimenh
    Level 10 (208,000 points)
    Applications
    Apr 6, 2015 7:33 PM in response to wclimenh

    These instructions must be carried out as an administrator. If you have only one user account, you are the administrator.

    This procedure is a diagnostic test. It makes no changes to your data.

    Please triple-click anywhere in the line below on this page to select it:

    syslog -k Sender kernel -k Message CSeq 'n Cause: -' | tail | awk '/:/{$4=""; print}' | pbcopy

    Copy the selected text to the Clipboard by pressing the key combination command-C.

    Launch the built-in Terminal application in any of the following ways:

    ☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

    ☞ In the Finder, select Go Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

    ☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.

    Paste into the Terminal window by pressing the key combination command-V. I've tested these instructions only with the Safari web browser. If you use another browser, you may have to press the return key after pasting.

    Wait for a new line ending in a dollar sign ($) to appear below what you entered.

    The output of the command will be automatically copied to the Clipboard. If the command produced no output, the Clipboard will be empty. Paste into a reply to this message.

    The Terminal window doesn't show the output. Please don't copy anything from there.

  • by wclimenh,

    wclimenh wclimenh Apr 6, 2015 7:42 PM in response to Linc Davis
    Level 1 (0 points)
    Apr 6, 2015 7:42 PM in response to Linc Davis

    Thanks - I'll try this in about 8 hours from now when I am back home, and revert thereafter.  Appreciate the quick responses.

  • by wclimenh,

    wclimenh wclimenh Apr 7, 2015 4:29 AM in response to Linc Davis
    Level 1 (0 points)
    Apr 7, 2015 4:29 AM in response to Linc Davis

    Have executed the command as instructed. Here is the output:

     

         Apr 6 06:27:10  kernel[0] <Notice>: Previous shutdown cause: -128

     

    Thanks in advance for your interpretation and advice.

  • by wclimenh,

    wclimenh wclimenh Apr 7, 2015 6:19 AM in response to wclimenh
    Level 1 (0 points)
    Apr 7, 2015 6:19 AM in response to wclimenh

    And as I just experienced another random restart (with same result for your command above), I am copying in the last two Console entries before the newest bootlog: BOOT_TIME entry, FYI:

     

    74//15 8:09:07.358 PM mds[32]: (Volume.Normal:166) vsd:0x7ff8a4163400 DisabledStore recycle:3 context:{

        DisabledRecycleCount = 3;

    }

    74//15 8:09:07.388 PM mds[32]: (Volume.Error:577) vsd:0x7ff8a387ca00 Open failed.  failureCount:3 {

        DisabledRecycleCount = 3;

    }

  • by Linc Davis,

    Linc Davis Linc Davis Apr 7, 2015 6:29 AM in response to wclimenh
    Level 10 (208,000 points)
    Applications
    Apr 7, 2015 6:29 AM in response to wclimenh

    A negative shutdown code may indicate a hardware problem. The precise meaning of the codes is not publicly documented.

    If you haven't already done so, you can try resetting the System Management Controller. Otherwise, or if the reset has no effect, see below.

    Make a "Genius" appointment at an Apple Store, or go to another authorized service provider. You may have to leave the machine there for several days.

    Back up all data on the internal drive(s) before you hand over your computer to anyone. There are ways to back up a computer that isn't fully functional—ask if you need guidance.

    If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.

    Keeping your confidential data secure during hardware repair

    Apple also recommends that you deauthorize a device in the iTunes Store before having it serviced.

    *An SSD doesn't need to be zeroed.

  • by wclimenh,

    wclimenh wclimenh Apr 7, 2015 6:54 AM in response to Linc Davis
    Level 1 (0 points)
    Apr 7, 2015 6:54 AM in response to Linc Davis

    Thanks - I've done an SMC reset numerous times - if experiencing a series of sequential shutdowns/restarts, it usually breaks the cycle and gives some respite for a time.

     

    I live in Bangkok, Thailand, and getting good technical service can be a challenge (there are authorized service providers, but language limitations are an issue).  Based on anything I've described, or that you've observed in other similar cases, is there any reason to believe it could be related to the power supply (this is my leading suspect)?  Or would you suspect another component as the guilty party?  If I do lug the iMac through the megacity to a provider, I would prefer to at least have a working theory to guide the conversation, if possible...

     

    Thanks again

  • by Linc Davis,

    Linc Davis Linc Davis Apr 7, 2015 7:11 AM in response to wclimenh
    Level 10 (208,000 points)
    Applications
    Apr 7, 2015 7:11 AM in response to wclimenh

    There have been cases in which that particular code seemed to be related to a memory fault, but that's not definite. You could try removing half the memory modules and testing. Then switch and test again.