[SOLVED] How do I adjust screen brightness on an Asus G750JS?

[m654321]

Many thanks misko_2083 for the detailed post you made on May 16.  What I wanted was to use the same key combinations to change the brightness of the backlight controller in LL (in a variable rather than fixed fashion), as used for win8.1 on the laptop mentioned, i.e...

• Fn+F5 - decrease brightness
  
• Fn+F6 - increase brightness
  

A  brightness scale will appear in the top right hand of the screen when either key combination is used.  On the net I found the following solution which works excellently (I have misplaced the reference for the original source)...

In order to get the Fn keys working, "acpi_osi=" needs to be inserted into the file    /etc/default/grub.  This will enable support of the Fn keys and, apparently, works for the newer Asus laptops.  For LL, you may need to first install gedit  from the synaptic package manager (install/remove software choice in menu) as this does not appear to be installed in thedownloaded iso file by default.  When gedit is installed, open the terminal and type the following code...

Code:

gksudo gedit /etc/default/grub

The etc/default/grub file will then open on your screen. Then look for this line in the file and make the change:

Code:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to...

Code:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi="

then save and run...

Code:

sudo update-grub

On reboot the Fn+F5 and Fn+F6 brightness keys will function.
Regards, Mike