I just got this today, plugged it in my arduino, and the arduino light starts dimming until you cannot see it any more over the course of 5 seconds. The Computer disconnects the arduino when the light is off (Ding Dong Sound). I found pulling the VIN Connector Jumper/Power Jumper will stop the short circuit and work, but that defeats the purpose, as the board wouldn't even powered.

Here is the video: YouTube

Is the motor board broken? If so in what way? are the wires on the board simply broken? Is it due to bad soldering?(I checked solder, looks fine).