How to fix my Trimline 2400.1 from blowing the house circuit breaker?

My (Hebb Industries) Trimline 2400.1 treadmill blew the house circuit breaker while the treadmill was being used. I moved it to another circuit and it did the same thing. If you merely plug the treadmill into the wall outlet, it blows the breaker without the treadmill even being turned on. I unplugged the two motors from the circuit boards and it still blew the breaker. I then reconnected both motors and disconnected the black and white (power?) leads to the controller. With everything connected except for those two leads, it does not trip the breaker. Would that indicate a bad (shorted) controller or could it still be a problem somewhere else?