Ender 3 Pro extruder drive rocking back and forth
Sounds like one end or the other in your stepper cable is not seated correctly or has shaken loose there are 4 wires if even one doesn't make proper contact you will get a shaking back and forth almost like a hard vibration. I always take a cable from one of the other steppers plug into this one move the motor with good stepper wire 10-20&nbsp;mm see what motor does if it is okay then you know it is a cable issue if not, it could be a bad board or stepper.