2PR
1-4-23
7402 Developing unit C non-installing error
The EEPROM of the developing PWB C
does not communicate normally.
Incompatible developing unit C is
installed.
Faulty connection
of the connector
between the devel-
oping PWB C and
drum relay PWB.
Check the installation of the developing unit
C and drum relay PWB and reinstall them if
necessary (See page 1-5-12).
Defective harness
between drum
relay PWB (YC2)
and engine PWB
(YC619), or
improper connec-
tor insertion.
Reinsert the connector. Also check for conti-
nuity within the connector harness. If none,
remedy or replace the harness.
Installation of
incompatible
developing unit C.
Install developing unit C compatible with the
specifications to the printer.
Defective toner
sensor C.
Replace the developing unit C (See page 1-
5-12).
Defective engine
PWB.
Replace the engine PWB (See page 1-5-
28).
7403 Developing unit M non-installing error
The EEPROM of the developing PWB M
does not communicate normally.
Incompatible developing unit M is
installed.
Faulty connection
of the connector
between the devel-
oping PWB M and
drum relay PWB.
Check the installation of the developing unit
M and drum relay PWB and reinstall them if
necessary (See page 1-5-12).
Defective harness
between drum
relay PWB (YC2)
and engine PWB
(YC619), or
improper connec-
tor insertion.
Reinsert the connector. Also check for conti-
nuity within the connector harness. If none,
remedy or replace the harness.
Installation of
incompatible
developing unit M.
Install developing unit M compatible with the
specifications to the printer.
Defective toner
sensor M.
Replace the developing unit M (See page 1-
5-12).
Defective engine
PWB.
Replace the engine PWB (See page 1-5-
28).
Code Contents
Remarks
Causes Check procedures/corrective measures