I cannot get the Ubuntu brightness slider to change the brightness of my (Dell) monitor which is attached by HDMI. I am using 21.10. This is a desktop system with no built in monitor. I can control the brightness via xrandr on the command line, but the gnome brightness slider does absolutely nothing. I can control the brightness slider either via the drop down in the top right corner or via keyboard function keys. Both work fine for moving the knob on the slider, but the brightness of the monitor is unaffected.
I have tried changing grub parameters but that seems to affect the mapping of keys to enable controlling the brightness slider, which isn't my problem.
I used to have video via my Vega enabled Ryzen CPU, and brightness didn't work. Now I have a dedicated Radeon card, and it still doesn't work.
I have searched extensively but all solutions that I find are focused on one of:
- making function keys work
- using xrandr or some other tool on the commandline
- installing alternative apps
The first two aren't my problem and the latter doesn't interest me.
Any pointers would be welcome.
2 Reset to default
