iMac 5K spontaneously restarts after sleep

If you have already been dealing with Apple for this issue and they replaced your system and now the new system is exhibiting the same behavior you should be dealing with Apple directly, preferably with the same person you dealt with before.

You should have gotten a case number. Refer to it when you call AppleCare.

I also have experienced this problem. 5k iMac i7, 295x graphics. This is the 2nd time this happened. Received the computer in early December, no issues until this week.

I have this exact same problem on my iMac Retina, 4GHz i7, 16GB ram, M295X.

Whenever I put it to sleep at night, I can sometimes hear it reboot(I hear the apple fanfare as it starts up) from the bedroom.

Most of the mornings I wake the computer I get the same message "a graphics problem has been detected". This message only comes up when the computer has self-rebooted from sleep.

At first I thought it had to be one of my external drives being connected to the computer, but I had it happen with no usb peripherals attached other than mouse and keyboard. My solution to this problem so far, shutting down the computer every night.

You say you've replaced your computer and you still get the same error. This makes me think this is a software issue and not a hardware issue.

In my case I hope that an update will fix this as I need my computer for work, also I love it very much and was going to buy it another 16GB of ram for our 2 month anniversary 😀

Hi Craig, I contacted Apple's tech support team on 12/26. Their advice was to first attempt resetting the system management controller and also to reset the NVRAM. After doing those two things, I am supposed to run two diagnostic tests by logging into a test account via safe boot and running the tests. I have three articles related to the two resetting preparations and the diagnostic tests. I would be happy to post links. With that said, I have not done this due to travel and a general lack of desire to commit that much time to the issue to-date.

Per Apple, if the issue occurs in a "new account in safe boot", that means it's a hardware issue. Otherwise, it is a piece of software (unlikely, very little additional software installed on this iMac) or Yosemite itself.

I have a friend that has the same exact computer as mine, with the exception of the hard rive (1TB fusion vs 3TB fusion). He is also experiencing the same issue. One interesting similarity we have found is that we are both running resolution that gives us slightly more 'real estate' than the "Best (Retina)" setting. Specifically, this setting appears to be 2880x1620. I would be interested to know if Craig and Morry are also running this resolution while experiencing this issue.

Last thing - I have not experienced the issue since 12/26 but have not used the computer much in the last several days. I'd say I'm about 25% on experiencing the issue on every wake from sleep.

I now it is not a real fix but you could just have your iMac shutdown at night and power up in the early AM using the schedule function until Apple fixes the real issue. That is what I do.

I haven't been in contact with Apple as such. I haven't had time to really think about the issue yet.

It is mostly an annoyance and does not at all interfere with my work as it only occurs when the computer is sleeping.

The computer has never had as much as a hiccup while I've been working on it.

My screen resolution is set at 3200x1800 and I'm pretty sure this happened at the recommended resolution (2560x1440) also.

I've had this problem since day one.

My hard drive is a 500GB SSD. I haven't installed too much software. I've installed the Adobe CC suite and steam, as well as Chrome browser and a few other video related apps(Redcine, gopro studio etc)

As I had this problem from the very start I'm certain that this happened even before I had installed any additional software.

Looking forward to hear what apple support will say about the problem, I'll still be "sitting on the fence" as I believe this to be software related 🙂

Thanks Craig and Morry - that is valuable information. The only extra software I have installed is Steam and Microsoft Office for Mac. As I try to put the pieces together, it appears that this is a Yosemite or graphics card driver issue, perhaps related to conflicts between Yosemite and the r9 M295x driver. That seems to be the most predominate commonality among our machines.

I have a MacBook Pro 17" (early 2008) and recently installed Yosemite and have had all kinds of problems, including it waking up by itself and several crashes in Mail. Not sure if it is hardware or Yosemite problem. Tech support has been hand-holding for several weeks now and the most recent way I got ti back to working was to insert an old Leopard disc and option startup. Not sure if your iMac has anything like this happening but, it seems that after I installed Yosemite, it gets very scary freezes and I get hours of sweat trying to get it to act normal. Working fin now but not sure if it is hardware or software and the only answer I keep getting is "get a newer model." I was considering buying a new iMac to replace my old MacBook Pro, but now after hearing your horror story, not sure if I should wait and find out what happens to you. Happy New Year Craig..

I do have the same problem, but it only seems to happen if I put the Imac to sleep manually, through the apple menu.

Hi Luis.

This is some new insight. I will have to try to see if it makes a difference to let it go to sleep on its own versus me putting it to sleep.

If it does, this is definitely a software issue.