Epson 1000 Reference Manual page 144

Inserting the upgrade board
The PCL5/RITech board is installed on the bottom right of the
controller board.
1. Locate connector CN 3 on the controller board. Position the
PCL5/RITech board as shown below, and carefully insert
its connector into connector CN 3.
2. Secure the PCL5/RITech board with the three screws that
came with it.
5-30 Options