It's been the one thing that's been keeping me from using Linux on my laptop. The screen brightness doesn't work. Normally, in Microsoft Windows, I can hold down the function key along with F2 or F3 to lower or increase the brightness, but with a fresh install of Linux Mint, or Ubuntu, adjusting screen brightness didn't work this way. 

So here's where I found the solution to my problem of not being able to adjust the brightness of my screen in Linux.


Pedrinho of the Linux Mint Forum suggests:

  1. Open terminal (as a superuser) and type: gksudo gedit /etc/default/grub
  2. In the text file that opens, find the line which says GRUB_CMDLINE_LINUX="" and, inbetween the "", insert the words "acpi_backlight=vendor" (the line will be as follows: GRUB_CMDLINE_LINUX="acpi_backlight=vendor"), save and close the file.
  3. Back again in the terminal session, type: sudo update-grub
  4. Reboot.

That did the trick for me. 

I noticed though, that under Linux, my screen can get darker than under Windows. I like this for working at night in the dark, and for the fact that it saves my battery. 

Also, I noticed, that if I make the screen dark enough it will go black. And once that happens, it doesn't turn light again unless I close the notebook and let the computer suspend, and then open it again.

All in all, I'm happy with this solution to adjusting the brightness of my Linux laptop.