I'm running Ubuntu 13.10 on a completely new machine, was fresh installed. After a while, while not working on it, the screen turns black, when you try to work again, you can't exit the black screen, you are forced to restart the computer. I tried various settings and also changed the setting in "brightness and lock" for when the screen turns off when inactive to a longer time. What can I do to rectify? This isn't normal about Ubuntu, right?
try following code to disable the black screen as I mention in here.
gsettings set org.gnome.settings-daemon.plugins.power active false gsettings set org.gnome.desktop.screensaver lock-enabled false gsettings set org.gnome.desktop.screensaver idle-activation-enabled false gsettings set org.gnome.desktop.session idle-delay 0