I have a Samsung Series 7 Chronos (700Z5C-S02UB) and a couple of kernel updates ago (I'm currently on 3.5.0-25-generic ), I lost the keyboard backlight support.
Any idea on how to turn it back on?

NOTE: I've already had samsung-tools, I've re-installed but still doesn't work

EDIT: I manage to get it working (somehow). What I found is: the ambient light autodetect works, but it seems to be unable to control the level of brightness. If I boot windows and set it to high, it works in Ubuntu (it might be just a coincidence tho)

1 Answer 1


Is there a /sys/class/leds/samsung::kbd_backlight?

If so, try

echo 3 > /sys/class/leds/samsung\:\:kbd_backlight/brightness

It could be any number between 0 and 8 indicating the level of brightness of the keyboard backlight.

Otherwise, try this:

sudo add-apt-repository ppa:voria/ppa
sudo apt-get update
sudo apt-get install samsung-tools samsung-laptop

Reboot, then

echo 8 > /sys/devices/platform/samsung/leds/samsung\:\:kbd_backlight/brightness
  • nope, I have /sys/class/leds/phy0-led . Not really sure to what device it belongs, but trying to set it didn't do anything either
    – GClaramunt
    Mar 7, 2013 at 12:58
  • okay, try the second method.
    – darksky
    Mar 8, 2013 at 6:57
  • no luck either :(
    – GClaramunt
    Mar 8, 2013 at 13:44
  • I think you may need to do this. Try opening /etc/default/grub and change GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor" save. Run in terminal sudo update-grub and restart.
    – darksky
    Mar 8, 2013 at 15:07
  • Ok, now is working, but I have only "quiet splash acpi_osi=Linux " I have a theory, tomorrow I'll test it. Thanks a lot for your ideas!
    – GClaramunt
    Mar 9, 2013 at 3:24

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