External Display won't turn off when connecting to Thunderbolt Dock

Question

Level 1

4 points

External Display won't turn off when connecting to Thunderbolt Dock

When connecting to external display (via thunderbolt dock or USB-C hub) and my macbook goes to sleep, lock, display off.. or anything that will trigger the monitor to shut off. It seems like only the built in monitor of my macbook pro shuts off, while external monitor remains on and turn back instead of displaying 'no signal' like how its meant to be when the monitor receive no signal.

Is there any settings I need to change in order to make my secondary monitor turn off like the built in monitor? I notice that this only happens when connecting to Thunderbolt docking or USB-C hub. No issue with straight USB-C to HDMI cable.

Posted on Oct 14, 2022 6:59 AM

Reply

Answer 1

chuckbl

Community Specialist

Oct 15, 2022 2:14 PM in response to tangtawan

Hello tangtawan,

Since this behavior only happens when connected to your dock or hub, you'll want to reach out to the manufacturers of those devices: Contact a third-party vendor - Apple Support They'd be in the best position to assist with troubleshooting their particular devices further.

Take care.

Reply

Answer 2

tangtawan Author

Level 1

4 points

Oct 15, 2022 10:27 PM in response to chuckbl

No, the problem isnt the dock. But the problem comes from either MacOS or MacBook itself. I have tried multiple docks and hubs including Thunderbolt and USB-C type, I even try it with different external displays. all have the same results, and also this doesnt happen to windows laptop.. so definitely its the Mac that is causing the problem.

it seems like the Mac is sending black image to the monitor instead of shutting it off

Reply

Answer 3

mingoslkd

Community Specialist

Oct 16, 2022 7:26 AM in response to tangtawan

Hi tangtawan,

When you close your MacBook Pro, it is expected that the external monitor will continue to be available, as shown here:

Connect your display

Connect your display to power, then connect your display to your Mac. Check the ports on your Mac to find out whether you need an adapter. If you're using a USB-C or Thunderbolt adapter to connect your display, the adapter must be compliant with DisplayPort Alt Mode, Thunderbolt 3, or Thunderbolt 4.

If you use an external keyboard and mouse with your Mac notebook, you can close the built-in display after you connect your external display. You might have to press a key or click your mouse to wake the external display. To use your Mac with the display closed, you need to connect your power adapter or connect an external display that also charges your Mac, such as the Apple Studio Display or 23.7-inch LG UltraFine 4K Display.

If your external display doesn't turn on after you connect it to your Mac, connect your display while your Mac is off, then wake or turn on your Mac.

Connect a display to your Mac - Apple Support

Take care!

Reply

External Display won't turn off when connecting to Thunderbolt Dock

Similar questions