.:Slackel - Hellenic Linux Distribution::.

OK.
last try:
1. Edit /etc/default/grub
Change the line GRUB_CMDLINE_LINUX_DEFAULT='quiet ' to GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_backlight=vendor acpi_osi=linux"
Save the file and run
sudo update-grub
reboot

2. If above does not work then run obkey
press + in the left side , you will sea A a. click on A then press fn+F11 for example. In the right side press + and choose execute then add in command xbacklight -10 and check enable
press + press + in the left side again, you will sea A a. click on A then press fn+F12 for example. In the right side press + and choose execute then add in command xbacklight +10 and check enable
Save the file
and check if pressing fn+f11 decrease and fn+f12 increase brightness.

Thanks. I applied the first advice. Nothing changed. I updated the kernel to 5.18.3 (x86_64). Nothing changed. I couldn't apply the second advice, because the fn+f11 is already reserved (audio volume increase) and the fn+f3, fn+f4 key combinations cannot be detected either by obkey or by xev. I could instead bind in obkey the f3, f4 keys solely, but I refrain from doing this because I find it very restrictive.

By the way, I noticed that the xbindkeys command is missing and slapt-get finds no relevant package.

dadim wrote: Thanks. I applied the first advice. Nothing changed. I updated the kernel to 5.18.3 (x86_64). Nothing changed. I couldn't apply the second advice, because the fn+f11 is already reserved (audio volume increase) and the fn+f3, fn+f4 key combinations cannot be detected either by obkey or by xev. I could instead bind in obkey the f3, f4 keys solely, but I refrain from doing this because I find it very restrictive.

It seems it is HP pavilion dm1-1200sv and radeon problem . I have an old HP G62 b80ev laptop with 2GB memory, intel dual core and there is no problem there. By the way did you tried to boot with a live iso from ubuntu to see if there keys are working?

dadim wrote: By the way, I noticed that the xbindkeys command is missing and slapt-get finds no relevant package.

Then type

djemos wrote:By the way did you tried to boot with a live iso from ubuntu to see if there keys are working?

After waiting for ages the current ubuntu desktop (22.04 LTS) live iso to boot, I found that neither this detects and responds to the hp screen brightness up & down combinations (fn+f4, fn+f3). Only the system's menu brightness slider works.