DOWNLOAD LG 29478 Service Manual ↓ Size: 11.88 MB | Pages: 55 in PDF or view online for FREE

Model
29478
Pages
55
Size
11.88 MB
Type
PDF
Document
Service Manual
Brand
Device
Washing Machine
File
29478.pdf
Date

LG 29478 Service Manual ▷ View online

Result
37.5 
41
Test points
Result
Test Points
(2) to (3)
Remarks
5-3. STATOR ASSEMBLY
42
Wiring
diagram
Function
Test points
(Windings)
Result
(Windings)
Circuit in the MAIN PCB / Wiring Diagram
The DD 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 
5-15 
5-15 
Test Points
(1) to (2)
(2) to (3)
(3) to (1)
WINDINGS
(1)
HALL SENSOR
(3)
(2)
43
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)
44
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 Figure 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 & 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 & blue wires for
continuity. Repair or replace harness as needed.
Result
8-12 k
8-12 k
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
(1)
(2)
(3)
(6)
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