The Prusa CORE One, and the Original Prusa XL, MK4/S, MK3.9/S are equipped with a loadcell. Thanks to this component, starting from firmware 6.0.0, the printer can detect whether the filament is stuck and not moving, for example when the nozzle is clogged.
If this is detected, the print pauses and the printer shows the message: "Stuck filament detected. The filament seems to be stuck. Please unload it from the extruder and load it again."
Once the unload button is pressed, the printer unloads the filament. After this, it prompts filament loading and resumes the print.
It is important to note that detecting stuck filament is possible only inside the Nextruder, as pressure builds up from the nozzle to the upper part of the Nextruder. However, if your filament is tangled on the spool, there will be no internal pressure, just outside tension, which the loadcell won't recognize.
Stuck filament detection won't be possible on MK3.5 and MINI/MINI+ as they aren't equipped with the loadcell sensor.
Screenshot from the Original Prusa MK4
