I have Ubuntu 16.04LTS running on my Dell XPS 15 9550. Until yesterday the fn-key for setting the brightness was able to set the brightness level to 0 (shutting backlight off completely) which I absoluetly appreciated while starting a movie on an external display. After the firmware update yesterday this feature is gone :(.

I searched the internet for a while and found the possibility to switching the backlight off by entering the command:

echo 0 > /sys/class/backlight/intel_backlight/brightnes

This actually does exactly what I want. But if I set the brightness to the lowest level by pressing fn-key it stops at 1.

I can see that by the command

cat /sys/class/backlight/intel_backlight/brightness

Is there a way to change the minimum brightness level to zero by pressing the fn-key?

-- Edit --

According to the post Can I adjust the minimum brightness for my laptop's LCD? there is a way of setting this over the fn-keys. But the script


is never called (Following the tutorial https://help.ubuntu.com/community/LaptopSpecialKeys).

acpi_listen gives me

video/brightnessdown BRTDN 00000087 00000000

But I was not able to figure out which script is actually triggered by the event (so far).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.