Hi pbhfromus,
We understand you're experiencing disconnections with your external monitor. Have you tested a different connection cable with the Mac and external monitor? Have you noticed the issue while a certain app is opened more than others? Be sure to try the steps in this article for troubleshooting your connection.
If your external display isn't detected or appears blurry when connected to your Mac
Even though your screen goes black intermittently, these steps can still be relevant to follow:
If your display is blank or not detected
Try these steps if you don't see an image on your display.
Check your cable or adapter
Disconnect the cable from your external display from your Mac, then reconnect it. If the cable from your external display doesn't connect to the ports on your Mac, you can use a USB-C or Thunderbolt adapter. If you're using a USB-C or Thunderbolt adapter to connect a display, the adapter must be compliant with DisplayPort Alt Mode or Thunderbolt / USB 4.
Check how many displays you can connect
If you're connecting multiple displays to your Mac, use the Tech Specs page to find out how many external displays your Mac supports.
1. Choose Apple menu > About This Mac, double-click your serial number, then press Command-C to copy it.
2. Go to the Tech Specs page, click the Search Tech Specs bar, press Command-V to enter your computer's serial number, then click Search.
3. Click the specs page for your Mac. The number of displays your Mac supports appears under Video Support or Graphics.
Keep us updated.
