LG LFX28977ST/01, LFX28977WB/01, LFX28977SW/01, LMX28987 SERIES Service Manual

REFRIGERATOR

SERVICE MANUAL

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

MODEL :

LFX28977ST /01 LFX28977WB /01 LFX28977SW /01

ENC(Engineering Change Number)

LFX28977 /01

Loc No. SPECIFICATIONS

503F

120A

409E

405J

319C

319A

Cover Assembly, Lamp

Duct Assembly, Multi

LED Assembly

Guide, Fan

Tray, Drip

- 2 -

CONTENTS

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

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

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

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

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

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

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

FAN AND FAN MOTOR(Evaporator) ................................................................................................................................. 7

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

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

MULTI DUCT ..................................................................................................................................................................... 9

MAIN PWB ..........................................................................................................................................................................9

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

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

FUNNEL REPLACEMENT ..................................................................................................................................................9

WATER BUTTON ASSMEBLY .........................................................................................................................................10

DUCT DOOR REPLACEMENT ........................................................................................................................................10

ICE CORNER DOOR REPLACEMENT ............................................................................................................................10

ICEMAKER ASSEMBLY ...................................................................................................................................................10

SUB PWB FOR WORKING DISPENSER ........................................................................................................................11

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

AUGER MOTOR COVER .................................................................................................................................................12

HOW TO REMOVE A ICE BIN HOW TO REMOVE A ICE BIN.........................................................................................13

HOW TO INSERT A ICE BIN ............................................................................................................................................13

HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER ..............................................................................14-15

WATER VALVE DISASSEMBLY METHOD .....................................................................................................................16

FAN AND FAN MOTOR DISASSEMBLY METHOD .........................................................................................................16

PULL OUT DRAWER .......................................................................................................................................................17

4. ADJUSTMENT ........................................................................................................................................................... 18-19

COMPRESSOR ............................................................................................................................................................... 18

Introduction of E-Linear Compressor ...........................................................................................................................18-20

5. CIRCUIT DIAGRAM ........................................................................................................................................................ 21

6. TROUBLESHOOTING ................................................................................................................................................ 22-52

Error Code Summary ....................................................................................................................................................... 22

Troubleshooting With Error.......................................................................................................................................... 23-35

Troubleshooting Else .................................................................................................................................................. 36-54

7. COMPONENT TESTING INFORMATION .................................................................................................................. 55-63

8. TRBOUBLESHOOTING ............................................................................................................................................. 64-68

9. OPERATION PRINCIPLE AND REPAIR METHOD OF ICEMAKER ........................................................................ 69-71

10. DESCRIPTION OF FUNCTION & CIRCUIT OF MICOM ........................................................................................... 72-76

11. EXPLODED VIEW & REPLACEMENT PARTS LIST

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.

- 3 -

1. SPECIFICATIONS

28 cu.ft.

ITEMS

DOOR DESIGN

DIMENSIONS (inches)

NET WEIGHT (pounds)

COOLING SYSTEM

TEMPERATURE CONTROL

DEFROSTING SYSTEM

DOOR FINISH

HANDLE TYPE

INNER CASE

INSULATION

DIMENSIONS

SPECIFICATIONS

Side Rounded

/4 X 35 3/8 X 69 3/4 (WXDXH) 28cu.ft.

324(28cu.ft.)

Fan Cooling

Micom Control

Full Automatic

Heater Defrost

Embossed Metal, VCM, Stainless

Bar

ABS Resin

Polyurethane Foam

ITEMS

VEGETABLE TRAY

COMPRESSOR

EVAPORATOR

CONDENSER

REFRIGERANT

LUBRICATING OIL

DEFROSTING DEVICE

LAMP

REFRIGERATOR

FREEZER

SPECIFICATIONS

Clear Drawer Type

Linear

Fin Tube Type

Wire Condenser

R-134a (140 g)

ISO10 (280 ml)

SHEATH HEATER

LED Module(24)

LED Module(12)

Depth w/ 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)

Description LFX28977** /01

35 3/8 in

32 7/8 in

29 in

47 5/8 in

68 3/8 in

69 3/4 in

35 3/4 in

39 1/4 in

44 1/4 in

- 4 -

2. PARTS IDENTIFICATION

ADJUSTABLE REFRIGERATOR SHELVING

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

GALLON STORAGE BINS

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

REMOVABLE ICE STORAGE BIN

The ice storage bin can be removed to fill ice buckets, coolers, or pitchers.

