LG GR-382R, LRTP1231xx, LRTP1231W Service Manual

SERVICE MANUAL

REFRIGERATOR

ATTENTION
Before start servicing, carefully read the safety instructions

in this manual

MODEL(S): GR-382R
LRTP1231W

Contents

Safety Precautions ----------------------------------------------- -------------------------------------- 1
Service Precautions ----------------------------------------------------------------------------------- 2-3
Specifications ------------------------------------------------------------------------------------------- 4
Feature Chart ------------------------------------------------------------------------------------------- 5
Circuit Diagram ------------------------------------------------------------------------------------------ 6-7
Cooling Systems ---------------------------------------------------------------------------------------- 8
Product Disassembly ---------------------------------------------------------------------------------- 9-11

Doors ------------------------------------------------------------- ----------------------------------------- 9
Door Switch ---------------------------------------------------------------------------------------------- 9
Electronic Control Display PCB ----------------------------------------------------------------- --- 9
Freezer Fan ---------------------------------------------------------------------------------------------- 10
Defrost Control ------------------------------------------------------------------------------------------ 10
Lamp ------------------------------------------------------------------------------------------------------- 10
Refrigerator Control Box ------------------------------------------------------------------------------ 11

Reversible Door --------------------------------------- --------------------------------------------------- 12-13
Adjustments ----------------------------------------------------------------------------------------------- 14-15

Compressor ---------------------------------------------------------------------- ------------------------ 14
PTC Starter----------------------------------------------------------------------------------------------- 14
Overload Protector (OLP) ---------------------------------------------------------------------------- 15
Troubleshooting ----------------------------------------------------------------------------------------- 16-21
Compressor & Electrical Components ------------------------------------------------------------ 16
PTC & OLP ------------------------------------ ---------------------------------------------------------- 17
Other Electrical Components ----------------------------------------------------------------------- 18
Service Diagnosis Chart ------------------------------------------------------------- ----------------- 19
Refrigerant Cycle --------------------------------------------------------------------------------------- 20-21

MICOM circuit & operation --------------------------------------------------------------------------- 22-39
Refrigerator Exploded View-------------------------------------------------------------------------- 40-41
Service Parts list----------------------------------------------------------------------------------------- 42-43

Safety Precautions.

Read the following inst ructions before servicing your refrigerator.

1. Unplug the refrigerator before
servicing.

2. Visually inspect for gas leakage or
short circuit.

3. If testing with the refrigerator
plugged in, wear rubber gloves to
avoid electric shock.

4. Do not touch frozen metal parts;
your hands could freeze to the
surface. This

5. Be sure that no water is dripping

may cause frostbite.

towards electrical or metal parts.

6. If you check the bottom part of the
refrigerator while the freezer

door is open, be careful standing
up. You

could bump your head.

7. When you tilt your refrigerator be
sure to take out all metal, glass, or
other loose

parts.

8. When servicing the evaporator,
wear cotton gloves to prevent cutting
by any of

the evaporator fins.

1

Service Precautions

Refrigerant Recharging

Test the compressor's operation before
recharging the refrigerant; this is very
important to detect failures and to
ensure the proper motor running, and
to identify failures immediately. If
failure has been detected, clean the
system from any other possible
R-134a residues by breaking the final
part of the compressor's service pipe
at it's thinnest part as shown in Fig. #1.
Replace the filter and any other part
that could be deteriorated. Unweld
and pull out the service pipe,
then place a new pipe extension with a
Hansen male connector and solder
the new pipe. See Fig. #2

0(absolute or -1 atm, -760 mm Hg.) It
is not recommend to run the vacuum
pump for more than 30 minutes. See

Figure 3.
In case there is a large leak and the
vacuum operation must stop,
you must add a small amount of
refrigerant to the system and check
with an electronic leak detector. If a
soldering failure is detected, open the
valve before soldering to equalize the
pressure and keep solder from being
blown out of the joint or sucked into
the piping.

It is necessary to open the valve
when soldering to allow the gases to
escape without forcing the molten
solder out of the joint. The extension
with the male Hansen connector
should be connected to a female type
connector to the vacuum pump's pipe.
See Fig. #3
System air evacuation starts as soon
as the pump begins to run. The
system must be kept under vacuum
until the low pressure gauge shows

As soon as the repair is completed,
charge the correct amount of
refrigerant into the system.
Remember that each system requires
a specific amount of refrigerant with a
tolerance of ±5 grams. See Figure 4.

Before performing this operation (if
the vacuum pump and charging
cylinder are still attached to the
system) be sure the valve between
the pump and the cylinder is closed to

2

Service Precautions

keep refrigerant out of the system.
See Figure 5.

For gas charging, check the
graduated scale on the cylinder to see
the amount of refrigerant that it
contains and the amount that will be
pumped into the system. For
example, if you have 750 grams of
refrigerant in the cylinder and we
have to pump 165 grams to the
system, this amount will be reached
when the indicator reaches 585
grams; remember that the indicator
shows a lower level of meniscus.

Do this after choosing the scale
corresponding to the gas pressure
indicated on the pressure indicator
located on the upper part of the
column. To let R-134a flow into the
system, open the valve at the
recharging cylinder's base. The total
amount of refrigerant should not be

installed in one session, as it could
block the compressor. Install 20~30
grams at a time and close the valve.
The compressor will run and the
pressure will drop. Then open the
valve and install other 20~30 grams
of refrigerant. Repeat this procedure
until the entire amount has been
added to the system. Under operating
conditions, the system pressure
should stabilize between 0.3 and 0.6
atm.

