LG GR-349STQA.CTIQRAN, GR-349, GR-389SQF, GR-389, LRBP1031T Service Manual

CAUTION

PLEASE READ CAREFULLY THE SAFETY PRECAUTIONS OF THIS BOOK
BEFORE CHECKING OR OPERATING THE REFRIGERA

TOR .

REFRIGERATOR

SERVICE MANUAL

http://biz.lgservice.com

MODEL:GR-349STQA.CTIQRAN

Color : Titanium

SAFETY PRECAUTIONS ....................................................................................................................................................... 2

SERVICING PRECAUTIONS.................................................................................................................................................. 3

SPECIFICATIONS................................................................................................................................................................... 4

PARTS IDENTIFICATION ....................................................................................................................................................... 5

REPLACEMENT OF DOOR OPENING TYPE ....................................................................................................................... 6

DISASSEMBLY.................................................................................................................................................................... 7-8

DOOR................................................................................................................................................................................... 7

DOOR SWITCH.................................................................................................................................................................... 7

FAN AND FAN MOTOR........................................................................................................................................................ 7

DEF' CONTROL ASM .......................................................................................................................................................... 8

LAMP.................................................................................................................................................................................... 8

ADJUSTMENT................................................................................................................................................................... 9-10

COMPRESSOR.................................................................................................................................................................... 9

PTC-STARTER ..................................................................................................................................................................... 9

OLP (OVER LOAD PROTECTOR) .................................................................................................................................... 10

CIRCUIT DIAGRAM.............................................................................................................................................................. 10

TROUBLESHOOTING..................................................................................................................................................... 11-16

COMPRESSOR AND ELECTRIC COMPONENTS............................................................................................................ 11

PTC AND OLP.................................................................................................................................................................... 12

ANOTHER ELECTRIC COMPONENT............................................................................................................................... 13

SERVICE DIAGNOSIS CHART.......................................................................................................................................... 14

REFRIGERATING CYCLE............................................................................................................................................ 15-16

MICOM FUNCTION & PCB CIRCUIT EXPLANATION................................................................................................... 17-33

EXPLODED VIEW .......................................................................................................................................................... 34-35

REPLACEMENT PARTS LIST............................................................................................................................................ 36-

Please read the following instructions before servicing your
refrigerator.

1. Check the set for electric losses.

2. Unplug prior to servcing to prevent electric shock.

3. Whenever testing with power on, wear rubber gloves to
prevent electric shock.

4. If you use any kind of appliance, check regular current,
voltage and capacity.

5. Don't touch metal products in the freezer with wet
hands. This may cause frostbite.

6. Prevent water from following onto electric elements in
the mechanical parts.

7. When standing up after having checked the lower
section of the refrigerator with the upper door open,
move with care to avoid hitting the upper door.

8. When tilting the set, remove any materials on the set,
especially the thin plates(ex. Glass shelf or books.)

9. When servicing the evaporator, wear cotton gloves.
This is to prevent injuries from the sharp evaporator
fins.

10. Leave the disassembly of the refrigerating cycle to a
specialized service center. The gas inside the circuit
may pollute the environment.

SAFETY PRECAUTIONS

CONTENTS

- 2 -

Air Recharging in Compressor

Test the refrigeration by connecting it electrically before
refilling operation. It is necessary to ascertain the function
of the motor-compressor and identify the defects
immediately. If defects have been found, empty the old
system of possible R134a residue by breaking off the end
of the extension piece at its narrow point. (Figure 1)

Replace the filter and any damaged components. Unsolder
and pull off the piece remaining inside the service tube and
then attach an complete extension with male Hansen and
at last, solder it to the same tube again. (Figure 2)

It is necessary to execute the soldering operation with
valve open so that the fumes caused by oil residue can
come out freely without blowholes between two tubes
during the heating of the point to be soldered.

The extension fitted with the male Hansen is connected to
the female fitting of the vacuum pump tube. (Figure 3)

Air evacuating from the system begins as soon as the
pump starts. The refrigeration system must be kept under
vacuum until the reading on the low-pressure gauge
indicates vacuum (0 absolute, -1 atm., -760 mm hg) in any
case it is advisable to keep the pump running for about 30
minutes. (Figure 3)

In case that a considerable leakage occurs it will be
necessary to stop the vaccum pump and to add a small
quantity of Freon to the system, if vacuum should not be
obtained (pressure gauge can't fall to 1 atmosphere), start
the refrigeration unit and find the leakage with the special
leak-finder. When the defective soldering point is visible,
re-do it after opening the extension tube valve and
reestablishing the normal outside pressure inside the
group.

