The duetwifi was in a plastic case to prevent the problem with metal surfaces.
I checked the wires again and they're OK.

The voltage of my power supply is 12V

Hello everybody,

my name is Julian, I'm from Germany and I decided to create my own 3D-printer.
Therefore I needed a board to control my printer. I chosen the DuetWifi.
I wired the Board (v1.0) like the wiring diagram on this page,
and have a problem.

To my problem:
Since the first run, the Board tells me, that drive 0 (X-MOT) is short-to-ground.
So I mixed the motors X Y and Z on the according drivers to see, that all motors work, obviously excluding the drive for the x-axis. The stepper which one was wired on the drive 0 and doesn't work there (vibrates back and forth and sounds horrible), however works on drive 1/2.
So I thought the fault is in the IC-module and I took a look at it and found a small circle. It looks like the plastic is melted marginal at this point.

Now my questions:
Is it possible, that the error cames from the stepper, because the board tells me the short curcuit before ever a motor ran?
What could be other causes ?
Was there any known production errors like this case ?

General conditions:
Specifications of the stepper:
Manufacturer Part Number 17HS19-2004S1
Step Angle 1.8°
Step Accuracy 5%
Holding Torque 59Ncm(83.6oz.in)
Rated Current/phase 2.0A
Phase Resistance 1.4ohms
Voltage 2.8V
Inductance 3.0mH±20%(1KHz)
Weight 400g

For the present, I think these are enough informations. If you need more, please comment.
Hope someone can help me.