Mountain Lion won't wake from sleep

I have instaled "SmartSleep" app and change hibernate settings to sleep only. I Think it has the same effect of your command. My Imac 27 is working better without freezing.

I had the same issue when i did the upgrade from Snow Leopard to Lion and used the same software. When I returned to sleep+hibernate everything was fixed.

I think there is something corrupted in /Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist when you upgrade.

Thanks

My pmset -g output is:

Active Profiles:

AC Power -1*

Currently in use:

hibernatemode 0

halfdim 1

womp 0

networkoversleep 0

sleep 30

powerbutton 0

ttyskeepawake 1

hibernatefile /var/vm/sleepimage

autorestart 0

disksleep 10

displaysleep 1

I am having problems with Mountain Lion waking from sleep also. I dont feel comfortable modifiying system settings for fear of screwing something else up. They better have a fix out for this soon!!!

This should help you Jeff:

`man pmset` at the terminal.

"We do not recommend modifying hibernation settings. Any changes you make are not supported. If you choose to do so anyway, we recommend using one of these three settings. For your sake and mine, please don't use anything other 0, 3, or 25.

hibernatemode = 0 (binary 0000) by default on supported desktops. The sys- tem will not back memory up to persistent storage. The system must wake from the contents of memory; the system will lose context on power loss. This is, historically, plain old sleep.

hibernatemode = 3 (binary 0011) by default on supported portables. The system will store a copy of memory to persistent storage (the disk), and will power memory during sleep. The system will wake from memory, unless a power loss forces it to restore from disk image.

hibernatemode = 25 (binary 0001 1001) is only settable via pmset. The sys- tem will store a copy of memory to persistent storage (the disk), and will remove power to memory. The system will restore from disk image. If you want "hibernation" - slower sleeps, slower wakes, and better battery life, you should use this setting."

[repost from: https://discussions.apple.com/thread/4148217?answerId=19084237022#19084237022]

I am having a similar issue. At first, my alarm clock 2 application would not wake the Mac from sleep. Help desk had me reset the computer and RAM, and then it worked. Now my keyboard will not wake the Mac from sleep, only my mouse. Please let us know if there is a fix for this, it is very frustrating.

Hi Guys

Yep, I have a similar issue but with an added twist which is that my 2011 MBA seems to also wake itself up occasionally since I upgraded to Mountain Lion.

Several times now I have put it to sleep (either by closing the lid or selecting 'sleep') and waited for the lights to go out and everything quiet. Then I open my bag some hours later to find it red hot and fans going like crazy. If I then open the lid, the machine does not come back up fully. Maybe I see the mouse cursor but nothing else. Then I need to hold the power button until it goes off again.

Taking a look with pmset I see that hibernate mode is set to 5. I have never modified this, so this is how my machine came. Interestingly this is not one of the values described as 'recommended' by Ellisonjay and is allegedly not the default shipped value for this machine (should be 3).

According to this article:

http://www.macworld.com/article/1053471/sleepmode.html

Mode 5 is fully hibernated mode (no power to RAM) which for a machine with SSD seems to make sense as the time penalty of reading back from SSD should be not so large.

So, yes, I want hibernate mode to work but, in the meantime, I hope mode 3 will at least stop my machine from waking up and frying itself inside it's case.

Interestingly, my iMac is sleeping "deeper" than ever, it's just hard to wake it up! I sleep next to my computer, and it seems like it's doing a better job of turning off my external hard drive (set on auto mode) and is quieter throughout the night. It's just really hard to wake it up, and when I do, the clock is wrong for about 10 seconds while it is waking up.

same here. MBA Dec 2011. Any update on parameter change solution?

Just a quick follow up.

I've now changed hibernatemode from 5 to 25 and, so far, it works just fine.

So, this is just going directly into full hibernation (no power to RAM). This is the behaviour I have always had with my MBA since out of the box. For an SSD based system, I don't see the need for anything more complicated than that. It's the most power efficient and resume time from hibernation is just 3-4 seconds for me anyway.

I'm pleased I was able to help.

Although the command fixes the issue, I confirm a delay of 4-5 seconds to wake comapring to almost 0sec on Lion. Booting from shutdown mode is also taking more time than before not much though.

Me too. Will a clean install fix it or do I wait for apple to fix it? I am not a Mac programmer and not interested in changing system settings. Thank you.

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.