Dave;

Replacing the NV O-rings uncovered another question - 2 O-rings or 3? The parts manual only shows two but the NV socket had three when I took it out. Was there a change at some point or did one of them not belong? The unexpected ring was at the base of the socket where it screws into the casing. The others were near the tip of the inserted end and in the middle on the NV side.