Baby Lock ProStitcher Version 14.04.0051 (BLPS3) Instruction and Reference Guide - Manual (Page 17)

Pro-Stitcher User Manual Installation | 3.9
4. Align the new Y-Encoder circuit board so the five pins
on the encoder fit into the five-pin connector on the
circuit board and gently push into position. The screw
hole on the circuit board should match up with the
hole in the encoder housing.
5. Replace the Phillips screw.
6. Plug the stitch regulator cable into the new Y-encoder circuit board.