I tried a lot of thing. Please see this topic for see the list that things than doesn't work
https://askubuntu.com/questions/1010405/the-brightness-of-laptop-screen- cannot-be-adjusted-with-either-the-buttons-or-th/1011557 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1751887 Title: The brightness of the screen cannot be adjusted with either the buttons or the slider. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1751887/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
