I cannot power it on. When I try to turn it on, I hear a pop coming from all my speakers and then the receiver turns off and the standby button flashes red. All I did was remove my subwoofer cable for one of my sub jacks in the media room and replace it with the one for my other sub jack. I even removed the sub cable completely, but the Denon still won't turn on. Really need some advise on this ... thanks.