While watching TV, A bold black and white mute icon popped up (different from he normal one, one Ive never seen before, and Ive been using this TV for over four years). Ive completely lost all sound, Ive tried to use all three of my remotes (my cable remote, my TV remote, and my audio converter remote, but nothing happens even as I adjust the volume. I cant say specifically which tv it is, as I said, its over four years old, a 42 inch Samsung TV. I would appreciate some help.