Windows not starting up (black screen)

Hi, My computer was working fine yesterday. I didn't shut it down, but hibernated it. And went to sleep before it was fully hibernated. When i woke up, it was still on and the desktop was black. I tried to restart, But the desktop is still black saying "no analog input". But the processor is still running with beep sound and lights on. I tried changing the cable, unplugging everything and...