Sharp MX-6240N / MX-7040N (serv.man26) Service Manual ▷ View online
MX-7040N TROUBLESHOOTING 7 – 49
U6-49
LCT3 lift trouble
U6-51
LCC - Main unit combination trouble
U6-53
Communication trouble between
LCT’s
U6-54
Option installation combination
trouble
U6-63
Manual feed tray descending trouble
U6-68
Manual feed tray p aper feed position
abnormality
U6-69
Manual feed tray lift trouble
Trouble content
The upper limit is not detected within the specified
time (A4 LCC: 10sec, A3 LCC: 8sec) when lifting.
(A3 3-stage LCT / A4 3-stage LCT)
The upper limit is not detected within the specified
time when lifting. The limit SW ON is detected when
lifting. The encoder signal does not vary when lifting.
(A3 2-stage LCT)
time (A4 LCC: 10sec, A3 LCC: 8sec) when lifting.
(A3 3-stage LCT / A4 3-stage LCT)
The upper limit is not detected within the specified
time when lifting. The limit SW ON is detected when
lifting. The encoder signal does not vary when lifting.
(A3 2-stage LCT)
Detail
PCU
Cause
Upper limit sensor abnormality, tray lift motor lock,
connector and harness connection trouble, PWB
trouble (A3 3-stage LCT / A4 3-stage LCT)
Sensor trouble, upper limit SW trouble, A3 2-stage
LCT control PWB trouble, broken gear, lift motor
trouble (A3 2-stage LCT)
connector and harness connection trouble, PWB
trouble (A3 3-stage LCT / A4 3-stage LCT)
Sensor trouble, upper limit SW trouble, A3 2-stage
LCT control PWB trouble, broken gear, lift motor
trouble (A3 2-stage LCT)
Check & Remedy
Use SIM04-02 and SIM04-03 to check the operation
of the upper limit sensor and the lift operation. Check
the wiring.
Fix the trouble, and use SIM15 to cancel the trouble.
(A3 3-stage LCT / A4 3-stage LCT)
Use SIM04-02 and SIM04-03 to check the operation
of the upper limit sensor, the upper limit SW, the
encoder sensor, and the lift motor.
Fix the trouble, and use SIM15 to cancel the trouble.
(A3 2-stage LCT)
of the upper limit sensor and the lift operation. Check
the wiring.
Fix the trouble, and use SIM15 to cancel the trouble.
(A3 3-stage LCT / A4 3-stage LCT)
Use SIM04-02 and SIM04-03 to check the operation
of the upper limit sensor, the upper limit SW, the
encoder sensor, and the lift motor.
Fix the trouble, and use SIM15 to cancel the trouble.
(A3 2-stage LCT)
Trouble content
An LCC of a different model which is not supported by
the machine is installed. (Improper combination of the
machine and the LCC model code.)
the machine is installed. (Improper combination of the
machine and the LCC model code.)
Detail
PCU
Cause
LCC control PWB trouble
PCU PWB trouble
PCU PWB trouble
Check & Remedy
Check to confirm the LCC model.
Check the LCC control PWB, and replace if
necessary.
Check the PCU PWB, and replace if necessary.
Check the LCC control PWB, and replace if
necessary.
Check the PCU PWB, and replace if necessary.
Trouble content
Communication error between the A3 2-stage LCT (1
series) and the A3 2-stage LCT (2 series)
Communication test error when turning ON the power
or after canceling the exclusive simulation.
series) and the A3 2-stage LCT (2 series)
Communication test error when turning ON the power
or after canceling the exclusive simulation.
Detail
PCU
Cause
Connection trouble or disconnection of the connector
and the harness
A3 2-stage LCT (1 series) control PWB trouble, A3 2-
stage LCT (2 series) control PWB trouble
Malfunction caused by noises
and the harness
A3 2-stage LCT (1 series) control PWB trouble, A3 2-
stage LCT (2 series) control PWB trouble
Malfunction caused by noises
Check & Remedy
Cancel the trouble by turning OFF/ON the power.
