Why Did My MBA Restart When Power Went Out?

Discussion in 'MacBook Air' started by jordii, Aug 19, 2015.

  1. jordii macrumors regular

    Joined:
    Sep 9, 2008
    #1
    My power went out for a minute while I was using my mid-2014 MacBook Air (plugged into wall charger, and using an external monitor, fwiw). Though the battery's fine, the computer restarted (and, strangely, my mouse tracking speed reset to "very slow").

    Can anyone account for this? Here's the crash report:


     
  2. motrek macrumors 68020

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    Sep 14, 2012
    #2
    There might have been a power surge that was related to the power outage that tripped a protective circuit in the laptop. Dunno just speculating.
     
  3. Boyd01 macrumors 68040

    Boyd01

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    #3
    Never saw that happen. But I remember many years ago I was sitting in a little office at a jobsite using my PowerBook G4 while a staff member sat across from me using his desktop PC. Suddenly the power went out and he lost everything and said something obscene while I just kept working. Then he looked over at me, kind of mad and said "why didn't your power go out???". I told him it was because I had a Mac. :D
     
  4. Newtons Apple macrumors G5

    Newtons Apple

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    Mar 12, 2014
    Location:
    Jacksonville, Florida
    #4
    I have pulled to power cord out of the wall to move to another location with my MBAir 13 and it never missed a bit. What you describe should not have happened.
     
  5. jordii thread starter macrumors regular

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    Sep 9, 2008
    #5
    Agreed. It's the strangest thing that's happened to me in 26 years of Mac computing. I should probably report it to Apple....not sure who to approach....
     
  6. Newtons Apple macrumors G5

    Newtons Apple

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    Mar 12, 2014
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    Jacksonville, Florida
    #6
    Like the others have said could be a fluke. Next time on your device try pulling out the cord and see if it happens again. Just pulled mine again and the screen does darken ever so slightly but it keep right on going.
     
  7. motrek macrumors 68020

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    Sep 14, 2012
    #7
    That's a power saving feature that you can disable in System Preferences.
     
  8. motrek macrumors 68020

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    Sep 14, 2012
    #8
    Uh, what are they supposed to do about it?
     
  9. jordii thread starter macrumors regular

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    Sep 9, 2008
    #9
    Uh, I don't need anything "done". But if computers with functional batteries require restart after power glitches, that's an edge case they'd surely like to know about.

    To thread:

    Shortly thereafter, my TM drive was reported to have irreparable problems, so the power glitch may have happened during a TM backup. I can understand why loss of power to the TM drive might crash the TM app, but I still don't understand the restart. And the slow mouse speed upon reset is another strange result.
     
  10. Gav2k macrumors G3

    Gav2k

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    Jul 24, 2009
    #10
    I think there was a surge. That caused your issue
     
  11. motrek macrumors 68020

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    Sep 14, 2012
    #11
    They obviously don't "require restart" after loss of power, or people would see their laptops turning off all the time when they disconnected them from the wall charger during normal use.

    What you saw was almost certainly a power surge that drove the laptop out of spec.

    You don't need to report this to Apple any more than I need to report to Apple that we had a lightning storm last week.

    If you're worried about this then invest in a UPS.
     
  12. jordii thread starter macrumors regular

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    Sep 9, 2008
    #12
    Awesome! Sounds like you're beginning to see my point.

    I have surge suppression for computer and external drives. Not that that's 100% reliable.

    My theory is that TM app had a particularly nasty crash when write to the TM drive was interrupted as drive suddenly dismounted during outage (the drive functions fine; it just had its directory farkled). So perhaps restart was due to kernel panic due to crash. I.e.more an indirect result of power problem, re: power impact on external drive in mid-write. If so, that's an interesting edge case.

    I'm not good at crash report decoding; I'd imagine such a scenario would be detectable from my report, above.
     
  13. motrek macrumors 68020

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    Sep 14, 2012
    #13
    To Apple, maybe. The dump you have above doesn't have symbol names, so nobody outside of Apple would be able to figure out anything useful from it.

    When my computer kernel panics and reboots, I get an option upon reboot to report the crash to Apple. Did you not see this dialog box?
     
  14. jordii thread starter macrumors regular

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    Sep 9, 2008
    #14
    No, I did not not see it. Why do you need to phrase things so snottily? it's so unnecessary.

    I sent the crash report. They have no way of knowing about the power issue.
     
  15. motrek macrumors 68020

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    Sep 14, 2012
    #15
    Tone of voice is hard to read from these posts. It wasn't my intention to be snotty with the question. I'm not sure how else to ask that question. "Didn't you see this dialog box?" "Did you see this dialog box?" These all seem basically the same to me.
     
  16. jordii thread starter macrumors regular

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    #16
    I appreciate your trying to help out, regardless of tone.

    Yes, I saw the dialog box. And sent a report. So...?
     
  17. motrek macrumors 68020

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    #17
    Oh. So you reported it to Apple. Nothing else to be done then. No symbols in the stack trace so nothing anybody else can do. I might start Time Machine over again with a different drive just to get yourself into a known-good situation.
     
  18. dwig macrumors 6502

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    Jan 4, 2015
    Location:
    Key West FL
    #18
    +1, a simple power loss won't cause a notebook with a good battery to reboot.

    Power outages often occur as a result of a failure in a piece of equipment that produces a surge or other power instability. A segment of the power grid may then shuts down, often just briefly, to protect itself.

    I highly recommend that you NEVER plug any computer equipment's power cord or brick directly into a wall outlet. Always use a surge protector. If the computer equipment doesn't have its own battery, then always use a UPS, which will provide both battery support but also surge protection.
     
  19. westom macrumors regular

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    Nov 8, 2009
    #19
    That part is correct. But the following recommendations are contradicted even by specification numbers provided by each plug-in protector. It does not even claim to protect from that type of surge. A UPS typically claims even less protection.

    A surge is blamed when consumers are at a loss to know what caused an anomaly. If he had that type of surge, then a surge blew through superior protection (already inside every computer) resulting in hardware damage.

    Protection from that type of surge must connect low impedance (ie less than 10 feet) to what can harmlessly absorb hundreds of thousands of joules. A solution that typically costs about $1 per protected appliance. How many joules does a UPS claim to absorb? Hundreds? Near zero protection is sufficient so that subjective claims and other myths are recommended using hearsay.

    Question is apparently why software (data) changes occurred. Existing computer hardware should have averted that change. That is not hardware damage created by a surge. Most only blame surges as if magic will explain a mystery.
     
  20. motrek macrumors 68020

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    Sep 14, 2012
    #20
    We didn't know that the computer was in the middle of doing something with external devices that lost power. That wasn't mentioned in the original post.
     

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