Linux – Turn off keyboard backlight when shutting down Linux


I bought a backlit keyboard a few days ago, and I have a problem with it:

  • When I shut down my PC from Linux, the keyboard backlight stays on after the PC turns off,
  • but when I shut down my PC from Windows, the backlight turns off.

How can I power off the keyboard when shutting down through Linux? My only way of accomplishing this right now is by manually using my fn key to turn off the backlight, and then using it again to turn the backlight back on after powering on the PC.

I'm not sure how relevant this is, but my Motherboard is Gigabyte F2A88XM-D3H and my keyboard is Metoo Zero (the backlit one with numpad and red switches).

Best Answer

In my Kubuntu the right place is /sys/class/leds/.

# ls /sys/class/leds/
dell::kbd_backlight  input4::capslock  input4::numlock  input4::scrolllock  phy0-led  xpad0

Most certainly, if your Metoo Zero backlight is there, it will be something other than dell::kbd_backlight, so the below commands are just examples.

# ls "/sys/class/leds/dell::kbd_backlight"
brightness  device  max_brightness  power  start_triggers  stop_timeout  subsystem  trigger  uevent
# cat "/sys/class/leds/dell::kbd_backlight/max_brightness"

This number suggests my backlight has three states. I can run (as root):

# echo 0 > "/sys/class/leds/dell::kbd_backlight/brightness"
# echo 1 > "/sys/class/leds/dell::kbd_backlight/brightness"
# echo 2 > "/sys/class/leds/dell::kbd_backlight/brightness"

It turned out the states are: 0=off, 1=dimmed, 2=bright.

If it works for you, make your Linux execute the appropriate command before it shuts down (I believe the way to do it is distribution-dependent).