A message for Linux.com registered users: We are in the process of making changes to the Linux forums. Starting Monday, 8/13/18 at 6:00 PM PT, you will be unable to access the forums. They will re-launch as soon as possible on Wednesday, 8/15/18 with new features and improved functionality. Thank you for your patience and stay tuned for the new improved forums.

August 28, 2009

Can't change brightness on Acer 4810t (8.04)

Forums: 

Hi

8.04 all working nice and stable on my new Acer 4810t dual core, but still with some outstanding issues.

I haven't found a way to get the brightness to change at all, am wondering if anyone can help.

Looking around the brightness control could be here:

/proc/acpi/video/VGA/LCD/brightness

and if I try

cat /proc/acpi/video/VGA/LCD/brightness

I get something like

~$ cat /proc/acpi/video/VGA/LCD/brightness
levels: 100 80 30 40 50 60 70 80 90 100
current: 70

which I've just noticed is controlled by the hotkeys. Unfortunately it has no effect on the brightness. Using the echo command has no effect on it.

There is also

/sys/class/backlight/acer_acpi/brightness

and if I try

cat /sys/class/backlight/acer_acpi/brightness

I get

9

but echo changes nothing.

There is also

/proc/acpi/acer/brightness

and if I try

cat /proc/acpi/acer/brightness

I get

8

but the echo command makes no difference.

Any ideas where I'm going wrong?

Jim

Click Here!