LG LFX25974 Series Service Manual

REFRIGERATOR

SERVICE MANUAL

CAUTION

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

MODEL : LFX25974**

COLOR : STAINLESS(ST)

WESTERN BLACK SUPER WHITE

CONTENTS

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

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

3. DISASSEMBLY ............................................................................................................................................................. 5-17

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

DOOR .................................................................................................................................................................................. 6

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

FAN AND FAN MOTOR(EVAPORATOR) .......................................................................................................................... 7

DEFROST CONTROL ASSEMBLY .................................................................................................................................... 7

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

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

MAIN PWB ........................................................................................................................................................................... 8

DISPENSER ....................................................................................................................................................................... 9

DISPLAY PCB ..................................................................................................................................................................... 9

ICE BUTTON ASSEMBLY .................................................................................................................................................. 9

WATER BUTTON ASSMEBLY ........................................................................................................................ 9

ICE COMPARTMENT DOOR REPLACEMENT .............................................................................................. 9

ICEMAKER REPLACEMENT ........................................................................................................................ 10

SUB PWB FOR WORKING DISPENSER ..................................................................................................... 10

CAP DUCT MOTOR REPLACEMENT .......................................................................................................... 11

HOW TO REMOVE THE ICE BIN ................................................................................................................. 12

HOW TO INSERT THE ICE BIN .................................................................................................................... 12

HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER ................................................................ 13

WATER VALVE DISASSEMBLY METHOD .................................................................................................. 15

BOTTOM DRAWER ....................................................................................................................................... 16

4. ADJUSTMENT .................................................................................................................................................................. 17

COMPRESSOR ................................................................................................................................................................ 17

5. CIRCUIT DIAGRAM ......................................................................................................................................................... 18

6. TROUBLESHOOTING ...................................................................................................................................................... 19

ERROR CODE SUMMARY .............................................................................................................................................. 19

7. PCB PICTURE ............................................................................................................................................................. 20-21

MAIN PCB ......................................................................................................................................................................... 20

DISPLAY PCB & SUB PCB .......................................................................................................................... 21

8. TROUBLESHOOTING WITH ERROR DISPLAY .................................................................................... 22-30

9. TROUBLESHOOTING WITH ERROR DISPLAY ........................................................................................................ 31-39

10. REFERENCE ............................................................................................................................................................. 40-43

11. COMPONENT TESTING INFORMATION ................................................................................................................ 44-52

12. COMPRESSOR TROUBLESHOOTING ................................................................................................................... 53-64

13. OPERATION PRINCIPLE AND REPAIR METHOD OF ICEMAKER ....................................................................... 65-66

ICEMAKER’S BASIC OPERATING METHOD ............................................................................................................... 65

ICE MAKER FUNCTIONS .............................................................................................................................................. 66

TROUBLE SHOOTING ICE & WATER SYSTEM ISSUES ............................................................................................ 66

14. DESCRIPTION OF FUNCTION & CIRCUIT OF MICOM ............................................................................................... 69

FUNCTION ................................................................................................................................................................ 69-72

15. EXPLODED VIEW ......................................................................................................................................................... 1-7

SAFETY PRECAUTIONS

Please read the following instructions before servicing your refrigerator.

1. Unplug the power before handling any elctrical componets.

2. Check the rated current, voltage, and capacity.

3. Take caution not to get water near any electrical components.

4. Use exact replacement parts.

5. Remove any objects from the top prior to tilting the product.

- 2 -

1. SPECIFICATIONS

25 cu. ft

ITEMS SPECIFICATIONS

DOOR DESIGN

DIMENSIONS (inches)

NET WEIGHT (pounds)

COOLING SYSTEM

TEMPERATURE CONTROL

DEFROSTING SYSTEM

DOOR FINISH

HANDLE TYPE

INNER CASE

INSULATION

DIMENSIONS

Side Rounded

X 34

X 69

308.65 (25cu.ft)

