Sharp MX-6500N / MX-7500N (serv.man21) Service Manual ▷ View online
MX-7500N TROUBLESHOOTING 7 – 29
F1-67
No. 2 lift motor trouble
F1-90
Communication trouble between the
decurler and the downstream units.
decurler and the downstream units.
F1-96
Decurler transport motor abnormality
(DCM100)
(DCM100)
F1-97
Decurler unit fan 1 (Upper cooling fan)
abnormality (DCFAN100)
abnormality (DCFAN100)
F1-98
Decurler unit fan 2 (Lower cooling fan)
abnormality (DCFAN103)
abnormality (DCFAN103)
F1-99
Decurler unit fan 3
(Transport motor cooling fan)
abnormality (DCFAN101)
(Transport motor cooling fan)
abnormality (DCFAN101)
F2-22
Discharge lamp trouble (K)
F2-23
Discharge lamp trouble (C)
F2-24
Discharge lamp trouble (M)
Trouble content
Abnormality of the tray-lift-up driving motor in the
lower side paper feed section of the inserter
lower side paper feed section of the inserter
Detail
PCU
Cause
Motor lock, control PWB trouble, home position sen-
sor breakdown, connection harness / connector con-
nection trouble.
sor breakdown, connection harness / connector con-
nection trouble.
Check & Remedy
Use Sim. 3-31 to check the operation of the No. 2 lift
motor.
Check connection from the control PWB to the motor.
Replace the control PWB and the sensor part.
motor.
Check connection from the control PWB to the motor.
Replace the control PWB and the sensor part.
Trouble content
Communication trouble between the decurler and the
units connected to the downstream of the decurler.
units connected to the downstream of the decurler.
Detail
PCU
Cause
Noise on the communication line, control PWB
trouble, disconnection of connector or harness.
trouble, disconnection of connector or harness.
Check & Remedy
Turn OFF/ON the power.
Check connection of the connector between the
decurler unit and the downstream units of the decurler.
Replace the control PWB of the downstream units of
the decurler.
Check connection of the connector between the
decurler unit and the downstream units of the decurler.
Replace the control PWB of the downstream units of
the decurler.
Trouble content
The transport operation of the decurler transport
motor is abnormal.
motor is abnormal.
Detail
PCU
Cause
Motor driver IC overcurrent detection, overheat
detection.
detection.
Check & Remedy
Use SIM3-51 to check the operation of the decurler
transport motor.
Replace the control PWB.
transport motor.
Replace the control PWB.
Trouble content
The operation of the fan in the decurler unit is
abnormal.
abnormal.
Detail
PCU
Cause
Motor lock, motor harness short/open, control PWB
trouble, disconnection of harness or connector.
trouble, disconnection of harness or connector.
Check & Remedy
Use SIM3-51 to check the operation of the decurler
unit fan 1 (Upper cooling fan).
Check connection from the control PWB to the fan
motor.
Replace the control PWB. Replace the fan motor.
unit fan 1 (Upper cooling fan).
Check connection from the control PWB to the fan
motor.
Replace the control PWB. Replace the fan motor.
Trouble content
The operation of the fan in the decurler unit is
abnormal.
abnormal.
Detail
PCU
Cause
Motor lock, motor harness short/open, control PWB
trouble, disconnection of harness or connector.
trouble, disconnection of harness or connector.
Check & Remedy
Use SIM3-51 to check the operation of the decurler
unit fan 2 (Lower cooling fan).
Check connection from the control PWB to the fan
motor.
Replace the control PWB. Replace the fan motor.
unit fan 2 (Lower cooling fan).
Check connection from the control PWB to the fan
motor.
Replace the control PWB. Replace the fan motor.
Trouble content
The operation of the fan in the decurler unit is
abnormal.
abnormal.
Detail
PCU
Cause
Motor lock, motor harness short/open, control PWB
trouble, disconnection of harness or connector.
trouble, disconnection of harness or connector.
Check & Remedy
Use SIM3-51 to check the operation of the decurler
unit fan 3 (Transport motor cooling fan).
Check connection from the control PWB to the fan
motor.
Replace the control PWB. Replace the fan motor.
unit fan 3 (Transport motor cooling fan).
Check connection from the control PWB to the fan
motor.
Replace the control PWB. Replace the fan motor.
Trouble content
When the discharge lamp open sensor is kept ON for
a certain time from turning ON the discharge lamp, it is
detected as a trouble.
a certain time from turning ON the discharge lamp, it is
detected as a trouble.
Detail
PCU
Cause
Contact trouble between the discharge lamp PWB (K)
and the PCU PWB.
