I use 18.10 and want to use an external monitor. The display of the GUI on the build-in laptop screen is ok, but when I plug in an external monitor using HDMI, it is not detected. randr says its disconnected. But in reality it is connected. I have 2 different graphics cards in my laptop: Intel UHD630 and Nvidia Quadro600. I tried to switch between them, but the Nvidia 390 drivers (which are the distro included ones) are not loaded. I also tried the ppa:grahics-drivers repository ones, but they don't work either. Checked via lsmod. Can anyone help me please? Or has anyone ever had this problem before? If yes, what was the solution?

The system-info in the systems-settings-app: says Intel UHD graphics. Is there any way to change graphics cards/drivers or make the Intel card recognize the external monitor?


Edit: The problem still exists in 18.04.5

  • What worked for me in a similar setup/problem was reinstalling my display manager (lightdm) and reconfiguring it, since there were some problems. After that, I could even switch to other display managers, which then also detected my external monitors – BenSower Jan 2 '19 at 10:34

I had the same issue with my laptop with ubuntu 18.04.

The problem first occured when i switched from GNOME desktop environment to GNOME wayland.

I restarted my laptop several times, and i also tried to just simply switching it off. I was so desperate that i even reinstalled the system but my monitor and TV was still not detected.

What worked for me is switching off my laptop through terminal with:


When i turned on my computer again my external monitor and TV was detected.

I hope this helps.

  • After trying everything else this worked for me. I'd like to know why, if anyone can provide more insight, but am happy it just works. Cheers. – Orgmo Dec 16 '19 at 11:58

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