Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I can't change my brightness on my laptop and I would like a help to solve this problem.

Using kcmshell4 kgamma I can change the constrast. But using xbacklight nothing happens.

If I put

xbacklight -get

I got a value, for example, 86.666667, but when I try

xbacklight -dec 40

Nothing happens.

The strange thing is that commands above (xbacklight -dec 40) can work if I suspend my session and reopen it again.

How can I solve this?

share|improve this question

Try using the

xbacklight -set


share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.