I have an Ender 3 V2 Neo that I’ve been running klipper on fire some years using a Raspberry Pi Zero 2w to controle it. I’ve swapped the hot end and everything for the Hero Me Gen 7 system.
This weekend I was trying to convert the printer to direct drive and wanted to swap out the stock 42x40 stepper motor for a smaller and lighter Simax3D Nema 17 stepper motor (42x23mm 0.7A-4.23V 2 phase 4 wires 1.8 degree). I assumed it would be an easy swap and so tried rubbing the meds stepper by just swapping the motors over on the wiring.
When I tried rubbing Extrude for a short 25mm run the stepper jolted slightly and stopped move. 
When I tried swapping the original stepper back in, it also now doesn’t move. 
What did I do wrong? What should I of done? What could now be the problem?
I’m assuming I’ve burnt it the stepper driver chip on the motherboard for the Extruder? All other strikers move fine! I have not tried the original E Stepper yet in one of the other positions.
From my testing the new steps sense to have the same wiring as the original. It came with a wire that has a twisted pair in the center just like on the printers original wiring.
Any help in diagnosing my problem would be much appreciated. Cheers.