I have a dell vostro 3650 running newest Ubuntu install. I read this laptop has a backlit keyboard. I've researched how to turn it on with no luck. I've tried hitting the Fn F6 keys and the Fn right arrow key.
According to the Manufacture,
Ports, Slots & Chassis --snip-- Optional backlit keyboard with numeric keypad
Also, i know that for any backlit keyboard that I have owned, I have had to cycle it dimmer > FN + F5 < then brighter > FN + F6 <
NOTE: Key combos assumed from blurry photos on manufactures site!