Epson LX-810 User Manual page 73

Interface Boards
2. Carefully insert the pins on the optional interface board into
the mating connector on the main board; then secure the board
with the three screws provided.
FG wire not attached
3.
If the FG wire is not attached to the interface board, attach the
plug end of the FG wire onto the FG pin located on top of the
interface board.
Using the Printer Options
4-22
FG wire attached