iMac won't wake up from sleep using keyboard or mouse

Finally my problem was solved after going through applecare. After a change of logic board, hard disk and graphics card, everything returns to normal.

(Finalmente, mi problema se resolvió después de pasar por AppleCare. Después de un cambio de placa base, disco duro y tarjeta gráfica, todo vuelve a la normalidad.)

So I have a 3.5 year old iMac and this little problem began over a year ago. It is intermittent. I have NO clue as to why it is happening but strongly suspect it is a software issue.

I did so many power reboots that my computer began losing it's connection to the Airport. Thought that was the problem, bought another one only to have it continue.

Finally found the SMC reset and that fixed it.

But it's happening again. Sure wish I knew how to stop this.

I am following this thread with great interest because I have this problem. It happens for me perhaps once a week or less - not that big a deal but certainly irritating and definitely not good for the imac. There was a firmware update mentioned - I tried it but the update was rejected. Apparently a common outcome. I hope Apple will address this issue.

This firmware only works for some people who have the relevant software. Switching off the blue tooth settings work. One short cut that works for me is using the other "sleep mode" toggle shortcut keys [Command-Option-Eject] effectively circumvents this issue for me too. It both sleeps and wakes my imac fine and avoids those intermittent issues that everyone seems to have using their computer normally.

You shouldn't introduce a term like "sulk mode" without defining it; I can't find any reference to this online except in this thread.

Also to add my little observation, when people are saying that the computer will not wake from sleep, are there any cases where the screen is dark except for the mouse cursor? Cuz that's what's happening for my user.

Would also like to know whether the "fix" proposed by an earlier user of an attempted "wake" followed by a deliberate "sleep" then by another attempted "wake," which should now work, has met with any success.

Agentbluescreen's assessment of 50ºC as "way too hot for a mechanical device" is completely fallacious. My Mini runs consistently at 57.2 - 60.2º and the fan is on minimal speed (barely audible). I've been using it for well over a year. The fan kicks up a notch, and secondary fan comes on, when it gets hotter.

Good Tip. The [command-option-eject] shortcut worked fine for me. Tried several times with no problems. Thanks.

I've had this prob since day one on my 21.5 imac.

Would not wake from sleep or it would freeze on the blue screen when switching users

Talked to a tech at the Genius bar about this and he suggested trashing the sleep image file.

/var/vm/sleepimage

Been a week and hasn't froze yet. (so far)

Ok, after weeks of back & forth with Apple, they have agreed to replace my 27" i3 w/ a new 27" 3.4 i7. I appreciate them standing behind their product, although, I believe that if I hadn't pushed so hard (20-25 calls) it wouldn't have happened. Good luck to all! I hope I don't have the same issue w/ the new Gucci machine on the way.

I'm happy for you but I honestly do NOT believe this is a hardware issue. I strongly suspect it is some sort of software or preferences conflict.

It may be, but if that were the case, why hasn't Apple found the fix? I'm thinking it is a combination of hardware/software. I'm just hoping the new one doesn't have the same issue - will respond if it does.

I didn't mean it was an OS problem ... I think it's a conflict caused by (probably) 3rd party software. I d/l a LOT of stuff. And this "coma" thing didn't start for me until after I'd had my computer for over a year. I think it's something *I* did.

Have any of you tried to disable the WakeOnLan setting, as recommended by some earlier in this thread.

It hasn't been long enough yet but the results so far for me after doing so are quite positive.

I have this issue but it's only slightly worse, as every time I hold down the power button to shut down and then hold it again to restart - my iMac reboots without mounting my 2nd partition - which is on the same drive as the OS!

So I have to reboot a 2nd time. This is my routine, two reboots a day on a 3-month old iMac.

And just to put the cream on top, "Wake for Network Access" doesn't even work - with my AppleTV. So someone has to manually press any key on my iMac to wake it up to use the AppleTV. So I'll try turning this off, since it doesn't work anyway.

This "going to sleep" functionality is obviously very complicated stuff. I've had some problem with it or other with PC's for the last 15 years.

Amazing how we think of creating robots and yet my computer still can't wake up from a sleep after 20 years of computing - regardless of manufacturer. You've gotta laugh.

Disabling 'Wake for network access' worked for the time I tried it, however this functionality is useful, so re-enabled after 10.6.8 on 27" mid 2010 iMac and its also promising so far.