What happened?
The filament sensor on the Prusa CORE One, and on the Original Prusa XL, MK4/S, MK3.9/S, MK3.5/S, and MINI/+ can detect filament runout, but also whether the filament is moving regularly or not.
In case of a detected blockage close to the filament sensor, the printer shows the message "Fil. Sensor Troubleshooting. If the filament sensor is unresponsive, clean it from debris. Alternatively, you can disable it".
Error name: Filament sensor stuck
Error code: #31113 (CORE One) #17113 (XL) #26113 (MK4S) #13113 (MK4) #27113 (MK3.9S) #21113 (MK3.9) #28113 (MK3.5S) #23113 (MK3.5) #12113 (MINI/+)
How to fix it?
Clean the filament sensor from possible debris.
For CORE One, XL, MK4/S, and MK3.9/S, refer to the Nextruder filament sensor article for accessing and cleaning methods.
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On MK3.5/S, loosen the bolt to remove the FS-cover, to gain access ot the IR filament sensor.
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On MINI/+, refer to the MINI/+ filament sensor article for accessing the sensor.
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