I picked up a used Rotel RP-2400 a while back, which is a belt drive semi-auto table. Problem is, it seems a tick too slow. It has no strobe and no speed control but I can tell it's slow. The belt looks new, and it's nice and tight but I have no idea if it's even the correct belt. I have a funny feeling that I'd be wasting $20 with a new belt. So I guess the question is, other than the belt, what can cause a slowdown? The platter turns freely and the motor runs smooth, so what else is there to check? Any suggestions?