High Sierra - iMac locks up every few days

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Level 1

9 points

High Sierra - iMac locks up every few days

I have an odd thing happening with my 2016 27" iMac, which seems to have started after updating to HS. Every 2~3 days after I go to wake it up (I don't usually shut down) it won't wake up. It seems to still be powered up (lights on for connected USB devices etc.) but it wont' respond to keyboard input. Each time I need to shut down by holding down the power button, then start it up again. When it starts up it seems to go through the startup sequence twice, including playing the startup sound twice.

I've done all the usual things (reset PRAM / NVRAM, fix permissions, reset SMC, dance around under a new moon etc.) and the system log doesn't show anything happening right before the machine locks up; there are no log entries while its "locked up", though.

Any ideas?

Posted on Dec 15, 2017 11:35 PM

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Answer 1

munkymajik

Level 4

1,505 points

Dec 15, 2017 11:38 PM in response to nong

It could be an issue with one or more of the USB devices you have connected when it sleeps.

Do you use a USB hub?

I'd try letting it sleep with all the USB devices disconnected except keyboard/mouse if you use USB ones. And then test each USB device with sleep/wake individually to see if one of them is causing the problem.

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Answer 2

nong Author

Level 1

9 points

Dec 16, 2017 12:42 AM in response to munkymajik

I've removed the hubs that were connected, but I still have an external drive - will try that.

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