Keyboard light keeps turning on after login and / or unlock

I have the same problem and it definitely happens when transitioning through the different stages of my booting process or unlocking process.

I can turn it off each stage and then the next stage it will come back on.


  1. Boot to grub (backlight comes on) and I unlock my partition for booting into linux. I turn off the back-light with the F10 key (Dell XPS 13)
  2. Goes into LightDM Greeter and the back-light turns on. I then have to turn off again with the F10 hot key
  3. Logged into mate desktop and back-light turns on again. I then have to turn it off again with the F10 hot key

This looks to have been resolved in UPower (but I don’t think mate uses that) as the fix didn’t work for me.

It would be great if we can get someone to help us troubleshoot this type of problem.

The solution that would be highly recommended for me is the one that works in Mint which is that the ambient light sensor is used to tell the back-light what level to be at (known to work on Thinkpad and Dell). But I know that is wishful thinking on my part.

I have the same issue with the Dell XPS 13. I also have this problem when disconnecting my battery or reconnecting it along with waking from sleep. For some strange reason, even if I change it in the BIOS it still kicks on.

I have the same issue with Lenovo T440s, Ubuntu Ubuntu 16.04 LTS, Mate 1.12.1.

Has everyone done their updates?:

Yes I’v done them all

Ok, I figured out the fix, at least for me, hopefully other people will benefit. This is a bug with UPower. In order to fix it, you need to edit the file


You need to change:



```<deny send_destination="org.freedesktop.UPower"

Finally you should reboot.  This should fix the problem.  This was recently fixed in unity-settings daemon but needs to be fixed in the mate-settings daemon:

@CrazyDesi I tried that and it made no difference for me. What laptop are you using?

I have a Dell XPS 13 9343. Make sure you are changing the correct option. There are two different things that say KbdBacklight. I had to scroll to see the second option. I accidentally changed the first option when I did it the first time.

Asus q400a same issue here


This sounds somewhat familiar to a problem that I have faced earlier this year when I purchased a Cooler Master keyboard + mouse Devastator combo.

The gimmic was that both the mouse and the keyboard had flashing lights dimming from/to all colors in the rainbow.

So I plugged the mouse in and it worked fine. But the keyboard had 0 light poping up on it yet it worked fine. After some mixed interactions with (I even claimed a RMA thinking it was defective), my girlfriend simply plugged it into a windoze 10 machine and THE LIGHTS WENT ON! Plugging it back however into a Linux host brought the same initial result: keyboard worked but not the lights.

At ths point I simply lost all hope of getting it working and reverted back to a “regular” keyboard.

This is probably not the answer you were looking for but, hey, true story nonetheless.



Let’s bring this VERY USEFUL Thread alive. :slight_smile:
I havent any Dell. Mine’s Asus Zenbook UX32VD.
That being said, the fix you proposed works for me, independently from what line I change from “allow” to “deny”. (Works with first as well as second line)
Problem: The Zenbook has no ON and OFF backlight switch. You can turn it off and on using Fn + LIght up or light down, until it is completely off, or completely on (Has 4 level OFF > LOW ON > MIDDLE ON > HIGH ON)
As i said, it works, but completely disable the possibility to turn the keyboard light on when it’s needed.
In the Zenbook, even when the screen dim down to save power, and then you dim up again moving the mouse, the keyboard light turn on again, even from OFF state.

Using Ubuntu Mate 16.04 with Mate 1.16.1 here.

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Works fine on Lenovo ThinkPad X230, can turn on keyboard light any time I wish. Thanks!!!

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fANTASTIC! This fix works beautifully for me.
My config:
Thinkpad X230 running ubuntu mate 16.04.2.

The keyboard backlight used to randomly keep turning itself on, changing the conf file as per your comment totally fixed this. Thanks @CrazyDesi

Loving ubuntu mate so far.

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This approach fix this problem in my Lenovo Thinkpad T450

This also works for my Lenovo Thinkpad T460

No approach mentioned in this post worked for me. I added my own here:

Note it doesn’t requiere root privileges. Hope it helps.

On Yoga 260 and Mint 18.2 this solution works partially:

  • if the keyboard is off, it will stay off, great!n?
  • BUT if the keyboard is on, it will turn off after a screen locking/closing lid action.

Any other solution that is able to keep the state of the keyboard after a screen locking actio

Ubuntu 17.10 & MATE Desktop 1.18.0

Ran into same issue of keyboard backlight always turning on after login.

My temporary workaround is simply to run the following as your normal user (no sudo):
gsettings set org.mate.power-manager kbd-brightness-on-ac 0

also, so that it doesn’t keep turning back on after coming back from idle when on battery:
gsettings set org.mate.power-manager kbd-backlight-battery-reduce false


Ubuntu Mate 18.04. Had the same issue on an Asus Zenbook UX330U. The above fix solved the problem.

…but now I can’t brighten or dim my keyboard at all, using fn + f3 (which normally dims the keyboard keys), nor fn + f4 (which normally brightens up the keyboard keys). I’m shining a flashlight on my keyboard to type right now. :frowning:

Note that Manjaro Gnome gets this right: fn + f3 and fn +f4 work as they should, and it always remembers the brightness level how you left it, and no fix/hack in /etc/dbus-1/system.d/org.freedesktop.UPower.conf was ever needed.