[SOLVED] Backlight brightness issues

Recently, I have encountered an unusual issue with the display of my device.
After waking my framework from sleep, the display would have an exaggeratedly low brightness, to the point that you could only see white colored elements by using a flashlight on the screen. The brightness keys didn’t work either, although they did seem to work in the desktop flyout. This behavior used to persist for a few minutes and then disappear, but right now, it seems to be stuck in this state.

I’m currently running EndeavourOS on a 12th gen Framework laptop with some small tweaks I read from in the Arch Linux wiki. I don’t think the issue is related to the operating system, but I’m still newish to Linux, so I might be wrong on that.

Hope anyone can give me a hand in troubleshooting this.

Some irrelevant notes

I originally posted this on Reddit, but I am reposting it here in hopes that it will reach more people.
I’m also planning on submitting a support ticket just in case.
I will also be testing some supported OS to see if that does anything.

Do you mean that the brightness keys on the keyboard weren’t working, but adjusting brightness from a control on the desktop worked?
Sounds like an OS bug. Where it’s temporarily not processing your brightness key presses.

The way to check would be to create a USB drive with a supported OS & see if the issue appears there. Ubuntu 22.04 LTS or Fedora 38
Framework | Linux Compatibility on the Framework Laptop

Nah. To be more specific, changing the brightness in any way inside the OS has no effect on the display’s brightness. The brightness keys do seem to be working according to the flyout that appears when clicking them. I specifically only mentioned that because I forgot, there were other ways to change that haha.

TLDR: Nope. Rather, changing the brightness through any “normal” means seems to do nothing.

How frequently does this occur?

You need to try a different OS. Because that’s what’s in control of sending commands to adjust the brightness. Your keypresses are just passed to the OS. You could just create a live USB to test, no need to do a full install to a usb drive.

I run linux full time myself. If I recall, I once blacked out my screen (on a different laptop) when adjusting brightness by script. I went lower with brightness than it normally lets you go.

Yep. I just blacked myself out by setting brightness to 0 via cmdline. And oddly, my brightness keys no longer worked!! Had to use a flashlight held against my screen to see and set brightness above 0 by cmdline, and now my brightness keys work again. I’m guessing backlight off (zero brightness) is just a different status & brightness keys won’t re-enable the backlight.

Try closing your laptop lid, then opening it. That worked for me when I again set brightness to 0 & it again caused my brightness keys to stop working.

post the output of

ls -l /sys/class/backlight/*/*brightness && cat /sys/class/backlight/*/*brightness

While we don’t test again this release specifically, the Manjaro instructions linked below should still hold true. Right now 100% of our efforts have gone into focusing on Ubuntu LTS and Fedora, but we do have a guide that may give you something to make sure your grub settings are correct.

To me that sounds like the backlight is completely broken. Does the screen produce any light at all in a dark room?

(Pointing up) This. @Jonathan_Haas has a fantastic suggestion to test with.

What he describes is the same as what I see when I turn off my backlight / set brightness to zero via cmdline. And brightness keys do not work with the backlight off.

A flashlight held against the screen needs to be held to light colored elements, or else the light is blocked from getting through, won’t spread somewhat to the nearby area. And I’m using a very bright 450 lumen light, something less, and you’ll only see white elements with little spread to the nearby area.

This could be a hardware issue, but it could also entirely be a bug with the OS just turning off the backlight.

This command will tell if the backlight is just turned off, as danso posted

ls -l /sys/class/backlight/*/*brightness && cat /sys/class/backlight/*/*brightness

If I add sleep 10 && before it & close my lid, it returns zero for brightness.

Small update on the issue

The issue disappeared after some days, which is odd but quite a relief.
That being said, I still haven’t been able to figure out what was the root of it, so I will probably see if I can reproduce it again whenever I have some spare time :smile:

Delighted to hear it has been resolved. I’ll mark this as such. If it crops up again, we’ll take another crack at it. When something is difficult to reproduce, it can be maddening to provide help for such issues. But I am glad it seems to be resolved.

Hello again. Well, I’m back at square one with this since yesterday :confused:

At the moment I have tried to check the brightness status with the command dando sent earlier. All values ​​are at 96000 which I assume means the problem is with the screen itself. I also tried to check if it would work correctly on Ubuntu and Fedora, but the results seem to be the same.

What I haven’t tried is to install Windows. Kind of an annoyance that you can test a live environment of it.

Just a general reminder, once we vary from defaults, this becomes increasingly difficult to track down and replicate.

On every 12th and 13th gen, among countless distros I’ve bounced off of them (tested PCLinuxOS over the weekend, for example), our brightness guide works. Meaning using the kernel paramter in grub,


Fedora 38

sudo grubby --update-kernel=ALL --args="module_blacklist=hid_sensor_hub"



Ubuntu 22.04.3

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash module_blacklist=hid_sensor_hub"


sudo update-grub


If this is not working, there is something different, done someplace, creating the issue. When troubleshooting, always start off with all external displays detached for troubleshooting. Make absolutely sure the guides we provide for Fedora and Ubuntu are followed on fresh installs.

For anyone in the future having this issue, the cause in my case was the cable on the back of the display panel becoming loose. I similarly had the backlight randomly be off after waking from sleep for a few months, but it always fixed itself shortly after. Eventually it stopped working completely and I ripped apart my laptop to find the monitor cable had angled weirdly, and plugging it back in properly fixed my issue completely.

That’s what the connector looked like, for reference.