I have assembled a Leo Rover which is now mostly working, but one of the wheels has a problem in the motor: the speed does not seem to be controlled properly (apparently it runs at constant speed when activated, in either direction). I have checked twice times all connections and they are ok. Connecting that motor to a different connector in the board makes no differencd: the motor behaves in the same way. Connecting one of the other motors (healthy) to the connector of the bad wheel this other motor still works well. Therefore, the problem seems to be in the motor. Any hint? Anything I can test/check/fix before ordering a new motor?
More (puzzling) info. During the tests another wheel (the opposite one) started doing the same. After some unsuccessful fiddling with the cables I decided to reflash the ROS firmware, and that made this second faulty wheel recover. The first one is still bad, though.