Currently Being ModeratedMar 25, 2012 6:16 AM (in response to Jon Israel)
everyone having this problem, please examine your area where the MAC device is located. I read on this thread where a person had a problem with their iMac running hot and that was their cause for not waking after sleep. after investigating, my mac was definitely hot to the touch at the back & top area and it was sitting pushed back as far as it could go on my desk where I guess it was not getting enough ventilation. I have since moved it out 2 inches so the top vent is not covered and I'm now going on 4 days with no problems waking from sleep. before I had to power it off/on 3-4 time per day. it worked for me so please investigate a possible over heating issue before restoring your hard drives and replacing your devices.
good luck and hopefully this simple solution works for many of you.
Currently Being ModeratedMar 26, 2012 5:19 AM (in response to mmorri12)
Unfortunately the problem has occured once again. I woke this morning to an iMac I could not awaken without powering off and on.
back to the drawing board...
Currently Being ModeratedMar 26, 2012 6:44 AM (in response to mmorri12)
Yea mine is out in the open and about a foot from the wall behind it.
Currently Being ModeratedMar 28, 2012 7:25 AM (in response to Qholmes)
I'm curious about Itunes... do you guys let itunes run in the background? I usually do for streaming music and movies to my appletv, but since it last locked up Monday, I've shut itunes down. and it's been trouble free so far.
Currently Being ModeratedMar 28, 2012 9:09 AM (in response to mmorri12)
itunes prevents mac from sleeping while playing, so if you are listening to music your mac wouldn't go to sleep.
probably in some cases audio daemon prevents mac from full sleep. in my case, if screen stays black I force mac to sleep with command option eject and then I can hear how it falls asleep. then I can wake up mac perfectly fine. For me screen stays black only if mac is not actually asleep.
I will try not to use itunes for a while to troubleshoot
Currently Being ModeratedMar 30, 2012 6:19 PM (in response to mmorri12)
since shutting down itunes and not letting it run minimized in the background, my iMac is still waking up from sleep with no issues. whether its a permanent solution, only time will tell. if/when it locks up I will reply...
Currently Being ModeratedApr 13, 2012 5:23 AM (in response to mmorri12)
I'm having the same problem. My bluetooth mouse and keyboard will not wake the imac. The only way get back on is to power off by holding down the power button or pull the plug. Any suggestions?
imac i3 3.2
Currently Being ModeratedApr 15, 2012 11:47 AM (in response to StarvinMarvin)
I didn't have any of these issues until I upgraded my Imac Mid summer 2007 model from 10.4 to 10.6. Now I get constant freezes from various causes. Sometimes it appears to be network related, other times it can't wake from sleep. I have been on the phone several times with Apple.
I ran the Apple Diagnostics, and it shows a Ethernet Controller error. Apple says that is causing all the problems.
I suspect more and more that there are more than one hardware issues with my Imac that did not affect OS 10.4, but now are affecting 10.6.
Because of all the problems, I decided to install Linux Mint as a dual boot. My Imac runs like a champ in Linux Mint without a single lockup. I will probably use Linux Mint for most things and Apple OS when I need to synch with my Iphone.
Currently Being ModeratedApr 15, 2012 12:19 PM (in response to Jon Israel)
I've been on to Apple support about this a couple of times now. They insist it isn't a hardware issue and must be software related, they say probably something ot do with other software installed on the machine (of which I have quite a bit so tracking it down may be tough).
On the first call they suggested I disconnect the power cord from the machine for a few minutes and then re-connect and re-boot. This provided a temporary fix, but the symptoms recurred after a coupel of weeks.
On the second call earlier this week they asked me to delete the plist file com.apple.PowerManagement.plist from Macintosh HD/Library/Preferences/SystemConfiguration. This gets re-created when you re-boot and I haven't had the problem since but I suspect it may come back sometime soon.
The next step they suggested was to re-boot in safe mode and see if the problem is ocurring there.
It would be nice if they responded to this thread though as lots of people seem to have this issue and it would be good to get to the bottom of it.
