Heating Without Water; Drain Malfunction - LG WM0742H*A Service Manual

HEATING WITHOUT WATER

When pressing SPIN SPEED and SOIL LEVEL
at the same time after draining, is the water
level frequency 255?
When pressing SPIN SPEED and SOIL LEVEL
buttons at the same time while wash, is the
water level frequency between 230 - 243?
YES
Check the voltage between two pins while
pressing the POWER button. Is the voltage
120V AC?

DRAIN MALFUNCTION

Is the drain hose twisted or frozen?
Is the impeller of the drain pump clogged?
Is the connector disconnected, disassembled?
Is the coil of the drain pump too high or low?
(resistance of coil is 10-20Ω)
When checking voltage between connectors
during spin, is the voltage 120V AC as in the
figure?
NO
NO
NO
NO
25
Replace the SENSOR
NO
SWITCH ASSEMBLY.
Replace the MAIN PWB
YES
ASSEMBLY.
Repair the DRAIN HOSE
YES
ASSEMBLY.
Remove foreign
YES
material.
Reconnect or repair the
YES
connector
Replace the DRAIN
YES
PUMP ASSEMBLY.
Replace the MAIN PWB
NO
ASSEMBLY.