LG LFC25765ST User manual

REFRIGERATOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE PRODUCT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
MODELS : LFC25765ST
LFC25765SW
LFC25765SB

CONTENTS
- 2 -
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.
SAFETY PRECAUTIONS ....................................................................................................................................................... 2
1.SPECIFICATIONS ................................................................................................................................................................... 3
2.PARTS IDENTIFICATION ....................................................................................................................................................... 4
3.DISASSEMBLY .................................................................................................................................................................... 5-9
DOOR ............................................................................................................................................................................... 5-6
DOOR ALIGNMENT ............................................................................................................................................................. 6
HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER ................................................................................ ... 7-9
4.ADJUSTMENT ...................................................................................................................................................................... 10
COMPRESSOR ................................................................................................................................................................. 10
5.CIRCUIT DIAGRAM .............................................................................................................................................................. 11
6.TROUBLESHOOTING .......................................................................................................................................................... 12
ERROR CODE SUMMARY ................................................................................................................................................ 12
7.PCB PICTURE ................................................................................................................................................................. 13-14
MAIN PCB .......................................................................................................................................................................... 13
DISPLAY PCB & SUB PCB ............................................................................................................................................... 14
8.TROUBLESHOOTING WITH ERROR DISPLAY ............................................................................................
.............. 15-22
9.TROUBLESHOOTING WITHOUT ERROR DISPLAY ................................................................................................... 23-28
10.REFERENCE .................................................................................................................................................................... 29-32
11.COMPONENT TESTING INFORMATION .................................................................................................................. 33-41
12.TROUBLESHOOTING .................................................................................................................................................39 -49
13.ICE MAKER AND DISPENSER WORKING PRINCIPLES AND REPAIR ................................................................. 50- 53
14.EXPLODED VIEW & REPLACEMENT PARTS LIST ...................................................................................................... 54

1. SPECIFICATIONS
- 3 -
Color WHITE BLACK STAINLESS
Dimensions (in)
Net Weight (lb)
Capacity
Refrigerant
Climate Class
Rated Rating
Cooling System
Temperature Control
Insulation
Compressor
Evaporator
Condenser
Lubricanting Oil
Drier
Capillary Tube
First Defrost
Defrost Cycle
Defrosting Device
Anti-freezing Heater
Water Tank
Auto ice maker
Case Material
Door material STAINLESS
Handle Type
Display Graphic
F, Drawer upper
Ice Tray & Bank
Lamp
Shelf
Egg Bank
Pantry
F, Drawer lower
Lamp
Shelf
GENERAL FEATURES
32 23/32 X 28 30/32 X 69 3/4 (WXDXH)
277 lb
25cu.ft.
R134A(125gr)
TEMPERATURE (N)
115/60
FAN COOLING
MICOM CONTROL
ISO8 (180 ml)
MOLECULAR SIEVE XH-7
Defrosting System FULL AUTOMATIC
HEATER DEFROST
7-50 HOURS
FIN TUBE TYPE
SPECIFICATIONS
MODELS
LFC25765SW LFC25765SB LFC25765ST
FREEZER
1EA PL+1EA PL
BULB
NO
1EA PL+1EA PL
NO
REFRIGERATOR
SPIRAL CONDENSER
CYCLO PENTANANE
LINEAR
ID Ø 0.75
4 HOURS
SHEATH HEATER
HIGH BRIGHTNESS LED
4EA(fixed)
NO
YES(No control)
EMBO
PCM
VISTA
RAPTOR ONLY
PIPE HEATER
NO
TWISTING

DIMENSIONS
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)
A
B
C
D
E
F
G
H
I
Description
LFC25765**
29
41 ¼
46 ¼
36 ¼
32 ¾
68 38
35 38
69 34
32 78

2. PARTS IDENTIFICATION
- 4 -
Digital Sensor
Control
Refrigerator Light
Shelves
Modular Door Bin
Glide'N'Serve
Ice Bin
Durabase
Divider
Dairy Bin
Modular Door Bin
Bottle Holder
Modular Door Bin
Pullout Drawer
Optibin Crisper
Keeps fruits and
vegetable fresh
and crisp
AUTOMATIC
ICEMAKER

