LG LTCS20020 User manual

MODELS:
REFRIGERATOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
Any reproduction, duplication, distribution (including by way of email, facsimile or other electronic
means), publication, modification, copying or transmission of this Service Manual is STRICTLY
PROHIBITED unless you have obtained the prior written consent of the LG Electronics entity from
which you received this Service Manual. The material covered by this prohibition includes, without
limitation, any text, graphics or logos in this Service Manual.
Copyright © 2020 LG Electronics Inc. All rights reserved. Only training and service purposes.
1
LTCS20020*
* = Color Code

CONTENTS
WARNINGS AND SAFETY PRECAUTIONS ......................................................................................
1. SPECIFICATIONS ...........................................................................................................................
2. PARTS IDENTIFICATION ...............................................................................................................
3. DISASSEMBLY ...............................................................................................................................
4. TROUBLESHOOTING COMPRESSOR .........................................................................................
4-1 Compressor activation defect ....................................................................................................
4-2 Service Diagnosis Chart ............................................................................................................
5. COMPRESSOR ...............................................................................................................................
6. CIRCUIT DIAGRAM.........................................................................................................................
2
3
4
5
11
11
18
19
21
SAFETY PRECAUTIONS
Please read the following instructions before
servicing your refrigerator.
1. Check the refrigerator for current leakage.
2. To prevent electric shock, unplug before
servicing.
3. Always check line voltage and amperage.
4. Use standard electrical components.
5. Don't touch metal products in the freezer with
wet hands. This may cause frost bite.
6. Prevent water from spiling on to electric
elements or the machine parts.
7. Before tilting the refrigerator, remove all
materials from on or in the refrigerator.
8. When servicing the evaporator, wear gloves to
prevent injuries from the sharp evaporator fins.
9. Service on the refrigerator should be performed
by a qualified technician. Sealed system repair
must be performed by a CFC certified technician.
7. TROUBLESHOOTING.....................................................................................................................
22
7-1 Compressor and Electric Components ..........................................................................................22
7-2 PTC and OLP.................................................................................................................................23
7-3 Other Electric Components ...........................................................................................................24
7-4 Service Diagnosis Chart ................................................................................................................25
7-5 Refrigerating Cycle.........................................................................................................................26
8. CIRCUIT OF MICOM .......................................................................................................................27
8-1 Function .........................................................................................................................................
27
9. SMART DIAGNOSIS & DOOR ALARM ......................................................................................... 31
10. EXPLODED VIEW .........................................................................................................................50
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.
2

3
P C M S T S P C M
P o ck et H andle
2 full + 1 s m all
Ice B in
H um idity C o ntro l
M O LE C U LA R SIE VE XH -7
ID Ø 0.75
4 H o urs
7 - 40 H o urs
H eater, S heath
E m bo ( N o rm al)
F in T ube T ype
W ire C o ndens er
P o lyo l E s ter (P O E ) R L-7H /7 cs t 220 ± 10 cc
G las s (1)
N/A
P las tic (2)
N o
N o
G las s (2)
LE D (1)
F an C o o ling
M IC O M co nt ro l
F ull A uto m at ic
H eat er D efro s t
P o lyurethan
BM G110NHMV
29.9 x 33.9 x 66.1 in
Super White / Stainless Steel / Western Black
LTCS20020*
91.6 k g
20 cu f t
R 600a
T em perat e (N )
115 V ~ / 6 0H z
Shelf
T ray m eat
T ray egg
B as k et, Q uantity
Lam p
Shelf
D es fro s ting D ev ice
C as e M ater ial
D o o r M aterial
H andle T ype
B as k et , Q uantity
Ice T ray & B ank
C o v er, T /V
Lam p
C o ndens er
Lubricanting O il
D rier
C apillary T ube
F irs t D efro s t
D efro s t C ycle
C o o lin g S ys t em
T em perat ure C o ntro l
D efro s ting Sys tem
Ins ulat io n
C o m pres s o r
E v apo rat o r
S P E C I F I C A T I O N S
C o lo r
D im ens io nes (W x D x H )
N et W eight
C apacity
R efrigerant
C lim ate C las s
R ated R ating
MODEL
SERUTAEFLARENEGROTAREGIRFERREZEERF
1. SPECIFICATIONS
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.

