I have installed Ubuntu 18.04 LTS on my HP zbook studio g4. This laptop comes with a nvidia quadro M1200 and is enabled in the BIOS as dedicated card.
I have found this answer: Backlight not working on Ubuntu 17.10, Lenovo P51, Xorg, NVIDIA Quadro M1200
But this worked not for me. The xbacklight does not respond when I do this in the terminal:
xbacklight =50
Then I tried to get the value which is the backlight at the moment, to see if the package responded:
xbacklight -get
but then there was no response.
The package is installed using
sudo apt install xbacklight
So I assumed that that is what I need to do.
I tried everything after a reboot after the grub was changed and the package was installed.
Is there someone who found already a solution for this problem?