Epson AcuLaser C9100 Reference Manual page 222

5. Confirm that the notch on the top edge of the ROM module
matches the catch on the socket. Then insert the ROM module
horizontally until it stops as shown below. If the ROM module
is correctly installed, the catch on the socket fits the notch on
the ROM module and the end of the socket sticks out as shown
below.
c
6. Reattach the cover to the right of the printer by inserting the
three projections at the bottom of the cover to the notches on
the printer, and then sliding the cover forward to firmly fit it
to the printer. Make sure the projection at the top of the cover
is inserted to the notch on the printer.
222
Installing Options
Caution:
❏ Do not force the ROM module into the socket.
❏ Be sure to insert the ROM module in the correct
direction.
❏ Never remove the ROM module installed on the
standard ROM socket (P).