I was printing something using TPU via my Micro Swiss extruder and hot end on my Creality CR-10. Unfortunately the filament started squeezing out of the extruder because the nozzle was too close to the bed. I raised the Z-axis, kept the nozzle heated, and retracted filament. I had to go backwards and forwards a bit and ended tugging quite hard to finally get the filament removed.
When I loaded filament again (any type) I just got a knocking sound but no movement.
I removed the extruder motor and tried driving it again and it was just making a small step forwards and backwards continually while trying to extrude or retract.
I ordered a new extruder motor and fitted it today but found it was doing exactly the same. I am using the EZBoard Lite from TH3D and am worried that I might have damaged the stepper driver. Has anyone got any advice about what I can try next? It was printing fine, with well calibrated E-steps prior to the TPU filament problem, so I can't believe this is in any way related to a firmware/settings problem. I would appreciate any ideas, particularly if anyone knows whether a stepper driver can be replaced on the TH3D EZBoard Lite. Yes, of course I am heating the nozzle.