I did unplug my powered usb hub in order to see if that was the cause of my frozen sleep issue. As soon as I unplugged the usb hub, it woke up refreshed every time. I am guessing that just ejecting the hub but not unplugging it may not give the same benefit.
Yes, it is a pain but, for my situation, I don't what to hard boot it, and actually in my case, I had to unplug it each time, either pulling it out of the back of the imac or from the power strip. I don't want to do the hard restart that often as I think it is a drain on the system over time. I chose to stop using the usb hub and to plug and unplug various usb items. I hope some kind fo firm ware update might allow me to use it again in the future, especially since I cannot return it as the night before I figured out it was the culprit, I recycled the plastic that it was shipped in so I cannot return it. But I am grateful to know the culprit and will either hang on to it hoping for a firmware update, or sell it on crag's list.
just wanted to clarify...
Right no worries.
Mine still wakes up about half the time (maybe a little more lately) - so I'm prepared to throw the dice for a while ;-)
In fact, it might be possible that not turning the USB external drive on (even though it's physically connected) might solve the problem for me.
I'm trialling now.
Although this is not a great solution either ;-)
But it might mean that I can fix the problem by buying a new Firewire800 (ie not USB) external drive.
But this doesn't address the problem. As many people have described it, it has nothing to do with what one does when one goes home at night; it's about what happens any time the computer goes to sleep. I am up and down from my computer all day, and it goes to sleep from time to time. I need to be able to tap a key and get back in business. The inability of some people to do that is what we're talking about here.
And I would hope that the responses would not all focus on presumed peripherals as well, because in our case, there are no peripherals other than mouse and keyboard. Occasionally there is a firewire hard drive attached, but that seems to make no difference in the recovery from sleep situation.
The situation did not always exist with the particular computer in question, so I have to believe that it was caused by some system software update, and that the solution needs to come from Apple. I have not yet personally called Apple about it because I don't feel I should have to pay an incident fee for something like this. But if there's no bona-fide solution forthcoming, I guess I'll have to do that.
Meanwhile, if anyone one there can suggest a generally-applicable solution that does not presume anything but the standard configuration, it would be much appreciated.
I don't know if there's a single solution. But I DO know that since I cleared the Wi-Fi in the systems preferences I've been problem free. I even plugged my hub back in and it's still working just fine. No more comas. knock on wood.
As to certain other not-so-nice responses ... file corruption occurs no matter what computer you are using. Proper maintenance is always necessary to keep your machine running problem free. You wouldn't drive your car and never change the oil.
Learning what small tasks you can do to keep your computer working in tip-top shape is one way to help yourself. There are many MANY websites devoted to this. A google search will bring up most of them.
Oh, and I believe Apple ALWAYS recommends backing up all your important files before you do ANY update. Blaming them is a bit counter-productive. But that's just my opinion and worth what you paid for it.
We will try the clear wifi prefs suggestion and report back, we are also going to reimage next week we will see what happens. Here is my original post in this thread...
"Mar 22, 2010 11:36 AM (in response to Jon Israel)
I have a similar problem. We have a lab of 16 20" iMac Intel (Mid 2007) running 10.5.8. All the Macs in the building are clones of the same OS and app image and I am only having trouble in this lab so I am pretty sure it is model specific. The problem appears to be not awaking from sleep. You walk up to a machine it appears to be shut down, if you put your ear to the machine you can hear it is on. The only way I have found to deal with the problem is to hold the start button down until you hear it shut off then restart."
My core i3 iMac (bought 12/10) never had this "won't wake from sleep" problem until sometime early last month (7/11). From then on, it would often not wake after sleeping (I sleep it multiple times per day): sometimes I would get 5 or 6 sleep cycles with it waking properly before it failed, and other times just one or two. I read through this thread (and others I could find) and tried all of the suggestions I could, but nothing would fix this seemingly random failure to wake problem. I use wired (USB) keyboard and mouse.
I did notice some predictive signs that my asleep iMac would not wake on the next attempt (this let me accurately predict when it would not successfully wake and I would have to do a hard shutdown and then restart). First, the top back of the case would get very very warm, even if I had used the computer just a few minutes (thus it started cool) before sleeping it; it was as hot as it gets when I run the processor hard with an app. This suggested that the computer was not truly asleep, but I could find no trick to wake it up. Also, when stuck in sleep mode, holding down a mouse button (USB) would light up the mouse, but still not wake the computer.
