LG WM3988HMA / WM3988HWA Service Manual ▷ View online
44
9-4. PUMP MOTOR ASSEMBLY
Wiring
diagram
diagram
Circuit in the MAIN PWB
Wiring Diagram
MICOM
IC
R
5V
Rg
Cg
Vdc
Rs
Cs
PCB
CONNECTOR
PUMP
Vac
2
1
4
3
Pump Driving circuit
MAIN PWB
BL4
1 2 3
1
2
3
3 2 1
3 2 1
3 2 1
1
2
3
4
1 2 3 4
BL3
SKY
SB
SB
BK
BN
BN
DRAIN
PUMP
PUMP
CIRCULATION
PUMP
PUMP
BK
Object
Function
Test
points
points
Result
* Each circuits of loads in wiring diagram are all same.
Two pump motors are used to drain the tub and to circulate the water / detergent solution.
Drain Pump
Drain Pump
Circulation Pump
Circulation Pump
Test Points
Result
(1) to (2)
10-20
Ω
Test Points
Result
(1) to (2)
18-30
Ω
T.P
For Drain
For Circulation
(1)(2)
(2)
(1)
(1)
(2)
45
9-5. INLET VALVE ASSEMBLY
Wiring
diagram
diagram
Circuit in the MAIN PWB
INLET
VALVE
VALVE
Vac
Rs
Vdc
Cg
Rg
IC
MICOM
Cs
PCB
CONNECTOR
Inlet valve driving circuit
Function
Test
points
points
and
Result
Depending on the cycle and water temperature, the controller will energize the hot or
cold water valve solenoids to meet the selected water temperature.
cold water valve solenoids to meet the selected water temperature.
After pull out the connector of defective valve, check the resistance.
Test points
(1)-(2)
Result
0.8-1.2 k
Ω
Wiring Diagram
MAIN
WASH
AG
VALVE
PRE
WASH
BLEACH
HOT
VALVE
1
2
1
2
1
2
1
2
1
2
RD
BL
BL
RD
NA
BL
WH
YL
NA
VI
GYOR BL
WH
BL3
4
3
2
1
1
2
3
1
2
3
4
3
2
1
4
3
2
1
4
3
2
1
COMMON
(BK)
(BK)
MIAN PWB
INLET VALVE
DRY
VALVE
1
2
* Each circuits of loads in wiring diagram are all same.
(1)
(1)
(2)
(1)
(2)
(2)
(1)
(2)
(1)
(2)
(1)
(1)
(2)
(1)
(2)
(2)
(1)
(2)
(1)
(2)
46
9-6. HEATER ASSEMBLY
Wiring
diagram
diagram
Circuit in the MAIN PWB
MICOM
12V
Heater
Vac
43
43
Tab Relay
Heater driving circuit
Wiring diagram
MAIN PWB
2 1
2 1
2 1
2 1
2 1
2 1
BK
BL
WH
YL
GY
RD
BL
BK
BK
Vac
YL
2 1
2 1
FUSE
FUSE
FUSE
DR
Y
HEA
TER
THERMOST
A
T
WASH
HEATER
HEATER
STEAM
GENERATOR
HEATER
GENERATOR
HEATER
DRY
HEATER
HEATER
Function
Test
points
Result
1. The Wash Heater is designed to raise the wash water to the desired temperature
selection during certain wash cycles.
2. The Steam generator heater is designed to make the water to the steam during
steam cycles.
Wash Heater
Steam Generator Heater
* Each circuits of loads in wiring diagram are all same.
Wash Heater
Steam Generator Heater
Dry Heater
Test Points
Result
(1) to (2)
12-18 Ω
Test Points
Result
(1) to (2)
12-18 Ω
Test Points
Result
(1) to (2)
10-40 Ω
(1)
(2)
Dry Heater
(2)
(1)
(1)
(2)
47
9-7. THERMISTOR ASSEMBLY
Wiring
diagram
diagram
Circuit in the MAIN PWB / Wiring Diagram
MAIN PWB
MICOM
NA3
BL
BN
WH
1
2
1
2
1
2
1
2
THERMISTOR
DA1
DA2
Dry
Wash
AG
1
2
1
2
1
2
1
2
1
2
3
3
3
3
4
5
6
1
5V
5V
R
R
R
R
C
C
C
C
2
3
4
5
6
Function
Test
points
points
The thermistor (temperature sensor) is used to monitor water temperature in the
tub, Steam Generator, Dry duct and Condensing duct.
tub, Steam Generator, Dry duct and Condensing duct.
(1)
(2)
(2)
(1) (2)
Wash Thermistor
Dry Thermistor
Dry Thermistor
(2)
(1) (2)
(1)
(2)
(3)
Steam generator Thermistor
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