random sleeping


macrumors regular
Original poster
Aug 2, 2010
Ever since I installed Mountain Lion, my Mac will just randomly go to sleep while I'm in the middle of something. It happens once, maybe twice a day. I usually just close the lid and wait about a minute before opening it back up, wakes up no problem.

Anyone else experiencing this?


macrumors 65816
Dec 8, 2006
Check energy saver in the system preferences. Set both to never and see if still happens.


macrumors member
Oct 23, 2003
Random sleep with iMac as well

I'm having this issue as well, not sure if it's due to high temps or 10.8.1 or what.

I've tried setting power saver to never sleep across the board and I've even tried running sleep preventing app "Caffeine" and it still happens. Not good.

To make matters worse, I'm trying to be pragmatic and backup via TimeMachine and it's going to sleep during that process, therefore hindering my backup.



macrumors 6502a
Apr 28, 2008
same issue

I'm having the same issue.

I assume that it only occurs on battery power. I just upgraded to 10.8.2 from Lion and this is the first time I've been using the computer for extended periods unplugged (13inch MBP 2009).

It is as if the computer can't sense that I'm still using it and thinks it has been inactive. Just goes straight to sleep randomly and takes a few clicks to wake up.

I must say there are some serious bugs in ML so far and this is on a clean install.

I will try resetting smc later.