I installed this with additional drivers for a nvidia gt520m but when I restart, black screen appear, this is a fresh elementary os loki; yesterday I installed manually the driver via terminal, but the black screen appear too; what I need to do? I can do CTRL + ALT + F1 but lightdm have some problem, so that restarted every 5 seconds, so I need to stop this via terminal with sudo /etc/init.d/lightdm stop; what is the problem? If I dont install the nvidia drivers, I can manage all in the graphical system, but when I reboot with the nvidia drivers, black screen!
The rule #1 for installing Nvidia Drivers is to disable the
xorg-nouveau graphics driver package. Because it makes your computer into a black screen.
See this post for installing apropiately the nvidia driver.