TV works, but DVD play gets no response

Question

My 50 inch Vizio seems to be out of whack. We've had it for a year used the DVD player, Wii and VHS player without incident. I swear I didn't change a thing and one day none of the extra components will function. Checked out all the connections and nothing seems to be wrong there. I am assuming the problem is with the TV since I can see the players running, but no picture or audio appears on the screen. However, I am a total tech idiot so any advice will be appreciated.