Discharge lamp PWB (K) trouble.
PCU PWB trouble.
and the PCU PWB.
Discharge lamp PWB (K) trouble.
PCU PWB trouble.
Check & Remedy
Use SIM5-4 to check lighting of the discharge lamp
(K) [DL_K].
Check the discharge lamp PWB (K).
Check the harness and the connector.
Replace the PCU PWB.
(K) [DL_K].
Check the discharge lamp PWB (K).
Check the harness and the connector.
Replace the PCU PWB.
Trouble content
When the discharge lamp open sensor is kept ON for
a certain time from turning ON the discharge lamp, it is
detected as a trouble.
a certain time from turning ON the discharge lamp, it is
detected as a trouble.
Detail
PCU
Cause
Contact trouble between the discharge lamp PWB (C)
and the PCU PWB.
Discharge lamp PWB (C) trouble.
PCU PWB trouble.
and the PCU PWB.
Discharge lamp PWB (C) trouble.
PCU PWB trouble.
Check & Remedy
Use SIM5-4 to check lighting of the discharge lamp
(C) [DL_C].
Check the discharge lamp PWB (C).
Check the harness and the connector.
Replace the PCU PWB.
(C) [DL_C].
Check the discharge lamp PWB (C).
Check the harness and the connector.
Replace the PCU PWB.
Trouble content
When the discharge lamp open sensor is kept ON for
a certain time from turning ON the discharge lamp, it is
detected as a trouble.
a certain time from turning ON the discharge lamp, it is
detected as a trouble.
Detail
PCU
Cause
Contact trouble between the discharge lamp PWB (M)
and the PCU PWB.
Discharge lamp PWB (M) trouble.
PCU PWB trouble.
and the PCU PWB.
Discharge lamp PWB (M) trouble.
PCU PWB trouble.
Check & Remedy
Use SIM5-4 to check lighting of the discharge lamp
(M) [DL_M].
Check the discharge lamp PWB (M).
Check the harness and the connector.
Replace the PCU PWB.
(M) [DL_M].
Check the discharge lamp PWB (M).
Check the harness and the connector.
Replace the PCU PWB.
MX-7500N TROUBLESHOOTING 7 – 30
F2-25
Discharge lamp trouble (Y)
F2-39
Process temperature sensor trouble
F2-40
Toner density sensor trouble (K)
F2-41
Toner density sensor trouble (C)
F2-42
Toner density sensor trouble (M)
F2-43
Toner density sensor trouble (Y)
F2-45
Color image density sensor trouble
F2-49
LSU thermistor trouble
F2-50
K drum phase sensor trouble
Trouble content
When the discharge lamp open sensor is kept ON for
a certain time from turning ON the discharge lamp, it is
detected as a trouble.
a certain time from turning ON the discharge lamp, it is
detected as a trouble.
Detail
PCU
Cause
Contact trouble between the discharge lamp PWB (Y)
and the PCU PWB.
Discharge lamp PWB (Y) trouble.
PCU PWB trouble.
and the PCU PWB.
Discharge lamp PWB (Y) trouble.
PCU PWB trouble.
Check & Remedy
Use SIM5-4 to check lighting of the discharge lamp
(Y) [DL_Y].
Check the discharge lamp PWB (Y).
Check the harness and the connector.
Replace the PCU PWB.
(Y) [DL_Y].
Check the discharge lamp PWB (Y).
Check the harness and the connector.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Process thermistor trouble.
Process thermistor harness connection trouble.
PCU PWB trouble.
Process thermistor harness connection trouble.
PCU PWB trouble.
Check & Remedy
Replace the process thermistor.
Check connection of the process thermistor harness
and the connector.
Replace the PCU PWB.
Check connection of the process thermistor harness
and the connector.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Toner density sensor output abnormality.
Sensor connector and harness connection trouble.
Developing unit trouble.
PCU PWB trouble.
Sensor connector and harness connection trouble.
Developing unit trouble.
PCU PWB trouble.
Check & Remedy
Replace the toner density sensor.
Check connection of the sensor connector and the
harness.
Replace the developing unit.
Replace the PCU PWB.
Check connection of the sensor connector and the
harness.
Replace the developing unit.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Toner density sensor output abnormality.
Sensor connector and harness connection trouble.
Developing unit trouble.
PCU PWB trouble.
Sensor connector and harness connection trouble.
Developing unit trouble.
PCU PWB trouble.
Check & Remedy
Replace the toner density sensor.
Check connection of the sensor connector and the
harness.
Replace the developing unit.
Replace the PCU PWB.
Check connection of the sensor connector and the
harness.