Fan Cooling

Micom Control

Full Automatic

Heater Defrost

PCM, Stainless

Bar

ABS Resin

Polyurethane Foam

(WXDXH) 25cu.ft

ITEMS SPECIFICATIONS

VEGETABLE TRAY

COMPRESSOR

EVAPORATOR

CONDENSER

REFRIGERANT

LUBRICATING OIL

DEFROSTING DEVICE

REFRIGERATOR

LAMP

FREEZER

Opaque Drawer Type

Linear

Fin Tube Type

Wire Condenser

R-134a (150g)

FREOLα8G (180 ml)

SHEATH HEATER

LED Module(21)

Bulb Lamp

Description LMX25986**

Depth w/ Handles

Depth w/o Handles

Depth w/o Door

Depth (Total with Door Open)

Height to Top of Case

Height to Top of Door Hinge

Width

Width (door open 90 deg. w/o handle)

Width (door open 90 deg. w/ handle)

- 3 -

34 1/4 in.

31 3/4 in.

27 7/8 in.

46 1/2 in.

68 3/8 in.

69 3/4 in.

35 3/4 in.

39 1/4 in.

44 1/4 in.

2. PARTS IDENTIFICATION

ADJUSTABLE REFRIGERATOR SHELVING

The refrigerator compartment shelves are adjustable to allow flexibility for storage needs.

GALLON STORAGE BINS

Two interchangeable bins can be arranged to suit your storage needs.

LED INTERIOR LAMPS

Refrigerator interior is lit by the LED array.

CAN STORAGE BIN

FIXED DOOR BINS

- 4 -

3. DISASSEMBLY

(1)

(2)

(4)

(3)

(6)

(7)

(8)

(5)

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 -FIG. 2

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

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

3. Disconnect door switch wire harness. Remove cover.

4. Pull out the tube(3).

5. Disconnect the two wire harnesses (4). Remove the grounding screw (5).

6. Rotate hinge lever (6) counterclockwise. Lift top hinge (7) free of hinge lever latch (8). CAUTION : When lifting hinge free of latch, be careful that door does not fall forward.

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

▶

Right Door -FIG. 3

1. Open door. Loosen top hinge cover screw (1). Lift up cover (2).

2. Disconnect door switch wire harness. Remove cover.

3. Rotate hinge lever (3) clockwise. Lift top hinge (4) free of hinge lever latch (5).

4. Lift door from middle hinge pin and remove door. CAUTION : When lifting hinge free of latch, be careful that door does not fall forward.

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

Figure 2 Figure 3

Figure 1

- 5 -

3-2 DOOR

●

Pillar Removal

1. Remove 2 screws.

2. Lift pillar up carefully.

3. Disconnect wire harness.

●

Door Gasket Replacement

1. Insert gasket into channel

Press gasket into channels on the four remaining sides of door.

●

Pillar Replacement

1. Connect wire harness.

●

Door Gasket Removal

1. Remove gasket

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

2. Insert pillar into channel.

Inserting pillar assy’ into bracket, door

3. Assemble 2 screws.

- 6 -

3-3 DOOR ALIGNMENT

If the space between your doors is uneven, follow the instructions below to align the doors: Remove the Base Grillie. Turn the leveling legs (CCW) to raise or (CW) to lower the height of the front of the refrigerator by using flat blade screw driver or 11/32" wrench. Use the wrench (Included with the User Manual) to adjust the bolt in the door hinge to adjust the height. (CCW to raise or CW to lower the height.)

* Ice Fan Scroll Assembly Replacement

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

2) Pull the grille forward as shown in the second picture.

3) Disconnect wire harness of the grille.

4) Remove the scroll assembly by loosening all screws.

(1) (2)

(3) (4)

3-4 FAN AND FAN MOTOR(EVAPORATOR)

1. Remove the freezer shelf.

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.

FAN MOTOR

BRACKET

MOTOR

Ice fan assembly

FAN

3-5 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 46°F (8°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 4)

2. Separate the connector with the Defrost Control assembly and replace the Defrost Control assembly after cutting the Tie Wrap. (Figure 5)

GRILLE ASSEMBLY

Figure 4 Figure 5

DEFROST-CONTROL ASSEMBLY

GRILLE

- 7 -

3-6 LAMP

Unplug Refrigerator, or disconnect power at the circuit breaker. If necessary, remove top shelf or shelves.

