2 Monitors Detected, but only 1 displaying picture

[ABC123]

My problem was second monitor was recognised in System Prefs but black or no signal detected on second. I can't remember if mirroring 1 to 2 helped / worked given the number of things I've tried in hope of solution...!

[jochem]

Originally Posted by SqueakyNinja

I've got two identical Dell U2515H, where the second one doesn't work unless being mirrored to. So I have the same resolution for both, and the same issue.

I did however luckily solved the issue for me. I swapped places of my HDMI cables, and then it worked. I guess on of the cables are of an older version and wasn't compatible with the displaylink adapter.

I will try again with different HDMI cables.

[drpmason]

I have a MBP M1 and just bought the Dell 6000 to run 3 external monitors

I can get 2 x DP>DP working but the DP>USB and/or DP>USBc wont work.

Does anyone know if this is a Monterey 12.3 problem with the Dell 6000 ports or with the Displaylink download?

My guess is its an Apple/Dell issue but any advice appreciated!

[Mecallie]

Originally Posted by SqueakyNinja

I've got two identical Dell U2515H, where the second one doesn't work unless being mirrored to. So I have the same resolution for both, and the same issue.

I did however luckily solved the issue for me. I swapped places of my HDMI cables, and then it worked. I guess on of the cables are of an older version and wasn't compatible with the displaylink adapter.

You absolute hero!

I was troubleshooting this in software for ages. Could not figure out why it would not work on one laptop with Linux mint and not on the other, also with Linux mint. I am also using two Dell U2515H screens: on my Dell laptop it works fine. On my Asus ExpertBook I saw 3 screens in the config, but only 1 external and the laptop screen would work. Seems it is some bizare HW issue with some USB C dongles (I am using a Lenovo ThinkPad USB-C dongle/dock) or something, can't be the cable, I did not replace that.

I just swapped the HDMI cables on the USB-C dongle: works! I now have an image on 3 screens (laptop + 2 external). Before that I would see 3 screens in the config panel (including the correct specs), but would get an image on my laptop and 1 external screen only.

Registered for the sole purpose of thanking you!