For years I have had a surround system set up on the "A" part of the receiver. I am adding speakers to B and want to play all (A & B). The front A speakers (center R and L) totally cut out when I move the switch to A & B. If in surround mode the rear speakers on A will play in this A & B mode, but not the front R & L. I haven't used the switch in years. Is it broken or is there something I am missing. I verified the wiring accuracy too. Nick:confused: