5 ways to fix MacBook /Pro/Air that won't wake up from sleep

Some MacBook, MacBook Pro or MacBook Air won't wake up from sleep. My MacBook Pro was one of them. I have been googling for two days, and I learnt different ways to fix the problem. Not all the MacBooks can be fixed by the same one solution. Here I collect five common ways to fix the waking up problem together (trying to save time for others). If your MacBook doesn't wake up from sleep, you may try and see which solution works for yours. If any solution works, you may leave a message including your MacBook model and the solution. It may help the others.

Solution 1.Select a Startup Disk in System Preferences

I learnt this solution from AJ's post. AJ said even in a single boot MacBook, a startup disk is rarely selected, and sometimes, this may stop MacBooks from waking up from sleep. Here is how to fix it:

  • Launch System Preferences from the Apple menu
  • Click on Startup Disk
  • Select the startup disk of the OS you are using (click the single disk if there is only one)
  • macbook startup disk selection

    Solution 2.reset SMC

    SMC stands for Mac's System Management Controller. Many strange behaviors are related to disorder SMC setting. By resetting SMC, you may fix sleep problem of your MacBook. Here is how to reset SMC of your MacBook.

    Reset SMC of a MacBook, MacBook Air, MacBook Pro with an internal battery you should not remove on your own:

    • Shutdown your MacBook/Pro/Air
    • Connect the MagSafe power adapter
    • Press the (Left side)Shift+Control+Option keys and the Power button at the same time
    • Release all keys and the power button at the same time
    • Press the power button to turn on the MacBook/Pro/Air.

    Reset SMC of a MacBook, MacBook Air, MacBook Pro with an battery you can remove:

    • Shutdown your MacBook/Pro/Air
    • Disconnect the power adapter from the computer, if it's connected.
    • Remove the battery.
    • Press and hold the power button for 5 seconds.
    • Release the power button.
    • Install the battery back and connect the power adapter.
    • Press the power button to turn on the computer.

    Solution 3.turn off Safe Sleep (hibernatemode)

    Safe Sleep(or hibernatemode) was introduced in 2005. This Feature writes the content of MacBook's RAM onto the hard disk before you put the MacBook to sleep. Normally, when Macbook wake up, it does not need to read the hard disk for the RAM's content, because RAM is not turned off when Mac is sleeping. Safe Sleep is there just in case that the MacBook is short of power and turn itself off or you remove/change the battery. And that is why it is call SAFE sleep.

    Sometimes, Safe sleep may cause MacBook can not wake up from sleep. You may try to turn it off, here is how:

    • Launch Terminal (/Applications/Utilities/Terminal.app)
    • run pmset -g | grep hibernatemode
    • If you see "hibernatemode 3", you may go on the process, or else you need to stop and try other solution
    • run sudo pmset hibernatemode 0
    • Enter your admin password

    This very solution fix my MacBook Pro. If it doesn't fix your problem, you can restore the safe sleep feature with running following command line in Terminal:

    sudo pmset hibernatemode 3

    Solution 4.Switch system to another hard disk if you have two

    If you have installed a second hard drive (or SSD) on your MacBook or MacBook Pro, and have waking up problem of the mac, you may try to install Mac OS X system on the other disk of the book.

    I have removed my optical drive of my MacBook Pro, and installed a second hard drive. When I installed Lion on the second hard drive, my MacBook Pro could not wake up from sleep. Then I tried installing Lion on the original hard drive, the MacBook Pro did not have the problem.

    Solution 5.Reinstall system

    Backup all you data, and try re-install the Mac OS X system. It always will be a solution to Mac problem.

    I hope some solution above will work for your MacBook. If not, maybe you just have a broken Mac, it is time call Apple.

19 Dec23:01
By Anonymous (not verified)

My sleep problem was due to Apple's hibernation being faulty on my 11" Air with memory hard drive. It would simply fail to wake up from sleep so I always had to reboot it. A widget called "Deep Sleep" fixed it.

See http://www.macworld.com/article/53471/2006/10/sleepmode.html

20 Dec00:57
By yang

Thanks for your information. I checked the document of the widget, and found I could turn off the safe sleep mode easily with "deep sleep" widget. It should work as good as the 3rd solution above, but it will be much easier for those don't like Terminal.

13 Feb06:12
By Anonymous (not verified)

I have a brand new MBA 13" i7 256GB and it wouldn't wake up from sleep (lid shut). I tried your advice with that (single) start up disk and the SMC reset and it works fine now! But I don't know which one of the two steps did the trick.....thanks a lot.

21 Jun02:38
By Anonymous (not verified)

I have a MBA with similar problem. I also read that the issue may be caused by a third-party application that has an automatic check for updates option in its preferences/control panel. The theory is that when sleeping, the check updates option may be invoked somehow and causing a conflict preventing the unit from triggering its wake mode when requested.

One Genius advised a poster to disable all check for updates options and apparently it worked.

01 Aug09:16
By Anonymous (not verified)

Reinstalling OS did it for me after trying 1 and 2,
Did not try solutions 3 & 4. Reinstalling Mountain Lion just seems to settle everything since none of the system preferences were changed that i could see.
This problem of not waking from sleep occurred at random on MacBook Pro in both Lion and Mountain Lion.

