iMac not waking up from sleep after Yosemite upgrade

Update:

disconnecting my machine from the server before sleep seems to prevent the issue

I am not connected to a server nor to an external hard drive. Ever since updating to 10.10.3, bluetooth routinely fails to wake the mac from sleep (Late 2013 27" iMac.) My only work around was to plug in a Dell PC USB keyboard and wired mouse. This has solved the problem but now I'm not working on the Mac keyboard which is annoying.

The issue was not happening for me in 10.10.2. Apple support wants me to reinstall the OS. Which is a joke. It must be. They ran ad campaigns lambasting MS for having to keep reinstalling the OS for minor issues, now they've done exactly that. Ironically, my windows 7 computer from 2010 has never had any issues, I've never needed to reinstall, and has never blue screened. Meanwhile this new mac has had nothing but minor issues like this one...

Very frustrating. And no word from Apple...

I'm still having problems with my Mac crashing and not waking up after upgrading to Yosemite. Disconnecting the backup Lacie drive seems foolish to me since the system is crashing so much I want to have a current backup.

Thanks, eerickso, for the thread and congrats for getting your problem resolved. I'm contemplating taking my computer to the Genius Bar as I'm completely lost on this. To make matters worse, my Mac Mail is also totally screwed up after the upgrade and my imap capability with GoDaddy is wiped out. I don't even know where to start.

BTW I got an request for a feedback survey from Apple while reading the thread and weighed in with as much disappointment as I could in the limited space provided. I can't believe no one from Apple is in this thread.

MacBook Pro (Mid 2009), Yosemite 10.10.3, blue tooth Apple keyboard, USB Kensington mouse, Lacie drive (not TB) USb connection.

PROBLEM SOLVED:

I suffered this problem for months and months, sometimes multiple times per week, and finally found the solution:

you have to turn off the setting that automatically puts your computer and display to sleep after a certain amount of time.

Settings>Energy Saver

Set both to Never.

I now just use option-command-eject button to shut off my computer's display at night but i don't ever put it to sleep. It uses more power I guess but it's minimal and i haven't suffered the grey screen of death since!

I suppose you could put it to sleep manually and see if it still creates the problem but i feel no need to do so since I am shutting down the display. Some people argue putting it to sleep actually lessens the life of your computer as well.

Regardless, the most important thing to me was shutting off the display and not getting the grey screen of death. So i consider this problem solved!

Yes, if you completely disable go to sleep it won't happen and this is a good temporary work around, but this doesn't really fix the problem. Only Apple can do that.

dshafe,

With all do respect, the problem is anything but solved. You've found a workaround yes. But now your computer never sleeps. I've found another solution. Use my old wired Dell keyboard, and Amazon mouse on my Mac and it works just fine. But that also isn't a real solution. I want to use the mac keyboard and have my normal layout. I want the bluetooth function that I paid for. And I want Apple to fix it for me and for everyone else who is having this problem without having to reinstall the OS (the exact thing they made fun of Microsoft for having to do) to fix it (only to probably find out that it's still an issue).

Fix it Apple! Please?

you are correct. if i could edit my post I'd say WORKAROUND

NP dshafe.

Hey...did 10.10.4 fix this?

This is happening to me as well. This is so frustrating.

Did you guys try the newest Beta of El Capitan?
Installing the Beta resolved the issue for me... My iMac wakes up everytime i push a button on the keyboard... Just not when I move the mouse as it used to be... But I'm fine with the keyboard waking it up 😀

As an administrator of iMac's across our networks, this issue is damming. We now have to have our iMac's powered on 24/7 for service until this major problem is resolved. I say major because is taking it's toll in electric. Apple needs to step up and resolve this issue.

I'm new to this thread but for the past year or so, I've been having the same issue where my iMac doesn't wake up from sleep. I hear the iMac running and the lights on my external drives also light up but my screen remains blank. The only thing I can do is hold on the power button and reboot it, which is a pain. I have not done the SMC reset or the safe mode option either, since I read how some of you have tried those options and the problem still persists. I think most of you are right it's related to the TB hard drive and the latest OS because I also have an external TB hard drive and I don't think I had this issue during the first few years I had this iMac. I have a mid 2011 iMac that's running on Version 10.10.5. I heard some of you had success by unplugging your TB hard drive, if I did that every time I put the computer to sleep, would that harm the external hard drive? The hard drive that I have is a WD 8TB hard drive that I use to mainly store all my iTunes media library (music, movies, television shows, etc). Also, I want to point out that this issue happens like 1 out of 3 or 4 times I try to wake it up from sleep. So every time that happens I do the reboot obviously, does that also harm my iMac? Sorry, if these questions seem kinda dumb but I'm not the most technological savvy guy. Besides unplugging the USB from my TB hard drive, are there any other suggestions or ideas that might help?

Hey Louie,

I have this exact problem as well, and I for one do not have an external HD and never have had one nor have I messed with the internal drive. So for some people, maybe that was the trigger that caused it, but it certainly isn't the exclusive cause/trigger. For me the problem started immediately after a 10.10.3 upgrade and subsequent upgrades to 10.10.4 and .5 have not solved the issue. (I have a 27" late 2013 iMac).

That being said, removing the external drive should not cause any problems. Those are designed to be powered on and off and plugged in and out all the time. I would recommend using the eject procedure on the drive to stop it before yanking the USB cord but other than that you'll be fine.

Hard shutting down the computer isn't a great thing. Modern harddrives autopark so you won't damage the drive per se but things that are supposed to be written aren't and the computer each time you starts thinks there's been an error so it'll go through a disk check and take longer to boot. My (temporary) solution is to get a wired keyboard and mouse (even a cheap amazon one) as it does not suffer from the bluetooth problem. It may be slow to wake (taking up to a minute to wake up because the bluetooth controller spazzes sometimes) but it'll fix the problem.

I'm in with Apple support since the iMac is still under warranty and I've been getting bounced around a bit. The senior support guy who seemed to be helping me with it suddenly stopped responding and it turns out he is at training so I have to go back through the rigmarole a bit. The usual NVRAM resets and even a reinstall of the OS did not fix the problem so I'm being escalated. There's stuff in the console indicating an issue with the IObluetooth controller. I'll keep you posted with any updates

Hmmm.

I never had the "does not wake after sleep" problem.

But now after installing El Capitan my iMac does not sleep and my hard drives keep spinning away, even with the "Put hard disks to sleep when possible".

I have to Shutdown each time ... frustrating !

Nevermind... My iMac returned back to the state in which it won't wake up from sleep after installing the Golden Master of El Capitan... Only solution is to shut down and restart... So frustrating...