Check the connector and the harness of the
communication line.
Replace the A3 2-stage LCT control PWB.
Check the connector and the harness of the
communication line.
Replace the A3 2-stage LCT control PWB.
Trouble content
Relay unit installation detection signal abnormality,
front LCT installation detection signal abnormality, 2-
series installation detection signal abnormality
front LCT installation detection signal abnormality, 2-
series installation detection signal abnormality
Detail
PCU
Cause
Combination error
Connection trouble of the connector and the harness
A3 2-stage LCT control PWB trouble
Connection trouble of the connector and the harness
A3 2-stage LCT control PWB trouble
Check & Remedy
Check the combination of options.
Check connection of the harness and the connector
from control PWB to each option unit.
Replace the A3 2-stage LCT control PWB.
Check connection of the harness and the connector
from control PWB to each option unit.
Replace the A3 2-stage LCT control PWB.
Trouble content
The lower limit position is not detected within the
specified time (10sec) from the start of descending the
manual feed tray.
specified time (10sec) from the start of descending the
manual feed tray.
Detail
PCU
Cause
Lower limit sensor trouble.
Manual feed tray lift motor lock.
Connection trouble of the connector and the harness.
PWB trouble.
Manual feed tray lift motor lock.
Connection trouble of the connector and the harness.
PWB trouble.
Check & Remedy
Use SIM04-02 and SIM04-03 to check the operations
of the lower limit position sensor and the manual fed
tray lift motor.
Wiring check.
Fix the trouble, and use SIM15 to cancel the trouble.
of the lower limit position sensor and the manual fed
tray lift motor.
Wiring check.
Fix the trouble, and use SIM15 to cancel the trouble.
Trouble content
The upper limit sensor turns OFF before turning ON
the pickup SOL. (Normally the upper limit sensor turns
OFF after turning OFF the pickup SOL when starting
lifting up.)
the pickup SOL. (Normally the upper limit sensor turns
OFF after turning OFF the pickup SOL when starting
lifting up.)
Detail
PCU
Cause
Sensor trouble.
Connection trouble of the connector and the harness.
PWB trouble.
The pickup roller remains in the lower position.
(Mechanism trouble)
Connection trouble of the connector and the harness.
PWB trouble.
The pickup roller remains in the lower position.
(Mechanism trouble)
Check & Remedy
Use SIM04-02 and SIM04-03 to check the operations
of the upper limit sensor and lift operations.
Wiring check.
of the upper limit sensor and lift operations.
Wiring check.
Trouble content
The upper limit is not detected within the specified
time (10sec) when lifting up.
time (10sec) when lifting up.
Detail
PCU
Cause
Upper limit sensor trouble.
Tray lift motor lock.
Connection trouble of the connector and the harness.
PWB trouble.
Tray lift motor lock.
Connection trouble of the connector and the harness.
PWB trouble.
Check & Remedy
Use SIM04-02 and SIM04-03 to check the operations
of the upper limit sensor and lift operations.
Wiring check.
Fix the trouble, and use SIM15 to cancel the trouble.
of the upper limit sensor and lift operations.
Wiring check.
Fix the trouble, and use SIM15 to cancel the trouble.
MX-7040N TROUBLESHOOTING 7 – 50
U6-73
LCT4 reverse winding detection
trouble
U6-74
LCT4 lock detection trouble
U6-79
LCT4 lift motor trouble
U6-80
Relay unit transport motor trouble
U6-81
Power unit cooling fan motor trouble
(1 series)
U6-82
EEPROM trouble (1 series)
U6-83
Room temperature thermistor
breakdown (1 series)
U6-84
Room humidity thermistor breakdown
(1 series)
U6-85
Transport motor 1 trouble (2 series)
Trouble content
It is detected that the wire of the tray is reversely
wound.
wound.
