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Mountain Lion goes to sleep while still in the middle of a task

4518 Views 21 Replies Latest reply: Oct 18, 2012 2:55 AM by ciclista71 RSS
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k1tka Calculating status...
Currently Being Moderated
Jul 29, 2012 5:47 PM

This happens with various different apps ie scanning with Image Capture and others that take a bit longer to finish. Also I've had this happening on my both machines, MBP i7 and Mac Pro Westmere 6 core. What is going on?

Oh and Lion did not have this problem, it started (with slow wake up and some wifi oddities) when I upgraded to Mountain Lion.

MacBook Pro, OS X Mountain Lion
  • Therabyte Level 4 Level 4 (1,070 points)

    I use Caffeine (now available from the Mac App Store). A free menubar utility which prevents sleeping. Been using it since SL, because this always was an issue with certain apps.

  • maninder288 Calculating status...

    hey frnd,

    hope i got a solution to this sleep problem, with my mac it was due to bottom of mac near the TAB key whenever got in contact with a magnet,it goes to sleep.

    hope u guys also got the same issue.

  • MNavarra Calculating status...

    I also have the same problem. Computer goes to sleep, whatever I am doing. I think that neither caffeine nor the new 'caffeinate' command are solutions, they are just temporary workarounds.

    They can't just let the computer go to sleep while it's performing any basic task (such as a download, or a video stream etc).


    Sleep mode was working perfectly in Lion, I really do not understand what kind of new policy they have implemented.

  • radio662 Calculating status...

    Same problem here but what worries me the most is that I update to 10.8.1 so they did not fix this obvious issue!

  • Retired Engineer Level 4 Level 4 (2,710 points)

    The only thing that keeps a computer from going to sleep is keyboard or mouse (trackpad) input.

    In otherwords there is a person actively using the machine.

    No computer that I am aware of monitors program activity to determine if it is okay to sleep.


    I always configure my computers to never sleep when operating on AC power.

  • radio662 Level 1 Level 1 (0 points)

    When will they finally fix this recession error. I'm falling asleep now

  • Pedro Perez Level 2 Level 2 (165 points)

    I have got the same problem ever since I updated to Mountain Lion. I record my TV shows to my computer. Once they are recorded, they're converted and sent to iTunes overnight. Once the task was done, it'd go to sleep. Well, that used to be the case until I updated to Mountain Lion. Now, the shows are recorded, but when I wake up in the morning, the computer is asleep, and the conversion is half-way done. This DID NOT used to happen. So, one does not necessarily need to be there typing or moving the mouse to keep the computer awake. If it is performing a task, why should it enter into sleep mode? Disklike.

    Glad to know I am not the only one dealing with this issue. It seems also like with every update of OS X my computers become slower. Restart has become slower. My PC(!!) at school is faster than my MBP. What gives!!


  • roadkillrob Level 1 Level 1 (0 points)

    Same problem here, Lion didn't have the issue, Mountain lion on my imac 27" will go to sleep in the middle of FTP sessions moving files, this is a new issue to ML.  10.8.1 fixed my other issue with it taking forever to wake up after sleeping or needing  to use the power button because the keyboard would not wake it up, but it didn't fix this issue.

  • radio662 Level 1 Level 1 (0 points)

    10.8.2 and still not fixed

  • zmSP94 Level 1 Level 1 (0 points)

    For me. It is TimeMachine, iTunes and Serviio from MBP 2009 regardless if AC adapter is attached or now. Apple said change your energy saving setting so the computer won't sleep before using TimeMachine. What! that's not green. While 10.8.2 is good, this 'feature' of trying to be green really *****. 


    Someone post said there is a command that the software can issue to prevent the system to go to sleep and that Serviio (streaming software) didn't do it.  If that's the case, i would imagine Apple software (TimeMachine and iTunes) would implement it if that's the correct thing...

  • radio662 Level 1 Level 1 (0 points)

    If that is the official responce from Apple meaning that they will not fix this than I deffinately will go back to Lion. If someone can direct me to a way to downgrade I would be very glad. I can use my timemachine but it would be nice if I could keep the system the way it is now without the regression from mountain lion.

  • radio662 Level 1 Level 1 (0 points)

    I downgraded with timemachine and that took me one night but little effort. The only thing I'm missing is the notes app. The rest seems really better. Video with VLC playes with less interuptions and most of all power management works. I'm carefull about the environment and will not let a computer on all day. I can advise the downgrade to others seriously! If a fix arises than an upgrade is easy with timemachine.

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