3

Feature Chart

FREEZER

Temperature

Control

Shelf

Ice Trays

Twist´n Serve

REFRIGERATOR

Temperature

Control

Fresh Meat

Tray

Lamp

Shelves

(Plastic or Glass)

Deodorizer

(Absorbs

Odors)*

Multi Air Flow

Air flow distributor

Freezer
Door Baskets

Refrigerator
Door Baskets

Vegetable Tray

(Keeps fruits and
vegetables fresh)

MODEL(S): GR-382R

LRTP1231W

* This part is only included in model LRTP1231W

Magic Crisper

(Vegetable Tray cover
that control humidity)

5

Leveling
Screws

Graphic Circuit Diagram

Brown

Red

Pink

Yellow
Blue

Violeta

Whitte

White

White

White

Brown

Red

Red

Blue

Orange

Orange

Yellow

Blue

c

C

C

Brown

Red

Orange

Orange

Blue

Black

Switch

Violet

Yellow

Thermal Fuse

Defrost Resistance

Evaporator

Defrost Resistance

Fan

(Heater Cord)

Sensor

Lamp

Control

Sensor

Brown

Blue

Red

Blue

Sensor

CON2

Defrost and Temperature Electronic Control

CON1

Black

Yellow

Blue

Black

Fan

Motor

Blue

AC Current

Brown

Pink

Blue

Pink

Black

OLP

M

Running Capacitor

COMPRESSOR

7

Cooling Systems

Direct System Indirect System

Important: Check that the air ducts are not

Cold Air

Temperature variation during defrosting time, depending upon the cooling system .

Temp.( ? )

4

3

-16

-18

Temp.( ? )

18

Warm Air

obstructed for a better cooling
performance.

Indirect System

Direct System

Refrigerator
Freezer

Tim
e

3

-3

-18

Tim
e

8

3. Product Disassemble.

Doors
Freezer Door

1. Remove hinge cover by pulling it
upwards.

2. Loosen the hexagonal bolts that
hold the upper hinge in place. See
Figure 1.

3. Remove door. See Figure 2.

Figure 1

Figure 2

4. Pull gasket to remove it. See
Figures 3 and 4.

2. Disconnect all switche's cables.

See Figure 8

Figure 7

Figure 8

Control Circuit ( Display PWB)

1. Remove the lamp cover by

inserting a screwdriver in the lower
side's holes. See Figure 9.

2. Loosen and remove the 2 screws.

See Figure 10.

Figure 3

Figure 4

Refrigerator Door.

1. Loosen the hexagonal bolts that
hold the central hinge in place.
See Figure 5.

2. Remove refrigerator door. See
Figure 6.

3. Pull out the gasket to remove it
from the door. See Figure 4 from
Freezer door.

Figure 5

Figure 6

Door Switch

1. Pull out the door switch out using

a flat head screwdriver. See
Figure 7

Figure 9 Figure 10

3. Pull out the Control Box. See

Figure 11.

4. Disconnect the connector from the

cable terminal. See Figure 12.

5. Remove the EPS Multi air duct

(insulation) from the control box.

6. Detach the electronic control

(Display, PWB). See Figure 13.

Figure 11

Figure 12

9

Figure 13

Fan and Fan Motor.

1. Remove freezer shelf.

3. Remove the ice bin assembly by
pulling it to the right side, until it
snaps out.

4. Remove Grill Fan screw cover.
See Figure 14.

5. Loosen the screw. See Figure 15.

6. Pull out the fan cover. Figure 16.

Defrost Control Assembly

1. The defrost control assembly

consists of one thermistor and a
fuse that melts with heat.

2. The termistor's function is to

sense the compartment's
temperature and automatically
stop the defrost. The termistor is
located beside of the evaporator
bracket.

3. The melting fuse is a safety device

to prevent an overheating of the
defrosting resistance when it
operates.

4. The fuse melts at 162° F and the

resistance heater stops.

5. To replace this components,

please follow the steps mentioned
at Figure 18.

Figure 14

Figure 15

6. Unplug the connector.

7. Remove the fan holder shroud.
Figure 17.

8. Remove fan and loosen both
screws that hold the bracket.

9. Remove the motor bracket and the
rubber parts. Pull out the fan
motor. See Figure 17.

Figure 16

Figure 17

1. Figure 18. Unplug the connector plugged to

Lamp.
Refrigerator Compartment Lamp

1. Remove the lamp cover with

a screwdriver or a similar tool.
See Figure 19.

2. Remove the lamp by unscrewing it

counterclockwise and replace it
with the same specifications
(125V,20W). Part Number
6912JB2002J.

10

Figure 13

Figure 19

Refrigerator Control Box.

Remove the lamp cover as mentioned
before.

1. Loosen the screws.

2. Remove the entire control box.
See Figure 20.

3. Disconnect the control box
connector. See Figure 21.

Figure 20 Figure 21

11

4. Reversible Door

PRECAUTION

1. Before reversing the doors, remove all foods and accesories,

like shelves or trays, which are not attached to the doors.

2. Use a Philips screwdriver, bolt driver, torque wrench, or spanner to
tighten and loosen the bolt.

3. Be careful not to drop the refrigerator or door when assembling or
disassembling lower hinge or the Adjustable Screw Assembly.

