On Windows, my Scroll Lock key turns on my keyboard backlight, but in EndeavourOS, xset led on or xset led 3 does nothing. It worked in Linux Mint, but not Arch.
Keyboard (from lsusb):
Bus 003 Device 003: ID 1a2c:2c27 China Resource Semico Co., Ltd USB Keyboard
Anyone here ever faced this issue?
Are you on wayland? xset is xorg.
On my Lenovo Legion, I can use:
echo <0|1|2> | sudo tee /sys/class/leds/platform::kbd_backlight/brightness
Where (for me) echo 0 = off, echo 1 = lowest, echo 2 = full.
What is the hardware?
Hi,
The command you suggested: echo 1 | sudo tee /sys/class/leds/platform::kbd_backlight/brightness worked for my laptop’s built-in keyboard backlight (where 1 = low brightness, 2 = full brightness).
For this Lenovo Laptop, I can also control it using the keyboard shortcut of fn + spacebar.
However, I’m trying to control the backlight on my external USB keyboard:
Bus 003 Device 003: ID 1a2c:2c27 China Resource Semico Co., Ltd USB KeyboardSo, what’s the result of ls -al /sys/class/leds?
You can use likely candidates from this with echo 1 | sudo tee /sys/class/leds/<whatever you choose>/brightness to test, and also get their status with sudo cat /sys/class/leds/*/brightness.
Sorry for the late reply, so I tried running all candidates found in ls -al /sys/class/leds and none of them turned on my USB keyboard light, they just turned on the light on my laptop’s keyboard 
For context, ls -al /sys/class/leds returned the following:
$ ls -al /sys/class/leds
total 0
drwxr-xr-x 2 root root 0 May 2 20:39 .
drwxr-xr-x 79 root root 0 May 2 20:37 ..
lrwxrwxrwx 1 root root 0 May 2 20:37 input11::capslock -> ../../devices/platform/i8042/serio0/input/input11/input11::capslock
lrwxrwxrwx 1 root root 0 May 2 20:37 input11::numlock -> ../../devices/platform/i8042/serio0/input/input11/input11::numlock
lrwxrwxrwx 1 root root 0 May 2 20:37 input11::scrolllock -> ../../devices/platform/i8042/serio0/input/input11/input11::scrolllock
lrwxrwxrwx 1 root root 0 May 2 20:40 input42::capslock -> ../../devices/pci0000:00/0000:00:14.0/usb3/3-5/3-5:1.0/0003:1A2C:2C27.000D/input/input42/input42::capslock
lrwxrwxrwx 1 root root 0 May 2 20:40 input42::numlock -> ../../devices/pci0000:00/0000:00:14.0/usb3/3-5/3-5:1.0/0003:1A2C:2C27.000D/input/input42/input42::numlock
lrwxrwxrwx 1 root root 0 May 2 20:40 input42::scrolllock -> ../../devices/pci0000:00/0000:00:14.0/usb3/3-5/3-5:1.0/0003:1A2C:2C27.000D/input/input42/input42::scrolllock
lrwxrwxrwx 1 root root 0 May 2 20:37 phy0-led -> ../../devices/pci0000:00/0000:00:14.3/leds/phy0-led
lrwxrwxrwx 1 root root 0 May 2 20:37 platform::fnlock -> ../../devices/pci0000:00/0000:00:1f.0/PNP0C09:00/VPC2004:00/leds/platform::fnlock
lrwxrwxrwx 1 root root 0 May 2 20:37 platform::kbd_backlight -> ../../devices/pci0000:00/0000:00:1f.0/PNP0C09:00/VPC2004:00/leds/platform::kbd_backlight
Looks like there is a driver of some sorts missing for the backlight to work. Does the backlight work under windows without added software?
Yes, works with no special software. Just pressing the Scroll Lock key on it will turn it on.
This is weird. If just Scroll Lock controls the backlight, it should work in Linux without changes. The fact that it doesn’t hints at something more happening behind the scenes.
Did you try with googling for your keyboard name + linux backlight, or googling the USB ID (lsusb shows it) + linux, or looking for which driver gets automatically picked by MS Windows for this keyboard?
Otherwise, I am out of ideas.
Does enabling scroll lock work? In KDE, open settings and go to keyboard → keybindings. Search fro scroll and enable Map Scroll Lock to Mod3
So I tried searching 1a2c:2c27 linux which is the ID for my keyboard and got https://linux-hardware.org/?id=usb:1a2c-2c27
However that seems to not have info on how I can turn on the backlight. Before I made the post here, I came across the URL you mentioned
But that also never worked for me so I had come to make this post.
This worked!!! Thank you so much!
This topic was automatically closed 2 days after the last reply. New replies are no longer allowed.