02 Aug06:20
By Anonymous (not verified)

The safe sleep fix did the trick. I was on the phone with apple support for an hour, came across this document and outsmarted apple's supervisor. The Internet is always one of the best places to go!

02 Aug15:31
By DJ Redline (not verified)

I'm running OSX Lion on my old Macbook Pro (3,1) 2.2 Intel Core Duo (with newly installed SSD + HDD). Had problem waking up from sleep. No glowing light and just a black screen.

Turning off safe sleep (hibernation) worked for me.


09 Sep03:24
By Ben the Computer Guy (not verified)

I have seen this problem many times with PGP Whole Disk Encryption installed on the drive also. This is because Apple is working at such a low-level with the drive at that point when it's resuming from hibernation. IT bypasses the preboot authentication for PGP to allow you to boot the operating system. So you just get a black screen.

A workaround is to create a symlink for the hibernation file to /dev/null with a terminal:

sudo pmset hibernatefile /dev/null

also the sudo pmset hibernatemode 0 usually works as well :)

14 Dec02:01
By Anonymous (not verified)

Finally... found someone who has the same issue :) Thanks for sharing!!

I have the exact same configuration and am experiencing the issue.

I have SSD in place of original HD and took out the optical drive and put the original HD in its place. If I close the lid, it will not wake up

How is yours configured?

If you have installed a second hard drive (or SSD) on your MacBook or MacBook Pro, and have waking up problem of the mac, you may try to install Mac OS X system on the other disk of the book.

I have removed my optical drive of my MacBook Pro, and installed a second hard drive. When I installed Lion on the second hard drive, my MacBook Pro could not wake up from sleep. Then I tried installing Lion on the original hard drive, the MacBook Pro did not have the problem.

24 Dec02:26
By Nolimeplease@gmail.com (not verified)

MacBook black early 2008 2.4 core duo 4.1 a1181 10.6.7

Suhweet! Thanks for your help!

So I just convert opti to ssd 120gb (89gb osx/31gb winxp), install fresh os on ssd boot, two new ram sticks.
Tried step 2, then 1, then 3 but couldn't make the character after the "g" in command: "pmset -g | grep hibernatemode". So I did some more research and found this.... Worked like a charm!!!

Disable Safe Sleep Mode In Lion
Safe Sleep, a feature of the Mac OS that writes the contents of the RAM to a file called sleepimage on the SSD/ disk to protect active data in the event the MacBook loses all power. Disabling safe sleep can free up precious storage space particularly when working with MacBook Airs and their SSD drives (128 GB and 256 GB).

Turning Off Safe Sleep

Open the Terminal (in Applications > Utilities), then type the following command:

sudo pmset -a hibernatemode 0

Press Enter. You’ll be prompted to enter your password. Do so, then press Enter again.

Next, type this command:

sudo rm /var/vm/sleepimage


If you decide to re-enable Safe Sleep, just replace the first Terminal command with this one:

sudo pmset -a hibernatemode 3

Changing the “0” to a “3” turns Safe Sleep back on, where data is saved during Sleep to both the RAM and the disk/SSD. Reboot after the change.

Disabling Safe Sleep doesn’t mean that you can’t put your Mac to sleep; closing the lid still puts it in a low-power state. It just means that if you lose all battery power while sleeping, you’ll lose your active data.

07 Jan01:11
By Anonymous (not verified)

Just slipped a new SSD in my MBP and Solution 3 got me straightened out. Thanks for posting this!

11 Jan20:04
By Kirill Benkovitch (not verified)

Disabling hibernate mode fixed the issue for me,but it kills the battery(

To disable hibernate mode, type this in the Terminal:

sudo pmset -a hibernatemode 0.

Anybody opened bugreport ?

09 Feb06:27
By Anonymous (not verified)

My wife has been complaining of this issue happening sometimes on her MacBook Pro (2011 model running lion), so I googled and came across this very helpful page. I tried steps 1 & 2 to no avail, when I was about to try step 3, I picked up the MacBook and it woke up! I realized that because it was stacked on top of my MacBook , the magnets in my MacBook was holding the reed switch closed in her MacBook Pro - keeping it in sleep mode. (Stacking laptops is a space saving measure in our house. We've done it for ages but I've only recently switched from pc to MacBook). I thought I'd post JUST INCASE anyone else is fault finding the issue while stacked on another MacBook.

09 Feb21:32
By Anonymous (not verified)

I'm running OSX Snow Leopard on macbook 3.1 and for me work reset smc.

11 Mar00:15
By Anonymous (not verified)

solution 3 worked for me with MBPR where I faced this issue after uninstalling deep sleep.
I found that the sleep mode was 5, so i changed it to 3 using the hereunder command
sudo pmset hibernatemode 3

03 Apr07:05
By Seth Evans (not verified)

Just to let you know I tried Method 3 and it did the job. My MBP now wakes up without a problem.


23 Jun21:40
By Swapnil (not verified)

Solution 3 worked for me thanks a lot ..... :)

24 Jul18:18
By Anonymous (not verified)

Thank you! You are a gem!

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