Because the melted alloy is sucked into the tubes and
block them, the pressure must be rebalanced when
vacuum is in the system in soldering. As soon as the

vacuum operation is over, add the quantity in grams of
R134a to the refrigeration system. Remember that every
system has an exact quantity of R134a with a tolerance of
±5 grams that can be added. (Figure 4)

Before performing this operation (if the vacuum pump and
refilling cylinder are connected), make sure that the valve
placed between the vacuum pump and the refilling tube are
closed in order to keep the Freon for addition to the system.
(Figure 5)

In addition, check the graduated scale on the cylinder for
the quantity of R134a to be added, for example, if we have
750 grams of Freon in the cylinder and must add 165
grams to the group, this amount will be reached when R­134a has dropped to 585 grams, remembering that the
indicator shows a lower limit of meniscus. Do this after
choosing the scale corresponding to the gas pressure
different scales reported as the same gas pressure
indicated by the pressure gauge on the top of the column.

To make R134a flow into the system, open the valve
placed at the base of the cylinder and connected to the
filling tube. The amount of Freon cannot be added to the
system all at once because it may cause a blocking of
the motor-compressor. Therefore, proceed by adding the
original quantity of about 20-30 grams and close the valve
immediately.
The pressure rises and the motor compressor must start
sucking the gas and lowering the pressure again.

Regulate the valve again, in the safe way until reaching the
quantity of R134a established for the system being
charged. When the system is running, the suction pressure
must be stabilized between 0.30 to 0.6 atmosphere.

POINT TO BE
BROKEN

CHARGE TUBE
EXTENSION

FEMALE
HANSEN

MALE HANSEN

SOLDERING POINTSERVICE TUBE EXTENSION

Figure 1 Figure 2

TO THE VACUUM
PUMP

PRESSURE
GAUGE

Figure 3

TO THE R134a CYLINDER

TO THE REFRIGERATION
SYSTEM

Figure 4

FILLING OR
CHARGE TUBE

VALVE TO BE OPENED
WHEN REFILLING

VALVE TO BE CLOSED
AFTER VACUUM

TO THE VACUUM PUMP

TO THE REFRIGERATION
SYSTEM

TO THE CHARGE 
CYLINDER

Figure 5

SERVICING PRECAUTIONS

- 3 -

1.Ref. No:

2.Ref. No:

ITEMS SPECIFICATIONS

DIMENSIONS (mm) 595(W)X626(D)X1880(H)

NET WEIGHT (kg) 74

COOLING SYSTEM Fan Cooling

REFRIGERATOR Knob Dial

FREEZER Button

Full Automatic

DEFROSTING SYSTEM

Heater Defrost

DOOR FINISH

Pre-Coated Metal

OUT CASE Painted Steel Sheet

INNER CASE ABS

INSULATION Polyurethane Foam

DEFROSTING DEVICE Heater, Sheath

REFRIGERANT

R134a(135g)

LUBRICATION OIL FREOL @ 22G(210 cc)

TEMPERATURE

CONTROL

ITEMS SPECIFICATIONS

Transparent Shelf(3 EA)

REFRIGERATOR Vegetable Container(2 EA)

COMPARTMENT

Vegetable Container Cover(1 EA)

Chilled Container(1 EA)*

Dairy Pocket Cover(1 EA)

Egg Tray(2 EA)

DOOR POCKET

Little Pocket(5 EA)

Bottle Pocket(1 EA)

FREEZER Tray Drawer(4 EA)

COMPARTMENT Ice Tray(1 EA)

COMPRESSOR PTC Starting Type

EVAPORATOR Fin Tube Type

CONDENSER Side & Wire Condenser

SPECIFICATIONS

- 4 -

* Optional Parts

ITEMS SPECIFICATIONS

DIMENSIONS (mm) 595(W)X626(D)X1710(H)

