LG LDN22735 Service Manual

REFRIGERATOR

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

MODELS:

LDN22735SW/ SB/ ST

CONTENTS

S a fe ty P r e c a u tio n s … … … … … … … … … … … … … … … … … … … … . 2 1 . S p e c if ic a t i o n s … … … … … … … … … … … … … … … … … … … … … … .. 3 2 . P a r t s Id e n tif i c a t i o n … … … … … … … … … … … … … … … … … … … … . 4 3 . D is a s s e m b ly … … … … … … … … … … … … … … … … … … … … … … … . 6 4 . A ju s t m e n t … … … … … … … … … … … … … … … … … … … … … … … … . . 8

5 . C ir c u it D ia g r a m … … … … … … … … … … … … … … … … … … … … … . . 1 0 6 . T r o u b le s h o o t in g … … … … … … … … … … … … … … … … … … … … … . 1 1

C o m p re s s o r & E le c tr ic C o m p o n e n ts … … … … … … … … … … … … … 1 1 P T C & O L P … … … … … … … … … … … … … … … … … … … … … … … .. 1 2 O th e r E le c t r ic a l C o m p o n e n ts … … … … … … … … … … … … … … … … 1 3 S e r v ic e D ia g n o s is C h a r t… … … … … … … … … … … … … … … … … … . 1 4 R e f r ig e r a tio n C y c le … … … … … … … … … … … … … … … … … … … … .. 1 5

7. D e s c r ip tio n O f F u n c t io n &C ir c u it O f M IC O M . . . . . . . . . . . . . . . . . . . . . . . 1 6

8 . R e f r ig e r a t o r E x p lo d e d V ie w&S e r v i c e P a r t s L is t … … … … . . . . . . . .

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 frostbite.

6. Prevent water from spiling onto electric elements or the machine parts.

7. Before tilting the refrigerator, remove all materials from on or in the refrigerator.

8. When servicing the evaporato,r 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.

3 6

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1. SPECIFICATIONS

22 cu. ft.

ITEMS SPECIFICATIONS

DOOR DESIGN Side Rounded

DIMENSIONS (inches)

NET WEIGHT (pounds)

COOLING SYSTEM Fan Cooling

TEMPERATURE CONTROL Micom Control

DEFROSTING SYSTEM

DOOR FINISH Embossed Metal, VCM, Stainless

HANDLE TYPE Bar, Al

INNER CASE ABS Resin

INSULATION Polyurethane Foam

32 7/8 X 31 3/4 X 68 1/2 (WXDXH) 22cu.ft

246.9 (

22cu.ft)

Full Automatic

Heater Defrost

ITEMS SPECIFICATIONS

VEGETABLE TRAY Opaque Drawer Type

COMPRESSOR PTC Starting Type

EVAPORATOR Fin Tube Type

CONDENSER Wire Condenser

REFRIGERANT R-134a (115 g)

LUBRICATING OIL Freol @ 10G (310 cc)

DEFROSTING DEVICE SHEATH HEATER

REFRIGERATOR 60 W (2EA)

LAMP

FREEZER 60 W (2EA)

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2. PARTS IDENTIFICATION

PARTSANDFEATURES

NOTE:This guide covers several different models.The refrigerator you have purchased may have some or all of the items listed below.The locations of the features shown below may not match your model.

Digital Sensor Control

Refrigerator Light

Shelves

Chef Fresh / Snack Pan*

Can Dispenser*

Optibin Crisper Keeps fruits and vegetable fresh and crisper

Customcube Icemaker

Ice Bin

Durabase

Divider

Filter (inside)*

Dairy Bin

Design-A-Door

Egg Box

Refrigerator Door Rack

Freezer Light

Wire Basket

Freezer Door Rack (Tilting*)

*on some models

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PARTSANDFEATURES

NOTE:This guide covers several different models.The refrigerator you have purchased may have some or all of the items listed below.The locations of the features shown below may not match your model.

