In this tutorial, we will see a solution that may render your brightness keys workable again in a laptop/notebook running Ubuntu/Linux Mint.
Before starting, you should bear in mind that this solution is not meant to fix all laptop or notebook models and is dedicated for users of intel cards for adjusting brightness levels. Also, this tip is only workable on Ubuntu/Linux Mint with GRUB 2.
You can check if you have an intel card by running this command:
If the returned outputs show this:
Then this solution may work for you. In the same terminal window, enter this command:
sudo gedit /etc/default/grub
Find this line:
Change it to this one:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
Save your file and exit, then run this command to update GRUB 2:
Finally, reboot your system.