Inputs do not work

The TV stopped displaying any pictures for any devices connected to the 4 HDMI inputs on the rear of the set. I've connected DirecTV, Cable, and my receiver to the all of the HDMI inputs with no picture displaying. I've reinitialized the set using both Menu2470/initalize/enter and Menu123enter/initialize reset the inputs to the HDMI 1 set it for cable and still nothing on the screen or audio. The components still function with the expected lower picture quality