There's green lights and or yellow lights that are on each of these controllers. You can swap out these controllers with one another. They act the same way. The lights can tell you which one is bad or all Mark and move them to try and eliminate whether it's a hydraulic motor issue or drive motor issue. Or use a good meter and test between U,V,W. If they are shorted you will have continuity. Between u&v or u&w or v&w. You shouldn't have any. Make sure you remove the motor leads before this test and power is off. Do this for each one. If your lights are steady green on the controller it's not faulty