NET WEIGHT (kg) 69

COOLING SYSTEM Fan Cooling

REFRIGERATOR Knob Dial

FREEZER Button

Full Automatic

DEFROSTING SYSTEM

Heater Defrost

DOOR FINISH

Pre-Coated Metal

OUT CASE Painted Steel Sheet

INNER CASE ABS

INSULATION Polyurethane Foam

DEFROSTING DEVICE Heater, Sheath

REFRIGERANT

R134a(135g)

LUBRICATION OIL FREOL @ 22G(210 cc)

TEMPERATURE

CONTROL

ITEMS SPECIFICATIONS

Transparent Shelf(2 EA)

REFRIGERATOR Vegetable Container(2 EA)

COMPARTMENT

Vegetable Container Cover(1 EA)

Chilled Container(1 EA)*

Dairy Pocket Cover(1 EA)

Egg Tray(1 EA)

DOOR POCKET

Little Pocket(3 EA)

Bottle Pocket(1 EA)

FREEZER Tray Drawer(4 EA)

COMPARTMENT Ice Tray(1 EA)

COMPRESSOR PTC Starting Type

EVAPORATOR Fin Tube Type

CONDENSER Side & Wire Condenser

* Optional Parts

or Vinyl Coated Metal

or Vinyl Coated Metal

GC-389

GC-349

NOTE : This is a basic model. The shape of refrigerator is subject to change.

PARTS IDENTIFICATION

- 5 -

Rotatable
Door Basket
(3 or 5)

Utility Corner
(movable)

Bottle Holder

2L Bottle
Door Basket

Leveling Screw

Egg Tray(1 or 2)

Freezer Temperature

Control

Removable

Glass Shelf(2 or 3)

Lamp

Multi-air Flow Duct

Fresh Meat Keeper

(Optional)

Refrigerator

Temperature Control

Vegetable Drawer

Used to keep fruits

and vegetables, etc.

fresh and crisp.

Ice Cube Tray

Freezer

Compartment

Removable

Plinth

1. PRECAUTION

1) Before reversing the door, first of all, you should take
out food and accessories like shelves or trays which are
not fixed in the refrigerator.

2) Use Torque Wrench or Spanner to fix or remove the
bolt.

3) Don't lay the refrigerator down in working with it, it will
cause to get out of order.

4) Be careful not to drop the door in disassembling or
assembling the freezer or the refrigerator door.

2. HOW TO REVERSE THE DOORS

1) Seperate screw ➋ and remove lower cover ➊ and move

cap lower cover

➌. And, seperate screw ➍, lower hinge

➎, and remove pin ➏. Separating the freezer door in

opening, and more the position the cap

➐.

Move the position of bracket door

➑ and screw ➒.

2) Separating screw and remove the center hinge
and the refrigerator door . Move the position of cap .
Move the position of bracket door and screw .

3) Move the position of upper hinge pin , and cap .
Assemble the refrigerator door . Assemble center
hinge and bolt . Assemble freezer door .
Assemble the lower hinge

➎, bolt ➍ and lower cover ➊.

REPLACEMENT OF DOOR OPENING TYPE

- 6 -

21

7

2

3

1

21

4

6

5

8

9

14

15

12

11

5

4

21

10

2

1

12

13

10

11

16

17

1110

12

16 17

13

15

12

11 10

21

14

Note: Reversing the doors is not covered by the
warranty.

1 DOOR

● Freezer Door

1) Loosen 2 screws and pull the Lower Cover.

2) Loosen hexagonal bolts fixing the lower hinge to the
body to remove the freezer door only.

3) Pull out the Door Gasket to remover from the
Door Foam Assy, F.

● Refrigerator Door

1) Loosen hexagonal bolts fixing the center hinge(Hinge,C)
to the body to remove the refrigerator door only.

2) Pull out the Door Gasket to remove from the
Door Foam Assy, R.

2 DOOR SWITCH

1) Loosen four screws in upper part and disconnect top
cover.

2) Disconnect Lead Wire from switch.

3) Disengage hook behind the switch by pressing it with
hands.

3 REFRIGERATOR ROOM LAMP

1) Remove the Cover Lamp, R by pulling with a 'Ð' type
driver.

2) Remove the Lamp by turning.

