Last night as I was starting a new print (AA battery storage box) the printer started making a chunking noise at the extruder and the filament stopped coming out. OUCH! I unloaded the filament and tried clearing the nozzle with a 0.4mm needle but, as I suspected, that didn't fix it. I used a bit of filament to probe the extruder and found that it seemed to stop just above the heatbreak. As it was late I just turned everything off and went to bed.
This morning I dismantled the extruder from the carriage and took a closer look. The block was just where the heat sink and the heatbreak meet apparently. I tried the heat and melt a piece to pull out the block but that didn't work. I'm not sure it would because the block was pretty far away from the hotend.
So I unscrewed the heat sink from the heatbreak. This was just a little scary because I didn't want to damage anything and the heater and sensor are in the heat block and pretty fragile but it did come apart. Once I got the heat sink loose it came off quite easily actually.
The problem was a tiny piece of filament that had lodged itself in the PTFE tube but it came out very easily once I had direct access to it.
Carefully reassembled the entire carriage and it's printing now. WHEW!
Submitted by Bill Waggoner on