Why aren't my bottom arrows lighting up?

[AC Question]

Bottom arrows don't lite up

My S4 arrows were always lit when the screen was on. The ones on either side of the big bottom button. They have never lit up! Defect or Setting?

 

[B. Diddy]

Re: Bottom arrows don't lite up

Welcome to Android Central! Please clarify--did they light up at one time, and now no longer light up? Or did they never light up?

Do you have any screen-dimming apps installed, like Lux? These can also turn off the backlights for the capacitative buttons.