Brightness control not working

[stlouis71]

Hello,

I have an Acer AOD270 netbook with Fedora 16 LXDE installed. Everything is functional, yet I cannot reduce the brightness using the brightness controls (on the arrow keys). This is a very big problem for me, and I cannot see to fix it. If you have any ideas, please help me.

Thanks.

[Doug G]

And if anyone know where there is a brightness applet for xfce I'd love to know. Using laptops has been very hard on my eyes ever since the fedora developers decided to remove brightness control from gnome2 and never offer a replacement.

[marko]

One option is xbacklight

su -c 'yum install xbacklight'

to install it and to use from a terminal:

xbacklight -set 50

for example would set the backlight to 50%

[Zvonet]

Hello. Thank you for the tipp, but it is not working in my case. Like stlouis71, I have an Acer AOD270 netbook, but with Fedora 17 xfce4. The graphic card is Intel GMA 3600. Like in stlouis71's case, everything works ok (except that sometimes computer strangely slows a bit) but I can not reduce screen brightness.

When I press Fn+brightness keys, the scale appears on my display and it changes, but this has no effect on the brightness itself. The same buttons for sound work without a problem.

I found some suggestions, tried them without success, so i would like to list them.

I tried the method with adding acpi_backlight=vendor and acpi_osi=Linux to /etc/default/grub (which is often suggested and it, apparently, works for many people) but for me it does not do the trick.

There is one other way that people suggest: echo 4 > /sys/class/backlight/acpi_video0/brightness. This does not work in my case, since I do not have the file in question. This works, however, for Acer Aspire 5749.

Furthermore, I found the following suggestion: adding following line to xorg.conf should help: Option "RegistryDwords" "EnableBrightnessControl=1". I am not able to find the mentioned file (xorg.conf). I searched it with find / -name '*xorg.conf*' but I did not find it (Xorg.conf neither).

I am running out of options. I have been trying for some time now, and still no luck. Can anyone help? Since I am not a Linux expert and since I am avare that this description could be better, I will gladly clarify or expand any part of this post (if I can).

Thank you.

[marko]

If nothing else, there's the command line way, this worked in Ubuntu and should work in Fedora too:

http://askubuntu.com/questions/14476.../149556#149556

the command in the post:

setpci -s "00:02.0" F4.B=35

In the post would command a brightness of 35%

[Zvonet]

marko, thank you very much. Problem solved. I really appreciate it.

Cheers,
Zvonet