I’m just putting this here for others to find. I started getting an error in the middle of a print that said my right hot end was clogged. It would feed the filament all the way to the hot end and then rewind it back into the AMS. After taking things apart to clear the path, it was obvious that there wasn’t a clog so I suspected the filament sensor on the right side was bad. I tried tracking down a replacement filament sensor but ran into trouble because I discovered there isn’t really a dedicated filament sensor. The part you want is the eddy current sensor that does multiple jobs. That part is also not sold separately from Bambu. The part you need to order is the Dual Extruder Idlers and Filament Sensor. That includes the idlers for right and left in addition to the sensors for both sides.
Here’s the page on how to replace it. Replace H2D & H2C Dual Extruder Idlers and Filament Sensor | Bambu Lab Wiki This may also help: Right Nozzle Eddy Sensor Replacement Guide for the H2C | Bambu Lab Wiki
In my case, I was sure the sensor was bad when I removed it and on the back (hidden) side, one of the surface mount components was dangling on just one side. When I touched it, it fell all the way off. If you look at the last picture, the bottom surface mount component is missing.
