Is your default brightness adjust not working? Many Linux users face this problem time and time again, across distros. Don't lose faith, because there's a good chance that this command will successfully alter your screen's brightness.
- Intel Integrated Graphics Card
NOTE: If you are running KDE and maybe don't prefer using the command line, then you can try the GUI based application available here. (Although, this fix works on KDE too.)
- Download script and move to /usr/local/bin [Refer screenshot]
- Run command with super user privilege
Manual/Info:$ sudo brightness
Syntax:$ sudo brightness <value>
Valid brightness value: 1-25
Example:$ sudo brightness 5
