Can't change screen brightness inside Linux on Acer

Question

Acer TravelMate 4740 series laptop.

Brightness control keys (Fn+Right/Left) work on Windows 7, but not on Linux(tried both Ubuntu and Kubuntu).

Linux shows the brightness bar(bulb) when the keys are pressed, it even increases and decreases, but the brightness does not change.

Volume keys (Fn+Up/Down arrow) work perfectly in all OSs.

Any solution? I guess this is a hardware problem with Acer.

score 2 · Answer 1 · edited Jun 09 '12 at 16:43

2

Just add

acpi_backlight=vendor

to your kernel parameters in the grub2.cfg file.

edited Jun 09 '12 at 16:43

slhck

answered Jun 09 '12 at 10:59

reza

score 0 · Answer 2 · edited Apr 13 '17 at 12:22

Try adding:

Option “RegistryDwords” “EnableBrightnessControl=1″

To the "Device" section in your xorg.conf.

I had a very similar problem on my Lenovo W510 with Ubuntu lucid and it was solved after setting this and logging out and in again.

Edit:
My laptop is not near me, but searching for a sample xorg.conf on the net I found many "almost duplicate" posts. Here is a sample on a one of them at askubuntu.com https://askubuntu.com/questions/83965/ubuntu-10-04-cant-adjust-brightness-on-my-lenovo-thinkpad

2 Answers2