We have 2 speaker zones though our Denon AVR-1905/785 receiver and suspect that a guest using the RC-978 remote while we weren't home may have mixed up the remote's settings. Now we can't shut off zone two or change it's mode. Not only that, every button on the remote simply turns the receiver off. The LED indicator light is always on. Switching batteries did nothing. Any advice

Audio Players & Recorders - Denon - AVR-2807 Receiver