Sharp MX-6240N / MX-7040N (serv.man26) Service Manual ▷ View online
MX-7040N TROUBLESHOOTING 7 – 37
H2-04
Non-contact thermistor lower main
compensation thermistor open
(TH_LM1_AD1)
H2-05
Non-contact thermistor upper sub
compensation thermistor open
(TH_US1_AD1)
H2-06
Upper edge section thermistor open
(TH_US2)
H2-07
Lower edge section thermistor open
(TH_LM2)
H3-00
Fusing section high temperature
trouble (TH_UM)
H3-01
Fusing section high temperature
trouble (TH_LM)
H3-02
Fusing section high temperature
trouble (TH_US)
Trouble content
The thermistor is open.
Detail
PCU
Cause
Thermistor trouble
Control PWB trouble
Fusing section connector connection trouble
AC power trouble
Fusing unit not installed.
Control PWB trouble
Fusing section connector connection trouble
AC power trouble
Fusing unit not installed.
Check & Remedy
Check connection of the harness and the connector
from the thermistor to the control PWB.
from the thermistor to the control PWB.
Trouble content
The thermistor is open.
Detail
PCU
Cause
Thermistor trouble
Control PWB trouble
Fusing section connector connection trouble
AC power trouble
Fusing unit not installed.
Control PWB trouble
Fusing section connector connection trouble
AC power trouble
Fusing unit not installed.
Check & Remedy
Check connection of the harness and the connector
from the thermistor to the control PWB.
from the thermistor to the control PWB.
Trouble content
The thermistor is open.
Detail
PCU
Cause
Thermistor trouble
Control PWB trouble
Fusing section connector connection trouble
AC power trouble
Fusing unit not installed.
Control PWB trouble
Fusing section connector connection trouble
AC power trouble
Fusing unit not installed.
Check & Remedy
Check connection of the harness and the connector
from the thermistor to the control PWB.
from the thermistor to the control PWB.
Trouble content
The thermistor is open.
Detail
PCU
Cause
Thermistor trouble
Control PWB trouble
Fusing section connector connection trouble
AC power trouble
Fusing unit not installed.
Control PWB trouble
Fusing section connector connection trouble
AC power trouble
Fusing unit not installed.
Check & Remedy
Check connection of the harness and the connector
from the thermistor to the control PWB.
from the thermistor to the control PWB.
Trouble content
Detail
PCU
Cause
The fusing temperature exceeds the specified level.
Thermistor trouble
PCU PWB trouble
Thermistor connector and harness connection trouble
HL control PWB trouble
Thermistor trouble
PCU PWB trouble
Thermistor connector and harness connection trouble
HL control PWB trouble
Check & Remedy
Use SIM44-14 to check the state of the thermistor.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Use SIM14 to cancel the trouble.
Replace the thermistor.
Replace the PCU PWB.
Check connection of the thermistor connector and the
harness.
Replace the HL control PWB.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Use SIM14 to cancel the trouble.
Replace the thermistor.
Replace the PCU PWB.
Check connection of the thermistor connector and the
harness.
Replace the HL control PWB.
Trouble content
Detail
PCU
Cause
The fusing temperature exceeds the specified level.
Thermistor trouble
PCU PWB trouble
Thermistor connector and harness connection trouble
HL control PWB trouble
Thermistor trouble
PCU PWB trouble
Thermistor connector and harness connection trouble
HL control PWB trouble
Check & Remedy
Use SIM44-14 to check the state of the thermistor.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Use SIM14 to cancel the trouble.
Replace the thermistor.
Replace the PCU PWB.
Check connection of the thermistor connector and the
harness.
Replace the HL control PWB.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Use SIM14 to cancel the trouble.
Replace the thermistor.
Replace the PCU PWB.
Check connection of the thermistor connector and the
harness.
Replace the HL control PWB.
Trouble content
Detail
PCU
Cause
The fusing temperature exceeds the specified level.
Thermistor trouble
PCU PWB trouble
Thermistor connector and harness connection trouble
HL control PWB trouble
Thermistor trouble
PCU PWB trouble
Thermistor connector and harness connection trouble
HL control PWB trouble
Check & Remedy
Use SIM44-14 to check the state of the thermistor.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Use SIM14 to cancel the trouble.
Replace the thermistor.
Replace the PCU PWB.
Check connection of the thermistor connector and the
harness.
Replace the HL control PWB.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Use SIM14 to cancel the trouble.
Replace the thermistor.
Replace the PCU PWB.
Check connection of the thermistor connector and the
harness.
Replace the HL control PWB.
