The problem described below riddled me for quite a while and couldn't find a straight forward answer anywhere online. I have found a solution and I would like to use this post as a documentation record.

When I press the key combinations Fn+F2 or Fn+F3 the popup indicating the the key combination was pressed shows up and the bar fills/empties correspondingly. However, the brightness of the screen remains the same.


This question was solved by the OP:

The working solution was found in this bug report. It reads as follows:

WORKAROUND: Changing /etc/default/grub from:



GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

save, sudo update-grub then restarting allowed brightness applet or keyboard Fn and Right or Left to change brightness.

Note that I did come across posts from people with a similar issue. Some resolved, some unresolved, but most of the posts were for different model laptops. Your mileage may vary.

Hardware/Software Configuration

  • Using 64-bit Ubuntu 11.10 with kernel version 3.0.0-12-generic, GNOME 3 shell (not Unity)
  • Hardware: HP dv7-6135dx Laptop, Intel Core-i5-2410, Mobile Intel HD Graphics/RADEON HD 6490M

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