One wheel not working

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.



As I wrote directly to you (may be useful for the rest):
If any of the motors drives only forward full speed or backward full speed, it means there’s no feedback from the enoders to the controller. Check all the connections between the encoder and the board on green, blue, white and yellow cables.
If the issue persists, it may mean that our supplier just sent us faulty motor and we can totally send new one as a warranty service.

Yes, thanks for the anwer. Also for anyone interested: I fully checked all connections and even removed the individual connectors and plugged them carefully to the board on a working wheel plug (one that works fine with one of the wheels that is ok), see image below. No luck, the faulty wheel is still faulty. Now waiting for the new one…


For future references: The motor had broken encoder (sic!)