ISSUE: Backlight brightness does not change.
More Detail: Brightness will not change, using both 'System Settings->Screen', or FN keys (Brightness bar shows and moves, but screen brightness does not change).
Notcied a post in this thread (http://ubuntuforums.org/showthread.php?t=1866283) about having multiple folders in Sys->Class->Backlight...
I HAVE TWO FOLDERS TOO!
'intel_backlight' and 'acpi_video0'
Using the function keys, alters the value in the acpi_video0's 'Brightness' file - But doesn't actually alter the brightness of the screen.
If I add 'backlight=vendor' in Grub, my function keys then edit the value in the 'Intel_Backlight brightness file. - But again doesnt actually change the brightness of the screen.
Computer: Fujitsu Siemans Pi2515, Intel Integrated Graphics, No hdd partition.
-Editing grub to contain: acpi_osi=Linux acpi_backlight=vendor
-sudo apt-get install acpi
-$ sudo setpci -s 00:02.0 F4.B=20
-Brightness does not adjust in fallback mode either.
-Reinstalling OS, Using Linux Mint (Same problem).
-Upgrading and downgrading BIOS.
Many thanks for reading, I understand this problem may need a bit of a Linux pro to sort. If anyones up for the challenge i'll spend any amount of time being walked through this, posting results. Don't want to give up here!