i nuke almost made me call the police

I got home from a long weekend and as I was unhooking the trailer, my wife was standing at the open door yelling for my help. I ran to her and heard a very loud banging sound from within the house. It took me a minute to realize it, but my sub was randomly popping and sounded like someone banging on a wall with both fists. Bad news is that I cannot get it to stop. Even if there is no input or output hooked up, I can hear the fan kick into high speed after a few seconds. I took off the cover an cleaned out any dust. The amp is 7 months old. Any advice would be apreciated. Thanks