Hey. I have an old 4 channel amp off a friend, and had to open it up to find that it was a Boss. The problem with it is I can only get two channels to run off it at a time. I'm only running one set of RCAs to it, and I'm trying to run 4 speakers from the amp. It has a 2, 3 or 4 channel switch, but switching this seems to have no effect at all. No matter what I do I can only get two speakers to work at once. I hope I've explained it well enough...short of pulling the whole thing apart I can't see what might be wrong. Any Ideas?