External Monitor Display Problems after Sleep with MacBook Air M1

Question

Level 1

4 points

External Monitor Display Problems after Sleep with MacBook Air M1

Dear Community,

I have the following setup: a Mac Book Air, M1 2020, 16GB RAM, 1TB SSD, OSX 11.2.3, connected to a LG UltraFine 32UN880-B over the included USB 3 cable. The OS seems to have troubles displaying on the external display, after sleep (amount of time is not important) the Desktop is displayed only in a portion of the screen and the setting for HDR ist lost. The error also reflects in a screenshot. Display drawing events after the sleep get partially rendered in the "dead" space, which is inaccessible to the cursor. Please see the images attached to get a better picture of the problem. The problem can be reset if HDR and screen scaling is set to a different value.

Things I already have tried:

Use a different cable
Disable Sync Options in Monitors preferences pane
Try different screen scalings in Monitors preferences pane
Try HDR enabled/disabled in Monitors preferences pane
Try TrueTone enabled/disabled in Monitors preferences pane
Try different sleep times
Reinstall the Operating System

As M1 does not have an option to reset PRAM, I am out of ideas how to get this problem solved. Any ideas from the community?

Yours sincerely, Julian.

MacBook

Posted on Mar 12, 2021 12:36 AM

Reply

Answer 1

Best reply

Julian. Author

Level 1

4 points

Mar 18, 2021 4:52 AM in response to Julian.

Dear Community,

I was able to solve this problem with the following steps:

Go to: /Library/Preferences/

Delete files: com.apple.windowserver.plist and com.apple.windowserver.displays.plist

Go to: ~/Library/Preferences/ByHost/

Delete files: com.apple.windowserver.XXXXXXXX.plist and com.apple.windowserver.displays.XXXXXXXXXX.plist

Empty trash. Restart.

In Screen Preference Panel disable HDR for the external display.

Reply

Answer 2

Chris_C1

Community Specialist

Mar 14, 2021 10:28 AM in response to Julian.

Greetings, Julian!

Welcome to Apple Support Communities! If we understand correctly, you're running into an issue with your external display when you wake from sleep. We can see why you want information on that. It looks like you have tried some great steps up to this point. When you have a moment, you may also want to look over and follow the steps on this page: Get help with video issues on external displays connected to your Mac.

We hope this information helps you out.

All the best.

Reply

Answer 3

Julian. Author

Level 1

4 points

Mar 18, 2021 3:29 AM in response to Chris_C1

Dear Chris,

Thank you for taking time to read through my issue. I went through the general external display page you sent me, but no luck. Any other idea where I can get more information? Can you point me to the right Log in the System where this error might be protocolled?

yours sincerely, Julian.

Reply