I just put together a i3a from DIY Tech shop, and the X/Y/Z steppers all work fine, but the extruder motor just twitches back and forth if I try to command it. I have verified it is not the stepper controller, but it is specific to the motor. The axis motors are all Casun 42SHD202-24T, but the extruder one is a longer nema17 Labeled as 17PM-402-P4V from Minebea-Matshushita. As said before the extruder controller works fine commanding the other steppers but not this specific motor. I also verified that the connectors on the RAMPS board ring out as 15 Ohm pairs. I am going to get in touch with vendor, but just wanted to get a head start and see if anyone had any ideas.
Thanks
CP
