Brother HL-1800 series - Manual (Page 110)

CHAPTER 4 OPTIONS
4-7
☛ ☛ ☛ ☛ 6.
Insert the Network Board connector into the PCB connector, and then secure
it with the two screws removed in Step 4.
Fig. 4-6
☛ ☛ ☛ ☛ 7.
Re-install the PCB Access Plate, and then secure it with the two screws you
removed in Step 3.
Fig. 4-7