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