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2HL/2HM/2HN-1
1-4-17
7403
Developing unit M non-installing error
No density detection signal is output
from toner sensor M in developing unit
M.
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 1-5-13).
Defective harness
between drum
relay PWB (YC1)
and engine PWB
(YC34), or
improper connec-
tor insertion.
Reinsert the connector. Also check for conti-
nuity within the connector harness. If none,
remedy or replace the harness.
Defective toner
sensor M.
Replace the developing unit M (See page 1-
5-13).
Defective engine
PWB.
Replace the engine PWB (See page 1-5-
30).
7404
Developing unit Y non-installing error
No density detection signal is output
from toner sensor Y in developing unit Y.
Faulty connection
of the connector
between the devel-
oping PWB Y and
drum relay PWB.
Check the installation of the developing unit
Y and drum relay PWB and reinstall them if
necessary (See page 1-5-13).
Defective harness
between drum
relay PWB (YC1)
and engine PWB
(YC34), or
improper connec-
tor insertion.
Reinsert the connector. Also check for conti-
nuity within the connector harness. If none,
remedy or replace the harness.
Defective toner
sensor Y.
Replace the developing unit Y (See page 1-
5-13).
Defective engine
PWB.
Replace the engine PWB (See page 1-5-
30).
7411
Drum unit K non-installing error
The EEPROM of drum PWB K does not
communicate normally.
Faulty connection
of the connector
between the drum
PWB K and drum
relay PWB.
Check the installation of the drum unit K and
drum relay PWB and reinstall them if neces-
sary (See page 1-5-15).
Defective harness
between drum
relay PWB (YC1)
and engine PWB
(YC34), 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 drum
unit K.
Install drum unit K compatible with the spec-
ifications to the printer.
Defective drum
PWB K.
Replace the drum unit Y (See page 1-5-15).
Defective engine
PWB.
Replace the engine PWB (See page 1-5-
30).
Code
Contents
Remarks
Causes
Check procedures/corrective measures
Summary of Contents for CLP 3521
Page 1: ...Service Manual Color Printer CLP 3521 CLP 3621 CLP 3626 Rev 2 0 Date 21 09 2010 2HNSM062 ...
Page 2: ...Service Manual Color Printer CLP 4521 CLP 4621 CLP 4626 Rev 2 0 Date 21 09 2010 2HNSM062 ...
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Page 15: ...2HL 2HM 2HN This page is intentionally left blank ...
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