Use this page to become mo re familiar with the parts and features of your refrigerator. Page references are
included for your convenience.
NOTE: This guide covers several models. The refrigerator you have purchased may have some or all of the i tems
listed below. The locations of the features shown below may not match your model.
Custom Cube Icemaker
A
Refrigerator Light (LED)
F
Refrigerator Temperature Control
D
Shelves
E
Freezer Shelf
B
A
B
C
D
E
F
H
J
G
I
L
GCrispers
HFreezer Door Bins
IDairy Bin
JRefrigerator Door Bins
Freezer Temperature Control
C
2. PARTS IDENTIFICATION
4
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.

If entrance is lees than 35 inch es wide, the refrigerator’s door will need to be removed.
IMPORTANT: Before starting, turn off and unplug the refrigerator. Remove all food and the racks from the doors.
TOOLS YOU MIGHT NEED OR USE
3/8 in
10 mm
Hex Socket Wrench Phillips Sc rewdriver No. 2 Flat Head Sc rewdriver Adjustable Wrench
WARNING
ELECTRICAL SHOCK HAZARD
Before you begin, either unplug the refrigerator or
turn off the power at the circuit breaker or fuse box.
Remove food and any door rack from the refrigerator.
Failure to do so could result in death or serious injury.
1. Removing Freezer Door
Gently pry off the Top Hinge Cover with a flat head
screwdriver and remove it. See Fig. 1.
Using 10 mm or 3/ 8 inch socket wrench, remove
the three bolts and lift the Top Hinge (See Fig. 2). Set
parts aside.
Lift freezer door slightly and remove it (See Fig. 3) Set
parts aside.
2. Removing Refrigera tor Door
Loose and remove the two bolts and the screw to
remove the middle hinge bracket from refrigerator
housing (Figure 4). Set parts aside (Figure 5).
Lift up door slightly and remove it (See Figure 6).
Hinge Pin
Middle Hinge Bracket
Fig. 1
Fig. 3
Middle
Hinge Bracket
Fig. 4
Fig. 5
1/4 in
(For additional support on this topic, including helpful videos, please visit us at: www.lg.com).
Fig. 2
Middle
Hinge Bracket
3. DISASSEMBLY
5
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.

To replace doors, begin with refrigerator door and then
follow with freezer door.
3. Replacing Refrigera tor Door
Set door on Bottom Hinge Pin (See Figure 7).
Place hinge pin of middle bracket inside the hinge pin
insert on the top of the door (See Figure 8). Hold the
door in place and line up the hinge with the holes in
the refrigerator housing.
Use the two bolts and the screw to refasten the middle
hinge with the refrigerator housing. See Figure 9.
4. Replacing Freezer Door
Set the freezer door onto the Middle Hinge pin (Figure
10).
Place upper hinge in the top of the freezer door and
line up the hinge with the holes in top of refrigerator.
Use the three bolts to fasten the hinge (See Figure 11).
Carefully, force the top hinge cover back into place over
hinge (See Figure 12).
REFRIGER TALLATION
Fig. 8
Fig. 9
Fig. 12
Bottom Hinge Pin
Fig. 6
Fig. 10
Fig. 7
REFRIGER TALLATION
Fig. 11
6
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.