Replace the developing unit.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Toner density sensor output abnormality.
Sensor connector and harness connection trouble.
Developing unit trouble.
PCU PWB trouble.
Sensor connector and harness connection trouble.
Developing unit trouble.
PCU PWB trouble.
Check & Remedy
Replace the toner density sensor.
Check connection of the sensor connector and the
harness.
Replace the developing unit.
Replace the PCU PWB.
Check connection of the sensor connector and the
harness.
Replace the developing unit.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Toner density sensor output abnormality.
Sensor connector and harness connection trouble.
Developing unit trouble.
PCU PWB trouble.
Sensor connector and harness connection trouble.
Developing unit trouble.
PCU PWB trouble.
Check & Remedy
Replace the toner density sensor.
Check connection of the sensor connector and the
harness.
Replace the developing unit.
Replace the PCU PWB.
Check connection of the sensor connector and the
harness.
Replace the developing unit.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Color image density sensor sensitivity adjustment
trouble.
Color image density sensor trouble.
Sensor harness and connector connection trouble.
Image density sensor dirt.
Calibration plate dirt.
Transfer unit lift operation trouble
PCU PWB trouble.
trouble.
Color image density sensor trouble.
Sensor harness and connector connection trouble.
Image density sensor dirt.
Calibration plate dirt.
Transfer unit lift operation trouble
PCU PWB trouble.
Check & Remedy
Replace the color image density sensor.
Check connection of the sensor harness and the
connector.
Clean the image density sensor.
Replace the calibration plate.
Repair the transfer unit lift mechanism.
Replace the PCU PWB.
Check connection of the sensor harness and the
connector.
Clean the image density sensor.
Replace the calibration plate.
Repair the transfer unit lift mechanism.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
The LSU temperature is outside of -28 degrees C - 78
degrees C.
LSU thermistor trouble.
LSU thermistor harness and connector connection
trouble
PCU PWB trouble.
LSU control PWB trouble.
degrees C.
LSU thermistor trouble.
LSU thermistor harness and connector connection
trouble
PCU PWB trouble.
LSU control PWB trouble.
Check & Remedy
Replace the PCU PWB.
Replace the LSU control PWB.
Replace the LSU.
Replace the LSU control PWB.
Replace the LSU.
Trouble content
Detail
PCU
Cause
Drum phase sensor trouble.
Drum phase sensor harness and connector
connection trouble
Drum drive section trouble.
PCU PWB trouble.
Drum phase sensor harness and connector
connection trouble
Drum drive section trouble.
PCU PWB trouble.
Check & Remedy
Use SIM30-1 to check the operation of "DHPD_K".
Replace the drum phase sensor.
Check connection of the drum phase sensor harness
and the connector.
Repair the drum drive section.
Replace the PCU PWB.
Replace the drum phase sensor.
Check connection of the drum phase sensor harness
and the connector.
Repair the drum drive section.
Replace the PCU PWB.
MX-7500N TROUBLESHOOTING 7 – 31
F2-51
CL drum phase sensor trouble (C)
F2-52
CL drum phase sensor trouble (M)
F2-53
CL drum phase sensor trouble (Y)
F2-58
Temperature/humidity sensor trouble
(HUD_M/TH_M)
(HUD_M/TH_M)
F2-64
Toner supply operation trouble (K)
F2-65
Toner supply operation trouble (C)
F2-66
Toner supply operation trouble (M)
Trouble content
Detail
PCU
Cause
Drum phase sensor trouble.
Drum phase sensor harness and connector
connection trouble
Drum drive section trouble.
PCU PWB trouble.
Drum phase sensor harness and connector
connection trouble
Drum drive section trouble.
PCU PWB trouble.
Check & Remedy
Use SIM30-1 to check the operation of "DHPD_C",
"DHPD_M", "DHPD_Y".
Replace the drum phase sensor.
Check connection of the drum phase sensor harness
and the connector.
Repair the drum drive section.
Replace the PCU PWB.
"DHPD_M", "DHPD_Y".
Replace the drum phase sensor.
Check connection of the drum phase sensor harness
and the connector.
Repair the drum drive section.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Drum phase sensor trouble.
Harness and connector connection trouble.
Drum drive section trouble.
PCU PWB trouble.
Harness and connector connection trouble.
Drum drive section trouble.
PCU PWB trouble.
Check & Remedy
Use SIM30-1 to check the operation of "DHPD_C",
"DHPD_M", "DHPD_Y".
Replace the drum phase sensor.
Check connection of the connectors and the harness.
Repair the drum drive section.
Replace the PCU PWB.
"DHPD_M", "DHPD_Y".
Replace the drum phase sensor.
