Nice computer. Usually works awesome. Just this one little bug every time I re-install the OS or upgrade it seems. Easy to fix but I always forget how to do it so here it is for everyone else who might be having issue. Might also solve all your other Intel brightness button issues so give it a shot! This also seems to work for 14.04 and maybe even 13.04 and before…
Read the whole blog article first, if you want, but just doing this worked for me:
Command in terminal:
sudo gedit /usr/share/X11/xorg.conf.d/20-intel.conf
Then paste all this stuff in and save it.
Section "Device" Identifier "card0" Driver "intel" Option "Backlight" "intel_backlight" BusID "PCI:0:2:0" EndSection
Then log out and back in again and my buttons were working.