Ubuntu fix Fn Brightness keys

So my Acer Aspire 5738 encountered the oh-the-Brightness-Function-keys-are-not-working-yet-again issue after the installation of Ubuntu 12.04. There is a simple fix and some related caveats. So here we go …..

#1 (open the file in gedit or vi)

$ sudo vi /etc/default/grub
[sudo] password for nikunj:

#2 (find an insert the arguments in gray)

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_osi=Linux acpi_backlight=vendor

#3 (update the grub configuration)

$ sudo update-grub
Generating grub.cfg …
Found linux image: /boot/vmlinuz-3.2.0-24-generic
Found initrd image: /boot/initrd.img-3.2.0-24-generic
Found linux image: /boot/vmlinuz-3.2.0-23-generic
Found initrd image: /boot/initrd.img-3.2.0-23-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 7 (loader) on /dev/sda1
Found Ubuntu 11.10 (11.10) on /dev/sda2

Just reboot the machine.


At times the screen would go entirely dark. Or would not apparently resume from a blank screen or when the screensaver gets active.

For such cases, all you need to do is press “Fn + Brightness UP button” and screen will GLOW. Simple!!

(This post is more like a NOTE TO SELF. But if it helps you in someway then its even better … AWESOME!! :D)


Works for Ubuntu 12.10 perfectly 🙂

Update (2013/01/08):

You can use “sudo gedit /etc/default/grub” if you are not very familiar with vi editor! 🙂

Update (2013/05/12):

For Ubuntu 13.04 do the following:

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_osi=Linux acpi_backlight=vendor

Update (2014/05/25):

Works on Ubuntu 14.04.