LG LFX28977ST/01 User manual

CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
MODEL : LFX28977ST /01
LFX28977WB /01
LFX28977SW /01
REFRIGERATOR
SERVICE MANUAL

ENC(Engineering Change Number)
- 2 -
Cover Assembly, Lamp
Duct Assembly, Multi
LED Assembly
LED Assembly
Guide, Fan
Tray, Drip
503F
120A
409E
405J
319C
319A
Loc No. SPECIFICATIONS
LFX28977 /01

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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.

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1. SPECIFICATIONS
DOOR DESIGN
DIMENSIONS (inches)
NET WEIGHT (pounds)
COOLING SYSTEM
TEMPERATURE CONTROL
DEFROSTING SYSTEM
DOOR FINISH
HANDLE TYPE
INNER CASE
INSULATION
ITEMS
Side Rounded
35 3/4 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
SPECIFICATIONS
VEGETABLE TRAY
COMPRESSOR
EVAPORATOR
CONDENSER
REFRIGERANT
LUBRICATING OIL
DEFROSTING DEVICE
ITEMS
Clear Drawer Type
Linear
Fin Tube Type
Wire Condenser
R-134a (140 g)
ISO10 (280 ml)
SHEATH HEATER
LED Module(24)
LED Module(12)
SPECIFICATIONS
LAMP REFRIGERATOR
FREEZER
DIMENSIONS
Depth w/ Handles
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)
A
B
C
D
E
F
G
H
I
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
Description LFX28977** /01
28 cu.ft.

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2. PARTS IDENTIFICATION
ADJUSTABLE REFRIGERATOR SHELVING
1
The refrigerator compartment shelves are adjustable to
allow flexibility for storage needs.
GALLON STORAGE BINS
2
Three interchangeable bins can be arranged to suit your
storage needs.
REMOVABLE ICE STORAGE BIN
3
The ice storage bin can be removed to fill ice buckets,
coolers, or pitchers.
LED INTERIOR LAMPS
4
Two separate LED arrays light the freezer and
refrigerator interiors.
SHORT N’TALL BIN
5
FIXED DOOR BIN
6

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3. DISASSEMBLY
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).
7. Place door, inside facing up, down onto a non-scratching surface.
CAUTION: When lifting hinge free of latch, be careful that door does not fall forward.
▶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).
5. Lift door up from middle hinge pin (9) door.
6. Place door, inside facing up, down onto a non-scratching surface.
CAUTION: When lifting hinge free of latch, be careful that door does not fall forward.
Correct Incorrect
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.

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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 snap
out.
3) Continue prying back along seam until all clips snap
out.
Figure 1
Handle
Frame Cover
●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.
Figure 4
Correct Incorrect
Gasket
Bracket Clip
Spring
Door
Frame
Figure 5
Correct
Incorrect
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.
<Inserting the Gasket Assembly into the Bracket Door>
Figure 2
Gasket
Bracket Clip
Gasket
Bracket
Door
Frame
Flat Tip
Screwdriver
3. Remove gasket
Pull gasket free from gasket channel on the three
remaining sides of door.
Figure 3

- 8 -
2) Press gasket into channels on the three remaining
sides of door.
Figure 6
3. Replace door frame cover
Starting at top of cover and working down, snap cover
back into door.
Figure 7
Figure 8
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.)
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.
Figure 9
FAN MOTOR
BRACKET
MOTOR
Shroud

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*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
(1) (2)
(3) (4)
(5) (6)
Figure 12
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)
Figure 10 Figure 11
GRILLE ASSEMBLY DEFROST-CONTROL
ASSEMBLY
3-6 LAMP
Unplug Refrigerator, or disconnect power at the circuit
breaker.
If necessary, remove top shelf or shelves.
1) Release 2 screws.
2) Hold both ends with your both hands and pull it
downward to remove it.
3-6-1 Refrigerator Compartment Lamp
Figure 13
3) Use a flat tool as shown below to remove the cover
lamp.
Figure 14
4) To remove the LED Assembly, open the Hook part to pull
it out as shown in the following picture.
Cover, lamp
Case, lamp
LED, Assembly
3) To remove the case lamp and cover lamp, release
another 2 screws as following picture.
Figure 15
1. Unplug refrigerator power cord form outlet.
2. Remove screw with driver.
3. Grasp the cover Lamp, pull the cover downward.
3-6-2 Freezer Compartment Lamp

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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.
Figure 16
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.
2) Remove the PWB cover
3) Disconnect wire harness and replace the main PWB in
the reverse order of removal.
3-10 DISPLAY PCB
As shown below, remove 1 case PCB fixing screw.
Remove the display PCB fixing screw.
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 direction and lift the
button in direction.
3-12 FUNNEL REPLACEMENT
Pull down and forward.
3) If nozzle is interfered with button,
push and pull out the bottom of
button.
4) Rmove the
connected part
of Lead wire.
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.
Case, PCB
Button Lever
Display PCB