LG WT-80PV Service Manual ▷ View online
12-2. How to diagnose and maintain according to symptoms
1) Power Failure
Where, what and how
Check results
Possible
reasons
Solution measures
Power
Yes
Electric
problems
1. Check if the socket is in poor
contact.
Replace plugs
Normal
None
2. measure voltage
0V Power
supply
Contact Power Supply Bureau
<1Ω
None
Washer harness
1. Measure power cord resistance with
plug short-circuit
Infinite
Power cord
cracks
Replace power cord
2. Check if all the connectors are
connected properly.
Separation of M and
F connectors
Poor contact
Connect again
3. Check all wire resistance Infinite
Harness
cracks
Replace harness
<0.5Ω None
>1Ω
Poor contact
Replace power cord
10-14V None
Replace
transformer
Electrical appliance
0V
Coil cracks
Replace filter
1.check if the fuse is damaged Yes
Bad
fuse
Replace
filter
PC board
Replace PC board if all
appliances are not damaged.
It must be that PC board damage if
problems are not mentioned above.
15% higher than
standard voltage.
29
2) Display problem
Where, what and how
Check results
Possible reasons
Solution measures
Main voltage
1. measure main voltage
Less than 85% of normal
voltage
Low voltage
Because of low voltage
supply. Please use
transformer if voltage is
keeping low.
2. measure external insert
row voltage if main
voltage is normal.
Less than 85% of normal
voltage
Wire is too small or there
are too many
connections on insert
row.
Use transformer
PC board
1. LED damage
2. LED drive circuit
damage
3. Chips damage
PC board damage
Replace PC board
3) Restart during working
Where, what and how
Check results
Possible reasons
Solution measures
Main voltage
1. measure plug voltage
during working
Less than 80% of normal
voltage
Main voltage is too low or
wire size is too small.
Because of low voltage
supply and please use
suitable wire.
2. restart fault repeats
during special periods
Temporary voltage surge
Because of environmental
condition(high-frequenc
y voltage around)
3. check if there is voltage
change.(such as flashing
lights)
Because of power supply
environment
PC board
Replace PC board
1. It must be PC board
fault if there is no
main voltage fault.
30
4) No water supply
Check
Check results
Possible reasons
Solution measures
Inlet valve
1． Water is not flowing
into inner tub and
there is current flow
though inlet valve is
working.
there is current flow
though inlet valve is
working.
1) Check if water tap is
close.
Close
Close
Explanation
2) check if the tap is
open
No
Use error
Open water tab
3)remove inlet valve and check
filter if problems are not
mentioned above.
mentioned above.
Filter is clogged
No cleaning
Use a brush to clean the
filter and filter should be
cleaned regularly.
cleaned regularly.
3) check whether
membrane hole is
clogged with foreign
objects or piston
inside valve is locked
if problems are not
mentioned above.
clogged with foreign
objects or piston
inside valve is locked
if problems are not
mentioned above.
Inlet valve fault
Replace inlet valve
2． If inlet valve is not
working and there is
no current sound
during water supply.
no current sound
during water supply.
1) Check if connectors
are not connected or
connected unproperly.
connected unproperly.
Poor connection
Connection fault
Connect
again
or
implement
troubleshooting caused by
poor connection.
troubleshooting caused by
poor connection.
2) Check inlet valve
resistance
Not between 0 。
8—1。2KΩ
8—1。2KΩ
Coil is cut off
Replace inlet valve
Pressure sensor
1 ． If error message “PE” is
1 ． If error message “PE” is
displayed: sensor fault.
“PE”error display
Connectors
do
not
connect or harness, coil is
cut off.
cut off.
Connect connectors or
replace harness. If coil is
cut off, replace the sensor.
replace harness. If coil is
cut off, replace the sensor.
2．Check BP sensor (pressure
sensor) frequency with no
load and no water supply.
load and no water supply.
Less than 20KHz
B、P sensor fault
Replace B、P sensor fault
Yes
Replace PC board
PC board
1．If inlet valve and sensor have
1．If inlet valve and sensor have
no fault, check the PC
board.
board.
31
5)
Continuous or intermittent water supply
Check
Check results
Possible reasons
Solution measures
Incorrect installation/water
leakage
1 ． Check if drain hose is
placed on the floor.(Pump
model)
Yes
Incorrect
installation
Drain hose should be
hang over standpipe or
wash tub. Replace parts.
2．Check leakage place
Water leakage from
some parts
Parts fault
Repair the parts
Pressure sensor
1 ． Check if wave wheel
rotates with no water supply.
No
No water pressure sensor
Check if pressure sensor
pipe is broken and repair
it.
2 ． Check if air hole is
clogged there is no sensor
fault.
Yes
Air hole is clogged
Repair air hole
Inlet valve
1． Is there water supply
under no power(power
is off)?
Yes
Inlet valve fault
Replace inlet valve
PC board
1．Press “POWER” and there
is water supply
immediately before
“START/PAUSE”
pressed.
Short-circuit
of
controlled
silicon
Replace PC board
32
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