9

I saw that the keyboard backlight was not working. How can that be fixed?

Hardware/OS

  • Dell Latitude E6540
  • Kubuntu 16.04 (xenial)
cyroxx
  • 191

1 Answers1

19

You may want to check the brightness settings for the Dell keyboard. The following procedure worked for me:

  1. Show the configured brightness:

    $ cat /sys/devices/platform/dell-laptop/leds/dell\:\:kbd_backlight/brightness
0

  2. See the maximum brightness:

    $ cat /sys/devices/platform/dell-laptop/leds/dell\:\:kbd_backlight/max_brightness
4

  3. Set the desired level of brightness (here: 4):

    $ echo 4 | sudo tee /sys/devices/platform/dell-laptop/leds/dell\:\:kbd_backlight/brightness

Slightly related: You might also want to configure the time-out interval for the backlight, using the stop_timeout setting. See also the article How to Configure the Keyboard Backlight Time-Out Interval in Ubuntu Linux in the Dell knowledge base.

cyroxx
  • 191
  • 1
    Thanks so much for your help on this, I would have never figured this out on my own. – James Adams Nov 28 '19 at 23:47
  • This works, but how can I make it persist after a reboot / sleep cycle? The brightness always resets to 0, and the keyboard buttons don't work to trigger the keys to light up. Every time I open up the laptop I have to set the desired brightness manually. I was hoping the latest kernel would fix it, but didn't help. I've installed every update possible. - DELL E6510 – CarComp Oct 19 '20 at 18:01
  • I wonder what is the catch for this not being in the GUI.. seems straightforward – Lucas Noetzold Dec 17 '21 at 13:41
  • it´s working, thank you... – Guilherme Mar 16 '22 at 12:33