Detail
PCU
Cause
Reverse winding detection SW ON
The wire is reversely wound.
Reverse winding detection SW trouble
Connection trouble of the connector and the harness
A3 2-stage LCT control PWB trouble
The wire is reversely wound.
Reverse winding detection SW trouble
Connection trouble of the connector and the harness
A3 2-stage LCT control PWB trouble
Check & Remedy
Check the wire.
Replace the reverse winding SW.
Check connection of the connector and the harness.
Replace the A3 2-stage LCT control PWB.
Replace the reverse winding SW.
Check connection of the connector and the harness.
Replace the A3 2-stage LCT control PWB.
Trouble content
It is detected that the tray lock mechanism
malfunctions.
malfunctions.
Detail
PCU
Cause
Tray lock mechanism breakdown
Connection trouble of the connector and the harness
Tray lock sensor trouble
A3 2-stage LCT control PWB trouble
Connection trouble of the connector and the harness
Tray lock sensor trouble
A3 2-stage LCT control PWB trouble
Check & Remedy
Check the tray lock mechanism.
Check connection of the connector and the harness.
Replace the tray lock sensor.
Replace the A3 2-stage LCT control PWB.
Check connection of the connector and the harness.
Replace the tray lock sensor.
Replace the A3 2-stage LCT control PWB.
Trouble content
The upper limit is not detected within the specified
time when lifting.
The upper limit SW ON is detected when lifting.
The encoder signal does not vary when lifting.
time when lifting.
The upper limit SW ON is detected when lifting.
The encoder signal does not vary when lifting.
Detail
PCU
Cause
Sensor trouble, upper limit SW trouble, A3 2-stage
LCT control PWB trouble, broken gear, lift motor
trouble
LCT control PWB trouble, broken gear, lift motor
trouble
Check & Remedy
Use SIM04-02 and SIM04-03 to check the operation
of the upper limit sensor, the upper limit SW, the
encoder sensor, and the lift motor.
Fix the trouble, and use SIM15 to cancel the trouble.
of the upper limit sensor, the upper limit SW, the
encoder sensor, and the lift motor.
Fix the trouble, and use SIM15 to cancel the trouble.
Trouble content
Relay unit transport motor abnormality
Detail
PCU
Cause
Motor lock
Motor RPM abnormality
Overcurrent to the motor
A3 2-stage LCT control PWB trouble
Motor RPM abnormality
Overcurrent to the motor
A3 2-stage LCT control PWB trouble
Check & Remedy
Use SIM04-03 to check the operation of the relay unit
transport motor.
Replace the motor. Replace the A3 2-stage LCT
control PWB.
transport motor.
Replace the motor. Replace the A3 2-stage LCT
control PWB.
Trouble content
A3 2-stage LCT power unit section cooling fan motor
abnormality
abnormality
Detail
PCU
Cause
Motor lock, motor harness short/open, A3 2-stage
LCT control PWB trouble, harness and connector
connection trouble
LCT control PWB trouble, harness and connector
connection trouble
Check & Remedy
Check connection from the A3 2-stage LCT control
PWB to the motor.
Replace the A3 2-stage LCT control PWB. Replace
the motor.
PWB to the motor.
Replace the A3 2-stage LCT control PWB. Replace
the motor.
Trouble content
The EEPROM contents are garbled.
Detail
PCU
Cause
A3 2-stage LCT control PWB trouble
Malfunction caused by noises
Malfunction caused by noises
Check & Remedy
Replace the A3 2-stage LCT controller PWB.
Trouble content
Room temperature thermistor open or short
Detail
PCU
Cause
Room temperature thermistor harness connection
trouble
Room temperature thermistor trouble
A3 2-stage LCT control PWB trouble
trouble
Room temperature thermistor trouble
A3 2-stage LCT control PWB trouble
Check & Remedy
Check connection of the harness and the connector of
the room temperature thermistor.
