LG 41472 Service Manual ▷ View online
24
CIRCUIT DIAGRAM
2 5
8-4. TROUBLESHOOTING WITH ERROR
INLET VALVE ERROR
Is displayed?
When you press both
WASH/RINSE button and
DELAY STRAT button
simultaneously,
is the water level < 246?
WASH/RINSE button and
DELAY STRAT button
simultaneously,
is the water level < 246?
Is filter inlet valve clogged
with foreign material?
with foreign material?
Check the connectors at the
main PCB and the water
valve. Are the connectors
loose or disconnected?
main PCB and the water
valve. Are the connectors
loose or disconnected?
Proceed to next step at right.
Is the resistance of fill valve
coil between 800 and
1200 Ω?
coil between 800 and
1200 Ω?
(Refer to 9-5 inlet valve
assembly.)
assembly.)
Clean or
replace the filter.
replace the filter.
Check the AIR
CHAMBER
and the tube
(clogged).
CHAMBER
and the tube
(clogged).
Yes
No
No
Yes
Yes
Reconnect or
repair
the connector.
repair
the connector.
Replace the
INLET VALVE
ASSEMBLY.
INLET VALVE
ASSEMBLY.
Yes
Yes
Is the voltage at the inlet
valve coil 120VAC with the
valve energized?
valve coil 120VAC with the
valve energized?
Replace the
INLET VALVE
ASSEMBLY.
INLET VALVE
ASSEMBLY.
No
Yes
Yes
Is the wiring correct? Refer to
the wiring diagram for correct
connections.
the wiring diagram for correct
connections.
(Refer to 9-5 wiring diagram)
Replace the
MAIN HARNESS.
MAIN HARNESS.
No
No
Is the water level still < 246?
Replace the MAIN PWB
ASSEMBLY.
ASSEMBLY.
ALWAYS CHECK FOR EXTERNAL CAUSES
Water supply shut off
Frozen water lines
Kinked fill hose
Low water pressure
Water supply shut off
Frozen water lines
Kinked fill hose
Low water pressure
Check the
pressure
switch. Refer to
test #2.
pressure
switch. Refer to
test #2.
Yes
No
No
26
DRAIN ERROR
Is displayed?
Check the connectors at the
main PCB and the drain
pump. Are the connectors
loose or disconnected?
main PCB and the drain
pump. Are the connectors
loose or disconnected?
Reconnect or
repair
the connector.
repair
the connector.
Yes
Circulation pump
Yes
Drain pump
Connection connector
No
No
When you press both
WASH/RINSE button and
DELAY START button
simultaneously, is the
water level <250?
WASH/RINSE button and
DELAY START button
simultaneously, is the
water level <250?
Proceed to next step at right
Check the air
dome and
pressure hose
for clogging.
Check the
pressure
switch. See
test #2.
dome and
pressure hose
for clogging.
Check the
pressure
switch. See
test #2.
Measure the resistance of
the drain pump motor. Is
the resistance between 10Ω
and 20Ω ?
the drain pump motor. Is
the resistance between 10Ω
and 20Ω ?
(Refer to 9-4 Pump motor
assembly.)
assembly.)
Replace the
DRAIN PUMP
ASSEMBLY.
DRAIN PUMP
ASSEMBLY.
Yes
Yes
Check the voltage between
the main PCB connectors
NA4-1 BN and BL3-1 BK. Is
the voltage 120 VAC ± 5%?
the main PCB connectors
NA4-1 BN and BL3-1 BK. Is
the voltage 120 VAC ± 5%?
TO TURN ON THE DRAIN PUMP:
1. Turn on the washer
2. Press the SPIN SPEED button to select LOW
speed.
3. Press the START/PAUSE button.
The drain pump will be energized for several
minutes at the beginning of the spin cycle.
ALWAYS CHECK FOR EXTERNAL CAUSES
Kinked or clogged drain hose
Frozen drain hose
Foreign objects clogging the drain pump filter
Foreign objects caught in pump impeller
Kinked or clogged drain hose
Frozen drain hose
Foreign objects clogging the drain pump filter
Foreign objects caught in pump impeller
Replace the
MAIN PWB
ASSEMBLY.
MAIN PWB
ASSEMBLY.
No
No
27
HEATING ERROR
Is displayed?
Check the connectors at the
main PCB, the heater and the
thermistor. Are the
connectors loose or
disconnected?
main PCB, the heater and the
thermistor. Are the
connectors loose or
disconnected?
Reconnect or
repair
the connector.
repair
the connector.
Yes
Yes
Check the resistance of the
heater. Is the resistance
between 12Ω and 18Ω ?
heater. Is the resistance
between 12Ω and 18Ω ?
(Refer to 9-6 Heater
assembly.)
assembly.)
Proceed to next step at right
Replace the
HEATER
ASSEMBLY.
HEATER
ASSEMBLY.
No
Yes
No
Check the thermistor
resistance. Is the resistance
correct according to the
chart?
resistance. Is the resistance
correct according to the
chart?
(Refer to 9-7 thermistor
assembly.)
assembly.)
Replace the
THERMISTOR
ASSEMBLY.
THERMISTOR
ASSEMBLY.
Yes
No
Are the thermistor terminals
dry and free of corrosion?
dry and free of corrosion?
[Note]
The temperature sensing circuits on the main
PCB are very simple, consisting only of resistors
and capacitors. Problems with wiring or
connections in the thermistor circuit are the
most likely cause for this error. Be sure to
check ALL connections and wiring thoroughly.
The main PCB should only be replaces as a last
resort, as it is unlikely to be the cause.
The temperature sensing circuits on the main
PCB are very simple, consisting only of resistors
and capacitors. Problems with wiring or
connections in the thermistor circuit are the
most likely cause for this error. Be sure to
check ALL connections and wiring thoroughly.
The main PCB should only be replaces as a last
resort, as it is unlikely to be the cause.
Replace the
THERMISTOR
ASSEMBLY.
THERMISTOR
ASSEMBLY.
Yes
Steam generator heater
Wash heater
Is the connector connected to
thermistor disconnected or
disassembled?
thermistor disconnected or
disassembled?
Reconnect or
repair
the connector.
repair
the connector.
Yes
No
Steam generator thermistor
Wash thermistor
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