Internal AMS rotating and not advancing the filament? Try this before completely disassembling the unit and having to deal with the magnets.
One of the simpler issues that can occur is the feeder “gears” getting clogged with residue.
Mine had quit feeding. I removed the hub and had issues feeding filament by hand while rotating the white gear. Removed the 4 screws and took it out. It didn’t look bad, but then i took a dental pick to one of the grooves and residue came out. The gear was so evenly coated it didn’t look like this was an issue. Cleaned both gears with a short bristled metal brush. Vacuumed the bottom gear after cleaning to remove residue.
If you have a small pipe cleaner (I didn’t have one on hand), you can run it through each inlet port while the gear and cover are off
You should then attach a short piece of tubing to each inlet port and blow it out with 60# air. Blow out around the bottom gear next. Put the upper gear and cover back in place. If you want you can stick a short piece of tubing in the outlet port and blow it in the other direction.
This following step may or may not be necessary, but it’s worth a try. I went ahead and did it. Cut off about 1/8" of the tube end going into the outlet port. Use a tool to deburr the INSIDE of the tube creating a SLIGHT bevel. Don’t over do this and create a thin edge.
My inner hub now feeds like a champ.
I get the feeling, this will become a yearly maintenance item for me, as it’s not difficult to do.