Digital Sensor Control

Refrigerator Light

Shelves

Chef Fresh / Snack Pan*

Can Dispenser*

Optibin Crisper Keeps fruits and vegetable fresh and crisper

Triple Ice Tray

Ice Bin

Durabase

Divider

Filter (inside)*

Dairy Bin

Design-A-Door

Egg Box

Refrigerator Door Rack

Freezer Light

Wire Basket

Freezer Door Rack (Tilting*)

*on some models

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3. DISASSEMBLY

3-1 DOOR

Refrigerator Door

1. Remove the hinge cover by pulling it upwards.

2. Loosen the hexagonal bolts attaching the upper hinge to the body and lift the freezer door.

HINGE COVER

BOLT

HINGE

Figure 1

3. Pull out the door gasket to remove from the door foam assembly.

GASKET

Freezer Door

1. Loosen the hexagonal bolts attaching the lower hinge to the body to remove the refrigerator door only.

LOWER HINGE

BOLT

Figure 3

2. Pull out the door gasket to remove from the door foam assembly.

3-2 DOOR SWITCH

1. To remove the door switch, pry it out with a slotted-type driver, as shown in (Figure 4).

2. Disconnect the lead wire from the switch.

Figure 2

LEAD WIRE

DOOR SWITCH

Figure 4

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3-3 FAN AND FAN MOTOR

1. Remove the freezer shelf. (If your refrigerator has an icemaker, remove the icemaker first)

2. Remove the grille by pulling it out and by loosening a screw.

3. Remove the Fan Motor assembly by loosening 2 screws and disassemble the shroud.

4. Pull out the fan and separate the Fan Motor and Bracket.

BRACKET

MOTOR

FAN MOTOR

3-5-1 Refrigerator Compartment Lamp

1. Unplug the power cord from the outlet.

2. Remove refrigerator shelves.

3. Release the hooks on both ends of the lamp shield and pull the shield downward to remove it.

4. Turn the lamp counterclockwise.

5. Assemble in reverse order of disassembly. Replacement bulb must be the same specification as the original (Max. 60 W-2EA).

FAN

GRILLE

Figure 5

3-4 DEFROST CONTROL ASSEMBLY

Defrost Control assembly consists of Defrost Sensor and FUSE–M.

The Defrost Sensor works to defrost automatically. It is attached to the metal side of the Evaporator and senses its temperature. At 72°C, it turns the Defrost Heater off.

Fuse-M is a safety device for preventing over-heating of the Heater when defrosting.

1. Pull out the grille assembly. (Figure 6)

2. Separate the connector with the Defrost Control assembly and replace the Defrost Control assembly after cutting the Tie Wrap. (Figure 7)

GRILLE ASSEMBLY

DEFROST-CONTROL ASSEMBLY

Figure 9

3-5-2 Freezer Compartment Lamp

1. Unplug refrigerator or disconnect power.

2. Reach behind light shield to remove bulb.

3. Replace bulb with a 60-watt appliance bulb.

4. Plug in refrigerator or reconnect power.

3-6 CONTROL BOX-REFRIGERATOR

1. First, remove all shelves in the refrigerator, than remove the Refrigerator control Box by loosening 2 screws.

CONTROL BOX

COVER LAMP

2. Remove the Refrigerator Control Box by pulling it downward.

3. Disconnect the lead wire on the right position and separate the lamp sockets.

Figure 10

3-5 LAMP

Figure 6

Figure 7

Figure 8

3-7 MULTI DUCT

1. Remove an upper and lower Cap by using a flat screwdriver, and loosen 3 screws. (Figure 11)

2. Disconnect the lead wire on the bottom position.

Figure 11

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4. ADJUSTMENT

4-1 COMPRESSOR

4-1-1 Role

The compressor intakes low temperature and low pressure gas from the evaporator of the refrigerator and compresses this gas to high-temperature and high-pressure gas. It then delivers the gas to the condenser.

4-1-2 Composition

The compressor includes overload protection. The PTC starter and OLP (overload protector) are attached to the outside of the compressor. Since the compressor is manufactured to tolerances of 1 micron and is hermetically sealed in a dust and moisture-free environment, use extreme caution when repairing it.

4-1-3 Note for Usage

(1) Be careful not to allow over-voltage and over-current. (2) If compressor is dropped or handled carelessly, poor

operation and noise may result.

(3) Use proper electric components appropriate to the

Particular Compressor in your product.

(4) Keep Compressor dry.

If the Compressor gets wet (in the rain or a damp environment) and rust forms in the pin of the Hermetic Terminal, poor operation and contact may result.

(5) When replacing the Compressor, be careful that dust,

humidity, and soldering flux don’t contaminate the inside of the compressor. Dust, humidity, and solder flux contaminate the cylinder and may cause noise, improper operation or even cause it to lock up.