4. Don´t lay the refrigerator down to work on it. It will cause
malfunction.

5. The doors may be reversed to provide left or right opening, depending upon the customer´s
preference.

HOW TO REPLACE THE DOOR OPENING LEFT TO RIGHT
(when converting from left-opening to right opening)

12

13 14

5. Adjustments

1- COMPRESSOR
1-1 Function

The compressor sucks low pressure
evaporated gas from the evaporator
and compresses it into high
temperature/high pressure gas and
sends it to the condensor.

1-2 Composition

The compressor includes the
compressing system, a motor, and an
enclosure. The PTC (thermistor) and
OLP (Overload Protection Device) are
attached to its exterior. Handle and
repair the compressor with care. It
includes parts manufactured to 1
micron tolerance, and is hermetically
sealed to exclude dust or humidity
after fabrication. Dust, humidity, or
flux getting into the refrigeration cycle
could clog it or otherwise affect the
cooling.

1-3 Use notes.

(1) Protect your refrigerator from over
currents or overloads.
(2) Do not bump or jar the
compressor. If it is bumped or
forced (dropping or careless
handling,) it could damage the
compressor or cause noise or
undesirable operation.
(3) Use only exact replacement parts
when repairing the compressor. If
the terminals become corroded, it
could affect operation. If the
replacement parts are of incorrect
values, operation and safety will
be compromised.

2- PTC
2-1 PTC Composition

(1) The PTC (Thermistor) is a
semiconductive starting
component that is made with
BaTiO .

(2) The higher the temperature, the
higher the resistance value will be.
This characteristic is used for
starting the motor.

2-2 PTC Function

(1) The PTC is attached to the
hermetic compressor and its used
for its starting.
This household refrigerator uses a
single induction motor. During
normal operation, the motor starts
with current flowing through both
the main and the auxiliary
windings. After the motor starts,
current to the auxiliary winding is
cut off.

2-3 PTC- Electric Diagram

According to motor starting method.

3

2-4 Motor restarting and PTC cooling.

(1) To restart normal operation after a
power interruption, wait 5 minutes
to let the pressure equalize and
the PTC to cool.
(2) During normal operation, the PTC
generates heat. If it has not had
time to cool after a power
interruption, the motor will not
restart until the PTC cools.

2-5 PTC OLP Relation

(3) If power is cut off during
compressor operation and then
restored before the PTC has
cooled down, it's resistance value
increases. As a result, the current
cannot flow to the auxiliary
winding and the motor cannot start
and the OLP operates due to the
current overflow through the main
winding.
(3) While the OLP repeats the
ON/OFF operation 3~5 times, the
PTC cools and the compressor
operates normally. If the OLP
does not operate when the PTC is
hot, the compressor motor will
overheat, causing a short circuit or
possibly a fire. Therefore, use a
fail-safe OLP.

2-6 Note on using the starting PTC

(1) Be careful not to cause an
overvoltage or short circuit.
(2) Do not force or bump it.
(3) Keep the OLP dry. If water or oil
gets into the OLP, the electrical
insulation can degrade and fail.
(4) Do not replace the PTC at your
own convenience. Do not
disassemble the PTC. If the PTC's
exterior is damaged, the
resistance value changes and
may cause failure during the
stating of the compressor's motor.
Use a PTC in good condition.

3- OLP
3-1 OLP Definition

(5) The OLP is a bimetallic, heat­ sensitive switch attached to the
compressor. Its function is to
protect the motor in the event of
overheating.
(6) When an overvoltage flows to the
motor, the bimetal reacts by
heating and activating (opening)
the OLP.

3-2 OLP Function

(7) Prevents the starting to the motor
winding.
(8) Do not turn the adjustment screw
during normal OLP operation.
(OLP connection diagram)

15

6. Troubleshooting

6-1 COMPRESSOR AND ELECTRIC COMPONENTS

1

Power Source.

Remove the PTC-Starter
from the Compressor

(Rating Voltage
10%)

Go to Step 2

and measure the voltage
between Terminal C of
Compressor and
Terminals 5 or 6 of PTC.

No Voltage.

OLP disconnected?.

Replace OLP.

Check connection
condition.

Go to Step 5

Reconnect.

Consult a qualified
electrician.

NO

Replace
Compressor.

YES

Go to Step 5

Go to Step 3

Go to Step 3

2

Check the
resistance of
Motor
Compressor.

Applied voltage isnÿ´t in
the range of Rating
Voltage 10%.

Check the resistance
among M-C, S-C and M-S
in Motor Compressor.

4

5

3

Check the
resistance of
PTC-Starter.

Check OLP.

Check
starting state.

Check the resistance of
two terminals in PTC­Starter.

Check if applying a
regular OLP.

Measure minimum starting
voltage after 5 min. for
balancing cycle pressure
and cooling the PTC.

OLP works within 30
seconds In forcible
OLP operation by
turning against power
on and off.

NO

Components start in
the voltage of Rating
Voltage 10% below.

Go to Step 4

Replacce
PTC-Starter.

NO

YES

YES

Replace OLP.

O.K.

NO

Go to Step 5

Go to Step 4

Go to Step 5

Go to Step 5

Go to Step 1

16

6-2 PTC AND OLP

Normal operation of
Compressor is
impossible or poor.

Separates the PT
from Compressor and
measure the
resistance between
No. 5 and 6 (only
RSIR Type) or No. 4
and 5 of PTC with a
Tes ter or Wheatstone
Bridge (Figure 22).