MX-7040N TROUBLESHOOTING 7 – 38
H4-00
Fusing section low temperature
trouble (TH_UM_AD2)
H4-01
Fusing section low temperature
trouble (TH_LM)
H4-02
Fusing section low temperature
trouble (TH_US)
H4-30
Upper main thermistor differential
input abnormality (TH_UM)
Trouble content
The fusing temperature does not reach the specified
level within the specified time from turning ON the
power relay.
level within the specified time from turning ON the
power relay.
Detail
PCU
Cause
Thermistor trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Check & Remedy
Use SIM14 to cancel the trouble.
Use SIM44-14 to check the state of the thermistor.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Replace the thermistor.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Use SIM44-14 to check the state of the thermistor.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Replace the thermistor.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Trouble content
The fusing temperature does not reach the specified
level within the specified time from turning ON the
power relay.
level within the specified time from turning ON the
power relay.
Detail
PCU
Cause
Thermistor trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Check & Remedy
Use SIM14 to cancel the trouble.
Use SIM44-14 to check the state of the thermistor.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Replace the thermistor.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Use SIM44-14 to check the state of the thermistor.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Replace the thermistor.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Trouble content
The fusing temperature does not reach the specified
level within the specified time from turning ON the
power relay.
level within the specified time from turning ON the
power relay.
Detail
PCU
Cause
Thermistor trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Check & Remedy
Use SIM14 to cancel the trouble.
Use SIM44-14 to check the state of the thermistor.
Use SIM05-02 to check the flashing operation of the
heater lamp.
Replace the thermistor.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Use SIM44-14 to check the state of the thermistor.
Use SIM05-02 to check the flashing operation of the
heater lamp.
Replace the thermistor.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Trouble content
The values of TH_UM_AD1 and TH_UM_AD2 do not
exceed the specified value within the specified time
from turning ON the HL_UM.
exceed the specified value within the specified time
from turning ON the HL_UM.
Detail
PCU
Cause
HL_UM does not turn on.
Thermistor trouble.
Harness trouble.
PCU PWB trouble
Thermistor trouble.
Harness trouble.
PCU PWB trouble
Check & Remedy
Use SIM05-02 to check the flashing operation of the
heater lamp.
When the heater lamp flashes normally, check the
thermistor and its harness.
Check the thermistor input circuit section of the PCU
PWB.
When the lamp does not light up, check for
disconnection in the heater lamp and breakage of
the thermostat.
Check the interlock switch.
Check the lamp control circuit of the AC PWB and
the PCU PWB.
Use SIM14 to cancel the trouble.
heater lamp.
When the heater lamp flashes normally, check the
thermistor and its harness.
Check the thermistor input circuit section of the PCU
PWB.
When the lamp does not light up, check for
disconnection in the heater lamp and breakage of
the thermostat.
Check the interlock switch.
Check the lamp control circuit of the AC PWB and
the PCU PWB.
Use SIM14 to cancel the trouble.
MX-7040N TROUBLESHOOTING 7 – 39
H4-31
Lower main thermistor differential
input abnormality (TH_LM1)
H4-32
Upper sub thermistor differential input
abnormality (TH_US1)
H5-01
5 times continuous POD1 not-reach
jam
H7-10
Recovery error from low fuse r temp.
(TH_UM_AD2)
H7-11
Recovery error from low fuse r temp.
(TH_LM)
L1-00
Scanner feed trouble
Trouble content
The lower main compensation thermistor and the
lower main differential thermistor do not exceed the
specified value within the specified time from turning
ON the lower main heater lamp.
lower main differential thermistor do not exceed the
specified value within the specified time from turning
ON the lower main heater lamp.
Detail
PCU
Cause
The lower main heater lamp does not turn ON.
Thermistor breakdown, harness trouble, PCU PWB
trouble
Thermistor breakdown, harness trouble, PCU PWB
trouble
Check & Remedy
Use SIM05-02 to check the flashing operation of the
heater lamp.
When the heater lamp flashes normally, check the
thermistor and its harness.
Check the thermistor input circuit section of the PCU
PWB.
When the lamp does not light up, check for
disconnection in the heater lamp and breakage of the
thermostat.
Check the interlock switch.
Check the lamp control circuit of the AC PWB and the
PCU PWB.
Use SIM14 to cancel the trouble.
heater lamp.
When the heater lamp flashes normally, check the
thermistor and its harness.
Check the thermistor input circuit section of the PCU
PWB.
When the lamp does not light up, check for
disconnection in the heater lamp and breakage of the
thermostat.
Check the interlock switch.
Check the lamp control circuit of the AC PWB and the
PCU PWB.
Use SIM14 to cancel the trouble.
Trouble content
The upper sub compensation thermistor and the
upper sub differential thermistor do not exceed the
specified value within the specified time from turning
ON the upper sub heater lamp.
upper sub differential thermistor do not exceed the
specified value within the specified time from turning
ON the upper sub heater lamp.
