I'm having some issues recently with my Mordaunt Short MS909W. It's not working at all right now. It has intermittently received signal from my Receiver, but only a couple times randomly, then the signal drops out. I've tried multiple cables, but the end result is the same. Not sure if it's the SW output on my receiver (Denon AVR-2809CI) or the SW itself. Any troubleshooting suggestions so I can determine what the problem is?