[HR][/HR]Try addin to GRUB these options “acpi_backlight=vendor acpi_osi=Linux”. It kinda did the trick for me. I mean I can now set the brightness from power management widget but the Fn combinations still don’t work. I have an Acer AO-756 but it’s an universal fix.
Instead of opening another thread I will post it here.
I have the same problem on an Acer 5755G. in the beginning I could not do anything but I saw the sun icon flashing as I was writing, no difference to brightness. Then I added the GRUB configuration value *acpi_backlight=vendor acpi_osi=Linux *and reloaded the config. The sun icon is showing when I click the buttons but nothing happens.
I agree but hardly ever use the keys. I use KDE mainly, so I can set a default backlight at System Settings > Power Management. I reduce its 100 percent default “On AC Power” profile, and rarely need to change it after that. In KDE the battery profiles are already set lower by default.
You are a bit luckier than some whose graphics driver and kernel support isn’t working, leaving them without any control on the backlight.
On an Acer Travelmate with Intel HD4000 the backlight works: a) by echoing the values in /sys/class/backlight/intel_backlight/brightness; b) by the applet in the power managment of Gnome/KDE.
This should mean that the video driver is working and the problem should be related to the hotkeys of the keyboard.
On the previous, similar, computer model everything was working well, though …
did you try to upgrade the standard 3.7 kernel to a newer version? In my case it fixed the problem with the brightness keys.
If it doesn’t work for you, add the following kernel parameter to the GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash” line:
I have a Lenovo yoga I had installed opensuse 12.3 and I have add to GRUB these options “acpi_backlight=vendor acpi_osi=Linux” and it work fine also the fn keys, but I have installed opensuse 13.1 and now it not work.