I just installed the Ubuntu 14.04 and I'm loving it. I've used other versions before, but it's getting better and better. But there's one problem: screen brightness. I use an LG R570 laptop, with an NVIDIA GeForce GT 335M graphics card. I should be able to adjust the screen brightness by pressing the Fn+Up/Down keys as I do in the Windows 8.1 (which I'm running in another partition of my HDD) but I can't. I've also tried to do it in the settings by dragging the screen brightness indicator from maximum to minimum, but nothing happens; my screen is at full brightness.
This is one of the things I've tried:
And I've got:
I removed the NVIDIA Graphics Driver so I don't have the X Server Settings program, and my computer shows my graphics card to be "Gallium 0.4 on NVA3".
Does anybody have a potential solution to this issue? I've had this issue back in the 12.04 days, and I think now I'd like to resolve this problem and be done with.