Replace the temperature and humidity sensor.
Check the A3 2-stage LCT control PWB.
the room temperature thermistor.
Replace the temperature and humidity sensor.
Check the A3 2-stage LCT control PWB.
Trouble content
Humidity thermistor open or short
Detail
PCU
Cause
Humidity thermistor harness connection trouble
Humidity thermistor trouble
A3 2-stage LCT control PWB trouble
Humidity thermistor trouble
A3 2-stage LCT control PWB trouble
Check & Remedy
Check connection of the harness and the connector of
the humidity thermistor.
Replace the temperature and humidity sensor.
Check the A3 2-stage LCT control PWB.
the humidity thermistor.
Replace the temperature and humidity sensor.
Check the A3 2-stage LCT control PWB.
Trouble content
Transport motor abnormality
Detail
PCU
Cause
Motor lock
Motor RPM abnormality
Overcurrent to the motor
A3 2-stage LCT control PWB trouble
Motor RPM abnormality
Overcurrent to the motor
A3 2-stage LCT control PWB trouble
Check & Remedy
Use SIM04-03 to check the operation of the transport
motor.
Replace the motor.
Replace the A3 2-stage LCT control PWB.
motor.
Replace the motor.
Replace the A3 2-stage LCT control PWB.
MX-7040N TROUBLESHOOTING 7 – 51
U6-86
24V power trouble (2 series)
U6-87
Power unit coolin g fan moto r trouble
(2 series)
U6-88
EEPROM trouble (2 series)
U6-89
Room temperature thermistor
breakdown (2 series)
U6-90
Room humidity thermistor breakdown
(2 series)
U7-50
MFPC PWB - Vendor machine
communication error
U7-51
Vendor machine error
UC-02
CPT - ASIC error
UC-12
CPT - ASIC abnormal trouble
(DSPF detection)
UC-20
DOCC ASIC error
Trouble content
The DC24V power is not supplied to the A3 2-stage
LCT.
LCT.
Detail
PCU
Cause
Connection trouble or disconnection of the connector
and the harness.
A3 2-stage LCT control PWB trouble
Power unit trouble
and the harness.
A3 2-stage LCT control PWB trouble
Power unit trouble
Check & Remedy
Check the connector and the harness of the power
line.
Check the 24V voltage with the power unit and the A3
2-stage LCT control PWB.
line.
Check the 24V voltage with the power unit and the A3
2-stage LCT control PWB.
Trouble content
A3 2-stage LCT power unit section cooling fan motor
abnormality
abnormality
Detail
PCU
Cause
Motor lock, motor harness short/open, A3 2-stage
LCT control PWB trouble, harness and connector
connection trouble
LCT control PWB trouble, harness and connector
connection trouble
Check & Remedy
Check connection from the A3 2-stage LCT control
PWB to the motor.
Replace the A3 2-stage LCT control PWB. Replace
the motor.
PWB to the motor.
Replace the A3 2-stage LCT control PWB. Replace
the motor.
Trouble content
The EEPROM contents are garbled.
Detail
PCU
Cause
A3 2-stage LCT control PWB trouble
Malfunction caused by noises
Malfunction caused by noises
Check & Remedy
Replace the A3 2-stage LCT control PWB.
Trouble content
Room temperature thermistor open or short
Detail
PCU
Cause
Room temperature thermistor harness connection
trouble
Room temperature thermistor trouble
A3 2-stage LCT control PWB trouble
trouble
Room temperature thermistor trouble
A3 2-stage LCT control PWB trouble
Check & Remedy
Check connection of the harness and the connector of
the room temperature thermistor.
Replace the temperature and humidity sensor.
Check the A3 2-stage LCT control PWB.
the room temperature thermistor.
Replace the temperature and humidity sensor.
Check the A3 2-stage LCT control PWB.