HOW TO REVERSEAND INSTALLTHE REFRIGER ATOR DOORS
You may find it more convenient to have the doors converted from the left opening type (factory installed) to the right
opening type. Directions refer to the right side as the side on your right as you face the unit.
1. Removing Freezer Door
Gently pry off the top hinge cover with a flat head
screwdriver and remove.
Using 10mm or 3/ 8 inch soc ket wrench, remove the
three bolts and lift off the top hinge. Set parts aside
Slightly lift up the refrigerator door and remove it.
Turn the freezer door upside d own on a non-scratch
surface. Loosen the screw to remove the Door
Closer/Stop and Hinge Pin Insert.
Move the Hinge Pin Insert Bracket to the other side of
the door, keeping the same orientation, and move the
Hinge Pin Insert into the hole on the left side of the
bracket.
Reverse the Door Closer/ Stop by flipping it over. Place
it
on top of the Hinge Pin Inse rt Bracket, and tighten both
down with the screw.
Pry off the cover on the top left side of the refrigerator to
uncover the screw holes.
Set the freezer door and top hinge parts to the side and
remove the refrigerator door.
Hinge Pin
Middle Hinge Bracket
Hinge Pin
Insert Bracket
Hinge Pin Insert
Cover
(on top of
refrigerator)
WARNING
ELECTRICAL SHOCK HAZARD
TOOLSYOU MIGHT NEED OR USE
m
Hex Soc ket Wr ench Phillips Screwdriver No. 2 Flat Head Screwdriver
Before you begin, either unplug the refrigerator or turn off the p ower at the circuit breaker or fuse box. Remove
food and any door rack from the refrigerator. Failure to do so could result in death or serious injury.
7
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.

2. Reversing and Reinst
alling Refrigerator Door
Using a ¼” socket wr
ench, loosen and remove Hinge
Pin fr
om the Middle Hinge Bracket. Remove washer
undernea
th the middle hinge and set aside.
NOTE: At this point the door
will be loose. Slightly lift the
door and remove it.
Loosen and remove the tw
o bolts and use the Phillips
head screwdriver to remov
e the Middle Hinge Bracket
from the refrigerat
or housing. Set parts aside.
Remove the washer fr
om the Bottom Hinge Pin.
Using a ¼” socket wr
ench, loosen and remove the
Hinge Pin from the Bott
om Hinge. Reattach the
Hinge Pin to the opposit
e side of the hinge.
NOTE:
NOTE:
WARNING:
This is easier to do
while the hinge is still
attached.
Using a 3/8’’ socket wrench with a 2-Inch extension
and screwdriver, loosen the two bolts and one screw, and
remove the Bottom Hinge from right side of the housing.
Remove the Decorative Caps on the bottom of the
refrigerator housing. You will need these holes for the
Bottom Hinge.
Move the Bottom Hinge to the left side of the housing,
keeping the same orientation, and reattach with the
two bolts and one screw. The flat screw must be
placed on the exterior side of the hinge. Move the
Decorative Bolt to the hole on the lower right side
of the housing.
Turn the refrigerator door upside down on a
nonsc
to remove the Bottom Hinge Pin Insert Bracket
with the Hingr Pin Insert.
If you reinstall or replace doors, move
ratching surf
The leveler is only present on some models.
ace. Loosen the two screws
Leveler
the leveler to the opposite side.
8
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.

Hinge Pin
Insert
Hinge
Pin Bracket
Door
Closer/
Stop
Door
Closer/
Stop
Hinge Pin
Insert
Hinge
Pin Bracket
With a flat-head screwdriver, carefully pry off and
remove the cover over the screw holes on the left side of
refrigerator housing.
Remove the outer lower Decorative Screw from the
housing at the area between the freezer and refrigerator
doors. (You will need this hole for the Middle Hinge
Bracket.)
Flip the Middle Hinge Bracket, (flange will now be on
top) position it on left side of the refrigerator and reattach
with two bolts and a Phillips screwdriver. Place the
refrigerator door down over the pin on the bottom hinge.
Place the washer between the refrigerator door and
middle hinge and re-attach Hinge Pin to Hinge Bracket
with a ¼” socket wrench.
NOTE: Bracke
NOTE:The Door Closer Stop is only presented on some
t has been flipped, but Hinge Pin stays
in the same orientation with its hexagonal end facing
upward.
Insert the Decorative Screw into the outer hole on the
right side of the housing. Attach cover on the right side.
Cover is force-fitted.
REATTACHING THE DOORS
Place the freezer door down over the Hinge Pin on the
Middle Hinge Pin Bracket.
Place the Upper Hinge Pin on top of the freezer door
and line up the Upper Hinge with holes on top of the
refrigerator. Use the three bolts to replace the Hinge.
Middle Hinge
Bracket
Flange
Decorative
Screw
Reverse the Door Closer/Stop by flipping it over. Place
it on top of the Hinge Pin Insert Bracket, and tighten
both down with the screw. Tighten the Hinge Pin
Bracket to the door.
models.
9
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.