Detail
PCU
Cause
The upper sub heater lamp does not turn ON.
Thermistor breakdown, harness trouble, PCU PWB
trouble
Thermistor breakdown, harness trouble, PCU PWB
trouble
Check & Remedy
Use SIM05-02 to check the flashing operation of the
heater lamp.
When the heater lamp flashes normally, check the
thermistor and its harness.
Check the thermistor input circuit section of the PCU
PWB.
When the lamp does not light up, check for
disconnection in the heater lamp and breakage of the
thermostat.
Check the interlock switch.
Check the lamp control circuit of the AC PWB and the
PCU PWB.
Use SIM14 to cancel the trouble.
heater lamp.
When the heater lamp flashes normally, check the
thermistor and its harness.
Check the thermistor input circuit section of the PCU
PWB.
When the lamp does not light up, check for
disconnection in the heater lamp and breakage of the
thermostat.
Check the interlock switch.
Check the lamp control circuit of the AC PWB and the
PCU PWB.
Use SIM14 to cancel the trouble.
Trouble content
Detail
PCU
Cause
A fusing jam is not canceled completely. (A jam paper
remains.)
POD1 sensor trouble
Fusing unit installation trouble
POD1 sensor connector and harness connection
trouble
PCU PWB trouble
Fusing unit, drive section trouble
remains.)
POD1 sensor trouble
Fusing unit installation trouble
POD1 sensor connector and harness connection
trouble
PCU PWB trouble
Fusing unit, drive section trouble
Check & Remedy
Replace the POD1 sensor.
Check installation of the fusing unit.
Replace the fusing unit.
Check or repair the fusing drive section.
Check connection of the POD1 sensor connector and
the harness.
Replace the PCU PWB.
Use SIM14 to cancel the trouble.
Check installation of the fusing unit.
Replace the fusing unit.
Check or repair the fusing drive section.
Check connection of the POD1 sensor connector and
the harness.
Replace the PCU PWB.
Use SIM14 to cancel the trouble.
Trouble content
The fusing temperature does not reach the specified
level within the specified time from stopping a job due
to fall in the fusing temperature.
level within the specified time from stopping a job due
to fall in the fusing temperature.
Detail
PCU
Cause
Thermistor trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Check & Remedy
Replace the thermistor.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Trouble content
The fusing temperature does not reach the specified
level within the specified time from stopping a job due
to fall in the fusing temperature.
level within the specified time from stopping a job due
to fall in the fusing temperature.
Detail
PCU
Cause
Thermistor trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Heater lamp trouble.
PCU PWB trouble.
Thermostat trouble.
Connector, harness connection trouble.
HL control PWB trouble.
Power unit trouble.
Check & Remedy
Replace the thermistor.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Replace the heater lamp.
Replace the PCU PWB.
Replace the thermostat.
Check connection of the connector and the harness.
Replace the HL control PWB.
Replace the power unit.
Use SIM5-2 to check the flashing operation of the
heater lamp.
Trouble content
Scanner feed is not completed within the specified
time.
time.
Detail
SCU
Cause
Scanner unit trouble.
SCU PWB trouble.
Scanner control PWB trouble.
Harness and connector connection trouble.
Scanner home position sensor trouble.
Scanner motor trouble.
SCU PWB trouble.
Scanner control PWB trouble.
Harness and connector connection trouble.
Scanner home position sensor trouble.
Scanner motor trouble.
Check & Remedy
Use SIM1-1 to check the scan operation.
Replace the scanner unit.
Replace the SCU PWB.
Check connection of the connectors and the harness.
Replace the scanner home position sensor.
Replace the scanner motor.
Replace the scanner unit.
Replace the SCU PWB.
Check connection of the connectors and the harness.
Replace the scanner home position sensor.
Replace the scanner motor.
MX-7040N TROUBLESHOOTING 7 – 40
L2-11
Lamp cooling fan motor trouble
L3-00
Scanner return trouble
L4-02
Paper feed motor trouble
L4-03
Fusing motor trouble
L4-06
Transfer unit lift trouble
L4-07
Transfer belt motor trouble
L4-08
Waste toner transport motor lock
Trouble content
A lock signal is detected during rotation of the fan.
A non-lock state is detected except when in rotation
for booting.
A non-lock state is detected except when in rotation
for booting.
Detail
SCU
Cause
Fan motor trouble.
Harness related to the fan motor
Circuit trouble
Harness related to the fan motor
Circuit trouble
Check & Remedy
Check the fan motor related circuits (SCN-Mother
PWB, SCNcnt PWB) and their harnesses and
connectors.
PWB, SCNcnt PWB) and their harnesses and
connectors.
