Just noticed the other day that my receiver has no LCD display (on the receiver itself) and it appears that there is no audio as well. I am not completely certain about the audio, because I am not sure what audio input is selected since I don't have the display. What could be causing this and what do I need to look at. Also, video is passing through the receiver as I am able to watch TV, just not able to turn up the surround sound. Powering off the unit will cut the signal to the TV so some parts of it appear to be working. any help would be greatly appreciated.

Audio Players & Recorders - Onkyo - HT-S767C System