Observation value is
220V/50Hz: 22 W ±30%
115V/60Hz: 6.8 W ±30%
240V/50Hz: 33 W ±30%
127,220V/60Hz:22 W ±30%

The Resistance value
is 0 or several
hundreds W

The value is ?

Check the other
electric components.

Replace PTC.

Separate the OLP
from Compressor and
check resistance value
between two terminals
of OLP with a Tester.
(Figure 23).

YES

NO

Check other electric
components.

Replace OLP

17

6-3 OTHER ELECTRIC COMPONENTS

No Cooling

Compressor
doesn´t run.

Check if current flows to
the following components.

a. Starting Devices Shorted or Broken

b. OLP Poor contact or shorted.

c. Compressor coil Coil Shorted.

d. Circuit Parts Poor contact or shorted.

Cause

Replace each
component.

Running state of
Compressor is poor.

Fan Motor doesn´t
run.

Check starting
voltage.

Check if current
flows to starting
devices.

Check current
flowing in sub-coil
of Compressor.

Check capacity of
OLP.

The items
described above
are normal.

Checker current
flow of the door
switch.

Check current
flowing in the fan
motor.

Low Voltage

Poor contacting
and broken.

Shorted

Lack of Capacity

Compressor

Motor Coil.

Poor contact

Coil is shorted

Raise the voltage.

Replace the
defective
component.

Replace the
Compressor.

Replace the
defective
component.

Much frost is on the
evaporator.

Check current flow
of the following
components:

· Defrost Control

Check current flow
of the following
components:

· L-CORD, TE-PLATE

18

Shorted

Replace PTC.

Replace PTC.

6-4 SERVICE DIAGNOSIS CHART

COMPLAINT POINTS TO BE CHECKED REMEDY

1. Is the power cord unplugged?

2. Check if the power switch is set to OFF.

No Cooling

Poor Cooling

Poor Freezing

Food in the refrigerator

is frozen

Moisture or ice forms in
the chamber of the set.

Moisture forms on the

outside

Abnormal Noise

Door doesn´t close well.

Ice and food smell

unpleasent.

3. Check if the fuse of power switch is
shorted.

4. Measure the voltage of power outlet.

1. Check if the refrigerator is placed close
to a wall.

2. Check if the refrigerator is placed close
to a stove, oven or in indirect sunlight.

3. Is the ambient temperature high or the
room door closed?

4. Check if putting in hot food.

5. Did you open the refrigerator door too
often?

1. Is the ambient temperature too low?
10°C (40°F).

3. Is food buckling the cooling air outlet?

4. Check if the PWB is set to MAX.

7. Is watery food kept?

8. Check if putting in hot food.

9. Did you open the refrigerator door too
often?

13. Check if ambient temperature and
humidity are high.

14. Is there a gap in the door gasket?

18. Is the refrigerator positioned in a firm
and even place?

19. Is something in the way behind the
refrigerator?

20. Check if the evaporating tray cover is
left off.

21. Check if the cover of mechanical room
in below and front sides is taken out.

26. Check if the door gasket area has
become dirty or contaminated.

27. Is the refrigerator placed in a firm and
even place?

28. Is too much food put in the refrigerator?

32. Check if the inside of the refrigerator
becomes dirty.

33. Did you keep fragrant foods without
wrapping?

34. It smells plastic.

In addition to the items described above, refer to the following to solve the complaint.

Check if frost forms
in the Freezer.

Defrosting is poor.

· Plug it to the outlet.

· Set the switch to ON.

· Replace a regular fuse.

· If the voltage is low, check the wiring or

call an electrician.

· Place the set with the space of about 10
cm.

· Place the set apart from these heat
sources.

· Is the ambient temeperature within spec?
(above 10°C or 40°F )

· Put food in after it cools.

· Don´t open the door too often and close it

firmly.

2. To make the freezer colder, set the COLD
AIR CONTROL to 7 and set the R control
button (PWB) to MAX.

5. Place food in high temperature section
(Front Part).

6. Set the button to MID.

10. Seal watery food with vinyl wrap.

11. Put food after it cools.

12. Don´t open the door too often and close it
firmly.

15. Wipe moisture with a dry cloth.

16. This does not occur if the temperature
and humidity are in the normal range.

17. Fix the gap.

22. Adjust the leveling screws. Position the
refrigerator properly.

23. Remove the objects.

24. Replace the tray.

25. Replace the cover.

29. Clean the door gasket.

30. Position the refrigerator in a firm place
and adjust the leveling screws.

31. Keep food from reaching to the door.

35. Clean the inside of the refrigerator.

36. Wrap fragrant food.

37. The new refrigerator smells of plastic, but
the odor will dissipate after a couple of
weeks.

Replace the
componets of the
defrosting circuit.

Check Refrigerating
Cycle.

The cycle is faulty.

19

Repair the cycle.

6-5 REFRIGERATING CYCLE

Troubleshooting Chart

CAUSE

LEAKAGE

CLOGGED BY

DUST

PARTIAL

LEAKAGE

WHOLE

LEAKAGE

PARTIAL

CLOG

WHOLE

CLOG

REFRIGERAT

CONDITION

Freezer and
Refrigerator don´t
get cold normally.

Freezer and
Refrigerator don´t
get cold at all.

Freezer and
Refrigerator don´t
get cold normally.

