Mac Forums

Mac Forums (
-   Apple Desktops (
-   -   iMac Freeze After Sleep Resolved (

kevn 03-04-2011 10:11 PM

iMac Freeze After Sleep Resolved

I am posting this message hoping to help others who may have the same problem that I did. I was having problems with my new 21.5" intel iMac frequently freezing after coming out of sleep. I think the problem was related in some way to the wireless keyboard or wireless mouse that came with the computer.

The problem would happen most frequently in the morning after it had been in sleep mode all night, but it sometimes happened if it had been in sleep mode for less time. The computer would sometimes allow me to type a few characters of my login password, or, it might type in the password completely and go to the desktop, and then the mouse and keyboard would become completely non-responsive. The only way to fix the problem was to press the power button on the back of the computer and reboot. This problem would occur every day, at least once or twice, sometimes more often.

I tried the hardware diagnostic software on the installation disk. This reported everything OK. I repaired disk permissions and reinstalled OS X 10.6.6. None of this worked. Apple phone support suggested that I try to troubleshoot by unplugging all USB devices, router, etc. reset PRAM and reset SMC. I did this but the problem continued. I brought the computer into an Apple store, and their diagnostics testing everything OK. The Apple Genius technician suggested that I continue to troubleshoot by eliminating hardware and software I had installed to see if this corrected the problem. None of this had any effect on the problem

What finally fixed the problem was this sequence: I disabled require password to log in, turned off the wireless keyboard and wireless mouse, performed another SMC reset shut down, unplugged the computer, pressed the power key for 15 seconds, then plugged the computer back in and rebooted, and at the same time did a PRAM reset with the command + option + P + R keys. When the computer booted up, I then turned on a different Apple wireless keyboard and mouse (which, as far as I know, should be identical models) and let the computer link to the new keyboard and mouse. I turned require password back on, as well as screen savers and sleep. This fixed everything. The computer has not frozen in the past four days.

I am not sure what to conclude about this, but it does seem to involve the wireless keyboard or mouse in some way, in my case. It would be nice to know if my other Mac wireless keyboard and mouse are actually broken or not, but since everything is working perfectly, I don't want to spend time trying to reconnect the other ones and find out. I would be very interested in any comments about this!

If you are having freeze after sleep problems, and you've tried everything Apple has suggested, I suggest you also try an alternate keyboard or mouse, even a cheap Microsoft USB version as troubleshooting tools.


kevn 03-10-2011 07:08 AM

It turns out the problem is back... I contacted Apple. They sent me a diagnostic program to run and send results back to them.

Enrico 05-08-2011 03:25 PM


Originally Posted by kevn (Post 1199745)
It turns out the problem is back... I contacted Apple. They sent me a diagnostic program to run and send results back to them.

Hey Kevin,

Any new on this? I have exactly the same problem.I didn't have any succes in troubleshooting so far.:'(

de_dicto 10-05-2011 06:17 PM

Same problem
I have the same problem. I am wondering whether the freeze would happen if one did not allow the display to sleep

Head_Unit 10-06-2011 02:08 AM


Originally Posted by de_dicto (Post 1305642)
I have the same problem. I am wondering whether the freeze would happen if one did not allow the display to sleep

Perhaps not. I had this same problem, on a machine that ran fine if never slept. Turned out to be a bad hard drive.

koppenhoefer 06-11-2012 09:41 AM

@Kevn,.. news on this?
@Kevn,.. What was the final resolution of your problem? We are now seeing this on our park of MBP's

thanks for any suggestions.

Awolowa 05-15-2013 10:24 AM


The situation on my end was present with both Lion and Mountain Lion.

I brought in my 17" late 2006 Intel iMac for a clean up and resolve some crashing issues. At that point, the freezing was a minor problem in comparison, so I wasn't even in for that.

My problems were not solved, but what ended up happening is that the tech traded my computer in for a 20" late 2006 Intel iMac., with the swap of computers, my problems were resolved. However, now I notice that the freezing is still here... and with a different computer, albeit basically the same model, with Mountain Lion versus Lion.

SO, what happens, and it's regular, is that when I sleep the computer, I can no longer wake it with the mouse or keyboard. And if I wake it with the power button, the cursor and keyboard is frozen.

SO, I unplug and re-plug the keyboard, and that works. So it's annoying, but that's the scoop. I tried a different keyboard and it does the same. So it's not the keyboard or my mouse.

No leads I reckon as of yet?

All times are GMT -4. The time now is 01:50 AM.

Powered by vBulletin
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.