Problem with iMac after period of inactivity

Question

Level 2

276 points

Problem with iMac after period of inactivity

My iMac with 10.11.6 is never switched off, the computer is set to "never sleep" and the display is set to turn off after 7 minutes of inactivity. For some months, including before I upgraded to 10.11.6, it has exhibited the following occasional problem: after a longish period of inactivity and then jiggling the mouse or keyboard, the log in screen appears but, after entering in my password, I just get a constant spinning beachball. If the log in screen doesn't appear, there is just a black screen with Mail and other notifications on but, otherwise, just a spinning beachball. With the black screen, clicking on a notification gets rid of it so there is some communication between the screen and mouse.

Most times, the computer starts up properly but, when the problem occurs, the only way to recover is to do a hard switch off and reboot. During this time, I can still connect to the iMac and access all files from a networked computer. A run of Etrecheck shows no problems and excellent" performance. Any suggestions as to what could be causing this problem?

iMac (21.5-inch, Late 2012), OS X Yosemite (10.10.1)

Posted on Sep 11, 2016 11:34 AM

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Answer 1

JovonaP.

Community Specialist

Sep 12, 2016 12:05 PM in response to bratman91

Hello bratman91,

Thank you for using Apple support Communities. It's my understanding you've been experiencing unexpected behavior and unresponsiveness after inactivity on your iMac. I know unresponsiveness can be very concerning, especially since this has been occurring for months. I am happy to help.

First, I recommend resetting the System Management Controller (SMC). This can resolve some unexpected sleep and performance issues. Follow the steps below.

Shut down the Mac.

Unplug the power cord.

Wait 15 seconds.

Plug the power cord back in.

Wait 5 seconds, then press the power button to turn on the Mac.

Reset the System Management Controller (SMC) on our Mac

If the issue persists I recommend testing this issue in safe mode. Starting in safe mode allows the Mac to run certain checks, prevent some startup items from automatically loading, and clearing certain caches. Please use the following steps to start in safe mode.

Start or restart your Mac.

Immediately after you hear the startup sound, press and hold the Shift key.

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

Have a great day!

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Answer 2

Eric Root

Level 10

685,251 points

Sep 12, 2016 1:42 PM in response to bratman91

My computer is set up in a similar manner and occasionally a restart is required to reset everything. Please post the Etrecheck report. Maybe someone can spot something that is contributing to the problem.

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Answer 3

Sep 12, 2016 1:58 PM in response to bratman91

It could be worth setting your display not to turn off and leave your Activity Monitor as the active window while you are not using your computer next time. Try sorting by CPU or Memory used, and see if any applications or processes become unresponsive or consume large amounts of resources.

I wouldn't recommend doing this for too long or to many times, since you don't want to risk display damage, but you might get some information if you try it once or twice.

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Answer 4

bratman91 Author

Level 2

276 points

Sep 19, 2016 3:16 PM in response to bratman91

Thank you to all those who replied to my query. After trying out many of the suggestions I decided to bite the bullet and do a clean install of El Capitan. So far, this seems to have done the trick but only time will tell!

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