Wake From Sleep Issue - 2012 w/ML

Discussion in 'MacBook Air' started by KPOM, Jul 26, 2012.

  1. KPOM macrumors G5

    Oct 23, 2010
    I was just about to declare my Mountain Lion update a success when I noticed a wake-from-sleep issue (ugh).

    I left it plugged in last night to test the PowerNap feature. When I opened the screen, it wouldn't wake up. I pressed the power button and it restarted. I closed and opened the lid, and it appeared to work. However, when I closed it again and opened the lid about 20 minutes later (again with it plugged it), it wouldn't wake up again. Has anyone else noticed this?

    Update: I closed the lid and put it in my bag, thinking I'd take it to the Genius Bar at lunch. When I arrived at the office, I noticed that the fans were running and it was hot to the touch (so it never actually went to sleep). Before Mountain Lion and the SMC update, it was running fine. I attempted to reinstall the SMC update but it said it wasn't applicable for my system (I checked and I downloaded the right one).
  2. DOGONO macrumors newbie

    Jul 25, 2012
    No sir. It's working as intended for me. I'm running a 2011 MBA. Perhaps our SMC update was slightly different from what the 2012 models came with? Dunno.
  3. KPOM thread starter macrumors G5

    Oct 23, 2010
  4. KPOM, Jul 26, 2012
    Last edited: Jul 26, 2012

    KPOM thread starter macrumors G5

    Oct 23, 2010
    I'm getting the dreaded 3 beeps. :(
    I'll take it into the Genius Bar tonight.

    Update: The hardware checks out OK. They are trying reinstalling the OS.
  5. KPOM thread starter macrumors G5

    Oct 23, 2010
    Update: I solved the issue by doing a clean installation. I went into the restore partition, erased the SSD, and reinstalled Mountain Lion clean. I then migrated from my pre-ML backup drive and was good to go from there. Oddly, the Apple Store's attempt to reinstall the OS appeared to work at first, but then the issue recurred later that evening. I'm guessing something was left over from my Lion installation that the clean installation took care of (and that Migration Assistant didn't copy over).
  6. sakabara macrumors newbie

    Apr 5, 2010
    Got the solution (at least for me…)

    To those who still have this problem of Macbook Air not waking up from sleep (closed lid, for more than a few hours of sleep). I was stucked with this problem myself (on a MacBook Air mid-2012, with ML installation over Lion) and could not find a culprit. Did the SMC reset many times to get back to work (hard reset). I finally found the solution, but it implies using the terminal. It seems to be a hibernate mode problem. Mine was set to 5, when the problem was persistent. I switched to 0 through the terminal and this morning when I woke up, my Mac wake up from sleep almost as fast as me ;-) . Here are the details:
    To check your hibernate mode:
    In the terminal:
    pmset -g

    This should allow you to see what your hibernatemode status is. Mine was:
    hibernatemode 5

    To switch your hibernate mode to 0
    sudo pmset -a hibernatemode 0

    Be careful with the consequences, though, you should check this page for more info about hibernate mode:

    There is also a discussion thread here
    that goes into details and give several testimonies with similar issues and how the hibernatemode change has solved (most of the time) their problems. I will test myself with modes other than 0 (not the safest of all modes...) but for the moment at least, my mac is responsive...

    For those who want more explanations about sleep modes and using Terminal to switch between them:

    Hope that this help... Good luck
  7. Macman45 macrumors G5


    Jul 29, 2011
    Somewhere Back In The Long Ago
    Seems to work fine out of the box for me, and I went over the top of Lion too...Was expecting to probably have to perform a CI, but it's all good. With 3 Macs, any time saved is worth it..:)

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