My receiver's audio dropped off about 40% and I can't figure out why. My TV's audio is fine, I don't think the settings have changed but I did push some buttons on the front of the receiver instead of the remote. It seems the surround system is muted, I have not tried a usb stick with music yet, but I will when the wife leaves for church..lol I have a feeling It has something to do with the Zone buttons. But not sure.