I have a late 2011 Macbook pro, and lately it hasn't been sleeping properly. If I close the lid for less than a minute and reopen it, it doesn't go to sleep while the lid is closed. The screen is still displayed immediately after reopening. Also, a few seconds after I open the machine, it will go to sleep on it's own. I have had the software checked and that doesn't seem to be the problem. What could be causing this and how do I get it fixed? It is still under warranty.

  • Which OS X version is your laptop running?
    – user15819
    Commented Sep 5, 2012 at 1:17
  • Same problem here: my MacBook Air from 2012 (OS X 10.7.5) doesen't go to sleep at closing the lid. I disabled "Dropbox Lan Sync" and checked if it has enough free harddrive space. still the same. It goes to sleep, if I don't close the lid after exactly 1 Minute not working on it (like I set in in energy-options). But not, if I close the lid: Then even the screen stays on, while the lid is closed. Sometimes it goes to sleep after some Minutes with lid closed (always more than 1 minute) but sometimes not. What do I have to look for on the console? in which log there would be a hint on what is ha
    – rubo77
    Commented Oct 8, 2012 at 9:30

3 Answers 3


If there is a process that is preventing sleep (rather than a bug in the sleep implementation), you can use "pmset -g" in a terminal window to list the process that is doing that. This is covered over on superuser.

Here is an an example on my system. First, with nothing preventing sleep:

$ pmset -g assertions | egrep '(PreventUserIdleSystemSleep|PreventUserIdleDisplaySleep)'
     PreventUserIdleDisplaySleep             0
     PreventUserIdleSystemSleep              0

Then I start music in iTunes:

$ pmset -g assertions | egrep '(PreventUserIdleSystemSleep|PreventUserIdleDisplaySleep)'
     PreventUserIdleDisplaySleep             0
     PreventUserIdleSystemSleep              1
    pid 264: [0x0000012c00000108] PreventUserIdleSystemSleep named: "com.apple.audio.'AppleHDAEngineOutput:1B,0,1,2:0'.noidlesleep" 
    pid 95390: [0x0000012c0001749e] PreventUserIdleSystemSleep named: "Nameless (via IOPMAssertionCreate)" 

How long does it take to get to sleep on its own if you leave it?

I'd suggest looking at the log entries in the Console.app to see what's happening when it tries to go to sleep.

A few things that I've encountered that can make a Mac slow to sleep:

  • Nearly full hard disk (can make it slow to write out the hibernation data)
  • Misbehving drivers (like, oh, I don't know, VMWare's virtual networking) that don't go to sleep quickly.

Aside from looking at the console for hints and checking your free disk space, this is the sort of thing where doing an SMC reset might actually be applicable.


Your problem same me. After this, i reinstall Mac because i can't debug my error.

However, you can try:

_If your Mac has got uTorrent and still running it, please EXIT it.

_If your Mac has got Dropbox, uncheck "Enable LAN sync"

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