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Possible Duplicate:
Screen Brightness not adjustable for Acer Aspire S3

Controls from "Brightness and Lock" were not working so I've tried a solution that involved changing grub, which I'm detailing below:

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX="quiet splash acpi_backlight=vendor"

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)

# Uncomment to disable graphical terminal (grub-pc only)

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux

# Uncomment to disable generation of recovery mode menu entries

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

After doing this, the brightness control disappeared like you can see enter image description here

Any ideas? Would love to be able to configure Brightness or even use apps like F.lux to regulate it automatically.

Edit: I've modified the following line to GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=" and now the brightness controls are back, but whatever I change the brightness remains the same. Just in case I'm using Intel H77

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marked as duplicate by Marco Ceppi Oct 22 '12 at 13:45

This question was marked as an exact duplicate of an existing question.

possible duplicate, see this and this (these also provide a better solution than the one suggested). – Eliran Malka Oct 22 '12 at 9:08

See the solution here. It uses xbacklight and runs xbacklight -set X as a startup program.

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Thanks Eliah! I ended up using xrandr --output VGA1 --brightness 1 to be able to adjust brightness. Hope Intel drivers get updated so I can adjust it through the GUI! – Juan Manuel Zolezzi Volpi Jul 23 '12 at 15:51
Use this app. It has GUI that works with xrandr. – Archisman Panigrahi Sep 17 '13 at 4:52

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