DOWNLOAD LG WT4801CW Service Manual ↓ Size: 10.9 MB | Pages: 50 in PDF or view online for FREE

Model
WT4801CW
Pages
50
Size
10.9 MB
Type
PDF
Document
Service Manual
Brand
Device
Washing Machine
File
wt4801cw.pdf
Date

LG WT4801CW Service Manual ▷ View online

37
Test points
(1)
(7)
(13)
(9)
(6)
(8)
(11)
(10)
(5)
(4)
(3)
(2)
(12)
No.
Parts
1
COVER
2
SCREW
3
LEAD WIRE
4
PACKING
5
SOLENOID
6
CASE
7
HAND WIRE
8
MICRO SW
9
SOL-SPRING
10
PLUNGER
11
KEY
12
LEVER
13
RUBBER CASE
38
5-3. STATOR ASSEMBLY
Wiring 
diagram
Function
Test points
(Windings)
Result
(Windings)
Circuit in the MAIN PCB / Wiring Diagram
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.
Result
5-15 Ω
5-15 Ω
5-15 Ω
Test Points
(1) to (2)
(2) to (3)
(3) to (1)
WINDINGS
(1)
HALL SENSOR
(3)
(2)
39
Test
point
and
Result
(Hall
Sensor)
- Voltage Testing Hall Sensor at Stator
If measuring voltage from the main PCB assembly to the Hall Sensor, use the following steps:
1. Unplug power cord.
2. Remove rear washer panel.
3. Locate hall sensor connector on the stator behind the rotor.
4. Place meter leads on terminals 5 to 4, white to gray.
5. Plug in power cord, close door, and press power button. 
    DO NOT PRESS START!
6.  You should measure 10 to 15 Vdc. If 10 to 15 Vdc is present, control board, white wire, and gray 
wire are OK! If not follow testing output voltages on control board in next section.
7.  To measure output signal voltage from the hall sensor, carefully  move test leads to terminals 1 to 
4, blue and gray. Slowly rotate motor rotor by hand. You should read a pulsing 10 Vdc. If 10 Vdc is 
measured from 1 to 4, move lead on blue wire to red wire, terminal 2. Repeat rotating motor rotor 
by hand. You should  read a pulsing 10 Vdc from red to gray.  
8.  If pulsing 10 Vdc is measured from 1 to 4 and 2 to 4, hall sensor  is OK! If either test netted only 9 
to 10 Vdc without changing (no pulsing) the hall  sensor is likely defective. Disconnect  power by 
unplugging washer and ohm check hall sensor to verify failure of the hall sensor.
The hall sensor determines the speed and direction of the motor. 
It also can read that the load is off balance when the drum speed fluctuates.
(1)
(2)
(3)
(4)
(5)
(1)
(2)
(3)
(6)
40
Test
point
and
Result
(Hall
Sensor)
- Voltage Testing Hall Sensor from the Main PCB Assembly
1. Unplug power cord.
2. Remove rear panel.
3. Remove washer top.
4. Remove main PCB assembly cover as shown in chart below.
5. Locate the blue hall sensor 6 wire connector using wiring diagram wire colors as your guide.
6. Plug in power cord, close door, and press power button. DO NOT  PRESS START!
7.  Place meter leads on white and gray wires. You should read 10 to 15 Vdc  output from the Main 
PCB Assembly to the Hall sensor. If no 10 to 15 Vdc is  measured the control board is defective.
8.  Place meters leads on blue to yellow. Turn motor rotor slowly by hand. You should measure  
 a pulsing 10 Vdc. Place meter leads on red to yellow. Turn motor rotor slowly by hand.  
You should measure a pulsing 10 Vdc. If both tests measure a pulsing 10 Vdc, 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 and blue wires for continuity. Repair or replace harness as needed. 
Result
8-12 kΩ
8-12 kΩ
10-15 Vdc
10 Vdc
10 Vdc
Test Points
(1) to (2)
(1) to (3)
(1) to (6)
(2) to (6)
(3) to (6)
Remarks
Voltage Input
Pulsing Signal
Pulsing Signal
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