I am using a Samsung NP-X420 with Ubuntu 14.04.5 LTS, Trusty Tahr, 32-bit. The screen is so bright that it is irritating my eyes. When I press the brightness adjustment keys on the keyboard (Fn+down arrow), I can see the brightness window appear on the top right corner. The brightness bar is also moving left and right, indicating that the brightness is changing, but in reality, nothing happens. The brightness remains harsh.
I am aware that this question might be labeled as duplicate of this question: How to adjust screen brightness in Ubuntu 14.04 (Trusty Tahr)? The issue is: I have tried the solution given by Serg but to no avail. Everything went good until the last step, where he opened the nano editor. When I put the value "0" in there, the brightness didn't change. It remained this harsh light.
Given that the first method didn't work for me, I tried the method given by this article: https://itsfoss.com/fix-brightness-ubuntu-1310/. When I used this command
ls /sys/class/backlight/ in the terminal, I got this output:
acpi_video0 intel_backlight. So far so good. Then I gave in this command:
sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf and it asked me for my password, which I successfully entered. So still nothing wrong there. But the issue lies with the following command:
sudo gedit /usr/share/X11/xorg.conf.d/20-intel.conf. When I put that in the terminal, this is what I get:
sudo: gedit: command not found.
Am I doing something wrong in any of the methods listed above? Is there another way to adjust the brightness? Do I need to install drivers? If yes, then please tell me which ones. I am not so familiar with Linux or in general, computer stuff. Can anyone please help? My eyes are burning.
Thanks in advance!