Corners
Fig. 37
SHROUD
GRILLE
FAN MOTOR
FAN
BRACKET
After changing the doors, make sure that the corners of the
Door Gaskets are not folded over. To ensure a good seal,
apply a small amount of silicon grease on the corners of
gaskets.
CLOSING AND ALIGNING THE DOORS
To avoid vibration, the unit must be leveled. If necessary,
adjust the Leveling Legs to compensate for unevenness of
the floor. The front should be slightly higher than the rear to
aid in door closing.
Your refrigerator has three front leveling screws, one on the
right and one on the left. If your refrigerator seems unstable
or if you would like the doors to close more easily, simply
adjust the inclination of the refrigerator by following the
instructions below:
NOTE: Third leveling screw is used for protection of hinge
lower.
1. Plug the refrigerator into a 3 prong grounded outlet. Move
the refrigerator into its final position.
2. Use a flat head screwdriver to adjust the leveling screws
(see Figure A), turning clockwise to raise the side of the
refrigerator and counter-clockwise to lower it. It may take
several turns to adjust it to the inclination you would like.
NOTE: Having someone push against the top of the
refrigerator takes some weight off the leveling screws. This
will make it easier to adjust the screws.
3. Open both doors again and check to make sure that they
close easily. If not, tilt the refrigerator slightly more to the
rear by turning both Leveling Screws clockwise. It may take
several more turns, and you should turn both Leveling
Screws the same times.
Figure A
DOOR ALIGNMENT
If the space between your doors is uneven, follow the
instructions below to align the doors.
1. Gently pry off the refrigerator door Top Hinge Cover with
a flat head screwdriver and remove. Loosen the Top Hinge
Bolts using a 10 mm or 13/32inch socket wrench or
opened wrench.
2. Have a second person hold the refrigerator door in its
proper position.
3. Replace the Top Hinge Cover.
FAN AND FAN MOTOR
1. Remove the freezer shelf. (If your refrigerator has an
icemaker, unplug and remove the icemaker first).
2. Remove the screw of the grille fan.
3. Remove the grille by pulling it out.
4. Remove the Fan Motor assembly by loosening 4 screws
and disassemble the shroud.
5. Pull out the fan and separate the Fan Motor and Bracket.
10
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.

4. TROUBLESHOOTING COMPRESSOR
4-1 Compressor activation defect
1
- Open PWB Cover
If COMP & FAN are not operated at the same time, check the operation after forcing the operation
in TEST MODE in MAIN PCB, and perform power RESET after checking the voltage on COMP side.
3
4
2
- Open back cover
2. Check wheter C-Fan
operates
1. CHECK COMP and
Discharge PIPE
temperature
- Check the number of LED blinking
(Refer to the next chapter for actions for
each number of LED blinking)
If COMP is normal it
will not blink
Test Mode Button
- Check disconnection in OLP
and Comp connection (U,V,W
=SB ,YL , RD)
11
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Only training and service purposes.

Is Comp in
operation?
Simple Check order
LED blinks 1 time Reset LED blinks 1 time Replace PCB
LED blinks 7 times Reset LED blinks 7 times Replace PCB
LED blinks 6
times
LED blinks 6
times
Check
Comp.
(Check C)
LED
Blinking?
No cold
air?
Check again
Reset
Heavy repair
Check again
Leakage?
Heavy repair Check again
Leakage?
Replace
Comp.
Replace PCB
Is Comp in
operation?
Check Comp.
(Check C)
Compressor SVC Manual
1. Check LED Trip
1. Separate PCB COVER, and check number of LED blinking.
2. Verify the actions for each number of blinking Check when it is not RESET(Before turning off the power of the
refrigerator).
3. Write the service information according to the number of LED blinking.
4. Write SVC information, and check again after power reset.
Refer to the actions for each number of Trip and LED blinking
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Only training and service purposes.
12

