Sharp MX-6500N / MX-7500N (serv.man21) Service Manual ▷ View online
MX-7500N TROUBLESHOOTING 7 – 45
U6-09
LCC lift motor trouble
U6-20
LCC control PWB - PCU PWB
communication error
communication error
U6-21
LCC transport motor trouble
U6-22
LCC 24V power abnormality
U6-23
A3 LCC tray descending trouble
(Reverse winding detection) (A3 LCC)
(Reverse winding detection) (A3 LCC)
U6-24
A3 LCC tray lock detection trouble
U6-28
LCT1 paper feed position abnormality
Trouble content
No variation in the motor rotation sensor signal
(encoder sign) is detected within the specified time
after booting or stopping the LCC lift motor.
(encoder sign) is detected within the specified time
after booting or stopping the LCC lift motor.
Detail
PCU
Cause
LCC lift motor rotation sensor trouble
LCC control PWB trouble
LCC lift mechanism trouble
LCC lift motor trouble
LCC control PWB trouble
LCC lift mechanism trouble
LCC lift motor trouble
Check & Remedy
Use SIM4-2 and 4-3 to check the operation of the LCC
sensor and the lift motor.
Check the LCC lift motor rotation sensor, and replace
if necessary.
Check the LCC control PWB, and replace if
necessary.
Check the LCC lift mechanism, and repair if
necessary.
Check the LCC lift motor, and replace if necessary.
Use SIM15 to cancel the trouble.
sensor and the lift motor.
Check the LCC lift motor rotation sensor, and replace
if necessary.
Check the LCC control PWB, and replace if
necessary.
Check the LCC lift mechanism, and repair if
necessary.
Check the LCC lift motor, and replace if necessary.
Use SIM15 to cancel the trouble.
Trouble content
Detail
PCU
Cause
Communication error between the LCC control PWB
and the PCU PWB.
Connection trouble of the harness and the connector
between the machine and the LCC and those of the
LCC control PWB.
LCC control PWB trouble
PCU PWB trouble
Malfunction due to noises.
and the PCU PWB.
Connection trouble of the harness and the connector
between the machine and the LCC and those of the
LCC control PWB.
LCC control PWB trouble
PCU PWB trouble
Malfunction due to noises.
Check & Remedy
Check to confirm the LCC model.
Check the connection of the harness and the
connector between the machine and the LCC and
those of the LCC control PWB, and replace if
necessary.
Check the LCC control PWB, and replace if
necessary.
Check the PCU PWB, and replace if necessary.
Check the connection of the harness and the
connector between the machine and the LCC and
those of the LCC control PWB, and replace if
necessary.
Check the LCC control PWB, and replace if
necessary.
Check the PCU PWB, and replace if necessary.
Trouble content
Transport motor abnormality
Detail
PCU
Cause
Motor lock
Motor RPM abnormality
Overcurrent to the motor
LCC control PWB trouble / A3 2-stage LCT control
PWB trouble
Motor RPM abnormality
Overcurrent to the motor
LCC control PWB trouble / 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 LCC / A3 2-stage LCT control PWB.
motor.
Replace the motor
Replace the LCC / A3 2-stage LCT control PWB.
Trouble content
The DV 24V power is not supplied to the LCC / A3 2-
stage LCT.
stage LCT.
Detail
PCU
Cause
Connection trouble or disconnection of the connector
and the harness.
LCC control PWB trouble / A3 2-stage LCT control
PWB trouble. Power unit trouble
and the harness.
LCC control PWB trouble / 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, the LCC
control PWB, and the A3 2-stage LCT control PWB.
line.
Check the 24V voltage with the power unit, the LCC
control PWB, and the A3 2-stage LCT control PWB.
Trouble content
It is detected that the wire of the LCC tray is reversely
wound. (A3 LCC / A3 2-stage LCT)
The lower limit position (full state) is not detected
within the specified time (A4: 10sec, A3: 8sec) from
the start of descending the LCT1 tray.
(A3 3-stage LCT / A4 3-stage LCT)
wound. (A3 LCC / A3 2-stage LCT)
The lower limit position (full state) is not detected
within the specified time (A4: 10sec, A3: 8sec) from
the start of descending the LCT1 tray.
