LG LRFD21855xx Service Manual

CAUTION

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

REFRIGERATOR

SERVICE MANUAL

COLOR:STAINLESS STEEL

MODEL: LRFD25850ST LRFD21855ST

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

1. SPECIFICATIONS............................................................................................................................................................... 3

2. PARTS IDENTIFICATION................................................................................................................................................... 4

3. DISASSEMBLY................................................................................................................................................................ 5-8

REMOVING AND REPLACING REFRIGERATOR DOORS ...............................................................................................5

DOOR.............................................................................................................................................................................. 6-7

TO REMOVE THE DISPENSER .........................................................................................................................................7

DOOR ALIGNMENT............................................................................................................................................................7

FAN AND FAN MOTOR...................................................................................................................................................... 8

DEFROST CONTROL ASSEMBLY.................................................................................................................................... 8

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

CONTROL BOX-REFRIGERATOR.................................................................................................................................... 8

MULTI DUCT ...................................................................................................................................................................... 8

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

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

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

OLP (OVERLOAD PROTECTOR).....................................................................................................................................10

TO REMOVE THE COVER PTC.......................................................................................................................................10

5. CIRCUIT DIAGRAM.......................................................................................................................................................... 11

6. TROUBLESHOOTING................................................................................................................................................. 12-17

COMPRESSOR AND ELECTRIC COMPONENTS.......................................................................................................... 12

PTC AND OLP.................................................................................................................................................................. 13

OTHER ELECTRICAL COMPONENTS ........................................................................................................................... 14

SERVICE DIAGNOSIS CHART........................................................................................................................................ 15

REFRIGERATION CYCLE .......................................................................................................................................... 16-17

7. OPERATION PRINCIPLE & REPAIR METHOD OF ICEMAKER .............................................................................. 18-21

8. DESCRIPTION OF FUNCTION & CIRCUIT OF MICOM ........................................................................................... 22-33

9. EXPLODED VIEW & REPLACEMENT PARTS LIST ..................................................................................................... 34-

CONTENTS

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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. Close the top door before opening the bottom door. Otherwise, you might hit your head when you stand up.

8. When tilting the refrigerator, remove any materials on the refrigerator, 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. Service on the refrigerator should be performed by a qualified technician. Sealed system repair must be performed by a CFC certified technician.

SAFETY PRECAUTIONS

21 cu. ft. / 25 cu. ft.

1. SPECIFICATIONS

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ITEMS SPECIFICATIONS

DOOR DESIGN Side Rounded DIMENSIONS (inches)

35 3/4 X 30

X 69

/4 (WX

DXH) 21cu.ft

35 3/4

X 34

X 69

(WXDXH) 25cu.ft

NET WEIGHT (pounds)

298 (

21cu.ft)

320 (

25cu.ft) COOLING SYSTEM Fan Cooling TEMPERATURE CONTROL Micom Control

Full Automatic

DEFROSTING SYSTEM

Heater Defrost DOOR FINISH Embossed Metal, VCM, Stainless HANDLE TYPE Bar INNER CASE ABS Resin INSULATION Polyurethane Foam

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 ISO10 (280 ml) DEFROSTING DEVICE SHEATH HEATER

LAMP

REFRIGERATOR 60 W (2EA) FREEZER 60 W (1EA)

2. PARTS IDENTIFICATION

- 4 -

Refrigerator Light

Shelves

Optibin Crisper

Keeps fruits and

vegetable fresh

and crisp

Customcube

Icemaker

Glide N Serve

Cover Front

Ice Bin

Durabase

Divider

Modular Door Bins

Filter

Pull out Drawer

Freezer Door Rack (LRFD25850** Only)

Modular Door Bin

Wine Holder

Dairy Bin

Egg Box

3-1 REMOVING AND REPLACING REFRIGERATOR DOORS

● Removing Refrigerator Door

CAUTION: Before you begin, unplug the refrigerator. Remove food and bins from doors.

Left Door

1. Disconnect water supply tube by pushing back on the disconnect ring (4).

2. Open door. Loosen top hinge cover screw (1). Use flat tip screwdriver to pry back hooks on front underside of cover (3). Lift up cover.

3. Disconnect door switch wire harness (2). Remove cover.

4. Attach the tube on the door with door.

5. Pull out the tube.

6. Disconnect the three wire harnesses (5). Remove the grounding screw (6).

7. Rotate hinge lever (7) counterclockwise and remove. Lift top hinge (8) free of hinge lever latch (9).

CAUTION: When lifting hinge free of latch, be careful that door does not fall forward.

8. Lift door up from middle hinge pin (10) and remove door.

9. Place door, inside facing up, down onto a non-scratching surface.

Right Door

1. Open door. Loosen top hinge cover screw (1). Lift up cover (3).

2. Disconnect door switch wire harness (2). Remove cover.

3. Disconnect wire harness (5). Remove the grounding screw (6).

4. Rotate hinge lever (7) clockwise and remove. Lift top hinge (8) free of hinge lever latch (9).

CAUTION: When lifting hinge free of latch, be careful that door does not fall forward.