Trouble content
Humidity thermistor open or short
Detail
PCU
Cause
Humidity thermistor harness connection trouble
Humidity thermistor trouble
A3 2-stage LCT control PWB trouble
Humidity thermistor trouble
A3 2-stage LCT control PWB trouble
Check & Remedy
Check connection of the harness and the connector of
the humidity thermistor.
Replace the temperature and humidity sensor.
Check the A3 2-stage LCT control PWB.
the humidity thermistor.
Replace the temperature and humidity sensor.
Check the A3 2-stage LCT control PWB.
Trouble content
Communication error between the MFP and the serial
vendor.
vendor.
Detail
MFP
Cause
Improper setting of the vendor machine specifications
(SIM26-3).
Vendor machine trouble.
MFPC PWB trouble.
Connector, harness connection trouble.
Strong external noises.
(SIM26-3).
Vendor machine trouble.
MFPC PWB trouble.
Connector, harness connection trouble.
Strong external noises.
Check & Remedy
Cancel the error by turning OFF/ON the power.
Check the connector and the harness in the
communication line.
Change the specifications of the vendor machine
(SIM26-3).
Replace the MFPC PWB.
Check the connector and the harness in the
communication line.
Change the specifications of the vendor machine
(SIM26-3).
Replace the MFPC PWB.
Trouble content
Detail
MFP (Notification of a trouble from the serial vendor)
Cause
Serial vendor machine trouble.
Connector, harness connection trouble.
Connector, harness connection trouble.
Check & Remedy
Err.XX is displayed on the operation panel of the
vendor. (XX is the detail code.)
Repair the vendor machine referring to the detail
code.
Check the connector and the harness in the
communication line.
vendor. (XX is the detail code.)
Repair the vendor machine referring to the detail
code.
Check the connector and the harness in the
communication line.
Trouble content
Detail
SCU
Cause
SCU PWB trouble. (CPT-ASIC trouble.)
Check & Remedy
Replace the SCU PWB.
Trouble content
Access abnormality to the CPT - ASIC (when the
ASIC operates abnormally)
ASIC operates abnormally)
Detail
SCU
Cause
B to B connector connection trouble.
DSPF PWB trouble.
CPT - ASIC trouble.
DSPF PWB trouble.
CPT - ASIC trouble.
Check & Remedy
Check the B to B connector.
Replace the DSPF PWB or the Option PWB.
Replace the DSPF PWB or the Option PWB.
Trouble content
Detail
SCU
Cause
SCU PWB trouble. (DOCC-ASIC trouble.)
Check & Remedy
Replace the SCU PWB.
MX-7040N TROUBLESHOOTING 7 – 52
UC-30
Anti-copy MODULE trouble
(DSPF detection)
UE-10
LCT1 suction fan motor trouble
UE-11
LCT1 exhaust fan motor trouble
UE-12
LCT1 warm air heater thermistor open
UE-13
LCT1 warm air heater th ermistor low
temperature trouble
UE-14
LCT1 warm air heater thermistor high
temperature trouble
UE-15
LCT1 warm air outlet port thermistor
open
Trouble content
Access abnormality to the DOCC-ASIC (when the
ASIC operates abnormally)
ASIC operates abnormally)
Detail
PCU
Cause
B to B connector connection trouble.
DSPF PWB trouble.
DOCC-ASIC trouble.
DSPF PWB trouble.
DOCC-ASIC trouble.
Check & Remedy
Check the B to B connector.
Replace the DSPF PWB or the Option PWB.
Replace the DSPF PWB or the Option PWB.
Trouble content
Suction fan motor abnormality
Detail
PCU
Cause
Motor lock
Motor RPM abnormality
Overcurrent to the motor
Harness and connector connection trouble
A3 2-stage LCT control PWB trouble
Motor RPM abnormality
Overcurrent to the motor
Harness and connector connection trouble
A3 2-stage LCT control PWB trouble
Check & Remedy
Use SIM04-03 to check the operation of the suction
fan motor.