Trouble content
Scanner return is not completed within the specified
time.
time.
Detail
SCU
Cause
Scanner unit trouble
SCU PWB trouble
Scanner control PWB trouble
Harness and connector connection trouble
Scanner home position sensor trouble
Scanner motor trouble
SCU PWB trouble
Scanner control PWB trouble
Harness and connector connection trouble
Scanner home position sensor trouble
Scanner motor trouble
Check & Remedy
Use SIM1-1 to check the scan operation.
Replace the scanner unit.
Replace the SCU PWB.
Check connection of the connectors and the harness.
Replace the scanner home position sensor.
Replace the scanner motor.
Replace the scanner unit.
Replace the SCU PWB.
Check connection of the connectors and the harness.
Replace the scanner home position sensor.
Replace the scanner motor.
Trouble content
A lock signal is not detected within the specified time
in ON operation of the paper feed motor after
warming-up or canceling a jam.
in ON operation of the paper feed motor after
warming-up or canceling a jam.
Detail
PCU
Cause
Paper feed motor trouble
Paper feed motor harness and connector connection
trouble
PCU PWB trouble
Paper feed motor harness and connector connection
trouble
PCU PWB trouble
Check & Remedy
Use SIM6-1 to check the operation of the paper feed
motor.
Replace the paper feed motor.
Check connection of the paper feed motor harness
and the connector.
Replace the PCU PWB.
motor.
Replace the paper feed motor.
Check connection of the paper feed motor harness
and the connector.
Replace the PCU PWB.
Trouble content
The motor lock signal is detected during rotation of the
fusing motor.
fusing motor.
Detail
PCU
Cause
Fusing motor trouble
Fusing motor harness and connector connection
trouble
PCU PWB trouble
Fusing motor harness and connector connection
trouble
PCU PWB trouble
Check & Remedy
Use SIM6-1 to check the operation of the fusing
motor.
Replace the Fusing motor.
Check connection of the fusing motor harness and the
connection.
Replace the PCU PWB.
motor.
Replace the Fusing motor.
Check connection of the fusing motor harness and the
connection.
Replace the PCU PWB.
Trouble content
A change in the primary transfer position sensor
cannot be detected within the specified time in lifting
operation of the primary transfer unit.
cannot be detected within the specified time in lifting
operation of the primary transfer unit.
Detail
PCU
Cause
Transfer unit position sensor trouble
Dirt on the transfer unit position sensor.
PCU PWB trouble
Connection trouble of the connector and the harness.
Transfer unit lift mechanism trouble
Primary transfer belt unit is not installed.
Dirt on the transfer unit position sensor.
PCU PWB trouble
Connection trouble of the connector and the harness.
Transfer unit lift mechanism trouble
Primary transfer belt unit is not installed.
Check & Remedy
Use SIM6-3 to check the separating operation of the
transfer unit.
Install the primary transfer belt unit.
Replace the transfer unit position sensor.
Clean the transfer unit position sensor.
Replace the PCU PWB.
Check connection of the connector and the harness.
Repair the transfer unit lift mechanism.
transfer unit.
Install the primary transfer belt unit.
Replace the transfer unit position sensor.
Clean the transfer unit position sensor.
Replace the PCU PWB.
Check connection of the connector and the harness.
Repair the transfer unit lift mechanism.
Trouble content
The motor lock signal is detected during rotation of the
transfer belt motor.
transfer belt motor.
Detail
PCU
Cause
Transfer belt trouble.
Harness/connector trouble between the PCU PWB
and the transfer belt motor.
Control PWB trouble.
Circuit trouble.
Harness/connector trouble between the PCU PWB
and the transfer belt motor.
Control PWB trouble.
Circuit trouble.
Check & Remedy
Use SIM25-1 to check the operation of the transfer
belt motor.
Check the harness and the connector between the
PCU PWB and the transfer belt motor.
belt motor.
Check the harness and the connector between the
PCU PWB and the transfer belt motor.
Trouble content
The waste toner lock sensor is detected during
rotation of the drum motor.
rotation of the drum motor.
Detail
PCU
Cause
Waste toner transport motor trouble.
Waste toner transport pipe clogging
Harness/connector trouble between the PCU PWB
and the waste toner transport motor.
Waste toner transport pipe clogging
Harness/connector trouble between the PCU PWB
and the waste toner transport motor.
Check & Remedy
Use SIM6-1 to check the operation of the waste toner
transport motor (WTM).
Check the waste toner transport pipe for clogging.
Check the harness and the connector between the
PCU PWB and the waste toner transport motor.
transport motor (WTM).
Check the waste toner transport pipe for clogging.
Check the harness and the connector between the
PCU PWB and the waste toner transport motor.
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