Had some bad weather roll through my area, causing my printer to power cycle and dump its wifi again, went to do a factory reset and calibration, keep getting a message asking to unload filament before proceeding, however the AMS is fully retracted, and nothing in the external. I know these do not have the same filament sensor as before, has anyone ran into this and is there a quick fix? Seems the filament sensor is acting up, however I’m unsure if it’s the main or aux nozzle causing the issue.
In the filament section on the printer’s display, you can see where the printer thinks the filament is and which extruder it is loaded into, start with this
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All were clear unfortunately which is why it had me confused. I performed a clog clearing procedure several times, didn’t help.
In the end, I turned both nozzles on one at a time to 250, and let them time out, material oozed out of both nozzles, I did this 3x each nozzle, and it finally let me reset the machine.
My only guess is enough material was in the pathway to confuse the sensor.
Have this happen all the time on H2 machines with multicolor printing using both nozzles. One nozzle color might be only 20 minutes of printing while the other nozzle color might be 20 hours.
Since by default the AMS does not unload the filament until the end of a print all that violent shaking the toolhead is doing can snap the filament right above the extruder.
So on particular prints prone to do this I just remove the PTFE tubing out of that tool head and pull out the piece of broken filament at the end when it thinks it’s still there.
The X2D is obviously different in a way the 2nd nozzle is the bowden and probably not setup on an AMS (maybe you do), but the same type of error can happen I suppose.
I thought about changing gcode to force the AMS to unload once it’s done with a color but it’s such an easy thing to clear I never did.
Great insight here, I am using the AMS and its always cleared itself without issues, but I do have over 200 hours on it already, so it’s possible just normal buildup overtime finally confused the sensor. never alarmed though, still ran fine but trying to fix my wifi issue the only thing I’ve found works is a reset and it just refused to work with me.
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Yeah. I’m mainly running some form of ABS and with all the heat for very long prints, it makes sense that the shaking in the PTFE tube finally snapps the filament where it does.
But I’ve never had it stuck. Obviously at the end of the print, the cutter is engaged and the AMS pulls it back. So what I find when I pull the PTFE tubing out is about an 1.5" long piece of broken filament just sticking up above the quick release for the PTFE on the toolhead.
I have similar problem. Just about 10 hrs. of printing. I have X2D combo with AMS2. Started with only 4 spools in AMS. 3 prints went fine. I have added external spool and cannot print ever since. HMS_07FE-2000-0002-0004: Please pull the external filament from the left extruder. That is a little problem. Left extruder is connected to AMS, right to external filament. Bambulab thinks, that I somehow have 3 sources. AMS and external to left extruder and another external to right extruder. I tried to reset to factory settings but Catch 22 works here - you have to unload all filaments first. And gues what, it still wants me to unload the one that doesn´t exist 
Anybody had the same problem?
Manually heat cycle the nozzles, I ran mine up to 250 and let it time out 3 times both sides, run the cleaner needle up into them while they’re hot, eventually it cleared and showed everything was unloaded as it should have.
If it’s thinking filament needs to be unloaded than my guess is it’s seeing filament somewhere it shouldn’t.
Go up to your machine’s screen where it shows extruder / nozzle (as if you were to switch between left and right nozzle screen).
Are any of the nozzles showing a green square icon inside the nozzle screen?
If so, the printer sees filament at the filament sensor.
Have you tried swapping the hotends (Left to right) and see if the problem follows the hotend?
I was sick, so I only got to it now. I had to remove the feeding tube to the left extruder and clean it. There was a piece of filament left after cutting, which was stuck above some previous debris, so the extruder couldn’t push it through. Everything is working now. Huge thanks to everyone who tried to help — as a Bambu beginner, I really appreciated it.
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I have had this occur 2 times now on my X2D. Pretty sure it is the same issue where the filament has set too long and is cold when cut. A piece of filament is broken just prior to the cutter which then bends in the filament sensor housing binding everything up. unfortunately the only way I have been able to correct it is to dis-assemble the head to pull out the sensor housing, then carefully disassemble it. Not the most fun task.