Hello Ubuntu community.

I've recently purchased the ASUS FX503VM laptop and I've managed to solve most of the "problems" so far in Ubuntu 18.04.

The one that is bugging me for a week now is the control of the keyboard brightness. My keyboard is always on and on full brightness all the time.

Because I do not need it on all the time and because of battery consumption I am trying a way to control it, since the Fn+Arrow Up and Fn+Arrow Down that are mapped on the keyboard do not work.

Some info on my system:

  1. I currently run 4.17.13-041713-generic kernel to get rid of the Elantech 1200 touchpad laggy issues (updated through Ukuu)

  2. Proprietary Nvidia drivers installed through the additional drivers tab (nvidia-drivers-396)

  3. acpi_listen and all other methods to show keymap/response from the Fn key show nothing but

  4. Fn+F3 (volume up icon), Fn+F2 (Volume down Icon) and Fn+F1 (Volume mute icon) work out of the box. All other Fn+X combinations do not work

  5. acpi_osi=/Linux/Windows do not change anything and acpi_backlight= break the touchpad (not recognised)

  6. I've managed to adjust the brightness through xbacklight and by re-mapping the keys to Super+F7 (low) and Super+F8 (high), replacing default Fn+F7 and Fn+F8 respectively

I think I can achieve the same for the keyboard brightness if I could use a similar custom command but...


  1. I have a script in /etc/acpi/ called asus-keyboard-backlight.sh that points at /sys/class/leds/asus::kbd_backlight but there is no such directory as asus::kbd_backlight (it should exist and at least contain a brightness and maybe a max_brightness file

  2. I cannot create the asus::kbd_backlight directory not even as root

  3. Ideally, and if I had this directory/files I could invoke /etc/acpi/asus-keyboard-backlight.sh up/down and control the brightness (maybe after remapping the keys to Super+Arrow UP/DOWN, since Fn is not recognised)

  4. I have two files in /etc/acpi/events that are named asus-keyboard-backlight-up and asus-keyboard-backlight-down respectively with the following contents

event=hotkey ATKD 000000c4 action=/etc/acpi/asus-keyboard-backlight.sh up


event=hotkey ATKD 000000c5 action=/etc/acpi/asus-keyboard-backlight.sh down

The problem is that I cannot understand to what the hotkey ATKD 000000c4 and 000000c5 keys correspond to or how I could change the key combination in this file to make it work.

Any ideas would be greatly appreciated.

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