Ricoh D146 Service Manual page 1821

4. Replace the installed FCU board [A] with a new FCU board ( x 1, stepped screw x 2,
x 1).
5. Reinstall the new fax unit, and then the slot cover ( x 2).
6. Remove the rear cover [A] ( x 4).
7. Attach the flat cable [A] to CN603 of the new fax unit.

Make sure that the blue tapes of the flat cable face outward.
SM 45 D163