I've just installed an Hemera direct drive on my Ender 3 and the extruder is not rotating. I'm trying to control it from the Ender 3 menu - Prepare->Move Axis->Extruder->Move 10mm->setting 10mm and pressing the knob. Visual inspection of the gears shows that they are not rotating. I've double checked that the Hemera extruder stepper motor cable is plugged in correctly on the board. Any ideas of what I can do to determine if I have a DOA Hemera?