MacOS Sierra - iMac won't restart

[macgabe]

I installed it on my 2012 iMac earlier seemed to be working OK (except for a volume problem in one app).
I tried restarting and now I can't get past the splash screen - Apple logo and loading bar.
Any ideas anyone or do I need to go to the Apple Store?

 

[grahamperrin]

Patience; how long have you waited?

 

[macgabe]

Managed to restart by resetting the PRAM! First time that has worked in 25 years …
[doublepost=1474485763][/doublepost]Waited hours I left it when I went off to dinner . It had already installed this was just a restart - should take 45 secs or so - couple of minutes max if it had installed some new software
[doublepost=1474485797][/doublepost]The actual installation was about 2 hours

 

[dany20mh]

I have the same problem too and I have tried the PRAM (the one that you did) yet, but when I hit the restart button, it closes all the app and then the dock stays there and iMac stay there too and doing nothing, even after you don't touch it, it goes to sleep and if you move the mouse or touch the keyboard it wake up and still there.
If I open for example Safari at that state, it try to do the restart again and this time everything will be gone and just a gray screen I can see and again nothing will happen.

 

[mmobie]

Same problem, tried everything to reboot, PRAM, safe mode, nothing, just get a blank screen after it tried to reboot for a very long time.

 

[dany20mh]

Same problem, tried everything to reboot, PRAM, safe mode, nothing, just get a blank screen after it tried to reboot for a very long time.

Sorry to hear but I'm glad I'm not alone in this, cause I was getting crazy with it

 

[Rod1]

I just can’t get it to go from the mountain photo when I try to do a restart.... it sits there and does nothing....switched off and started again, but still nothing... what’s PRAM and safe mode and how do I try them please......

 

[grahamperrin]

Consider https://forums.macrumors.com/posts/23563261 under Sierra bricked my Mac

… what’s PRAM and safe mode and how do I try them please

How to Reset NVRAM on your Mac - Apple Support

macOS Sierra: Start up in safe mode