The brightness icon is shown but nothing happens. Even if I try to change the brightness in "System Settings" nothing happens. The thing is it didn't happen with Ubuntu 13.04, so I would like to know how to solve it or how to erase the upgrade to use the 13.04 version.


Got the workaround for this

Edit the file /etc/default/grub. Change the line:



GRUB_CMDLINE_LINUX="quiet splash acpi_osi=Linux acpi_backlight=vendor"

and then save and then run:

sudo update-grub

Then restart the computer, then it should work.

This might allow you to reduce the brightness from 'Brightness & Lock' in system settings. But your function combination keys might not work. Though this is not a perfect solution, you can get the job done with this :-)

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  • thanks for this solution, but it doesn't work for me. As a matter of fact, the brightness settings disappear entirely from the system settings if I do this --- slider is gone. – Ingo Oct 21 '13 at 6:43

Sort of worked for me. The hotkeys sort of work sometimes, I have at least dimmed the display from where it was.

The settings slider don't work at all!

The catalyst control for brightness works.

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One thing to try would be to create the file /usr/share/X11/xorg.conf.d/20-intel.conf with the following content:

Section "Device"

    Identifier  "card0"
    Driver      "intel"
    Option      "Backlight"  "intel_backlight"
    BusID       "PCI:0:2:0"


...and log out and back in again to see if it works. Try it without any additional kernel parameters.

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