1) FAILED: the rejigged gsd-backlight-helper from here without success.
What I tried:
1) Following the post exactly, eg
renamed the file to "gnome-settings-daemon".
sudo cp gsd-backlight-helper /usr/lib/gnome-settings-daemon
2) FAILED: I noticed a folder called "gnome-settings-daemon-3.0"; I thought perhaps gsd-backlight-helper should be there. But after moving it in and rebooting no change.
3) FAILED: Following the wiki I added "acpi_osi=Linux acpi_backlight=vendor" to the line starting GRUB_CMDLINE_LINUX in
Now the brightness keys bring up a little display, but the brightness doesn't change.
4) FAILED: Adding "acer_wmi.blacklist=yes" to the line mentioned in 3. So I deleted it again.
5) Finally... SUCCESS: using Snow Dimon's method.
Paste in the script to handle the backlight keys:
sudo leafpad .backlight
save, and make the script executable:
while [ "$1" != "exit" ] ; do
echo $n > /sys/class/backlight/psb-bl/brightness
This script needs to be able to write to the brightness it mentions. But this is a system file that's created afresh (?) each time we boot. So we need to enable writing to it each time we boot, by modifying rc.local, which runs each time we boot (pretty much?):
sudo chmod 755 /.backlight
sudo leafpad /etc/rc.local
Above the exit line paste in this:
Now set the .brightness script to run on startup. (I used Settings->Settings manager->Session and startup-> Application Autostart. Scroll down to see the "Add" button, click and give a name and more importantly the path to the backlight script, When I restarted this worked for me.
sudo chmod 666 /sys/class/backlight/psb-bl/brightness