I have a laptop ideaPad z400 from lenovo that there is a brightness trouble. When it was with windows 10. I were with the same problem, but I could fix easily installing default driver. But now, I've installed ubuntu 16.04 LTS and initially it wasn't any problem but, when I tried to change the brightness, it keep very low.

1 Answer 1


I have the same laptop and the same problem. Here is the solution I found:

  1. Run:

    ls /sys/class/backlight/*/brightness

    You should see:

  2. You need to adjust the first line (adjusting the second line won't do anything). Find the current brightness:

    cat /sys/class/backlight/ideapad/brightness
  3. Find the maximum brightness:

    cat /sys/class/backlight/ideapad/max_brightness
  4. Adjust it to the desired value, say 15, by:

    echo 15 | sudo tee /sys/class/backlight/ideapad/brightness

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