2

I tried re-installing Kali Linux for other reasons, and still don't see it

For some reason, running latest Kali Linux, the brightness slider is absent in the top right right-click menu where it usually is, like in my friend's laptop.

It's frustrating because I am not able to change the brightness to get better battery life on my laptop. If someone could help me with it, that would be great.

Perhaps it's best I mention right away that although I was able to install xbacklight by

apt-get install xbacklight

the commands show no output and do not reduce brightness for my laptop at all.

I also have seen forums explaining how to manually edit /sys/class/backlight files to change the brightness, but I don't have any further directories to find that file from. The /sys/class/backlight folder doesn't have any file or subsequent folders inside.

The 'Battery & Lock' tab inside the settings app is also not there, and there's no option to change brightness in the Power tab.

Could someone explain a fix for me please?

Improve this question
0

1 Answer 1

Reset to default
3

First check whether your laptop's back-light is detected or not by your OS kernel. The folder /sys/class/backlight should not be empty.

If your laptop back-light manufacture is Intel edit the following file to change brightness.

sudo vim /sys/class/backlight/intel_backlight/brightness

An empty /sys/class/backlight/ folder indicate backlight hardware is not detected.

If so please add this two option "video.use_native_backlight=1 acpi_backlight=vendor" (without quotes) in grub command line before system boot up. Press e to edit the grub command line before your system boot and add the above options after quiet splash. After edit last part of your grub command line shall look like

....quiet splash video.use_native_backlight=1 acpi_backlight=vendor....

Then boot the system. You shall find some content under sys/class/backlight/ folder now. Now edit /sys/class/backlight/intel_backlight/brightness to change brightness. You may also try one grub option at a time.

If this solves the problem update grub options and regenerate grub configuration to make the change permanent. Once the backlight is detected by Operating system the slider option shall reappear (I am not sure).

You may consult this article also https://askubuntu.com/questions/476664/cannot-change-backlight-brightness-ubuntu-14-04

Improve this answer
0

You must log in to answer this question.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.