Executar no terminal
sudo -H gedit /usr/share/X11/xorg.conf.d/20-intel.conf
O editor será aberto. Publique este texto
Section "Device"
Identifier "card0"
Driver "intel"
Option "Backlight" "intel_backlight"
BusID "PCI:0:2:0"
EndSection
Salve o arquivo e reinicie.