Hisham Sadek

How to Fix Gnome Screen Brightness Keys Bug

While Experiencing Gnome 3.10 on Ubuntu 13.10 especially that it is much faster and useful than unity, I have experienced a bug with screen brightness key, the key to set brightness down was not working, the other up key was working fine and the system indicator was also working fine, after some search it was a bug that others with intel motherboards suffer from. This post tells you how to fix it in 2 minutes.

Thanks to Jessica Lambiase for the fix

First you need to check whether this fix would actually work for you or not open the terminal and type this command

    ls /sys/class/backlight

this command checks if you have the intel backlight or not as the fix should only work with it. you should see some result like


if this is the result, you can proceed, and edit the grub file assuming your system has GRUB2 installed

    sudo gedit /etc/default/grub

Find the following


And replace it with

    GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Save the file, close it then fire the command for updating grub2

    sudo update-grub2

Reboot your computer and you can now have a fully functioning screen brightness keys .