Whats wrong with my Xbox?

When we went on vaction i brougt my 360 with me for late night entertainment and i brougt it home and it worked fine. But the next morning It wouldn't output video i could hear it start up but my tv was still black and the tv was fine. I pulled the xbox out without unpluging it and my elbow bupped it and it red ringed. But the dasterdly rings left and it still wouldent put out video. Can you please tell me whats wrong with my darling.

Maybe your video output needs to be reset. Follow the directions on this page: 
http://support.microsoft.com/kb/911059
 
Or just hold Y and RT while turning it on.