sudo apt-get update
sudo apt-get install xbacklight xfce4-power-manager xfce4-power-manager-data
After this must to go in: /etc/xdg/lxsession/Trisquel-mini
and edit the file "autostart" . Remove what you have and replace with these:
@lxpanel --profile Trisquel-mini
@xscreensaver -no-splash
@xfce4-power-manager
@pcmanfm --desktop --profile Trisquel-mini
@/usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1
Than restart your pc. Try Fn+your_key for brightness.
If is working in this way than these is a bug in Trisquel-mini and someone
must to assign it in bug-tracker with above solution.