Bolt

Lower Hinge

Figure 6

GASKET

Figure 7

Hinge, C

Bolt

Figure 8

Figure 9

DISASSEMBLY

- 7 -

Figure 10

4 FAN AND FAN MOTOR

1) Remove freezer drawers.

2) Remove two cap, screws and loosen two screws in Grille Fan.

3) Pull out the Grille Fan and Shroud, F.

4) Disconnect the housing of lead wire.

5) Separate the Fan Assy.

6) Losse 2 screw fixed to the Bracket.

7) Pull out Shroud, F remove the Fan Motor Assy.

8) Separate the Motor Bracket and Rubber.

5 DEFROST CONTROL ASSY

Defrost Control Assy consists of Thermistor and Fuse, Melting.
Thermistor functions to defrost automatically and it is attached to
metal side of the Evaporator and senses temperature.

Fuse, Melting is a kind of safety device for preventing overheating
of the Heater when defrosting.

At the temperature of 72¡C, it stops the emission of heat from the
Heater.

1) Pull out the Shroud, F after removing the Grille.

2) Separate the connector connected with the Defrost Control
Assy and replace new one.

6 DAMPER CONTROL

1) Remove the Cover Lamp, R and loosen 2 screw.

2) Pull the Control Box, R and separate the lead wire
housing.

3) Remove the Cover Lamp, R.

4) Separate the Insulation Multi Duct and Control Box, R.

5) Disassemble the Knob.

6) Separate the Damper Control and Control Box, R.

7) Separate the Damper Control and Resistor.

8) Disconnect the lead wire.

7 HEATER, SHEATH

In this refrigerator, Heater, Sheath is used for defrosting
heater. During heating, the temperature of heater rises
about 300~500¡C. Therefore, be careful not to burn while
servicing.

1) After removing the Grille and Shroud, separate the
Heater, Sheath by disconnecting the connectors.

2) Exchanged Heater, Sheath and connected the housing.

REFRIGERATOR ROOM LAMP

GUIDE FAN

FAN

SHROUD

FAN MOTOR

GRILLE

Figure 13

Figure 14

Figure 11

Figure 12

- 8 -

Heater, Sheath

Fuse, Melting

Thermistor

Figure 14

Figure

A

B

12 B

A

Note: A has been only applied to Voltage 110-127V area.

Fuse, Melting

Thermistor

Heater, Sheath

B has been only applied to Voltage 220-240V area.

1 COMPRESSOR

1) Role

The compressor intakes low temperature and low pressure
gas evaporated from Evaporator of the Refrigerator, and
condenses this gas to high temperature and high pressure
gas, and then plays delivering role to Condenser.

2) Composition

The Compressor is Composed of Compressor Apparatus
compressing gas, Compressor Motor moving Compressor
Apparatus and Case protecting Compressor Apparatus
and Motor. There are PTC-Starter, and Over Load
Protector (OLP) in the Compressor outside.

On the other
hand, because the Compressor consists of 1/1000mm processing
precision components and is sealed after production in absence
of dust or humidity, deal and repair with care.

3) Note for Usage

(1) Be careful not to allow over-voltage and over-current.
(2) No Strike

If applying forcible power or strike (dropping or careless
dealing), poor operation and noise may occur.

(3) Use proper electric components appropriate to the

Compressor.

(4) Note to Keep Compressor.

If Compressor gets wet in the rain and rust in the pin of
Hermetic Terminal, the result may be poor operation
and poor contact may cause.

(5) Be careful that dust, humidity, and flux welding don't

inflow in the Compressor inside in replacing the
Compressor. Dust, humidity, and flux due to welding
which inflows to Cylinder may cause lockage and noise.

2 PTC-STARTER

1) Composition of PTC-Starter

(1) PTC (Positive Temperature Coefficient) is a no-contact

semiconductor starting device which uses ceramic
material and this material consists of BaTiO

3.

(2) The higher the temperature is, the higher becomes the

resistance value. These features are used as starting
device for the Motor.

2) Role of PTC-Starter

(1) PTC is attached to Hermetic Compressor used for

Refrigerator, Show Case and starts Motor.