4-2 PTC-STARTER

4-2-1 Composition of PTC-Starter

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

semiconductor starting device which uses ceramic material consisting of BaTiO

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

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

4-2-2 Role of PTC-Starter

(1) The PTC is attached to the Sealed Compressor and is

used for starting the Motor.

(2) The compressor is a single-phase induction motor.

Durign the starting operation, the PTC allows current flow to both the start winding and main winding.

4-2-3 PTC-Applied Circuit Diagram

Starting Method for the Motor

OVERLOAD PROTECTOR

PTC

Resistance Starter Capacitor Running

PTC STARTER

COMPRESSOR MOTOR

SEALED TERMINAL

Figure 12

4-2-4 Motor Restarting and PTC Cooling

(1) It requires approximately 5 minutes for the pressure to

equalize before the compressor can restart.

(2) The PTC device generates heat during operation.

Therefore, it must be allowed to cool before the compressor can restart.

4-2-5 Relation of PTC-Starter and OLP

(1) If the compressor attempts to restart before the PTC

device is cooled, the PTC device will allow current to flow only to the main winding.

(2) The OLP will open because of the over current

condition. This same process will continue (3 to 5 times) when the compressor attempts to restart until the PTC device has cooled. The correct OLP must be properly attached to prevent damage to the compressor. Parts may appear physically identical but could have different electrical ratings. Replace parts by part number and model number. Using an incorrect part could result in damage to the product, fire, injury, or possibly death.

4-2-6 Note for Using the PTC-Starter

(1) Be careful not to allow over-voltage and over-current. (2) Do not drop or handle carelessly. (3) Keep away from any liquid.

If liquid such as oil or water enters the PTC, PTC materials may fail due to breakdown of their insulating capabilities.

(4) If the exterior of the PTC is damaged, the resistance

value may be altered. This can cause damage to the compressor and result in a no-start or hard-to-start condition.

(5) Always use the PTC designed for the compressor and

make sure it is properly attached to the compressor. Parts may appear physically identical but could have different electrical ratings. Replace parts by part number and model number. Using an incorrect part could result in damage to the product, fire, injury, or possibly death.

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4-3 OLP (OVERLOAD PROTECTOR)

4-3-1 Definition of OLP

(1) OLP (OVERLOAD PROTECTOR) is attached to the

Compressor and protects the Motor by opening the circuit to the Motor if the temperature rises and activating the bimetal spring in the OLP.

(2) When high current flows to the Compressor motor, the

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

4-3-2 Role of the OLP

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

for the Refrigerator. It prevents the Motor Coil from being started in the Compressor.

(2) For normal operation of the OLP, do not turn the Adjust

Screw of the OLP in any way.

(OVERLOAD PROTECTOR cross section)

Part No. Name

Base, phenolic (UL 94 V-0 rated) Movable arm support, plated steel Stationary contact support, plated steel Heater support, plated steel Heater, resistance alloy Disc, thermostatic alloy Movable arm, spring temper copper alloy Contact, movable, silver on copper Contact, stationary, silver on copper Slug, plated steel Cover, polyester (UL 94 V -0 rated) Pin connector, plated copper alloy (To engage 2.33/2.66 mm dia. pin) Quick-connect terminal, brass, conforms to UL 310, MEMA DC-2, DIN 46344

Figure 13

Electrical

characteristics

part number

12345678

330 FBYY -S1 BOX98

Customer part number

Lot code/ date code

Physical

termination part number

4-4 TO REMOVE THE COVER PTC

1) Remove the Cover Back M/C.

(2) Remove the screw on Cover PTC.

(3) Remove two Housings on upper part of Cover PTC.

(4) Take out the cover PTC from upper to lower position

like .

(5) Turn 45 ¡ in the direction of and take it out.

(6) Assembly in reverse order of disassembly.

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5. CIRCUIT DIAGRAM

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6. TROUBLESHOOTING

6-1 COMPRESSOR AND ELECTRIC COMPONENTS

Power Source.

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

No Voltage.

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

(Reated Voltage ±10%)?

YES

OLP disconnected?

Advise customer that power supply needs to be checked by an electrician.

YES

Replace OLP.

Check connection condition.

Reconnect.

Check resistance of Motor Compressor.

Check resistance of PTC-Starter.

Check OLP.

Check starting state.

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

Check resistance of two terminals in PTC-Starter.

