Take off the arm tube and turn it over and check to make sure there isn't anything up inside the cylinder that would hinder the very sharp pivot point to seat correctly.
Also make sure that the very sharp pivot point is just that VERY sharp. If it got bumped or hit or dropped somehow, it would have damaged the point and made it blunt.
Also make sure that the very sharp pivot point is just that VERY sharp. If it got bumped or hit or dropped somehow, it would have damaged the point and made it blunt.