3-6-1 Refrigerator Compartment Lamp

1) Release 2 screws.

2) Hold both ends with your both hands and pull it downward to remove it.

3) Use a flat tool as shown below to remove the cover lamp.

3-7 MULTI DUCT

1. Remove the upper and lower Caps by using a flat screwdriver, and remove 2 screws. (Figure 6)

2. Disconnect the lead wire on the bottom position.

Figure 6

3-8 MAIN PWB

1) Loosen 3 screws on the PWB cover.

4) As shown below, use a flat tool to remove the cover lamp.

Cover, Lamp

3-6-2 Freezer Compartment Lamp

1. Unplug refrigerator power cord from outlet.

2. Remove screw with driver.

3. Grasp the cover Lamp, pull the cover downward.

LED, Assembly Case Lamp

2) Remove the PWB cover

3) Disconnect wire harness and replace the main PWB in the reverse order of removal.

- 8 -

3-9 DISPENSER

1) Pull out the drain 2) Hold the inner side of cover dispenser with both hands at the handle side to pull it out forward.

3) If nozzle is interfered with button, push and pull out the bottom of button.

CAUTION: When replacing the dispensor cover in the reverse order of removal, be careful that the lead wire does not come out and the water tube is not pinched by the dispensor.

4) Remove the connected part of Lead wire.

3-11 ICE BUTTON ASSEMBLY

1) Remove the screw fixing the button lever.

2) Push the spring from the hanging hook to remove it.

3) Apply some pressure to the rib in button in

Button Lever

direction.

direction and lift the

3-12 WATER BUTTON ASSMEBLY

1) Remove screws.

2) Grasp the Button assembly and lift up.

Button Lever

3-10 DISPLAY PCB

As shown below, remove 1 case PCB fixing screw. Remove the display PCB fixing screw.

Case, PCB Display PCB

3-13 ICE COMPARTMENT DOOR REPLACEMENT

1) Loosen the front screw as shown in the picture.

2) Lift up the hinge with one hand.

3) Pull out the Ice Compartment Door with the other hand.

hinge

- 9 -

3-14 ICEMAKER REPLACEMENT

1) Remove the stainless screws marked in the picture below.

2) Grasp the bottom of motor cover assembly and pull it out slowly.

Caution: Check to see if the housing is stuck to mold and taped. If the housing is not on its original position, it will disturb Cover, motor to be positioned to the unit.

3-15 SUB PWB FOR WORKING DISPENSER

1) Disconnect the wire harness.

3) Disconnect wire harness from wall of compartment.

2) Loosen the screw on the sub PWB and replace the sub PWB in the reverse order of removal.

In-door motor

- 10 -

3-16 CAP DUCT MOTOR REPLACEMENT

1) Separate the Housing of the Cap Duct Motor.

2) Unscrew 3 screws to disassemble the motor.

3) When replacing to a new Motor, always check position of the Duct Door and Link to install the Motor.

Duct Door

Link

Cap Duct Motor

NG Position

4) Assemble on the screws.

5) Connect the Housing.

- 11 -

3-17 HOW TO REMOVE THE ICE BIN



1) Grip the handles, as shown in the picture.

2) Lift the lower part slightly.

3-18 HOW TO INSERT THE ICE BIN

1) Insert the Ice Bin, slightly tilting it to avoid touching the Icemaker. (Especially, Ice-Detecting Sensor)

3) Take the Ice Bin out slowly.

- 12 -

3-19 HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER

3-19-1 Follow Steps to Remove

Step 1) Open the freezer door.

Step 2) Remove the lower basket.

Step 3) Remove the two screws from the guide rails (one

from each side).

Step 5) Remove only 1 screw of gear ice, and disassemble

the bar and gear ice

Step 4) Removal of the freezer door is done by lifting

clear of the rail support.Fully extend both rails.

