LG WT5070C series Service Manual page 42

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.
- 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.
Test
4. Place meter leads on terminals 5 to 4, white to gray.
point
5. Plug in power cord, close door, and press power button.
DO NOT PRESS START!
and
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.
Result
(Hall
Sensor)
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.
Test Points Result
3 MΩ ↑
(1) To (4)
(2) To (4) 3 MΩ ↑
9 kΩ ↑
(1) To (5)
(2) To (5) 9 kΩ ↑
(2) (4)
(1) (3) (5)
Remarks
Resistance
Resistance
Resistance
Resistance
42