(2) Compressor for household refrigerator applies to

single-phase induction Motor.
For normal operation of the single-phase induction

motor, in the starting operation flows in both main coil
and sub-coil. After the starting is over, the current in
subcoil is cut off. The proper features of PTC play all
the above roles. So, PTC is used as a motor starting
device.

3) PTC-Applied Circuit Diagram

● According to Starting Method for the Motor

4) Motor Restarting and PTC Cooling

(1) For restarting after power off during normal

Compressor Motor operation, plug the power cord after
5 min. for pressure balance of Refrigerating Cycle and
PTC cooling.

(2) During normal operation of the Compressor Motor, PTC

elements generate heat continuously. Therefore,
if PTC isn't cooled for a while after the power has been
shut off, Motor can't operate again.

5) Relation of PTC-Starter and OLP

(1) If the power is off during operation of Compressor and

the power is on before the PTC is cooled, (instant shut­off within 2 min. or reconnect a power plug due to
misconnecting), the PTC isn't cooled and a resistance
value grows. As a result, current can't flow to the sub­coil and the Motor can't operate and the OLP operates
by flowing over current in only in the main-coil.

(2) While the OLP repeats on and off operation about 3-5

times, PTC is cooled and Compressor Motor performs
normal operation.

If OLP doesn't operate when PTC is not cooled,
Compressor Motor is worn away and causes circuit­short and fire. Therefore, use a properly fixed OLP
without fail.

6) Note to Use PTC-Starter

(1) Be careful not to allow over-voltage and over-current.
(2) No Strike

Don't apply a forcible power or strike.

(3) Keep apart from any liquid.

If liquid such as oil or water away enter the PTC,
PTC materials it may break due to insulation
breakdown of the material itself.

(4) Don't change PTC at your convenience.

Don't disassemble PTC and mold. If the exterior to the
PTC-starter is damaged, resistance value is altered and
it may cause poor starting of the compressor motor
may cause.

(5) Use a properly fixed PTC.

PTC STARTER

HERMETIC
TERMINAL

COMPRESSOR
MOTOR

C

M

S

M

3

6

5

S

PTC

OVERLOAD PROTECTOR(O.L.P)

RSIR

Figure 19

ADJUSTMENT

- 9 -

3 OLP (OVER LOAD PROTECTOR)

1) Definition of OLP

(1) OLP (OVER LOAD PROTECTOR) is attached to the

Hermetic Compressor and protects the Motor by cutting
off current in Compressor Motor in case of over-rising
temperature by Bimetal in the OLP.

(2) When over-voltage flows to Compressor motor, the

Bimetal works by heating the heater inside the OLP,
and the OLP protects Motor by cutting off current which
flows to the Compressor Motor.

2) Role of the OLP

(1) The OLP is attached to the Hermetic Compressor used

for the Refrigerator and Show Case and prevents the
Motor Coil from being started in the Compressor.

(2) Do not turn the Adjust Screw of the OLP in any way for

normal operation of the OLP.
(Composition and connection Diagram of OLP)

CIRCUIT DIAGRAM

CONTACTING
POINT

COVER

BIMETAL

CONTACTING
POINT

HEATER

TERMINALS

ADJUST
SCREW

HEATER

BIMETAL

Figure 20

NOTE : 1. This is a basic diagram and specifications vary in different localities.

- 10 -

3854JS8003Y

2.Circuit 2 has been only applied to C4 C5 B3 power cord type.

3854JS8003Z

1 COMPRESSOR AND ELECTRIC COMPONENTS

TROUBLESHOOTING (Mechanical Part)

- 11 -

1


2

3

4

5

2

5

5

3

4

5

5

1

43

YES

YES

YES

NO

YES

YES

NO

NO

5

YES

NO

YES

Power
Source.

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

No Voltage.

(Rating Voltage
±10%)?

Replace OLP.

Reconnect.

Replace
PTC-Starter.

Replace OLP.

O.K.

Check connection
condition.

OLP disconnected?

Advise the customer
to use a regular
Trans.

Replace Compressor.

OLP works within
30 sec. in forcible
OLP operation by
turning instant power
on and off.

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

Applied voltage isn't
in the range of Rating
Voltage ±10%.

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

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.

Check the
resistance of
Motor
Compressor.

Check the
resistance of
PTC-Starter.

Check OLP.

Check
starting state.