3. DISASSEMBLY
- 5 -
3-1 DOOR
ჀRefrigerator door
1. Remove the top hinge cover and disconnect the wire
harness.
2. Remove the ground screw.
3. Rotate the lever hinge and lift off hinge.
4. Lift off the refrigerator door.
5. Replace in the reverse order.
ჀDoor gasket replacement
1. Insert gasket bracket clips
1) Insert gasket bracket edge beneath door frame edge.
2) Turn upper gasket bracket spring so that both 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. 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.
Figure 2
Frame Cover
Handle
Figure 5
Correct Incorrect
Figure 3
Gasket
Bracket Clip
Gasket
Bracket
Flat Tip
Screwdriver
Figure 4
Spring
Gasket
Bracket Clip
Figure 1
HINGE COVER
HINGE
ჀDoor gasket removal
1. Remove door frame cover
Starting at top of cover and working down, snap cover
out and away from door.
Door
Frame
Door
Frame

2. Insert gasket into channel
1) Snap gasket assembly into the door bracket.
Inserting the gasket assembly into the bracket door
3. Replace door frame cover
Starting at top of cover and working down, snap the
cover back into door.
2) Press gasket into channels on the three remaining
sides of door.
Figure 7
Figure 9
Figure 8
3-2 DOOR ALIGNMENT
If the space between your doors is uneven, follow the
instructions below to align the doors:
1. With one hand, lift 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 the product.)
Correct
Figure 6
Incorrect
- 6 -

- 7 -
3-3 HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER
3-3-1 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.
NOTE : THIS TAB MUST BE PUSHED IN TO RELEASE THE GEAR.
Step 4) Lift the freezer door up to unhook it from the rail
support and remove.
Pull both rails to full extension.

- 8 -
3-3-2 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 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.
Step 3) Insert the rail into the left side gear, and insert the
gear into the clip.

- 9 -
3-3-3 PULL OUT DRAWER
To separate the drawer, push the front left and right hooks in ཰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 ི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.

- 10 -
4. ADJUSTMENT
4-1-1 Role
4-1 COMPRESSOR
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
(1) Remove the Cover Back M/C
(2) Loosen two screws on comp base
(3) Use a L-shaped flap tooll to pry off the cover
(4) Assembly in reverse order of disassembly
4-2-3 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 416.7us 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
416.7us and if the condition fits more than three times at
Comp ON, the Trip occurs.
- IPM fault Trip
It occurs if FO signal received from IPM is LOW. For
every 416.7us, check whether FO signal is LOW. The trip
occurs if it is found three times during the five
periods(83ms).

