HELP!! I have added an extra powersupply to my Prusa Mendel 3d printer.

You can also check if there is power on VMOT pin, if no power here - there is something broken on your board,

Weird enough, i uploaded the firmware again and now everything works! Even though i haven’t changed anything in the software.

Anyway… thank you so much for your extensive help guys!

Is this also a 3D parts?

@YASURS_LLC what do you mean? If i share the part designs?
They are om http://thingiverse.com . I did not design them…