(A3 3-stage LCT / A4 3-stage LCT)
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
LCC control PWB trouble. (A3 LCC)
A3 2-stage LCT control PWB trouble (A3 2-stage LCT)
Remaining quantity sensor abnormality, LCT1 tray lift
motor lock, connector and harness connection
trouble, PWB trouble
(A3 3-stage LCT / A4 3-stage LCT)
The wire is reversely wound.
Reverse winding detection SW trouble
Connection trouble of the connector and the harness
LCC control PWB trouble. (A3 LCC)
A3 2-stage LCT control PWB trouble (A3 2-stage LCT)
Remaining quantity sensor abnormality, LCT1 tray lift
motor lock, connector and harness connection
trouble, PWB trouble
(A3 3-stage LCT / A4 3-stage LCT)
Check & Remedy
Check the wire.
Replace the reverse winding SW and the LCC control
PWB. / Replace the A3 2-stage LCT control PWB.
Check connection of the connector and the harness.
(A3 LCC / A3 2-stage LCT)
Use SIM04-02 and SIM04-03 to check the operations
of the remaining quantity sensor and the LCT1 lift
motor. Check the wiring.
(A3 3-stage LCT / A4 3-stage LCT)
Replace the reverse winding SW and the LCC control
PWB. / Replace the A3 2-stage LCT control PWB.
Check connection of the connector and the harness.
(A3 LCC / A3 2-stage LCT)
Use SIM04-02 and SIM04-03 to check the operations
of the remaining quantity sensor and the LCT1 lift
motor. Check the wiring.
(A3 3-stage LCT / A4 3-stage LCT)
Trouble content
The LCC / A3 2-stage LCT tray lock mechanism
malfunctions.
malfunctions.
Detail
PCU
Cause
Tray lock mechanism breakdown
Connection trouble of the connector and the harness
Tray lock sensor trouble
LCC control PWB trouble / A3 2-stage LCT control
PWB trouble
Connection trouble of the connector and the harness
Tray lock sensor trouble
LCC control PWB 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 LCC control PWB. / Replace the A3 2-
stage LCT control PWB.
Check connection of the connector and the harness.
Replace the tray lock sensor.
Replace the LCC control PWB. / Replace the A3 2-
stage LCT control PWB.
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. The pickup roller remains in the lower
position. (Mechanism trouble)
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.
MX-7500N TROUBLESHOOTING 7 – 46
U6-29
LCT1 lift trouble
U6-33
LCT2 reverse winding detection
trouble
trouble
U6-34
LCT2 lock detection trouble
U6-39
LCT2 lift trouble
U6-43
LCT3 reverse winding detection trou-
ble
ble
U6-44
LCT3 lock detection trouble
Trouble content
The upper limit is not detected within the specified
time (A4 LCC: 10sec, A3 LCC: 8sec) when lifting up.
(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 up.
(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
It is detected that the wire of the tray is reversely
wound.
wound.
Detail
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
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 (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, 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, 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
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 malfunc-
tions.
tions.
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.
MX-7500N TROUBLESHOOTING 7 – 47
U6-49
LCC - Main unit combination trouble
U6-51
LCC - Main unit combination trouble
U6-53
Communication trouble between
LCT’s
LCT’s
U6-54
Option installation combination trou-
ble
ble
U6-63
Manual feed tray descending trouble
U6-68
Manual feed tray paper feed position
abnormality
abnormality
U6-69
Manual feed tray lift trouble
U6-73
LCT4 reverse winding detection trou-
ble
ble
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 trou-
ble (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 trou-
ble (A3 2-stage LCT)
connector and harness connection trouble, PWB trou-
ble (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 trou-
ble (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 communi-
cation line.
Replace the A3 2-stage LCT control PWB
Check the connector and the harness of the communi-
cation 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.
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.
MX-7500N TROUBLESHOOTING 7 – 48
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
U6-82
EEPROM trouble
U6-83
Room temperature thermistor
breakdown
breakdown
U6-84
Room humidity thermistor breakdown
U6-85
Transport motor 1 trouble (2 series)
U6-86
24V power trouble (2 series)
U6-87
Power unit cooling fan motor trouble
(2 series)
(2 series)
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 trou-
ble
LCT control PWB trouble, broken gear, lift motor trou-
ble
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
Over current to the motor
A3 2-stage LCT control PWB trouble
Motor RPM abnormality
Over current 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
Over current to the motor
A3 2-stage LCT control PWB trouble
Motor RPM abnormality
Over current 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.
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 con-
nection trouble
LCT control PWB trouble, harness and connector con-
nection 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.
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