Imac late 2015, bought 01/2016, not my first mac but first with this issue which developed about a month ago. When put to sleep I wont turn the screen on, it plays music when I push play on keyboard but screen is black. I have to restart it to screen to work. Resetting SMC and NVRAM didn't help, its really annoying because have to leave it with screen saver on,
iMac (Retina 5K, 27-inch, Late 2015), OS X El Capitan (10.11.5), 24gb ram
Run the Apple Hardware Test.
marcipaw,
Do you have any Antivirus, cleaning or ANY third party maintenance utilities installed on the computer?
No 3rd party software is installed, what I discovered so far that this issue is user specific, on test account there were no problems with waking. Interesting fact is that when connected to Applecare and sharing screen with them they could see my screen just fine while all I saw was a black screen. I'm doing clean install right now
I did do Time Machine recovery two weeks before this issue arose.
Let us know what occurs after re-installing OS X, did you do a format and install or just a re-install? There is a huge difference!
First I did just reinstall and recovery from time machine that it made no difference, right now I'm doing erase, reformat and clean install of OS with recovery of data and applications from time machine but without recovery of computer and network settings, will see how it turn out
one of the 2015 iMacs I support would not wake from sleep (at least on my side) and Apple detected an issue with the GPU that was not picked up by Apple Hardware Test.
In my case, problem is with one user, additional account on same computer does not experience the same issue
If your problem persists, you can run an EtreCheckreport of your system. We can then look for obvious issues. Please click the link, download the app and run the report. Once you have the report, please copy and paste it to your reply to this post.
If you would like more info on what EtreCheck is, simply click the link and you will find a description of the app.
So fresh install of the OS did the trick, everything is back to normal. I will get Etreckeck just so I can have a baseline if any other issues develop, thank you all for your help.
imac won't wake
