Comment 2 for bug 1423914

This affects me too: The screen goes black after leaving the laptop alone for a while. If you move the mouse or clicking a key, the mouse cursor will be visible and movable. But you won't see the login-screen. This happens every time.

Pressing Ctrl+Alt+F1 and then Ctrl+Alt+F7 is a workaround, that make the login-screen appear.