Slightly off topic here. I just picked up a used 50' Hitachi rear projection TV. The picture isn't bad for my basement 'den' but it needs to be focused since 'the move'. I'd like to read up on improving the color focus/confocus. I've played with the 2 dozen knobs for adjusting the focus, but I think one of the beams is knocked off beyond the range of the controls. Any suggestions? Thanks in advance.