High Sierra iMac Freeze after Target display mode

Question

Level 1

23 points

High Sierra iMac Freeze after Target display mode

I have been using my 2016 MacBook Pro with touchbar with late 2013 iMac using Apple Thunderbolt adapter and Apple Thunderbolt cable for over a month with no problems, until I upgraded to High Sierra. Now I can still connect but after iMac goes to Sleep or when I am trying to disconnect, instead of disconnecting the iMac will freeze, get non responsive to Cmd+F2 and I pretty much has to force restart using power button. Anyone else having same problem and how to fix it?

Macbook Pro 2.5GHz, Mac OS X (10.5.4), iPhone 3G, 80GB iPod, 500 GB Time Capsule, 160 GB Apple TV, Sony

Posted on Nov 29, 2017 7:38 PM

Reply

Answer 1

Dec 6, 2017 2:08 PM in response to Shaunik

I have this same issue. I have a late 2013 imac and a early 2015 macbook pro. Both have High Sierra. Entering target display mode using thunderbolt cable works fine, exiting does not. Doesn't matter what you do, disconnect the cable, hitting f2 again, if the machines have gone to sleep, it will not recover and I have to restart using power button. I have tried resetting SMC, zapping PRAM on both, still does not work. I can't imagine the power button restart is good for the iMac. I have this in another thread as well but no response. It seems to be related to High Sierra as it was working just fine before.

Reply

Answer 2

Dec 15, 2017 7:28 AM in response to kadogvideo

I also have the same issue. I have a late 2013 iMac and an early 2015 MacBook Pro 13". Both have High Sierra 10.13.2 Entering target display mode using thunderbolt cable works fine, exiting does not. Doesn't matter what you do, disconnect the cable, hitting cmd+f2 again, if the machines have gone to sleep, it will not recover and I have to restart using power button. I have tried resetting SMC and nothing has improved.

Reply

Answer 3

Shaunik Author

Level 1

23 points

Dec 15, 2017 7:43 AM in response to faraday15

It's really frustrating. Even more frustrating is lack of support in this forum. These are comments to kb article not some random question on a third party website. You'll imagine there will be better moderation.

Reply

Answer 4

Shaunik Author

Level 1

23 points

Jan 10, 2018 12:02 PM in response to SeaPapp

Yes Mike, I was able to finally commit myself to invest time in restoring a perfecting working iMac just to resolve the issue and guess what didn't change anything. Considering this issue has been there for so long and different Macs with different configurations are experiencing the same problem, it's got to be something with the High Sierra update.

Reply

Answer 5

SeaPapp

Level 7

26,486 points

Jan 10, 2018 1:19 PM in response to Shaunik

I suppose it's possible that there could be some poorly written or incompatible software installed,although usually an SMC reset two or three times and at worst reinstalling the OS corrects the issue, would you run and post the result of etrecheck? http://etrecheck.com/ That might offer some clue as to what may be going on.

Reply

Answer 6

Shaunik Author

Level 1

23 points

Jan 11, 2018 5:45 PM in response to SeaPapp

Did Etrecheck on both Macs and even tried an older MacBook Pro but still same behavior. The only error in red was Time machine not configured. The error with the display not behaving was not shown in the events in the end either.

Reply

Answer 7

SeaPapp

Level 7

26,486 points

Nov 30, 2017 2:45 AM in response to Shaunik

Try resetting the SMC on both How to reset the System Management Controller (SMC) on your Mac - Apple Support

Reply

Answer 8

Shaunik Author

Level 1

23 points

Nov 30, 2017 12:03 PM in response to SeaPapp

Thanks, Mike,

Just did it, it is still showing the same behavior.

Reply

Answer 9

Shaunik Author

Level 1

23 points

Dec 6, 2017 4:14 PM in response to kadogvideo

I finally called Apple Support and they want me to reinstall MacOs but I am not sure if a patch or update will fix it. Clearly it is software related issue.

Reply

Answer 10

SeaPapp

Level 7

26,486 points

Dec 15, 2017 4:14 PM in response to Shaunik

So have you done as Apple Support recommended and reinstalled the OS?

Reply

Answer 11

SeaPapp

Level 7

26,486 points

Jan 12, 2018 2:41 AM in response to Shaunik

Could you post the etrecheck report for the iMac that's freezing?

Reply