Check resistance of two terminals in OLP.

Check the power supply under load. (Compressor attempting to re-start after being off for 5 minutes).

Open or short

Supply voltage rating with ±10%.

The range of resistance is between 1~50W (OK)

Replace Compressor.

4.5~9 W

Open

Not open

Open or short

YES

Did compressor start?

Replace PTC-Starter.

Replace OLP.

YES

Compressor is OK

Replace the compressor

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6-2 PTC AND OLP

Normal operation of Compressor is impossible or poor.

Separate PTC-Starter from Compressor and measure resistance between No. 5 and 6 of PTC-Starter with a Tester. (Figure 14)

Separate OLP from Compressor and check resistance value between two terminals of OLP with a Tester. (Figure 15)

Observation value is 115V/60Hz : 6.8 ±30%

The resistance value is 0 (short) or

(open).

Shows continuity

Open

Replace PTCStarter.

Check another electric component.

Replace OLP.

Figure 14

Figure 15

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6-3 OTHER ELECTRICAL COMPONENTS

Not cooling at all

Compressor doesn't run.

Poor cooling performance

Compressor runs poorly.

Check for open short or incorrect resistance readings in the following components

a. Starting devices

b. OLP

c. Compressor coil

d. Wiring harness

Check starting voltage.

Check voltage at starting devices.

Cause

Short, open, or broken.

Poor contact or shorted.

Coil open or shorted.

Poor contact or shorted.

Low voltage.

Poor or broken or open contact.

Replace indicated component.

Advise customer that the Power supply needs to be checked by an electrician.

Replace indicated component.

Fan motor doesn't run.

Heavy frost buildup on EVAPORATOR.

Check current flowing in sub-coil of Compressor.

Check rating of OLP.

Check wiring circuit.

Check Fan Motor.

Check current flow in the following components: Sensor Fuse-M

Check current flow in the Defrost Heater.

Shorted.

Lack of capacity.

Wire is open or shorted.

Coil is shorted or open.

Open.

Replace indicated component.

Replace Defrost Heater.

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6-4 SERVICE DIAGNOSIS CHART

COMPLAINT POINTS TO BE CHECKED REMEDY

No Cooling.

Cools poorly.

Foods in the Refrigerator are frozen.

Condensartion or ice forms inside the unit.

Condensartion forms in the Exterior Case.

There is abnormal noise.

• Is the power cord unplugged from the outlet?

• Check if the power switch is set to OFF.

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

• Measure the voltage of the power outlet.

• Check if the unit is placed too close to the wall.

• Check if the unit is placed too close to the stove, gas cooker, or in direct sunlight.

• Is the ambient temperature too high or the room door closed?

• Check if food put in the refrigerator is hot.

• Did you open the door of the unit too often or check if the door is sealed properly?

• Check if the Control is set to Warm position.

• Is food placed in the cooling air outlet?

• Check if the control is set to colder position.

• Is the ambient temperature below 41°F(5° C)?

• Is liquid food sealed?

• Check if food put in the refrigerator is hot.

• Did you open the door of the unit too often or check if the door is sealed properly?

• Check if the ambient temperature and humidity of the surrounding air are high.

• Is there a gap in the door gasket?

• Is the unit positioned in a firm and even place?

• Are any unnecessary objects placed in the back side of the unit?

• Check if the Drip Tray is not firmly fixed.

• Check if the cover of the compressor enclosure in the lower front side is taken out.

• Plug into the outlet.

• Set the switch to ON.

• Replace the fuse.

• If the voltage is low, correct the wiring.

• Place the unit about 4 inches (10 cm) from the wall.

• Place the unit away from these heat sources.

• Lower the ambient temperature.

• Put in foods after they have cooled down.

• Don't open the door too often and close it firmly.

• Set the control to Recommended position.

• Place foods in the high-temperature section. (front part)

• Set the control to Recommended position.

• Set the control to Warm position.

• Seal liquid foods with wrap.

• Put in foods after they have cooled down.

• Don't open the door too often and close it firmly.

• Wipe moisture with a dry cloth. It will disappear in low temperature and humidity.

• Fill up the gap.

• Adjust the Leveling Screw, and position the refrigerator in a firm place.

• Remove the objects.

• Fix the Drip Tray firmly in the original position.

• Place the cover in its original position.

Door does not close well.

Ice and foods smell unpleasant.