LED INTERIOR LAMPS

Two separate LED arrays light the freezer and refrigerator interiors.

SHORT N’TALL BIN

FIXED DOOR BIN

- 5 -

3. DISASSEMBLY

Correct

Incorrect

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 (3). Lift up cover.

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

4. Pull out the tube.

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

6. Rotate hinge lever (7) counterclockwise. 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.

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 (3).

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

3. Disconnect wire harness (5).

4. Rotate hinge lever (6) clockwise. 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.

5. Lift door up from middle hinge pin (9) door.

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

Figure 2 Figure 3

Figure 1

1) Insert the tube until you can see only one of the lines printed on the tube.

2) After inserting, pull the tube to ascertain that it is secure.

3) Assemble clip.

- 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.

●

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.

Frame Cover

Handle

Figure 1

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 snap out.

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

Gasket

Door

Bracket Clip

Frame

Gasket Bracket Clip

Spring

Door Frame

Correct Incorrect

Figure 4

4) Push in remaining clip until you hear it 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.

Flat Tip

Screwdriver

3. Remove gasket

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

Gasket

Bracket

Figure 2

Figure 3

- 7 -

Incorrect

Correct

Figure 5

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 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.)

Figure 6

Figure 7

Figure 8

3-4 FAN AND FAN MOTOR(EVAPORATOR)

1. Remove the freezer drawer. (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 four screws and pulling the grille forward.

4. Remove the Fan Motor assembly by loosening 3 screws and disassembling the shroud.

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

FAN MOTOR

Shroud

- 8 -

BRACKET

MOTOR

Figure 9

* Ice Fan Scroll Assembly Replacement

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

2) Pull out the cover sensor to disassemble using tools shown in the figure.

3) Pull out the cover grille to disassemble using tools shown in the figure.

4) Put your hand into the inside of grille to disassemble shown in the figure.

5) Disconnect wire harness of the grille

6) Remove the scroll assembly by loosening all screws

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.

Figure 12

(1) (2)

(3) (4)

(5) (6)

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 46F(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 10)

2. Separate the connector with the Defrost Control assembly and replace the Defrost Control assembly after cutting the Tie Wrap. (Figure 11)

GRILLE ASSEMBLY

DEFROST-CONTROL ASSEMBLY

3) To remove the case lamp and cover lamp, release another 2 screws as following picture.

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

Figure 13

4) To remove the LED Assembly, open the Hook part to pull it out as shown in the following picture.

Case, lamp

Cover, lamp

3-6-2 Freezer Compartment Lamp

1. Unplug refrigerator power cord form outlet.

2. Remove screw with driver.

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

LED, Assembly

Figure 14

Figure 10

Figure 11

Figure 15

- 9 -

3-7 MULTI DUCT

1. Remove the upper and lower Caps by using a flat screwdriver, and remove 2 screws. (Figure 16)

2. Disconnect the lead wire on the bottom position.

3-8 MAIN PWB

1) Loosen the 3 screws on the PWB cover.

2) Remove the PWB cover

Figure 16

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) Rmove the connected part of Lead wire.

3-10 DISPLAY PCB

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

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

3-9 DISPENSER

1) Pull out the darin 2) Hold the inner side of

cover dispenser with both hands at the handle side to pull it out forward.

Case, PCB

Display PCB

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 FUNNEL REPLACEMENT

Pull down and forward.

- 10 -

3-13 WATER BUTTON ASSMEBLY

1) Romove screws.

2) Grasp the Button assembly and lift up.

Button Lever

3-14 DUCT DOOR REPLACEMENT

1) Pull up and out on the dispenser cover to remove.

