Marantz SR5001 "jam speaker turn" Questions

...turn down the volume all the way when switching these buttons. This unit is probably jam packed with electronics so it might be hare to get to the switches. As far as the distortion. It could be that ...

...at modes for 5.1. swap the audio jacks and then try. Speaker cables and connectors might have been jammed, make sure they are connected to designated ports. Make sure the type of cable supported or ...