When purchasing the Original Prusa MINI+, kit or semi-assembled, there is an option to add a filament sensor to the printer. It can also be purchased separately later.
This sensor assembly uses an IR sensor which is triggered by a mechanical lever. The electronics are the same as in the filament sensor assembly of the Original Prusa MK2.5S, MK3S, and MK3S+.
The sensor assembly is attached to the PTFE tube that leads into the extruder. If the filament runs out, the printer will pause your print, unload the remaining filament, and wait for a new filament to be loaded.
When the IR filament sensor is installed, you can see its status in the printer's menu under Info -> Sensor info:
If the sensor has been installed, activated and the status remains N/A, check the IR filament sensor cable connections on the sensor and on the Buddy board:
In case the printer does not detect a filament runout, there might be two issues:
To access the sensor for testing, unscrew the two M3x12 screws on each end of the sensor cover (blue circles).
The end of the lever needs to be between the plastic parts of the sensor while the status is 0. Move the lever by hand and see if it moves easily. In case it does not move, loosen the middle screw (purple circle).
If the status is either 0 or 1, regardless of the lever position, the sensor is malfunctioning.
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And if that doesn't do the trick, you can send an inquiry to firstname.lastname@example.org or through the button below.