Problems with M14x

Hello everyone.

Let me just say that i absolutely love my M14x and till today it has worked flawlessly. The problem im having however, is sort of complicated. When i connect my laptop to my LCD tv via an HDMI cord, in order to watch movies, the laptop screen goes blank. All that can be seen is the blank zoomed in desktop wallpaper. Even when i navigate looking at the tv screen and go to my documents and play a movie via VLC media player, nothing plays. It used to work just fine until today. Ive watched hundreds of movies on the same Tv before. Any help would be appreciated.