I just got a 831krss and I had the same problem! The dealer changed out the unit and the new unit the center channel did not work. The next one I had very loud static coming from my rear sperkers. My third unit is working fine so far. As far as I am concerned CONCERTONE makes a horrible product, the money that we pay for our campers you would think that FR would put a better sound system in the campers. Good thing that I have a very good dealer that has not given me any problems with the returns! I recommend take it to the dealer that you purchased it from and get a new unit. I read a post from somewhere that FR might be going with another manufacture for the surround sound head unit. Good luck!!!