Step 6) Remove 2 screws of both side of supporter covers

tv and disassemble the supporter cover tv.

- 13 -

3-19-2 Follow Steps to Reinstall

Step 1) Insert both side of supporter cover tv into connector

rails, and then screw them.

Step 3) Put gear ice assembled with the bar by screw into

connector rail’s hole.

Step 5) The rail system will align itself by pushing the rails

all the way into the freezer section. Pull the rails back out to full extension.

Step 2) Assemble a bar and

Push the otherside of the gear to inside of the bar.

Step 4) Insert opposite gear ice into connector rail and

screwthem

Step 6) Reinstall the freezer door by inserting the rail tabs

into the guide rail.

Step 7) Reinstall the two screws into the guide rails

(one from each side).

Assemble them like as pictures

Step 8) Reinstall the lower basket, and close the freezer

door.

- 14 -

3-20 WATER VALVE DISASSEMBLY METHOD

1) Turn off the water. Then separate the water line from the valve.

3-21 FAN AND FAN MOTOR DISASSEMBLY

METHOD

1) Using a short screwdriver, loosen one SCREW in DRAIN PIPE ASSEMBLY and one connected to the MOTOR COVER.

MOTOR COVER

2) Separate the Cover Back M/C and Valve Screw.

Cover Back M/C

3) Separate the housing and pull out the valve.

Housing

4) Lay a dry towel on the floor and get ready to spill water from the water filter. Pull out the Cilp. Then press the collet to separate the tube from the connector and pour out the water until emptied.

2) Pull and separate the FAN ASSEMBLY and MOTOR turning counterclockwise based on the MOTOR SHAFT.

FAN ASSEMBLY

The assembly is in the reverse order of the disassembly and take special care for the following details.

1. Be careful not to bend the tube during assembly.

2. Press the WATER DISPENSER button until water pours out and check for leakage in the CONNECTOR TUBE (It differs by the water pressure but usually takes about 2 minutes until water pours out.)

MOTOR

Collet

Tube

Insert Line

Clip

- 15 -

3-22 FREEZER DRAWER

To remove the freezer drawer, pull the drawer open to full extension. Remove the lower DuraBase ®basket by lifting the basket from the rail system.

- 16 -

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 Note for Usage

(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 Cover PTC Compressor may fail due to breakdown of their insulating capabilities.

(4) Always use the Parts 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. Use only approved substitute parts.

4-1-3 Remove the cover PTC

4-1-4 Compressor protection logic

Since linear Comp conducts linear reciprocating motion, we have protection logic for compressor, motor and PCB as the below.

- Stroke Trip During the operation, if stroke is above the target value, decrease the target volt by 3V.

- Current Trip Current trip is set in order to protect compressor mechanical part and drive from the overcurrent that might arise during the operation. Check the current for every 416.7㎲ and if the Trip exceeds 1.86Arms more than three times at Comp ON, forcibly stop and restart six minutes later.

- Lock Piston Trip If stroke is under 5mm even if the current is more than 14Arms, Take it as ‘piston lock’ and restart after 2’30” of Comp OFF. Check the current and stroke for every

416.7㎲ and if the condition fits more than three times at Comp ON, The Lock Point Trip occurs.

- IPM fault Trip It occurs if FO signal received from IPM is LOW. For every 416.7㎲, check whether FO signal is LOW. The trip occurs if it is found three times during the five periods(83ms).

(1) Remove the Cover Back M/C

(2) Loosen two screws on comp base

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

- 17 -

5. CIRCUIT DIAGRAM

- 18 -

6. TROUBLESHOOTING

6-1 Error Code Summary

WARNING: When you check the Resistance values,

be sure to turn off the power. And wait for the voltage-discharge sufficiently.

NOTE) 3 hours before the error : Press the Ice Plus button and Freezer button simultaneously

3 hours after the error : All errors, except for "Er rt", "Er SS", "Er IS(except for Icing sensor)", "Er gF", "Er It" error, are displayed. "Er IS" which is displayed without input of user is the error of Icing Sensor.

Error Detection

LG LFX25974 Series Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual