Keyboard's light is not working When I press the F5/F6 button, the HUD shows a decreasing/increasing bar related to the keyboard's brightness (image). 



So far so good… The problem is: the keyboard stays completely dark, no light is emitted from the keyboard, even though the bar is moving when I press the keys F5 and F6. 

I've already tried to reset PRAM and SMC but it didn't fix my problem. What should I do?
If you go to Keyboard in System Preferences, there is a check box titled "Adjust keyboard brightness in low light".  If that is turned off, does your problem still present itself?