I'm using normally the ubuntu, version: ~$ cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=13.10 DISTRIB_CODENAME=saucy DISTRIB_DESCRIPTION="Ubuntu 13.10" And so, for no reason, the screen goes black and come back to login screen. This not happen on login screen, like login screen infinite loop problem. I get the login and use it normally then suddenly the screen goes black. I was using Ubuntu 14 and for this problem I formatted and installed Ubuntu 13, but the problem remains.