Does anyone know how the right side filament sensor on the H2D works? Is it optical or is there like a hall effect sensor or a button? I got this failure to retract error that ruined a print. Eventually I tracked it to the filament sensor on the right. There is nothing stuck in it. I have the toolhead half apart. When I remove the screw for the sensor and pull it away from the filament path the filament indicator light turns off, when I put it back on it and stick a piece of filament down the path it will come on and go off about 50% of the time. Sometimes it goes off when the filament is gone, sometimes the indicator stays lit. When I try to look down where the filament is supposed to “look” through I can’t see any filament at all. The sensor clearly works, but whatever way is supposed to trip the sensor is not working apparently.
This is a Hall-effect sensor with a moving magnet. The filament pushes the magnet away, triggering the sensor.
You might want to check if the magnet can move freely. Some debris might restrict it moving freely, causing the 50% failure rate.