Ricoh D177 Service Training page 27

 Each PCDU [A] has a seal [B] that must be removed during
installation.
 Do this before you turn the main switch on, or the
development units can be severely damaged.
Slide 27
 This is different from the Met-C1abcde, and more similar to the Ap/At-C3 series.
Removing the PCDU Seals
27
Met-C1yz Training