Finally, I noticed that the router could tell me if the "sleeping" iMac would be able to wake up on the next try. The router has a light for each connection that is active, and sleeping computers are not seen by the router as active. What I noticed was that when my iMac was going to be able to successfully wake up from sleep, its light on the router would not be lit (i.e., the iMac was truly and properly asleep), but when it was NOT going to be able to wake up, the light on the router would remain lit (i.e., the iMac was NOT truly and properly asleep).
This last observation had 100% accurate predictive ability - it was never wrong about whether I would be able to successfully wake up the sleeping iMac. Useful as that was, it was not a solution to the problem, and I was doing hard shutdowns followed by restarts one, two, or up to four times per day. A Mac user should not have to deal with this.
The iMac's hard drive is partitioned, with one used as the startup disk (no docs, etc), and I had done a backup in early June 2011 (using Carbon Copy Cloner), so I decided to try running off that backup and see if I still had the "won't wake from sleep" problem (which I did NOT have at the time of the backup). Over the course of several days and many sleep-wake cycles, I never had a problem waking the iMac from that backup, so I decided to restore the backup to the internal hard drive and see what happened. I did that restore about 10 days ago, and have gone through over 50 sleep-wake cycles without a single "won't wake from sleep" failure.
Thus, I have fixed the problem, but still don't know what was causing it. The startup disk backup is 10.6.7, and the startup disk that had all of the waking problems was (it's gone - trashed) 10.6.8. There were undoubtedly a number of other differences between the two, such as other Apple updates, as well as a few installed (non-Apple) apps, so I can't say if it was the OS update causing the problem, or something else.
When I have some time, I am going to start doing Apple updates one at a time and see if the "won't wake from sleep" problem comes back, and I am going to keep good records of everything that gets installed from now on.
Ok I was in the same boat as all of you until about 10 minutes ago. I was having the same problem with my wireless keyboard and mouse. My Macbook Pro 17' would not wake up from sleep mode and if it did it would only stay awake for like a second. it was really making me mad and then i noticed that after all this work it would make me even madder if my laptop died on me. So in hand i plugged in it and then tapped a key and it turned on. So just so we can say we have tried everything lets just try something simple and plug it in and then see if it will work because it worked for me so maybe it will work for you too.
I spent all this afternoon setting up my new 21.5 inch iMac bought today, installing software updates and then transferred all my stuff from my old machine (a first-gen intel which can't run Lion). Played with it for 5 mins, though how great it was, then put it to sleep and took all the packaging to the recycling bin. And it wouldn't wake. Tried most of what I could find on the net, and none of it worked. Resigned myself to having to drive back to the large non-Apple store where I bought it tomorrow.
Three hours later, plugged it back in, and it came on, so I altered a few security settings to limit the opportunity for store staff to go through my documents. Set it to sleep again, and of course, I've got the same problem again. Tried all the key combinations in this thread, but it still won't work.
Tomorrow am, if by chance it will run again, I'll upgrade to Lion, and see if that helps, along with the various changes to sleep settings suggested. I'm disgusted that Apple are shipping machines that do this, and miserable I've had to go back to my 5 year-old iMac to post this.
I had this same problem and I think I finally solved the issue.
It seems as if the mac was shutting down because of heat issues. When I looked at the Activity Monitor, it told me that there was a process that was consistently taking 15-20% of the CPU. After a while, the processor would get too hot and trigger an automatic shutdown to protect the hardware.
I determined the issue was a driver that I installed for my printer (in my case a Panasonic). I had to uninstall the driver and things are now back to normal. What was also weird was that the process would go down to 0% cpu when I turned the printer off. I'm suspecting that unplugging USB hubs helped because they disabled certain peripherals. I suggest people try to diagnose the problem by checking what is running using the Activity Monitor.
Hope this helps.
So I went back to the big electrical retailer where I bought my iMac yesterday...and it worked perfectly. I was really embarrassed; but it slept, woke up, restarted, shut down and started up three times for each option. So no way I could claim there was a problem. They looked at me kindly, and I left.
Came home, it booted up as it should, but when I put it to sleep, guess what? It wouldn't wake up....so after a random series of pushing the off button, unplugging and plugging in (one of which made the fan blow like my desk fan), I finally got it back up and rebooted. Still no peripherals other than the bluetooth keyboard and the mouse.
So then I set about installing Lion, successfully, via the App Store. And the problem is still there; if it's put to sleep, it won't wake. I've managed - after zapping the PRAM - to reboot it, changed all the settings as per the advice in this thread, and clearly, the problem is still there. So I've set it so that the machine never sleeps, and will shut it down completely every night. AAAAAAAAAARGH!