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Display Glitch When Waking from Sleep with External Monitor

I have a 2019 16" MacBook Pro and an Asus external monitor.


Sometimes when I wake the computer after it has been asleep for a while, the internal display is unusable while an external monitor is connected. The external display shows "No Input" and the built in display turns black with the occasional flash of a distorted desktop.


If I disconnect the external monitor, then the internal display returns to normal with no issues until I reconnect the external display, at which point it becomes unusable again. The only way I've found to resolve this is to restart the computer, at which time everything works normally.


I've already tried resetting the PRAM and that didn't help.

MacBook Pro with Touch Bar

Posted on Jan 9, 2020 8:24 AM

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Question marked as Best reply

Posted on Jan 12, 2020 3:52 PM

Hello Rybel LLC., 


Thank you for posting in the Apple Support Communities. I understand your MacBook Pro is not waking from sleep while connected to your Asus external monitor. 


Resetting the PRAM was a great step to take. You’ll also want to:


  • Reset the SMC.
  • Disconnect external devices other than your Apple keyboard, mouse, and display. If that resolves the issue, gradually reconnect your devices, testing each time, until you find the device that is interfering with sleep. Then check the documentation that came with the device, or contact the device manufacturer.
  • Start up in Safe Mode to see if the issue is related to non-Apple startup items, login items, or kernel extensions. 
  • Try to isolate the issue by using another user account.”


You’ll find additional steps to take here: If your Mac doesn’t sleep or wake when expected


If you continue to have problems, you may want to Contact Apple Support


I hope these steps help.

Have a great day!

Similar questions

3 replies
Question marked as Best reply

Jan 12, 2020 3:52 PM in response to Rybel LLC.

Hello Rybel LLC., 


Thank you for posting in the Apple Support Communities. I understand your MacBook Pro is not waking from sleep while connected to your Asus external monitor. 


Resetting the PRAM was a great step to take. You’ll also want to:


  • Reset the SMC.
  • Disconnect external devices other than your Apple keyboard, mouse, and display. If that resolves the issue, gradually reconnect your devices, testing each time, until you find the device that is interfering with sleep. Then check the documentation that came with the device, or contact the device manufacturer.
  • Start up in Safe Mode to see if the issue is related to non-Apple startup items, login items, or kernel extensions. 
  • Try to isolate the issue by using another user account.”


You’ll find additional steps to take here: If your Mac doesn’t sleep or wake when expected


If you continue to have problems, you may want to Contact Apple Support


I hope these steps help.

Have a great day!

Display Glitch When Waking from Sleep with External Monitor

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