Actions for each number of LED blinking
LED 6 times repeated
Blink Blink Blink Blink Blink Blink Off Blink Blink Blink Blink Blink Blink Off Repeated
Circuit over-
current
error
1. Check normal
operation after
power reset
2. If same error occurs
after 1, replace
PCB.
3. If same error occurs
after 2, replace
COMP unit.
1
LED 7 times repeated
Blink Blink Blink Blink Blink Blink Blink Off Blink Blink Blink Blink Blink Blink Blink Off Repeated
PCB defect
part (IPM)
1. Check normal
operation after
power reset
2. If same error occurs
after 1, replace
PCB.
2
LED 1 time repeated
Blink Off Blink Off Blink Off Blink Off Blink Off Blink Off Blink Off Blink Off Repeated
AD-offset
Error
1. Check normal
operation after
power reset
2. If same error
occurs after 1,
replace PCB.
3
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Only training and service purposes.
13

Actions for each Trip and number of LED blinking
1. LED blinking 1 time (AD-offset Error)
Blink OFF Blink OFF
Check
protection
logic
LED blinking 1
time
AD-offset Error
Is it out of Spec.?
(2.2-2.8V)
Replace
PCB
Power Reset
Objective: to detect Motor voltage or current sensing defect
Actions: check CC310 voltage and if it is outside 2.2~2.8V, replace PCB
Copyright © 20 LG Electronics Inc.All rights reserved.
Only training and service purposes.
14

2. Current Trip and LED blinking 6 times (Current Trip)
Check
Protection
Logic
Check Current or LED
blinking 6 times (Current
Trip)
Check inspection
procedure again
Power
Reset
Replace
Compressor
Intermittent
operation of
Compressor
Check PCB
output
Did Current trip
occur?
Check
Compressor
defect
Modify
HarnessP
Check HarnessP
U.V.W
Replace PCB
Check PCB output
Actions for each number of TRIP and LED blinking
knilBknilBknilBknilBknilBBlink
off/on within 3 min.
1. If it blinks 6 times, but there is no significant difference between the temperature inside the refrigerator and
the set temperature, there is no problem in PCB, Compressor, or Cycle.
2. If it blinks 6 times and problem such as no cooling occurs, it means cycle leakage or cycle clogged (moisture, trash).
Cause: Cycle leakage or clogging, excessive Compressor temperature increase, compressor piston locked, PCB IPM
device burned due to Condenser fan defect
Cause: Over-current protection
Action: Check PCB output, Check operation of the Compressor single unit, leakage inspection and check cycle clogging
(For re-vacuum, 30min. additional vacuum)
OFF
W
VU
15
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Only training and service purposes.

Check
protection
logic
Check IPM Fault or
LED blinking 7
times(IPM Fault)
Compressor is not
activated
Check Point A short
circuit IPM output
>80V-20%
Replace PCB
Re-confirm
inspection
procedure
Visual
verification of
IPM burn
Power
Reset
3. LED blinking 7 times (IPM Fault)
Actions for each TRIP and the number of LED blinking
FFOknilB Blink Blink Blink Blink Blink Blink
Cause: IPM Short, defect(burned or damaged)
Objective: Protection of the over-current caused by IPM short or defect.
Actions: Visual verification of IPM burn when COMP is not in operation. Check whether
there is a short circuit in U, V, or W part.
Replace PCB
U
GND
GND
P/N: EBR807574**
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Only training and service purposes.
16

4-1 ANOTHER ELECTRIC COMPONENTS
Poor contacting.
Coil is shorted.
Shorted.
Check current flowing
in door S/W.
Check current flowing
in the Fan Motor.
Check current flowing
of the following
components.
Def. Sensor
FUSE-M
Check current flowing
of the following
components.
Heater plate
Heater cord
Fan motor doesn't run.
Much frost are sticked
to the EVAPORATOR.
Replace each
component.
Replace each
component.
Replace each
component.
Multi
Tester
Motor resistanceCompressor
BMG110NAMV
ambient temperature or operation condition.
Cooling ability is poor
Check COMPRESSOR & HARNESS
Measure COMP connector resistance (Power & Common)
Check insulation destruction : measure the resistance between the COMP
power connector and the grounding. Copyright © 2020 LG Electronics Inc. All rights reserved.
Only training and service purposes.
17
Copyright © 2020 LG Electronics Inc.All rights reserved.
Only training and service purposes.