Freezer and
Refrigerator don´t
get cold at all.

EVAPORATOR

CONDITION

Low flowing sound of
refrigerator is heard
and frost forms in inlet
only.

Flowing sound of
refrigerant is not heard
and frost isn´t formed.

Flowing sound of
refrigerant is heard and
frost forms in inlet only.

Flowing sound of
refrigerant is not heard
and frost isn´t formed.

TEMPERATURE

OF THE

COMPRESSOR

A little higher than
ambient temperature.

Equal to ambient
temperature.

A little higher than
ambient temperature

Equal to ambient
temperature.

REMARKS

1. A little refrigerator
has leaked.

2. Refrigerator runs
normally if you
recharge it.

3. No discharging of
refrigerant.

4. Refrigerator runs
normally if yoy
recharge it.

5. Normal discharginf
of refrigerant.

6. The capillary tube
is faulty.

7. Normal discharging
of refrigerant.

MOISTURE

Cooling operation
stops periodically.

Flowing sound of
refrigerant is not heard
and frost melts.

Lower than ambient
temperature.

CLOG

COMPRESSION

COMPRESSION

DEFECTIVE

Leakage Detection
Check for a leak which may be in the oil discharge in the compressor or in the evaporator.

Check if
Compressor runs.

Moisture clog

CO

COMPRESSION

Normal formed frost.

Freezer and
refrigerator don´t get
cold.
No compressing
operation.

YES

Faulty Compressor

Low flowing sound of
refrigerant is heard and
frost forms in inlet only.
Flowing sound of
refrigerant is not heard
and no frost.

Check if frost forms
on the evaporator.

Normal amount.

A little higher than
ambient temperature.

Equal to ambient
temperature.

No frost or forms in
inlet only.

Observe the
discharging amount
of refrigerant.

Large or small amount.

Recharge refrigerant to
compressor and check
cooling operation.

Check for oil leaks.

8. Cooling operation
restarts when
heating the inlet of
capillary tube.

9. Low pressure on
high side.

· No pressure of
high pressure side
in compressor.

YES

Check Compressor

Clogged by dust.

20

Slight frost forms on
Evaporator.

Refrigerant leakage.

(Locate and repair the leak.)

General Control of Refrigerating Cycle.

NO. ITEMS CONTENTS AND

SPECIFICATIONS

1 WELDING ROD

2 FLUX

3 DRIER ASSEMBLY

1. H3O

Ag: 30%, Cu: 27%, Zn: 23%, Cd: 20%
Brazing Temperature: 710~840°C

2. BCuP2
Chemical Ingredients
Cu: About 93%
P: 6.8 %
Rest: within 0.2%
Brazing Temperature: 735~840°C

Ingredients and Preparation:

Borax 60%
Fluoridation Kalium: 35%
Water: 5%

· Assemble the drier within 30 minutes after unpacking.

· Keep the unpacked drier at the temperature of

80~100°C

Chemical Ingredients

REMARKS

1. Recommended H34 containing 34% Ag in the
Service Center.

2. Don´t store the drier outdoors, because humidity
damages it.

4 VACUUM

DRY AIR AND NITROGEN

5

GAS

6 NIPPLE AND COUPLER

7 PIPE

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,
indicates no vacuum leakage state.

3. Vacuum degree of vacuum pump must be 0.05 Torr.
below after 5 minutes.

4. Vacuum degree must be the same of the value
described on item (2) above for more than 20 min.

· The pressure of dry air must be more than 12 ~6Kg/cm2.

· Temperature must be more than –20 ~ -70°C.

· Keep the pressure to 12~6Kg/cm2 also when

substituting dry air for Nitrogen gas.

1. Check if gas leaks with soapy water.

2. Replace Quick Coupler in case of leakage.

1. Put all joint pipe in a clean box and cover tightly with the
lid so dust or humidity do not contaminate.

3. Apply M/C Vacuum Gauge withou fail.

4. Perform vacuum operation until a proper vacuum
degree is built up.

5. If a proper vacuum degree is not built up, check the
leakage from the Cycle Pipe line parts and Quick
Coupler Connecting part.

6. Check if gas leaks from connecting part of coupler.

21

7. MICOM Function & Circuit

7-1 FUNCTION
7-1-1 FUNCTION

1. When the appliance is plugged in, it is set to Medium. Each time the button is pushed, it cycles
through Medium Medium/High High Low Medium/Low Medium.

2. When the power is initially applied or restored after a power failure, it is automatically set to
Medium.

Temperature

Control

TEMP °F (° C)

ROOM REFRIGERATOR

Low

46.4 (8) 39.2 (4) 37.4 (3) 34.7 (1.5) 30.2 (-1)

Medium

Low

Medium

Medium

High

High

22

7-1-2 DEFROSTING

1. The defrosting is performed each time when the total running time of the
compressor reaches 10 hours.

2. After the power is turned on (or restored after a power failure), the defrosting
starts when the total running time of the compressor reaches 4 hours.

3. When the temperature of the defrosting sensor reaches 13 °C or above, the
defrosting stops. If the temperature does not reach 13 °C in 2 hours after the

defrosting starts, the defrosting error code is displayed. (Refer to 7-1-4 Error
Diagnostic Mode).

4. With the defective defrosting sensor (cut or short-circuited wire), the defrosting
will not be performed.

7-1-3 SEQUENTIAL OPERATION OF ELECTRIC COMPONENTS

The electric components, such as the compressor, defrosting heater, and cooling
fan, starts sequentially to avoid noise and damage to the part which may result
from the simultaneous start of various components on turning the power on or after
the completion of a test.

