Jim-airbook
Level 1 (4 points)
Mac OS X

Q: i-Mac 5K will not shutdown after Sierra install

After installing the Sierra update, my i-Mac 5K Retina will not completely shutdown.  I select shutdown from the Apple logo and it starts shutting down but the screen stays on although very dark.  The only way I can get it to shutoff is forcing it by holding the button until it powers off completely.

 

Is this a known bug, or is there something I can do to get this fixed?

 

JK

iMac with Retina 5K display, macOS Sierra (10.12)

Posted on Sep 25, 2016 7:09 AM

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Jim-airbook

Q: i-Mac 5K will not shutdown after Sierra install

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  • by jeremy_v,

    jeremy_v jeremy_v Sep 26, 2016 1:18 PM in response to Jim-airbook
    Community Specialists
    Sep 26, 2016 1:18 PM in response to Jim-airbook

    Hello Jim-airbook,

    Thank you for using Apple Support Communities. It's my understanding your iMac won't successfully shutdown after updating to Sierra. I want to make sure you're able to completely shutdown as expected.

    First, I recommend resetting the System Management Controller (SMC). Follow the steps below to reset the SMC on your iMac.

    1. Shut down the Mac.
    2. Unplug the power cord.
    3. Wait 15 seconds.
    4. Plug the power cord back in.
    5. Wait 5 seconds, then press the power button to turn on the Mac.

    Reset the System Management Controller (SMC) on your Mac

    If the issue persists, test the issue in safe mode. Starting in safe mode allows your Mac to run certain checks, prevent startup items from automatically launching, and delete cache. Follow the steps below to start in safe mode.

    1. Start or restart your Mac. 
    2. Immediately after you hear the startup sound, press and hold the Shift key.
    3. Release the Shift key when you see the Apple logo appear on the screen.

    After the Apple logo appears, it might take longer than usual to reach the login screen or your desktop. This is because your Mac performs a directory check of your startup disk as part of safe mode.

    To leave safe mode, restart your computer without pressing any keys during startup.

    Try safe mode if your Mac doesn't finish starting up

    Cheers!

  • by Jim-airbook,

    Jim-airbook Jim-airbook Sep 26, 2016 1:31 PM in response to jeremy_v
    Level 1 (4 points)
    Mac OS X
    Sep 26, 2016 1:31 PM in response to jeremy_v

    Thanks.  I tried this as well as safe mode.  Interestingly in safe mode it would shut down completely right away.  I was eventually told that there was some task running in the background that the computer needed to finish and I should let it run and it would shut down.  I left it running when I went to bed and it had turned off by morning.  Seems now to shut down completely.  Strange, but problem solved.  Thanks for your help.