Half way through a large PLA print I found the top of the print was soft and flexible, it however looked complete with a off colour. I ran a manual filament purge to find the bozzle had blocked. To save time I fitted a new nozzle and ran the filament test again to find the extruder gears were making a loadish noise due to the gears not being able to feed filament. I removed the hot end and tried to extrude filament again to hear the same noise once again. I the stripped the extruder and found that the gear on the tensioner was seized. I blew it out with some compressed air, there was no improvement following this, Q20 sprayed into the gaps on the parts loosened the gear up. I followed this up with another compressed air shot and then things loosened up completely. I suspect a piece of filament had worked its way between the gear and the side of the tensioner arm.
