I purchased a Denon 1802 to run in a second system a couple of weeks ago. I am using it as a pre-pro with Marantz MA500s driving the fronts and center. The rears are powered by the Denon. Last night I was watching the end of Fight Club at reference level, when the receiver shut down. I thought this was odd, as I don't think I was stressing the internal amps driving only one set of speakers. Upon power up, there was a flash of fire? and a puff of smoke. Now when I try to power up it shuts down immediately. Any ideas what's going on? Fortunately, I purchased it at a local dealer who (I think) will exchange it without too much difficulty. Do I need a more powerful piece?