I checked my mc18's RC servo as it appear to be not functioning properly. Hooked up a battery to the W/R and W/BL wires and nothing. I guess that means the servo is dead.

I am wondering if I can use a donor mc21, or 28 servo as a replacement or is there a way to fix mine. Hooked up the battery to the W and W/BL wires and the motor spins fine. Seems like the potentiometer is dead. Resistance is 0-2 ohms only.

Suggestions?