I have a Denon AVR-790 amp used in conjunction with a Sony Bravia KDL-40XBR7 & Direct TV HD box. All was working well until recently. All compontents are connected to Avr-790 via HDMI and then I have a single HDMI cable going to TV. The problem is is Audio is now not working. I also have a Sony DVD player and no Audio from it either. When I go into the manual setup for the amp and select HDMI Setup - when I choose TV, the Audio plays from the TV, so I know it not the Direct TV box. What settings do I need to check on the Amp to find the issue? Could it be a bad cable? No one changed any setting and no power surges. Obviously I have the device input set correctly. Any help would be appreciated. The system is new within last 4 months.