Check connection of the connectors and the harness.
Repair the drum drive section.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Drum phase sensor trouble.
Harness and connector connection trouble.
Drum drive section trouble.
PCU PWB trouble.
Harness and connector connection trouble.
Drum drive section trouble.
PCU PWB trouble.
Check & Remedy
Use SIM30-1 to check the operation of "DHPD_C",
"DHPD_M", "DHPD_Y".
Replace the drum phase sensor.
Check connection of the connectors and the harness.
Repair the drum drive section.
Replace the PCU PWB.
"DHPD_M", "DHPD_Y".
Replace the drum phase sensor.
Check connection of the connectors and the harness.
Repair the drum drive section.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Temperature/humidity sensor trouble.
Process humidity sensor harness and connector
connection trouble
PCU PWB trouble.
Process humidity sensor harness and connector
connection trouble
PCU PWB trouble.
Check & Remedy
Replace the temperature/humidity sensor.
Check connection of the temperature/humidity sensor
harness and the connector.
Replace the PCU PWB.
Check connection of the temperature/humidity sensor
harness and the connector.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Toner motor trouble.
Toner density sensor trouble.
Connector/harness trouble.
PCU PWB trouble.
Toner cartridge trouble.
Developing unit trouble.
Tone hopper section trouble
Toner density sensor trouble.
Connector/harness trouble.
PCU PWB trouble.
Toner cartridge trouble.
Developing unit trouble.
Tone hopper section trouble
Check & Remedy
Replace the toner motor.
Replace the toner density sensor.
Connector and harness check.
Replace the PCU PWB.
Replace the toner cartridge.
Replace the developing unit.
Check the toner hopper section.
Replace the toner density sensor.
Connector and harness check.
Replace the PCU PWB.
Replace the toner cartridge.
Replace the developing unit.
Check the toner hopper section.
Trouble content
Detail
PCU
Cause
Toner motor trouble.
Toner density sensor trouble.
Connector/harness trouble.
PCU PWB trouble.
Toner cartridge trouble.
Developing unit trouble.
Tone hopper section trouble
Toner density sensor trouble.
Connector/harness trouble.
PCU PWB trouble.
Toner cartridge trouble.
Developing unit trouble.
Tone hopper section trouble
Check & Remedy
Replace the toner motor.
Replace the toner density sensor.
Connector and harness check.
Replace the PCU PWB.
Replace the toner cartridge.
Replace the developing unit.
Check the toner hopper section.
Replace the toner density sensor.
Connector and harness check.
Replace the PCU PWB.
Replace the toner cartridge.
Replace the developing unit.
Check the toner hopper section.
Trouble content
Detail
PCU
Cause
Toner motor trouble.
Toner density sensor trouble.
Connector/harness trouble.
PCU PWB trouble.
Toner cartridge trouble.
Developing unit trouble.
Tone hopper section trouble
Toner density sensor trouble.
Connector/harness trouble.
PCU PWB trouble.
Toner cartridge trouble.
Developing unit trouble.
Tone hopper section trouble
Check & Remedy
Replace the toner motor.
Replace the toner density sensor.
Connector and harness check.
Replace the PCU PWB.
Replace the toner cartridge.
Replace the developing unit.
Check the toner hopper section.
Replace the toner density sensor.
Connector and harness check.
Replace the PCU PWB.
Replace the toner cartridge.
Replace the developing unit.
Check the toner hopper section.
MX-7500N TROUBLESHOOTING 7 – 32
F2-67
Toner supply operation trouble (Y)
F2-70
Improper toner cartridge detection (K)
F2-71
Improper toner cartridge detection (C)
F2-72
Improper toner cartridge detection (M)
F2-73
Improper toner cartridge detection (Y)
F2-74
Toner cartridge CRUM error (K)
F2-75
Toner cartridge CRUM error (C)
F2-76
Toner cartridge CRUM error (M)
F2-77
Toner cartridge CRUM error (Y)
F2-78
Registration/BK image density sen-
sor trouble
sor trouble
Trouble content
Detail
PCU
Cause
Toner motor trouble.
Toner density sensor trouble.
Connector/harness trouble.
PCU PWB trouble.
Toner cartridge trouble.
Developing unit trouble.
Tone hopper section trouble
Toner density sensor trouble.
Connector/harness trouble.
PCU PWB trouble.
Toner cartridge trouble.
Developing unit trouble.
Tone hopper section trouble
Check & Remedy
Replace the toner motor.
Replace the toner density sensor.
Connector and harness check.
Replace the PCU PWB.
Replace the toner cartridge.
Replace the developing unit.