Check connection of the harness and the connector.
Replace the A3 2-stage LCT control PWB.
fan motor.
Check connection of the harness and the connector.
Replace the A3 2-stage LCT control PWB.
Trouble content
Exhaust fan motor abnormality
Detail
PCU
Cause
Motor lock
Motor RPM abnormality
Overcurrent to the motor
Harness and connector connection trouble
A3 2-stage LCT control PWB trouble
Motor RPM abnormality
Overcurrent to the motor
Harness and connector connection trouble
A3 2-stage LCT control PWB trouble
Check & Remedy
Use SIM04-03 to check the operation of the exhaust
fan motor.
Check connection of the harness and the connector.
Replace the A3 2-stage LCT control PWB.
fan motor.
Check connection of the harness and the connector.
Replace the A3 2-stage LCT control PWB.
Trouble content
The thermistor is open.
Detail
PCU
Cause
Warm air heater (thermistor) trouble
A3 2-stage LCT control PWB trouble
Warm air heater harness and connector connection
trouble
A3 2-stage LCT control PWB trouble
Warm air heater harness and connector connection
trouble
Check & Remedy
Check the harness and the connector from the warm
air heater (thermistor) to the A3 2-stage LCT control
PWB.
air heater (thermistor) to the A3 2-stage LCT control
PWB.
Trouble content
The temperature does not reach the specified level
within the specified time after turning ON the power
relay.
within the specified time after turning ON the power
relay.
Detail
PCU
Cause
Warm air heater (thermistor) trouble
Warm air heater trouble
Warm air heater harness and connector connection
trouble
A3 2-stage LCT control PWB trouble
Thermostat trouble.
AC power trouble
Insertion detection switch 2 trouble
Heater relay PWB trouble
Warm air heater trouble
Warm air heater harness and connector connection
trouble
A3 2-stage LCT control PWB trouble
Thermostat trouble.
AC power trouble
Insertion detection switch 2 trouble
Heater relay PWB trouble
Check & Remedy
Check the warm air heater (thermistor) and its
harness.
Check the thermistor input circuit section of the A3 2-
stage LCT control PWB.
Check for disconnection of the warm air heater and
the thermostat.
Check the insertion detection switch 2.
Check the heater relay PWB.
Check the heater control circuit of the AC PWB and
that of the A3 2-stage LCT control PWB.
harness.
Check the thermistor input circuit section of the A3 2-
stage LCT control PWB.
Check for disconnection of the warm air heater and
the thermostat.
Check the insertion detection switch 2.
Check the heater relay PWB.
Check the heater control circuit of the AC PWB and
that of the A3 2-stage LCT control PWB.
Trouble content
The warm air heater temperature exceeds the
specified level.
specified level.
Detail
PCU
Cause
Warm air heater (thermistor) trouble
A3 2-stage LCT control PWB trouble
Warm air heater harness and connector connection
trouble
Heater relay PWB trouble
A3 2-stage LCT control PWB trouble
Warm air heater harness and connector connection
trouble
Heater relay PWB trouble
Check & Remedy
Check the warm air heater (thermistor) and its
harness.
Check the thermistor input circuit section of the A3 2-
stage LCT control PWB.
Check the heater relay PWB.
Check the heater control circuit of the A3 2-stage LCT
control PWB.
harness.
Check the thermistor input circuit section of the A3 2-
stage LCT control PWB.
Check the heater relay PWB.
Check the heater control circuit of the A3 2-stage LCT
control PWB.
Trouble content
The thermistor is open.
Detail
PCU
Cause
Thermistor trouble.
A3 2-stage LCT control PWB trouble
Connector connection trouble
A3 2-stage LCT control PWB trouble
Connector connection trouble
Check & Remedy
Check connection of the harness and the connector
from the thermistor to the A3 2-stage LCT control
PWB.
from the thermistor to the A3 2-stage LCT control
PWB.
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