Currently Being ModeratedApr 25, 2012 3:20 AM (in response to Jon Israel)
I have the same problem. It's really time Apple took responsibility for this. My solution so far has been to manually put the computer to sleep whenever I plan to leave it for more than a few minutes - it normally does come back on. It's only when it goes to sleep of it's own accord that it won't wake up. Is there a bigwig at apple that we can write to about this - there are now 32 pages of people with the same problem. The macbook pro had the same issues and it looks like Apple have now taken responsibility and offered to fix them all for free, even if they're out of warrenty.
Currently Being ModeratedApr 28, 2012 6:00 PM (in response to Jon Israel)
I was having the same problem and someone posted to go to system preferences and make sure the screen saver started up before going to sleep. Worked for me and my son. What surprised me is that the default setting was allowing it to sleep before the screen saver was activated even though there was a caution sign stating it would happen. Six months and no more problems for me. I was actually on here looking for the poster to let him know he had the right solution for me.
Currently Being ModeratedJun 11, 2012 6:45 PM (in response to Jon Israel)
I had similar issues, iMac wouldn't wake from sleep, whether I put it to sleep or let it drift off. I have a wired keyboard and bluetooth mouse, and neither worked, I had to force shutdown every time (have a mid 2007 model, running Lion 10.7.4).
These 2 steps worked for me, I'm not having this issue at all anymore.
First, I reset the SMU:
On restart, the cooling fans were running non-stop, even if I shutdown and restarted. To fix this, I reset the SMC:
Not sure how or why all of this worked, but after months of looking for answers, this was it for me. Good luck, what a pain.
Currently Being ModeratedJun 20, 2012 9:51 PM (in response to Tumanga)
I have this problem since May. Usually it won't wake up in the morning. Sent it to apple store and it is said the video card was bad and get replaced. But the problem still remains. Then apple advisor asked me to uncheck all my iCloud items but the problem still remains. I'm waiting for the further reply from apple.
Currently Being ModeratedJul 14, 2012 9:43 AM (in response to 老玉米)
I posted last year about this problem with my mid-2010 iMac. I never had any problems under 10.6.7, but updating to 10.6.8 led to the iMac being unable to fully wake from sleep about one quarter of the time, what I came call being stuck in a "coma" (requiring a hard shutdown and then reboot). As I have the OS on its own partition, I experimented several times by restoring back to 10.6.7, using for a while and noting the results of sleep/wake cycles, then updating to 10.6.8 and again noting. It is clear that simply by updating to 10.6.8 the problem appeared. A representative example from my notes: under 10.6.7, 37 sleeps with 37 successful wakes and no instances of remaining in a "coma" (HD running but screen black and unable to do anything but hard shutdown and reboot); after updating to 10.6.8, 90 sleeps with 70 successful wakes and 20 coma incidents. I should add that during these experiments I made sure not to update any software other than the OS X itself in going from 10.6.7 to 10.6.8, including not installing any software at all while running 10.6.8. It is clear to me that for this computer the issue was coming from 10.6.8. I should add that this was not a wireless issue as I use both wired mouse and keyboard.
Interestingly, we also have a late-2009 iMac, and it has never had any "coma" problems, even under 10.6.8.
Seeing many reports here that upgrading to 10.7 Lion did not make the problem disappear for people, I was reluctant to do that upgrade. I did finally decide, however, to go ahead and upgrade the mid-2010 iMac to 10.7.4, and so far I have not had the "coma" issue after 20 sleep cycles (where under 10.6.8 I would have expected to have 4 to 5 failures to successfully wake). I sure do hope that this is the end of the issue for me because it was not good to be stuck at 10.6.7.
Currently Being ModeratedAug 4, 2012 3:07 AM (in response to charche)
I'm having the same problems with my imac and I am also running 10.7.4. I've also noticed that when the computer goes into sleep mode it causes one of my hard drives to keep constantly activating, every few minutes, as if being woken up and then immediately being sent back to sleep.
In response to 'Jabowic' I checked my screen saver and it was set to go off every 45 minutes, and the computer to sleep within 1 hour, so I don't think that was the issue.
I wouldn't expect a fix from Apple any time soon. I just switched the computer sleep setting to 'Never'. I lost files from their last 'update' when my iMac was turned into a brick. Now this. Can't wait to see what the next update does.