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Ok well I have tried close to every single post about this problem that I could find and can not find a perm a fix for it.

The fn + brightness up/down buttons do not work at all they show it changing the brightness but it is still as max brightness and it starts to burn your eyes after a while.

What can I do to fix the problem?

I'm using the full desktop version of ubuntu.

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In terminal:

sudo gedit /etc/default/grub

Look for the line that says this:


Modify it as to say

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Save the file, shut down the window and insert the following in the terminal:

sudo update-grub

Reboot your laptop and (hopefully) it will work. I'm not guaranteeing anything, but this worked for my Acer and seems to work for a lot of models.

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