On my Lenovo ThinkPad W510 the brightness up/down buttons did not work after the installation of Linux Mint Uma. More precise, the graphical interface showing the brightness bar did pop up, but it had no visual effect on the screen.
To resolve this issue try this:
- If you do not have the file /etc/X11/xorg.conf and have an Nvidia graphics card, you may create an xorg.conf by the command
sudo nvidia-xconfig - Edit /etc/X11/xorg.conf. In its Section “Device” enter an additional line:
Option “RegistryDwords” “EnableBrightnessControl=1” - Edit /etc/default/grub and correct the contents of GRUB_CMDLINE_LINUX_DEFAULT:
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_backlight=vendor acpi_osi=linux”
- Update grub by
sudo update-grub - Reboot
In my case this procedure did the trick. Since I had to find my way through lots of different solutions and suggestions I thought it was a good idea to put these details together here for your convenience.
PS:
If you still have problems, this article may help you:
Kolloquia 