In the morning only buttons didn't work, now even through the settings. I did few updates today and as a result I had to reinstall drivers. Now I cannot change my brightness in any way..
14.04 nvidia geforce 720M at the moment open source drivers, 331 prop, tested gave me an error that took me 2h to repair..
I can't really say which answer helped me. I made today 20 different things and nothing worked after reboots.
Installing Brightness Controller was a cheating solution which I accepted when I had enough. One of the tips made me install some small program and add hot keys for the brightness. I try to refresh website after few hours and I start lowering brightness (I made F5 to lower it).
