Q: Mountain Lion won't wake from sleep

I was just at apple store and genius said that happened to him also. He said to tell the computer not to put hard drives to sleep in power settings.

Kinda sounds to me a little like: "If the air is bad, hold your breath for the rest of your life..."  =)

I am havine same issues with my 2011 i7 MBA.  It will not come out of Sleep without rebooting. I tried the Preference tweak that the Apple guys told the other user here (don't sleep the SSD's) wihch didn't work.  I am not going to run Unix commands to fix this--Apple needs to get a patch out or tell us how to tweak the preferences.

@ttrq01 Here is the problem. The default sleep modes on all shipping Macs are 0, and 3.  If you're not in 0, or 3. You're not btw if you're having this issue. Then as they say quite clearly on the man page for pmset, it is "not supported."

They are not going to "patch" this as it's "not supported", and you should not be in an unsupported configuration unless a 3rd party app made it so. (me assuming) Thus Apple has done nothing, and the blame rests with the app at fault. So I might suggest you figure out the offending app, and send the dev some hate mail. (or kindly ask for an update either will do)

ellisonjay,

Thx for the advice and counsel. Guess I am configuring the kernel afterall.  :-)

Some questions...

1) can I find out what mode I'm in or should I just change it to 0 or 3?

2) what is your recommendation -- 0 or 3?

3) will the offending App keep changing this?

4) how can I find out offending App?

Thx again!

Never mind #2 above. I saw your post. I have MBA so I should select 3?

I have a MBA too, and I use 25. 3 is the supported mode.

when in doubt type `man pmset` `pmset -g` shows your current settings.

Mine did, so I removed it. It was called deepsleep.

After you repair it, and confirm it's working. Be aware what apps you used if the problem reappears.

I have a 13 inch MId 2011 MBA (SSD) and I am having the same issue. My MBA won't wake up from sleep.

I checked the my hibernation setting and it was set to 3.  After reading your post I changed it to 25, and again it wouldn't wake up from sleep.

Now, I have to shutdown the computer everytime to avoid the force shutdown out of hibernation. I called Applecare and they couldn't help me out. It's very disappointing on Apple. Let me know if you figure out something else...

Thx. Will try your suggestions.

@carlos134 did you try this: http://support.apple.com/kb/ht3964 first? I did this before looking at my pmsettings. I have seen others reset their pram as well.

I have the exact same issues with my 2010 MBP (13"). I Have tried resetting the SMC, PRAM and the hibernate settings. Nothing works. Very annoying. I might have to downgrade back to lion for this.

Some more information: I have not installed any programs what so ever. This was a complete clean install. The problem started occuring a few days after an upgrade, so I decided to perform a clean install. This did not solve the issues.

Message was edited by: w.engelsman

fwiw, I was already showing a "3" hibernate setting.

@ttrq01 The post I read some where said that the power managment settings got corrupted for him. So he "set" them again, and it fixed his problem.

I think unplugging my iMac for 10 minutes fixed it.

I think it is an enhancement, whatever it is doing, it is turning my LaCie external hd off better now, so my room is much quieter during sleep mode.

Everyone,

My problem has now been fixed!  I called Apple Technical support and after 2 hours with Level 2, everything is now in order.  I can Sleep the system and Wake it without any issues.  I have been testing it all evening and all is working fine.

Apple thinks there was a corruption in one or more of the preferences files in the Preferences folder associated with the user account giving me troubles (we determined that my other account was able to sleep/awake fine).  They believe that the corruption happened when I upgraded from Lion last week.  We slowly rebuilt all of my preferences and we were never able to find the offending file but all is now working. 

In some cases we put back the original preferences files and in other cases it was simple enough to just reset the preferences for an App.  Apple initially tried a number of the remedies discussed in this thread without any success.

Thanks to all of you for your assistance!