23

7-1-4 ERROR DIAGNOSTIC MODE

1. The error diagnostic mode indicates when a fault may affect the performance of
the product occurs while operating the product.

2. Even if a function control button is pushed when an error occurs, the function
will not be performed.

3. When the error is cleared while the error code is displayed due to a fault, the
refrigerator returns to the normal condition (Reset).

4. The error code is displayed by the refrigerator temperature indication LED on
the display of the refrigerator while the remaining LEDs are off.

24

7-2 PCB FUNCTION

7-2-1 POWER CIRCUIT

The second part of the Transformer is composed of the power supply for the
display and relay drive (12 Vdc) and for the MICOM and IC (5 Vdc).
The voltage for each part is as follows:

VA1 prevents overvoltage and noise. When 175 V or higher power is a pplied, the
inside elements are short-circuited and broken, resulting in the blowout of the fuse
in order to protect the elements of the secondary part of the Transformer.

25

7-2-2 OSCILLATION CIRCUIT

This circuit is to generate the base clock for calculating time and the synchro clock
for transmitting data to and from the inside logic elements of the IC1 (MICOM). Be
sure to use the exact replacement parts since the calculating time by the IC1 may
be changed or it will not work if he OSC1 SPEC is changed.

7-2-3 RESET CIRCUIT

The reset circuit is for allowing all the functions to start at the initial conditions by
initializing various parts including the RAM inside the MICOM (IC1) when the
power is initially supplied or the power supply to the MICOM is restored after a
momentary power failure. For the initial 10 ms of power supply, LOW voltage is
applied to the MICOM RESET terminal. During a normal operation, 5 V is applied
to the RESET terminal. (If trouble occurs in the RESET IC, the MICOM will not
work).

26

7-2-4 LOAD DRIVE CIRCUIT

1. Load Drive Condition Check

FEEZER
FAN

COOLING
FAN

MELTING

FUSE

DEFROST

HEATER

Load Type

Measurement Location

Condition

Compressor, Freeze Fan

Motor

A B

ON 1 V or below

OFF 12 V

Defrosting Heater

27

7-2-5 TEMPERATURE SENSOR CIRCUIT

REFRIGERATOR-SENSOR

DEFROST-SENSOR

The upper CIRCUIT reads REFRIGERATOR temperature and DEFROST ­SENSOR temperature for defrosting into MICOM. OPENING or SHORT state of
each TEMPERATURE SENSOR are as follows:

SENSOR CHECK POINT NORMAL (-30 -50)

Refrigerator Sensor POINT A Voltage

0.5 V 4.5 V 0 V 5 V

Defrosting Sensor POINT B Voltage

SHORT-

CIRCUITED

OPEN

28

7-2-6 TEMPERATURE COMPENSATION & OVERCOOLING/UNDERCOOLING
COMPENSATION CIRCUIT

1. Refrigerator Temperature Compensation

Refrigerator

Resistance

(RCR1)

180 KW

56 KW

33 KW

18 KW

12 KW

10 KW

8.2 KW

5.6 KW

3.3 KW

2 KW

470 KW

Temperature

Compensation

°F (°C)

41 (+5.0)

39.2 (+4.0)

37.4 (+3.0)

35.6 (+2.0)

35.24 (+1.8)

32 ( 0 )

30.2 ( -1.0 )

28.4 ( -2.0 )

26.6 ( -3.0 )

24.8 ( -4.0 )

23 ( -5.0 )

Remark

Compensation by raising

the temperature

Standard Temperature

Compensation by

lowering the temperature

Table of Temperature Compensation by adjusting the resistance (Difference with the current
temperature).

Example. If the refrigerator compensation resistance (RCR1) is changed from 10 K (the current
resistance) to 18 K (the adjustment resistance) of the refrigerator rises 33.8°F (+1°C).

29

7.2.7 KEY BUTTON INPUT & DISPLAY LIGHT ON CIRCUIT

The circuit shown above is to determine whether a function control key on the operation display is
pushed and to turn on the corresponding function indication LED. The drive type is the scan type.

30

7-3. RESISTANCE SPECIFICATION OF SENSOR

TEMPERATURE SENSOR

°F (°C)

RESISTANCE OF REFRIGERATOR

(DEFROST) SENSOR

-4 -20 77 KW

5 -15 66 KW

14 -10 47.3 KW

23 -5 38.4 KW

32 0 30 KW

41 +5 24.1 KW

50 +10 19.5 KW

59 +15 15.9 KW

68 +20 13 KW

77 +25 11 KW

86 +30 8.9 KW

104 +40 6.2 KW

122 +50 4.3 KW

1. The resistance of SENSOR HAS 5% common difference.

2. Measure the resistance of SENSOR after leaving it over 3 minutes in measuring temperature. This
postponing is necessary because of perceiving speed.

31

7-4. TROUBLE SHOOTING

* Replace the PWB when there´s no trouble after checking the contents of trouble.

REMEDY

Certify Fuse.

Certify outlet voltage.

Use boosting

Transformer.

Reconnect

CONNECTOR.

Replace Transformer

Replace Compressor.

Replace OLP, PTC.

Replace MAIN PWB

(RY1).

Verify the black wire of

MAIN PWB

CONNECTOR

(CON1).

