We have an Ariel ACES (ariel computerized exercise system) isokinetic dynamometer that has developed a problem. We have tried to contact the manufacturer but have not heard back. It is about 10 years old and used in our biomechanics undergraduate labs. We think the stepper motor has failed (the lever arm is locked in one position and will not move). It appears to be communicating with the PC as we can hear the motor when advancing through various software commands. If anyone has some advice (before we start tearing it apart), it would be greatly appreciated.