5. Lift door up from middle hinge pin (10) and remove door.

6. Place door, inside facing up, down onto a non-scratching surface.

3. DISASSEMBLY

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- 6 -

3-2 DOOR

● Door Gasket Removal

1. Remove door frame cover

Starting at top of cover and working down, snap cover out and away from door.

2. Remove gasket bracket clips

There are two clips on each door. Start bracket removal near one of the middle clips.

1) Pull gasket back to expose gasket bracket clip and door frame.

2) Insert a flat tip screwdriver into seam between gasket bracket and door frame and pry back until clips snaps out.

3) Continue prying back along seam until all clips snap out.

3. Remove gasket

Pull gasket free from gasket channel on the three remaining sides of door.

● Door Gasket Replacement

1. Insert gasket bracket clips

1) Insert gasket bracket edge beneath door frame edge.

2) Turn upper gasket bracket spring so that the spring ends are in the door channel.

3) Push in clip until you hear it snap securely into place.

4) Push in remaining two clips until you hear each snap securely into place.

Note: Make sure that no part of gasket bracket edge

protrudes from beneath door frame edge.

2. Insert gasket into channel

1) Snap gasket assembly into the door bracket.

Frame Cover

Handle

Figure 1

Figure 2

Figure 3

Door

Frame

Gasket Bracket Clip

Spring

IncorrectCorrect

Figure 4

Figure 5

Correct

Incorrect

Gasket

Door

Bracket Clip

Frame

Flat Tip

Screwdriver

Gasket

Bracket

- 7 -

2) Press gasket into channels on the three remaining sides of door.

3. Replace door frame cover

Starting at top of cover and working down, snap cover back into door.

3-3 TO REMOVE THE DISPENSER

1. Use fiat tip screwdriver to pry back hooks on botton underside of cover dispenser.

2. Pry off cover dispenser.

Disconnect wire harness.

3. Replace cover dispenser in opposite manner and order of removal.

3-4 DOOR ALIGNMENT

If the space between your doors is uneven, follow the instructions below to align the doors:

1. With one hand, lift up the door you want to raise at middle hinge.

2. With other hand, use pliers to insert snap ring as shown.

3. Insert additional snap rings until the doors are aligned. (Three snap rings are provided with unit.)

Figure 6

Figure 8

Figure 9

Figure 10

Figure 7

3-5 FAN AND FAN MOTOR

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

2. Remove the plastic guide for slides on left side by unscrewing phillips head screws.

3. Remove the grille by removing one screw and pulling the grille forward.

4. Remove the Fan Motor assembly by loosening 2 screws and disassembling the shroud.

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

3-6 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 12)

2. Separate the connector with the Defrost Control assembly and replace the Defrost Control assembly after cutting the Tie Wrap. (Figure 13)

3-7 LAMP

3-7-1 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. Assembly is the reverse of disassembly. Replacement bulb must be the same specification as the original (Max. 60 W2EA).

3-7-2 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.

3-8 CONTROL BOX-REFRIGERATOR

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

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

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

3-9 MULTI DUCT

1. Remove the upper and lower Caps by using a flat screwdriver, and remove 2 screws. (Figure 17)

2. Disconnect the lead wire on the bottom position.

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GRILLE

FAN MOTOR

FAN

BRACKET

MOTOR

Figure 11

GRILLE ASSEMBLY

Figure 12

DEFROST-CONTROL ASSEMBLY

Figure 13

Figure 14

Figure 15

CONTROL BOX

COVER LAMP

Figure 16

Figure 17

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. Contamination in the cylinder 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

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.

4. ADJUSTMENT

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PTC STARTER

SEALED TERMINAL

COMPRESSOR MOTOR

PTC

OVERLOAD PROTECTOR

Resistance Starter Capacitor Running

Figure 18

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.

4-4 TO REMOVE THE COVER PTC

(1) Remove the Cover Back M/C. (2) Disconnect two housing upper side of comp connected

in.

(3) Loosen two screws on comp base.

(4) Use a L-shaped flap tool to pry off the cover. (5) Assembly in reverse order of disassembly.

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Part

Customer part number

Lot code/ date code

330 FBYY -S1 BOX98

12345678

Physical termination part number

Electrical

characteristics

part number

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)

(OVERLOAD PROTECTOR cross section)

Figure 19

2 3

5. CIRCUIT DIAGRAM

- 11 -

6. TROUBLESHOOTING

- 12 -

6-1 COMPRESSOR AND ELECTRIC COMPONENTS

YES

The range of resistance is between 1~50Ω(ok)

Open or short

YES

Power Source.

No Voltage.

(Rated Voltage ±10%)?

Replace OLP.

Reconnect.

Reference Page12.

Did compressor start?

Compressor is OK

Replace the compressor

Check connection condition.

OLP disconnected?

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

Replace Compressor.

Supply voltage rating with ±10%.

Applied voltage isn't in acceptable range. (115V ±10%)

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

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).

Check resistance of Motor Compressor.

Check resistance of PTC-Starter.

Check OLP.

Check starting state.

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