- 11 -
5. CIRCUIT DIAGRAM
CHANGE IN DIFFERENT LOCALITIES AND MODEL TYPE.
EARTH PART ON CIRCUIT DIAGRAM ARE SUBJECT TO
F/L DOOR S/W ,PLUG TYPE,SMART BUZZER, REACTOR, FUSE AND COMP'
CIRCUIT DIAGRAM
- N: NEUTRAL
WH/BK
RD
23 F/L DOOR S/W
24 MOTOR
STEPPING
GN/YL (GN)
PLUG TYPE
LIVE FUSE PART
REACTOR
NEUTRAL
F-LAMP
WH 2
BK 1SB
YL
YL/BL
18
19
21
20
2
1
CON10
CON1 BN
17
BL/WH
WH
BL/WH
16
15
14 F-SNR
D-SNR
BN F/U DOOR S/W
BL
22 M
BL(N) BK
BL
BN
BO
PILLAR HTR
DEF-HEATER FUSE-M
BL(N)
BL(N)
BL(N)
7
11
9
WH
BK
13
C
D
BO
12
PR/WH
GY/WH
HEATER
WATER PIPE
2
8
4
6
10
PK
BO/BL
WH/RD
PR
GY M
C-FAN
F-FAN
R-SNR
M
RD
O.L.P
BL(N)
GY
BK
COMPRESSOR EARTH PART
F
LINEAR COMP.
3
1
CON7
2
1
BO
RD ICE MAKER
SENSOR
2
1
3
4
9
5
11
8
7
10
CON3
6
12
PILOT VALVE
2
1
3
5
4
5
7
6
BN
BO
CAPACITOR PART
CON201 8
4
6
10
5
CON4
BL
YL
BN
PR
SB
PK
GY
7
9M
HALL
IC
ICE MAKER
MOTOR
ICE MAKER
TEST S/W
ICE MAKER
STOP S/W
2
1
3
4
BL 5
7
6
GN/YL
F
17
15
14
8
6
5
2
1
4
BL/WH
RD
BO
WH/BK
GY
B
A
E
R-DOOR S/W
3
2
1
BN
EARTH
PAR T
4
WH/BK
RD
BO
BN
PWB ASSEMBLY
DISPLAY
3
WH
PCB ASSEMBLY, MAIN
9
11
8
10
18
22
16
20
13
12
7
10
9
3
11
BN
BN
GY
SB
BK
B
RT - SENSOR
21
19
CON2
SMART
BUZZER
1
2
3
1
2
3
E
D
LED MODULE
BK
LED MODULE
R-ROOM
R-ROOM
BK
BL
BL
RD
RD
CON5
MEZ64210003
PR: PURPLE
BL: BLUE
WH: WHITE
BL/WH: BLUE/WHITE
RD: RED
PK: PINK
GY: GRAY
BO: BRIGHT ORANGE
PR/WH: PURPLE/WHITE
WH/RD: WHITE/RED
BO/BL: BRIGHT ORANGE/BLUE
YL/BK: YELLOW/BLACK
GN/YL: GREEN/YELLOW WH/BK: WHITE/BLACK
SB: SKY BLUE
BN: BROWN
BK: BLACK
YL: YELLOW
A
C

- 12 -
6. TROUBLESHOOTING
6-1 Error Code Summary
NO Error Detection
Category
1Normality None Normal operation of Display
2Freezer Sensor
Error Er FS Short or Disconnection of Freezer Sensor
3Refrigerator
Sensor Error Er rS Short or Disconnection of Refrigerator Sensor Check each sensor and its
connector.
Error Generation Factors Remark
WARNING:When you check the Resistance values, be sure to turn off the power.
And wait for the voltage-discharge sufficiently.
Error Display
Freezer
Temperature
Ref.
Temperature
4Defrosting
Sensor Error Er dS Short or Disconnection of Defrosting Sensor
5Icing Sensor
Error Er IS Short or Disconnection
of Icing Sensor
6Poor Defrosting Er dH
Even though it is passed
1 hour since then Defrosting,
if Defrosting sensor is not
over 8°C, it is caused
Temperature Fuse
Disconnection, Heater
disconnection, DRAIN Jam,
Poor Relay for Heater
7
Abnormality of
BLDC FAN Motor
for Freezer
Er FF
It is caused when feedback
signal isn’t over 65 seconds
during BLDC FAN motor
operating
Poor BLDC Motor
connection, DRIVE IC,
and TR
8
Abnormality of
BLDC FAN Motor
for Mechanic
Room
Er CF
It is caused when feedback
signal isn’t over 65 seconds
during BLDC FAN motor
operating
Poor BLDC Motor
connection, DRIVE IC,
and TR
9Communication
Error Er CO
Communication Error
between Micom of Main
PWB and Display Micom
Poor Communication
connection,Poor TR of
Transmitter and Receiver

- 13 -
7. PCB Picture
7-1 Main PCB
P/No & MFG Picture
EBR73304219
(2011.07~)
CON201 CON1
CON2 CON3
CON5 CON7
CON4

- 14 -
7-2 Display PCB & Sub PCB
P/No
Display PCB
EBR42479302
(2010.07~)
Picture
CON01

