Recently replaced the nozzle and printer was working great. Went to change the spool to change colour and it wouldn’t withdraw the ABS filament. Tried to extrude and it wouldn’t do that either. Have took apart the printer head to clean the gear but it hasn’t helped - noticed that the filament that’s against the gear is “worn down” so maybe there’s nothing for the gear to bite onto to make it move??? Any ideas how to get it out???
If you are sure the nozzle is heating up, try pushing on the filament while extruding.