LG 8806084066640 Service Manual ▷ View online
37
FOR AUTHORIZED SERVICE TECHNICIAN
9-2. DOOR LOCK SWITCH ASSEMBLY
Wiring
diagram
Circuit in the MAIN PWB / Wiring Diagram
MAIN PWB
Vdc
Vac
MICOM
12V
4 1
3 2
4 1
3 2
Relay
Relay
NA4
1
2
3
4
1
2
3
4
2
3
4
PT
C
PT
C
Door switch
SOLENOI
D
5
YL
BL
RD
BK
AC
Common
terminal
of valve
Function
The door lock switch assembly consists of a heating PTC, a bimetal,
a protection PTC, and a solenoid. It locks the door during the wash cycle.
1.Operation for door closing
- After the system turns on, PTC heating starts up through terminals 2 and
4 authorizing the power on.
- After PTC heating starts up and before solenoid operation is driven,
force the system to the off position through CAM.
Door close
- Authorizing one impulse through terminal 3~4 (PTC & solenoid) will
make the door locked.
- Door lock is detected when switches in terminal 4~5 are set closed.
CAM rotation will forcibly clear off the connection.
The maximum, allowable number of impulse authorizations is 2.
Upon the third authorization of the impulse, the position of CAM goes
back to the door-open position.
- Authorizing the impulse occurs in 4.5 seconds upon input for max
performance and two authorization processes are allowed at most.
Normal operation period of PTC heating: 1.5 – 5 seconds.
(Defects from the development process.)
2.Operation for door opening
- With a temporary stop, door automatically opens by CAM rotations after
authorizing the impulse from the terminal, 3 ~ 4 and the power turns
off – maximum of 3 times of the authorizing period.
- Upon the fourth authorization of the impulse, the position of CAM goes
back to the door-close position.
38
FOR AUTHORIZED SERVICE TECHNICIAN
Test
points
Result
Test Points
(2) to (4)
(3) to (4)
(4) to (5)
(2) to (4)
(3) to (4)
(4) to (5)
(2) to (4)
Result
700-1500 Ω
60-90 Ω
Infinity
120 Vac
Remarks
At 77
°F
(25
°C
)
At 77
°F
(25
°C
)
Voltage Input
39
FOR AUTHORIZED SERVICE TECHNICIAN
9-3. STATOR ASSEMBLY
Wiring
diagram
Circuit in the MAIN PWB / Wiring Diagram
MAIN PWB
MICOM
Ha
12V
NA1NA
WH
WH
GND
MO
TO
R
Hb
Ha
RD
RD
BL
BL
GY
YL
w
w
v
u
v
u
BL
RD
RD
RD4
IPM
GY
YL
w
u
v
BL
RD
1
1 1
2
3
4
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
3
2
2
1
3
4
1
2
3
4
5
1
2
3
4
5
2
3
4
1
2
3
4
Hb
Function
Test points
(Windings)
Result
(Windings)
The Direct Drive motor can be driven from stopped to maximum speed in infinite
steps in either direction.
There are 36 poles on the stator; 12 permanent magnets spaced around the rotor.
There are no brushes to wear out. Unlike a more traditional brushless motor, the
rotor surrounds the stator rather than being attached to it.
Test Points
Result
(1) to (2)
(2) to (3)
(3) to (1)
(2) to (3)
(3) to (1)
5-15 Ω
5-15 Ω
5-15 Ω
5-15 Ω
5-15 Ω
WINDINGS
HALL SENSOR
(1) (2)
(3)
40
FOR AUTHORIZED SERVICE TECHNICIAN
Test Point
and
Result
and
Result
(Hall
Sensor)
1. Unplug power cord.
2. Remove rear panel.
3. Remove washer top.
4. Remove main PCB assembly cover as shown in figure below.
5. Locate the white hall sensor 4-wire connector using wiring diagram wire colors
as your guide.
6. Plug in power cord, close door, and press the button. DO NOT PRESS START!
7. Place meter leads on White & Gray wires. You should read 10 to 15 V
DC
output
from the Main PCB Assembly to the Hall sensor. If no 10 to 15 V
DC
is
measured, the control board is defective.
8. Place meters leads on Blue to Gray. Turn motor rotor slowly by hand. You
should measure a pulsing 10 V
DC
. Place meter leads on Red to Gray. Turn
motor rotor slowly by hand. You should measure a pulsing 10 V
DC
. If both tests
measure a pulsing 10 V
DC
, hall sensor and harness OK. If either or both tests
measures 9 to 10 volts, but does not pulse or change, Hall sensor has failed
and must be replaced. IF zero (0) voltage is measured on either test, check red
blue wires for continuity. Repair or replace harness as needed.
- Voltage Testing Hall Sensor from the Main PCB Assembly
Test Points
(1) to (2)
(1) to (3)
(1) to (4)
(2) to (4)
(3) to (4)
(1) to (3)
(1) to (4)
(2) to (4)
(3) to (4)
Result
8-12 k
8-12 k
8-12 k
10-15 V
DC
10 V
DC
10 V
DC
Remarks
Voltage Input
Pulsing Signal
Pulsing Signal
Pulsing Signal
(1) (3)
(2) (4)
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