ᓸ
ᓸ
ᓸ
ᓸ
ᓸ
ᓸ
ᓸ
- 15 -
8. Troubleshooting With Error Display
0 Short
Open
Normal
Change the sensor
Replace the refrigerator
Check the Temp and
resistance (Table-1)
Result SVC Action
8-1 Freezer Sensor Error (Er FS)
No
1
2
Checking flow
Check for a loose connection.
Check the Blue/White to
Blue/White.
Result & SVC Action
<Temperature table-1>
(1) To (2)
-22°F / -30°C
-13°F / -25°C
-4°F / -20°C
5°F / -15°C
14°F / -10°C
23°F / -5°C
32°F / 0°C
Result
40.5 ~ 38.5
30.5 ~ 28.5
23 ~ 21.5
17.5 ~ 16.5
13.5 ~ 12.5
10.5 ~ 9.5
8 ~7.5
The sensor is determined by
the temperature.
For example, 23 indicates -4°F.
<CON7>

- 16 -
0 Short
Open
Normal
Change the sensor
Replace the refrigerator
Check the Temp and
resistance (Table-2)
Result SVC Action
8-2 Refrigerator Sensor Error (Er rS)
No
1
2
Checking flow
Check for a loose connection.
Check the White to White.
Result & SVC Action
<Temperature table-2>
(1) To (2)
23°F / -5°C
32°F / 0°C
41°F / 5°C
50°F / 10°C
59°F / 15°C
Result
38.5 ~ 36.5
30.5 ~ 29.5
24.5 ~ 23.5
20 ~ 19
16 ~15.5
The sensor is determined by
the temperature.
For example, 30 indicates 32°F.
<CON7>

- 17 -
8-3 Icing Sensor Error (Er IS)
0 Short
Open
Normal
Change the sensor
Replace the refrigerator
Check the Temp and
resistance (Table-1)
Result SVC Action
No
1
2
Checking flow
Check for a loose connection.
Check the Red to Bright Orange.
Result & SVC Action
<Temperature table-1>
(1) To (2)
-22°F / -30°C
-13°F / -25°C
-4°F / -20°C
5°F / -15°C
14°F / -10°C
23°F / -5°C
32°F / 0°C
Result
40.5 ~ 38.5
30.5 ~ 28.5
23 ~ 21.5
17.5 ~ 16.5
13.5 ~ 12.5
10.5 ~ 9.5
8 ~7.5
The sensor is determined by
the temperature.
For example, 23 indicates -4°F.
<CON9>

- 18 -
0 Short
Open
Normal
Change the sensor
Replace the refrigerator
Check the Temp and
resistance (Table-3)
Result SVC Action
8-4 Defrost Sensor Error (F dS)
No
1
2
Checking flow
Check for a loose connection.
Check the Orange to Orange.
Result & SVC Action
Check the Brown to Brown.
The sensor is determined by
the temperature.
For example, 23 indicates -4°F.
<Temperature table-3>
(1) To (2)
23°F / -5°C
32°F / 0°C
41°F / 5°C
50°F / 10°C
59°F / 15°C
Result
38.5 ~ 36.5
30.5 ~ 29.5
24.5 ~ 23.5
20 ~ 19
16 ~15.5
<CON7>

- 19 -
8-5 Defrost Heater Error (Er dH)
Fuse-M
Def
Heater
Def
Sensor
0
34 ~ 42
21
Go to the 3
Change Fuse-M
Go to the 3
Change Fuse-M
Go to the 3
Go to the 5
Part Result SVC Action
No
1
2
Checking flow
Check the Door gasket.
Check the Defrost control part.
3 Input Test 3 Mode.
(Push the button 3 times)
4 Check the Blue to Orange.
Result & SVC Action
Fuse
M
Def Heater
Def
Sensor
5 Release the test mode.
Push the button 1 times. (Normal)
<CON3>
<CON3>
Result
112 ~ 116 V
0 V
SVC Action
Go to the 5
Replace Main PCB
6 Check the Blue to Orange.
Result
0 V
112 ~ 116 V
SVC Action
Explain to customer
Replace Main PCB