Unable to use external monitor


New Member
Jun 1, 2019
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Hello all,

I have problems using external monitors with Ubuntu 18.04. I use an HP laptop and I want to connect two different external monitors, one that I have at home (LG) and one that I have at work (Dell). In the two cases I have the same issue: the laptop's screen turns black and never connects.

Any idea how can I do this?

Thank you in advance for any help!

What model of HP Laptop?

Are the screens totally blank or do you see a flashing cursor at the top left?
Have you tried plugging in the monitor and then rebooting? It may not "hot-plug".
Yes, I've tried too. When I reboot it initialy gets connected (I can see in the two screens the same thing), but it never ends to reboot. It seems like the laptop gets blocked in the process...
I had this problem with a couple of installations 3 or 4 years ago. What I found was that brightness was being set to 0 on the main display. Try increasing brightness, see what you can see.

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