Check the toner hopper section.
Replace the toner density sensor.
Connector and harness check.
Replace the PCU PWB.
Replace the toner cartridge.
Replace the developing unit.
Check the toner hopper section.
Trouble content
Detail
PCU
Cause
An improper toner cartridge is inserted. (The main unit
detects a toner cartridge of a different specification.)
Toner cartridge trouble.
PCU PWB trouble.
detects a toner cartridge of a different specification.)
Toner cartridge trouble.
PCU PWB trouble.
Check & Remedy
Replace the toner cartridge.
Replace the PCU PWB.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
An improper toner cartridge is inserted. (The main unit
detects a toner cartridge of a different specification.)
Toner cartridge trouble.
PCU PWB trouble.
detects a toner cartridge of a different specification.)
Toner cartridge trouble.
PCU PWB trouble.
Check & Remedy
Replace the toner cartridge.
Replace the PCU PWB.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
An improper toner cartridge is inserted. (The main unit
detects a toner cartridge of a different specification.)
Toner cartridge trouble.
PCU PWB trouble.
detects a toner cartridge of a different specification.)
Toner cartridge trouble.
PCU PWB trouble.
Check & Remedy
Replace the toner cartridge.
Replace the PCU PWB.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
An improper toner cartridge is inserted. (The main unit
detects a toner cartridge of a different specification.)
Toner cartridge trouble.
PCU PWB trouble.
detects a toner cartridge of a different specification.)
Toner cartridge trouble.
PCU PWB trouble.
Check & Remedy
Replace the toner cartridge.
Replace the PCU PWB.
Replace the PCU PWB.
Trouble content
Detail
PCU
Cause
Toner cartridge (CRUM) trouble.
PCU PWB trouble.
Connector and harness trouble between PCU PWB
and toner cartridge
PCU PWB trouble.
Connector and harness trouble between PCU PWB
and toner cartridge
Check & Remedy
Replace the toner cartridge.
Replace the PCU PWB.
Check the connector and the harness between the
PCU PWB and the toner cartridge.
Replace the PCU PWB.
Check the connector and the harness between the
PCU PWB and the toner cartridge.
Trouble content
Detail
PCU
Cause
Toner cartridge (CRUM) trouble.
PCU PWB trouble.
Connector and harness trouble between PCU PWB
and toner cartridge
PCU PWB trouble.
Connector and harness trouble between PCU PWB
and toner cartridge
Check & Remedy
Replace the toner cartridge.
Replace the PCU PWB.
Check the connector and the harness between the
PCU PWB and the toner cartridge.
Replace the PCU PWB.
Check the connector and the harness between the
PCU PWB and the toner cartridge.
Trouble content
Detail
PCU
Cause
Toner cartridge (CRUM) trouble.
PCU PWB trouble.
Connector and harness trouble between PCU PWB
and toner cartridge
PCU PWB trouble.
Connector and harness trouble between PCU PWB
and toner cartridge
Check & Remedy
Replace the toner cartridge.
Replace the PCU PWB.
Check the connector and the harness between the
PCU PWB and the toner cartridge.
Replace the PCU PWB.
Check the connector and the harness between the
PCU PWB and the toner cartridge.
Trouble content
Detail
PCU
Cause
Toner cartridge (CRUM) trouble.
PCU PWB trouble.
Connector and harness trouble between PCU PWB
and toner cartridge
PCU PWB trouble.
Connector and harness trouble between PCU PWB
and toner cartridge
Check & Remedy
Replace the toner cartridge.
Replace the PCU PWB.
Check the connector and the harness between the
PCU PWB and the toner cartridge.
Replace the PCU PWB.
Check the connector and the harness between the
PCU PWB and the toner cartridge.
Trouble content
Transfer belt substrate reflection rate abnormality
Detail
PCU
Cause
Image density (registration) sensor trouble (Sensor
sensitivity adjustment trouble).
PCU PWB trouble.
Image density (resist) sensor connector and harness
connection trouble
Image density (registration) sensor dirt.
Transfer belt dirt, scratch.
sensitivity adjustment trouble).
PCU PWB trouble.
Image density (resist) sensor connector and harness
connection trouble
Image density (registration) sensor dirt.
Transfer belt dirt, scratch.
Check & Remedy
Replace the image density (registration) sensor.
Replace the PCU PWB.
Check connection of the connector and the harness of
the image density (resist) sensor.
Clean the image density (registration) sensor.
Clean or replace the transfer belt.
Replace the PCU PWB.
Check connection of the connector and the harness of
the image density (resist) sensor.
Clean the image density (registration) sensor.
Clean or replace the transfer belt.
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