Defrosting is
poor.
4-2 SERVICE DIAGNOSIS CHART
Cooling is
impossible.
Is the power cord unplugged from the outlet?
Checked if the power S/W is set to OFF.
Check if the fuse of power S/W is shorted.
Measure the voltage of power outlet.
Check if the set is placed close to wall.
Check if the set is placed close to stove, gas,
cooker and direct rays.
Is the ambient temperature high or the room door
closed?
Check if putting in hot foods foods.
Did you open the door of the set too often or check
if the door is closed up?
Check if the Control is set to Min .
Are foods placed in cooling air outlet?
Check if the Display LED is set to 0-1 .
Is the ambient temperature below 5 C.
Is watery foods kept?
Check if putting in hot foods.
Did you open the door of the set too often or check
if the door is closed up.
Check if ambient temperature and humidity of
surrounding air are high.
Is the gap in the door packed?
Is the set positioned in a firm and even place?
Does any unnecessary objects exists in the back
side of the set?
Check if the Drip tray is not firmly fixed?
Check if the cover of mechanical room in below
and back side is taken out.
Check if the door packing becomes dirty by filth
such as juice.
Is the set positioned in a firm and even place?
Is too much food putted in the set?
Check if the inside of the set becomes dirty.
Did you keep smelly foods without wrapping?
It smells plastic.
Plug to the outlet.
Set the switch to ON.
Replace a regular fuse.
If voltage is low, wire newly.
Place the set with the space of about
10cm
Place the set apart from these heat
appliances.
Make the ambient temperature below.
Put in foods after they get cold cold.
Don t open the door too often and
close it firmly.
Set the control to mid-position.
Place foods in high temperature
section. (Front part)
Set the Display LED to 3 .
Set the Display LED to 5-6 .
Seal up watery foods with wrap.
Put in foods after they get cold.
Don t open the door too often and
close it firmly.
Wipe dew with a dry cloth. This
happening is solved in low temperature
and humidity naturally.
Fill up the gap.
Adjust the leveling screw, and position
in the firm place.
Remove the objects.
Fix it firmly on an original position.
Place the cover at an original position.
Clean the door packing.
Position in the firm place and adjust the
adjust screw.
Keep foods not to reach the door.
Clean the inside of the set.
Wrap smelly foods.
The new products smell plastic, but it is
removed after 1-2 weeks.
Cooling ability is
poor.
Foods in the
refrigerator
are frozen.
Dew or ice forms in
the chamber of the
set set.
Dew forms in the
Out Case.
Abnormal noise
generates.
To close the door
is not handy.
Ice and foods
smell unpleasant.
In addition to the items describes left, refer to the following to solve the complaint.
Check if dew forms
in the freezer.
Replace the
components of
defrosting circuit.
Check refrigerator
Cycle.
The cycle is
faulty. Repair the cycle.
COMPLAINT POINTS TO BE CHECKED SERVICE ACTION
18
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Only training and service purposes.

