I have a Toshiba Satellite C655D-S5209 with Ubuntu 12.04. I am unable to change the screen brightness. Fn+F6 and Fn+F7 move the brightness indicator, but actual brightness does not change.
I have tried several fixes but none have worked so far:
Updated Bios to newest version and updated graphics driver to latest version.
Tried editing grub about 100 times to include several suggested acpi options - none helped
acpitools - didn't work so removed.
fnfx-client - didn't work so removed.
xorg.conf - might have done something wrong with this because it broke my system, and had to use recovery mode.
The screen hurts my eyes. Either need a fix, some window tinting to put on my screen, or to reinstall Windows.