I own a Klipsch Synergy 10" sub. I think it's 420W. It was fine yesterday when I turned it off at 9PM because it was getting late. Today when I turned it on, I only get a hum out of it. Everything has worked fine for quite a long time before today. I haven't moved or added any cables anywhere. My LFE signal is sent from my Yamaha reciever over a Monster Subwoofer Cable (the cloth coated looking one) with a Y adapter.We haven't had any power outages or storms ovenight, and it is plugged into a power strip. Does this sound like the amp died overnight while it was off for some reason? Could something have fallen loose inside that I can try to fix?