Repair the leak and

recharge the

refrigerant.

Replace FAN

MOTOR.

Replace DOOR

LINER.

Verify MOTOR and

the connection of the

black wire of MAIN

PWB CONNECTOR

(CON1).

See DEFROSTING

trouble

Replace SENSOR.

CONTENT

CHECKING

POINTS TO

STATE OF

METHOD

CHECK

TROUBLE

POWER SOURCE is

incorrect.

Is the voltage

correct? connector

connection is poor.

Transformer Fuse

open.

COMPRESSOR lock

or blocked.

OLP or PTC is

defective.

COMPRESSOR

RELAY is defective.

CONNECTING WIRE

is defective.

FREEZER/REFRIGE

RATOR door open.

Verify the correct bulb

is used.

Check the connector.

GERATOR.

MAIN PWB

CONNECTOR.

1. FREEZER/REFRI

2. LAMP is dim.

3. The connection of

Al the DISPLAY

LED OFF.·DISPLAY LED

represents

abnormal

operation.

·

Check the main PWB.

operate?

1. Does compressor

1. NO COOLING

Refrigerant leakage.

Measure the amount

of frost on Evaporator

and the surface

temperature of

condenser pipe.

2. Does refrigerant

leak.

FAN MOTOR is

defective.

DOOR LINER

contact.

CONNECTING WIRE

is defective.

Check the main PWB.

MOTOR operate?

1. Does FAN

Poor DEFROSTING.

Certify the amount of

frost on evaporator.

normal?

2. Is DEFROSTING

1. FREEZER

TEMPERATURE is

too warm.

SENSOR

RESISTANCE is

incorrect.

Check the SENSOR

resistance in the

refrigerator.

3. Is SENSOR

normal?

COOLING

POWER SOURCE

CLASSIFICATION

32

REMEDY

CONTENT

CHECKING

METHOD

Be sure door closes.

Replace FAN MOTOR.

Remove Impurities.

See POOR

DEFROSTING.

FAN MOTOR is poor.

AIR FLOW blocked.

EVAPORATOR frozen.

See if FREEZER

TEMPERATURE Iis too

warm.

Check the amount and

speed of cool air being

supplied inside the

refrogerator.

Replace HEATER.

Replace

TEMPERATURE

FUSE.

Check evaporator

connection and wire of

MAIN PWB

CONNECTOR.

Replace DEF-

SENSOR.

Replace RY2 of MAIN

PWB.

HEATER disconnection.

TEMPERATURE FUSE

disconnection.

Poor Connection.

DEFROST SENSOR is

defective.

HEATER RELAY is

defective.

Check the main PWB.

Remove ice and

impurities.

Check HEATER

PLATE.

DRAIN PIPE is blocked.

Check DRAIN PIPE.

Reassemble DOOR.

Replace GASKET.

Attachment is incorrect.

DOOR sealing is

incorrect.

Check the attachin of

DEFROST-SENSOR.

Check the gap in the

door gasket.

CHECK

TEMPERATURE

normal?

MOTOR blow

POINTS TO

STATE OF

1. Is FREEZER

TROUBLE

REFRIGERATOR

enough cool air?

1. Does HEATER emit

2. Does the FAN

TEMPERATURE is too

warm.

POOR COOLING

heat?

2. Is the DRAIN PIPE

blocked?

NO DEFROSTING.

POOR DEFROSTING

3. Does ice remains

after DEFROSTING?

CLASSIFICATION

33

7-4 MAIN PWB ASSEMBLY AND PARTS LIST.
7-4-1 MAIN PWB ASSEMBLY.

34

7.5 PWB DIAGRAM

REFRIGERATOR-LAMP

FREEZER FAN/MOTOR

COOLING FAN/MOTOR

MELTING
FUSE

DEFROST­HEATER

38

REFRIGERATOR-SENSOR

DEFROST-SENSOR

39

8. Exploded View

The parts of refrigerator and the shape of each part may vary by market area.
Capacitors and fuse are optional parts.
Optional parts:

40

D

A

41

9. Service parts list

Loc. Descripción GR-382R

Part Number

103A HANDLE,BACK
103B HANDLE,BACK
104C LEG ASSEMBLY
105A DRAIN,PIPE-Z
106A ADJUSTABLE LEG
106B ADJUSTABLE LEG
110A PWB(PCB) ASSY,DISPLAY
110B ICE TRAY GUIDE

REFRIGERATOR CONTROL BOX

120A

ASSEMBLY
120B REFRIGERATOR CONTROL BOX COVER
120E DUCT,INSULATION
120G DUCT,INSULATION
125A ICE TRAY
125H ICE TRAY SUPPORTER
125L ICE TRAY HOLDER
129A DUCT GUIDE
131A ICE BIN
149A FREEZER SHELF
149B MEAT TRAY
149C REFRIGERATOR SHELF ASSEMBLY
149E REFRIGERATOR SHELF ASSEMBLY
151A VEGETABLE TRAY
154A VEGETABLE TRAY COVER
158C LAMP COVER
200A FREEZER DOOR ASSEMBLY
201A FREEZER DOOR FOAM ASSEMBLY
203A FREEZER DOOR GASKET ASSEMBLY
205A DOOR BASKET
210A DOOR STOPPER
210B STOPPER GUIDE
212G NAME PLATE,P(H)
230A REFRIGERATOR DOOR ASSEMBLY
231A REFRIGERATOR DOOR FOAM ASSEMBLY

