Q: Shut down
I shut down my iMac overnight due to thunderstorms. 21 inch, 2.8 GHz intel core i5, 8g ram, running 10.11.6. Sometimes when I come downstairs the next morning it has not completed shutdown. There is a black screen with spinning lines (not the beach ball) at the bottom and I have to shut it down with the power button. (Jiggling the mouse or tapping keyboard does not wake it up).
Any ideas what might be causing it or what to do about it?
Thanks
Posted on Jul 28, 2016 6:42 PM
If you see a spinning globe instead of an Apple logo, it means your Mac is starting from a network-based startup disk like Netboot or Internet Recovery instead of a connected or built-in startup disk. If you didn't mean for your Mac to start this way, press and hold the power key to turn off your Mac. Then, press the power key again to start up normally.
About the screens you see when your Mac starts up - Apple Support
Posted on Jul 28, 2016 8:07 PM