Filament sensor didn't trigger

What happened?

If, during the filament load-to-nozzle process, the extruder's filament sensor is not triggered, the printer will display an error.

How to fix it?

Assembly

• Remake the filament sensor calibration.
• Make sure that the PTFE tube is fully pushed into the Festo fitting on the extruder and the MMU unit, and that the fitting is fully tightened, with no gap.
• If you use an alternative MMU-to-Extruder PTFE tube, make sure it is not excessively long. The original tube is 360mm long. The MMU can adapt to tubes between 350 mm to 380 mm.
• Open the extruder idler and make sure there is no leftover filament blocking the new filament from loading.

MK3/S/+, MK3.5/S	MK4/S, MK3.9/S, CORE One

Filament

• The filaments must have a sharp tip to load properly into the printer. If the tip is deformed, bent, or larger in diameter, cut it off.
• Inspect the last 40cm (15") of each filament to make sure there are no dents.
• If the filament is still not being pulled, check the assembly.