Short circuited 37D Gearmotor?

Last friday I bought my second 37D mm Gearmotor (more specific this one

However it won’t start. I was going to hook it up to a power supply at my university to look at the encoder values using a oscilloscope, but I did not get that far. When I just connected the red and black wires to the power supply I saw a voltage drop (to near 0V from about 5V) and an increase in current (don’t remember exactly the current, because I removed the cable as fast as possible).

I suspect that something is short circuited. But this is the first time I connect the motor. However I have physically mounted the motor into my chassis and some of the cables became worn (but the cables themselves are not shorted). When I tested the motor with the power supply it was not mounted into my robot.

Between the red and black wire I measure 30 ohm at the broken motor and 5 ohm at the working.

How can I further investigate this?
Can it be the capacitor that is broken?

Thanks in Advance!


I am sorry you are having problems with your gearmotor. Which capacitor do you suspect is broken, and why do you think it is broken? How did the cables become worn? Could you post pictures of your whole setup and close-up pictures of the motor that is having problems (including some of the worn cables and the capacitor you think is broken)?

- Grant