I have a denon multizone receiver avr-688 and 5 speakers, with a sony dvd player. My dvd player is connected to the receiver with a digital coax cable and component cables. The video to receiver to tv connection is fine when a dvd is played. However, I get no sound through the receiver. When using analog left and right cables, the sound is fine, but obviously I get no surround sound. When I switch to 5 channel stereo or a surround setting with the coax cable, I get a horrible noise, and I get no sound even in direct or stereo modes. My receiver plays radio and ipod just fine. Could the receiver be broken for digital signal, or could a setting be wrong?