2) Disconnect the wire harness.

3) Remove the funnel

4) Replace in reverse order.

3-16 ICEMAKER ASSEMBLY

1) Loosen two screws as shown in the first picture.

2) Disconnect the wire harness & ground screw replace theIcemaker assembly in the reverse order of removal.

3) It separates a ground connection screw.

3-15 ICE CORNER 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 Corner Door with the other hand.

hinge

- 11 -- 11 -

3-17 SUB PWB FOR WORKING DISPENSER

1) Loosen the screw on the sub PWB.

2) Pull the sub PWB down.

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

3-18 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 hold the Duct Door with your hand to install the Motor.

Cap Duct Motor

Duct Door

4) Assemble on the screws.

5) Contract the Housing.

- 11 -

- 12 -

3-19 AUGER MOTOR COVER

1) After removing the icemaker remove the (5) stainless screws holding the auger motor cover, shown in the picutres below.

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

3) Disconnect wire harness of motor cover assembly. There is a auger motor on the back, as shown in the picture.

Auger Motor

- 13 -

3-20 HOW TO REMOVE A ICE BIN



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

2) Lift the lower part slightly.

3-21 HOW TO INSERT A ICE BIN

1) Insert the Ice Bin, slightly tilting it to avoid touching the Icemaker. (especially, icemaker lever)

※ Insert the ice bin carefully avoid contacting the automatic

shut off arm.

3) Take the Ice Bin out slowly.

- 14 -

3-22 HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER

3-22-1 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) First: Remove the gear from the left side first by releasing the tab behind the gear, place a screwdriver between the

gear and the tab and pull up on the gear.

Second: Remove the center rail.

Third: Remove the gear from the right side by following the same steps for the left side.

Step 4) Lift the freezer door up to unhook it from the rail

support and remove. Pull both rails to full extension.

NOTE: THIS TAB MUST BE PUSHED IN TO RELEASE THE GEAR.

- 15 -

3-22-2 Follow Steps to Reinstall

Step 1) Reinstall the right side gear into the clip.

Step 2) Insert the rail into the right side gear. Gears do not

need to be perpendicular to each other.

Step 4) 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 3) Insert the rail into the left side gear, and insert the

gear into the clip.

Step 5) Reinstall the freezer door by inserting the rail tabs

into the guide rail.

Step 6) Reinstall the two screws into the guide rails

(one from each side).

Step 7) Reinstall the lower basket, and close the freezer

door.

- 16 -

3-23. WATER VALVE DISASSEMBLY METHOD

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

3-24. 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 Mechanical Cover and Valve Screw.

Mechanical Cover

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 te 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 MOTOR

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.)

- 17 -

3-25 PULL OUT DRAWER

Hook

To separate the drawer, push the front left and right hooks in ① direction to pull up and remove. Then gently lift the gear part of rear left and right side of the drawer and pull it out in ③ direction.

To install, reposition the gear part of rear left and right side of the drawer after pulling out both rails as much as possible, and gently push down both left and right side while checking the hook on the front part.

- 18 -

4. ADJUSTMENT

PTC STARTER

SEALED TERMINAL

COMPRESSOR MOTOR

OVERLOAD PROTECTOR

Resistance Starter Capacitor Running

PTC

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 performing repairs.

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.

4-2-3 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. Use only approved substitute parts.

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 BaTiO3.

(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 Compressor Motor.

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

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

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. Use only approved substitute parts.

- 19 -

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.

(OVERLOAD PROTECTOR cross section)

Customer part number

12345678

Lot code/ date code

Physical termination part number

Electrical

characteristics

part number

330 FBYY -S1 BOX98

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 19

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

in.

(3) Loosen two screws on comp base.

- 20 -

5. CIRCUIT DIAGRAM

- 21 -

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" error, are displayed.

Error Detection

Freezer Sensor

Poor Defrosting Er dH

Abnormality of

BLDC FAN Motor

for Ice Making

Error Display

LG LFX28977ST/01, LFX28977WB/01, LFX28977SW/01, LMX28987 SERIES Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual