I am facing a problem with display brightness in Ubuntu or other versions of Linux. Running a Linux distro as live or HDD installation or inside the installation, display brightness is automatically set to the highest value, I'm unable to decrease it, this is an annoying problem at night.
I have tried about 25 different Linux Distros in my laptop another 3 laptops of friends but the same problem, no problem with the desktop as the monitor has its own brightness control switch.
My laptop is Acer 5830TG, i5 2410M @ 2.3 GHz, ram-3gb, HDD-640gb @5400 rpm, NVIDIA GT540M, chipset-Intel HM65. OEM os- windows7 Home Premium.
I have tried the Fn+< (left arrow key) as in windows, Ubuntu is showing that brightness is decreased but not really, display brightness is same.
Also tried Ubuntu display brightness applet.
And at Terminal
~$ sudo setpci -s 00:02.0 F4.B=** where
** is two digit hex value, 00:02.0 is internal display adapters(Intel HD 3000) hardware address(lspci | grep VGA).
Nothing happened, display brightness remained the same.