I got a Packard Bell EasyNote LM86 and the problem is I cannot set the brightness. I have tried with both the hotkeys which is Fn and either F11 to turn down and F12 to turn up. I have also tried through the command line by doing

echo 50 > /proc/...

and also tried through the GNOME brightness applet.


3 Answers 3


I managed to fix the problem by using this PPA and setting acpi_backlight=vendor as a boot parameter.

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    – intuited
    Apr 13, 2011 at 7:27

Same solution as one-liner

For this solution no nano knowledge is required. It is also handy for multi-machine installation scripts.

sudo sed -i 's|^GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"|GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux"|' /etc/default/grub && sudo update-grub

I have a Packard Bell EasyNote TJ68 and this fix worked for me.

sudo -H gedit /etc/default/grub

Change the line GRUB_CMDLINE_LINUX="" into


save, exit, and run

sudo update-grub

Restart your system


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