W
VU
Multi
Tester
There may be resistance value differences of
several according to the ambient temperature or
operation condition.
Motor resistance
Compressor
BMG110NAMV
5. COMPRESSOR
1.How to find out Inverter BLDC Compressor defect
1-1. How to measure Compressor winding resistance
Standard for judging normality
Standard for judging defect
Cautions
If Inverter BLDC Compressor defect occurs, you can check in the following order.
When the resistance value of Harness(connected to Compressor) connecting Main PWB Connect201(CON201), if the
resistance value shows the value of the level in the following figure, you can say that it is normal.
If the resistance value measured in point A in the figure shows infinity or several hundred , check the locking status of
Compressor connecting Harness-P(Lead Wire) in the machine room, separate machine room Connect(B point in the figure),
and measure resistance value of Connect again. If the resistance value shows the standard resistance value, Compressor can
be judged to be normal. Check Harness connection status.
(Machine Room Connect Contact Defect, CON201 Housing Contact Defect, Harness Disconnection) If the resistance value
measured at B point also shows infinity or several hundred , disassemble Cover PTC of the Compressor connector, and check
the locking status of the terminal at D point in the figure. If it is normal, check the contact status of O.L.P fixed inside Cover
PTC. The problem in O.L.P. may be judged by the resistance values at both ends of O.L.P. If both ends of O.L.P. are measured
and the resistance value shows 5 or less, it is normal. If the resistance value is big, it may be judged as O.L.P. disconnection,
and compressor does not operate because of no power supply.
If there is no problem in the connection status, and resistance value shows infinity or several hundred , it may be judged as
Compressor defect.
If there is no problem with the resistance value of the Compressor, it may be Main PWB defect, so check
PCB defect.
During the judgment of defect through resistance measurement, if the resistance values of No.1 and No. 3 of CON201 show
the value in the level presented below, motor winding may be judged as normal.
1. Make sure to turn off the power of the refrigerator, and measure after several minutes have passed.
2. If the resistance is not correctly measured, you may have wrong judgment.
(The resistance value may have differences of several )
13.85 ± 5
V
W
U
Compressor terminal
Multi Tester
C OLP
Multi Tester
D
19
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Only training and service purposes.

General Control of Refrigerating Cycle
ITEMSNO.
1
2
3
4
5
6
7
WELDING
ROD
(1) H 30
Chemical Ingredients
Ag : 30%, Cu : 27%, Zn : 23%, Cd : 20%
Brazing Temperature : 710~840°C
(2) Bcup-2
Chemical Ingredients
Cu : About 93%
P : 6.8~7.5%
The rest : within 0.2%
Brazing Temperature : 735~840°C
Ingredients and how to make
Borax 30%
Borax 35%
Fluoridation kalium : 35%
Water : 4%
Mix the above ingredients and boil until
they are transformed into liquid.
(1) Assemble the drier within 30min. after
unpacking.
(2) Keep the unpacked drier at the temperature
of 80~100°C.
(1) When measuring with pirant Vacuum gauge
of charging M/C, vacuum degree is within 1
Torr.
(2) If the vacuum degree of the cycle inside is 10
Torr. below for low pressure and 20 Torr. for
high pressure, it says no vacuum leakage
state.
(3) Vacuum degree of vacuum pump must be
0.05 Torr. below after 5 min.
(4) Vacuum degree must be same to the value
described item (2) above for more than 20
min.
(1) The pressure of dry air must be more than
12~16Kg/cm2
(2) Temperature must be more than -20~-70°C.
(3) Keep the pressure to 12~6Kg/cm2also when
substituting dry air for Nitrogen Gas.
(1) Check if gas leaks with soapy water.
(2) Replace Quick Coupler in case of leakage.
Put all Joint Pipe in a clean box and
cover tightly with the lid so that dust or
humidity is not inserted.
Recommend H34 containing 34% Ag in the
Service Center.
Make amount for only a day.
Holding period : 1 day
Close the cover of container to prevent dust
putting in the FLUX.
Keep it in a stainless steel container.
Don't keep the drier in a outdoor because
humidity damages to it.
Apply M/C Vacuum Gauge without fail.
Perform vacuum operation until a proper
vacuum degree is built up.
If a proper vacuum degree isn't built up,
check the leakage from the Cycle Pipe line
part and Quick Coupler Connecting part.
Check if gas leaks from connecting part of
Coupler.
FLUX
DRIER
ASM
VACUUM
PIPE
DRY AND
AIR
NITROGEN
GAS
NIPPLE AND
COUPLER
CONTENTS AND SPECIFICATIONS REMARKS
20
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