Screen Brightness controls
The sven keyboard daemon, which is in the system tray,
calls a couple scripts to control the screen brightness.
Unfortunately this varies a bit between computers. There are a
couple things that can go wrong with this.
1) Sven might not be configured to use the correct keys for your
2) The two scripts that Sven calls
(/usr/bin/brightness-up and /usr/bin/brightness-down) could be
using the wrong file in /sys
So the first thing to do is open a terminal and type: brightness-up
and then press Enter.
If it changes the screen brightness then it's probably problem 1,
and you need to right-click on the sven tray icon and select
Preferences. If you get an error about file not found , then it's
probably problem 2.
The brightness-up script looks like this:
DEVICE= #radeon_bl0, acpi_video0, etc
[ -z $DEVICE ] && DEVICE=$(ls $DEVPATH | head -n 1)
[ -z $DEVICE ] && exit 1
CURRENT=$(( CURRENT + STEP ))
if [ "$CURRENT" -gt "$MAX" ]; then CURRENT=$MAX; fi
echo $CURRENT > $DEVPATH/$DEVICE/brightness
For problem 2, you'll need to replace the DEVICE
with the correct filename. You'll
also need to make the corresponding changes to
For problem 1, you'll need to edit the Brightness down and Brightness up
properties in Sven (right click and select Preferences).