REFRIGERATOR DOOR GASKET

ASSEMBLY

233A
241A DOOR BASKET
241B DOOR BASKET
241C DOOR BASKET
241D DOOR BASKET
281A HINGE COVER

3650JJ2003A 3650JJ2003B

3650JJ2003E 3650JJ2003F
4981JA3006A 4981JA3006A
5250JA2009A 5250JA2009A

3J04686A

3J04686A 3J04686A
6871JB2036A 6871JB2036A
4974JJ1003A 4974JJ1003A
4995JJ1001E

4994JJ1001A
5208JJ1006A 5208JJ1006A
5208JJ1005A 5208JJ1005A
3390JJ1003A 3390JJ1003A
4980JJ1001A 4980JJ1001A
4930JJ3001A 4930JJ3001A
4974JJ1001A 4974JJ1001A
5074JJ1001A 5074JJ1001A
5026JJ1001B 5026JJ1001B
3390JJ1002A 3390JJ1002A
5027JJ2001A 5027JJ2003A
5027JJ2002A 5026JJ1002A
3390JJ1001A 3390JJ1001A
3550JJ1003B 3550JJ1003B
3550JJ1004B 3550JJ1004A
3581JJ8009B
5433JJ0011A
4987JJ1001A 4987JJ1001A
5004JJ1001B 5004JJ1001B
4620JJ2004A 4620JJ2001A
4974JA3031A J325-00033A
4140JD1020P
3581JJ8010A 3581JJ8002D
5433JJ0012B 5433JJ0005B
4987JJ1001C 4987JJ1001B

5004JJ1004B 5004JJ1004B
5004JJ1002B 5004JJ1002B
5004JJ1003B 5004JJ1003B
5004JJ1005B 5004JJ1005B
3550JJ2011A 3550JJ2004B

11Ft3

LRTP1231W

Part Number

3J04686A

4995JJ1001F

4994JL1001A

3581JJ8001D
5433JJ0003D

4140JD1020B

42

11Ft3

Loc. Descripción GR-382R LRTP1231W

281B UPPER HINGE ASSEMBLY
282B CENTER HINGE ASSEMBLY
283B LOWER HINGE ASSEMBLY
301A EVAPORATOR ASSY
303A SPACER,INSULATION
303B SPACER AS SY
304A MECHANICAL AREA COVER
307A COMPRESSOR ASSEMBLY
308A PTC ASSEMBLY
309A OLP
310A PTC COVER
312A BUSHING
314A COMPRESSOR BUSHING
315A COMP BASE ASSY,STD
315B ROLLER
315C PIN
317A DRIER ASSY
318A DRIER HOLDER
319A DRIP TRAY
319C FAN GUIDE
323B CONDENSER ASSY,WIRE
327A BUSHING
328A BUSHING
329A FAN ASSEMBLY
329C FAN ASSEMBLY
330B FREEZER SHROUD ASSEMBLY
332A FAN GRILLE ASSEMBLY
401A DEFROST CONTROL ASSEMBLY
404A FAN MOTOR (MECHANICAL AREA)
405A MOTOR BRACKET
405C FAN MOTOR BUSHING
406B DOOR SWITCH
407A HEATER,PLATE
410H CAPACITOR[M/R]
411A CONNECTOR ASSEMBLY
418A HEATER,CORD
420A MOTOR(MECH),COOLING
501A MAIN PWB ASSEMBLY
501F PWB ASSEMBLY

604F DEODORIZER COVER

155J NAME PLATE,P(H)

409B LIGHT BULB

604G DEODORIZER

4775JA3015C 4775JA2001D

4775JA3009B 4775JA3009A

4775JA2020A 4775JA2023B

5421JA2359B 5421JA2359A

4826JJ2001A 4826JJ2001A

4827JJ3001A 4827JJ3001A

3551JJ2002A 3551JJ2002A

2521JA1006A 2521C-B5602

6748JA3001A 6748C-0004D

6750JA3001A 6750C-0005D

3550JA2158A 3550JA2087B

5040JA3044A 5040JA3021A

4J03277A 4J03277A

3103JJ2001C 3103JJ2001A

3J02312A 3J02312A

4J04238A 4J04238A
5851JJ2002A 5851JJ2002A
4930JJ3002A 4930JJ3002A
3390JJ0001A 3390JJ0001A
4974JJ1002A 4974JJ1002A
5403JA1039A 5403JA1039A
5040JJ3003A 5040JJ3003A
5040JJ3002A 5040JJ3002A
5901JJ1001A 5901JJ1001A
5901JJ1001B 5901JJ1001B
4999JJ1001A 4999JJ1001A
3531JJ1001A 3531JJ1001A
6615JB2005C 6615JB2005A
4680JB1033B 4680JB1033D
4810JA3007A 4810JA3007A

J756-00008B J756-00008B
6600JB1002K 6600JB1002K
5300JB1080F 5300JB1080F

0CZZJB2003G J513-00003C

6877JK3001A 6877JK1002A
5300JB1079F 5300JB1079C

4680JB1017Q 4680JB1017C
6871JB1115A 6871JB1115B

3550JJ2001B 3550JJ2001A
3550JJ2002A 3550JJ2002A
4140JJ2001A 4140JJ2001A
6912JB2002J 6912JB2002J

NO DEODORIZER 5986JA3007B

43

P/No. 3828J8331B

Electronics Inc.