LG LFCS25426 SERIES User manual

REFRIGERATOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE PRODUCT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
MODELS : LFC25776SW
LFC25776SB
LFC25776ST
WESTERN BLACK( SB )
COLORS : SUPER WHITE(SW)
STAINLESS(ST)
LFCS25426* Diamond Black

- 2-
CONTENTS
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
4. ADJUSTMENT ..................................................................................................................
COMPRESSOR ............................................................................................................................... .................................. 13
5. CIRCUIT DIAGRAM ............................................................................................................. ............................................ 14
6. TROUBLESHOOTING ....................................................................................................................................................... 15
ERROR CODE SUMMARY ................................................................................................................................................ 15
7. PCB PICTURE ............................................................................................................................................................. 16-17
MAIN PCB .......................................................................................................................................................................... 16
DISPLAY PCB & SUB PCB ............................................................................................................................................... 17
8. TROUBLESHOOTING WITH ERROR DISPLAY ........................................................................................................ 18-25
9. TROUBLESHOOTING WITHOUT ERROR DISPLAY ................................................................................................ 26-31
10. REFERENCE ............................................................................................................................................................. 32-35
11. COMPONENT TESTING INFORMATION ................................................................................................................ 36-44
12. TROUBLESHOOTING ............................................................................................................................................... 45-56
13. ICE MAKER AND DISPENSER WORKING PRINCIPLES AND REPAIR ................................................................ 57-60
14. EXPLODED VIEW & REPLACEMENT PARTS LIST ................................................................................................ 61-65
3.DISASSEMBLY---------------------------------------------------------------------------------------------------------------------------------------5-12
REMOVING AND REPLACING REFRIGERATOR DOORS -------------------------------------------------------------------------------5-6
DOOR -------------------------------------------------------------------------------------------------------------------------------------------------------7
DOOR ALIGNMENT -------------------------------------------------------------------------------------------------------------- -----------------------8
LAMP------------------------------------------------------------------------------------------------------------------------- --------------------------------8
MULTI DUCT------------------------------------------------------------------------------------------------------------------- ----------------------------8
MAIN PWB--------------------------------------------------------------------------------------------------------------------- -----------------------------8
HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER-----------------------------------------------------------------------9-10
WATER VALVE DISASSEMBLY METHOD-------------------------------------------------------------------------------------------------------11
FAN AND FAN MOTOR DISASSEMBLY METHOD--------------------------------------------------------------------------------------------11
PULLOUT DRAWER------------------------------------------------------------------------------------------------------------------------------------12
13
................................................

1. SPECIFICATIONS
Opaque Drawer Type
Linear
Fin Tube Type
Spiral Condenser
R-134a (125 g)
ISO10 (280 ml)
SHEATH HEATER
LED Module (27)
Bulb Lamp
VEGETABLE TRAY
COMPRESSOR
EVAPORATOR
CONDENSER
REFRIGERANT
LUBRICATING OIL
DEFROSTING DEVICE
REFRIGERATOR
FREEZER
LAMP
ITEMS SPECIFICATIONS
Side Rounded
35 X 34 X 69 (WXDXH) 25cu.ft
324.18 (25cu.ft)
Fan Cooling
Micom Control
Full Automatic
Heater Defrost
PCM, VCM, Stainless
Bar
ABS Resin
Polyurethane Foam
DOOR DESIGN
DIMENSIONS(inches)
NET WEIGHT(pounds)
COOLING SYSTEM
TEMPERATURE CONTROL
DEFROSTING SYSTEM
DOOR FINISH
HANDLE TYPE
INNER CASE
INSULATION
ITEMS
25cu.ft
SPECIFICATIONS
Description LFC25776**
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
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.
DIMENSIONS-
-3-

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
Mullion

-5--5-
3. DISASSEMBLY
3-1 REMOVING AND REPLACING REFRIGERATOR DOORS
REFRIGERATOR DOOR REMOVAL (CONT.)
To remove the left refrigerator door:
Open the door. Remove the top hinge cover screw (1).
Use a flat blade screwdriver to lift the tabs
on the front underside of the cover(2).
Lift up the cover.
Disconnect all the wire harnesses (3).
Remove the grounding screw(4).
Rotate hinge lever (5) counterclockwise.
Lift the top hinge (6) free of the hinge lever latch (7).
IMPORTANT: When lifting the hinge free of
The latch, be careful that the door does not fall
forward.
Lift the door from the middle hinge pin and remove the
door.
Place the door, inside facing up, on a nonscratching
surface.
To remove the right refrigerator door:
• Open the door. Remove the top hinge cover
screw (1).
• Use a flat blade screwdriver to lift the tabs
on the front underside of the cover(2).
Lift up the cover.
• Rotate hinge lever (3) clockwise.
Lift the top hinge (4) free of the hinge lever
latch (5).
IMPORTANT: When lifting the hinge free of
the latch, be careful that the door is heavy
and may fall forward.
• Lift the door from the middle hinge pin and
remove the door.
• Place the door, inside facing up, on a non-
scratching surface.
2
(2)
(3) (4)
(5)
(1)
-5-

REFRIGERATOR DOOR REINSTALLATION
Install the right-side door first.
Lower the door onto the middle hinge pin as
shown.
Make sure the plastic sleeve is inserted in the
bottom of the door.
Install the left-side door.
Lower the door onto middle hinge pin.
Fit the top hinge (1) over the hinge lever latch
(2) and into place. Rotate the lever (3)
clockwise to secure the hinge.
Install the grounding screw (4) and connect all
the wire harnesses (5).
• Fit the top hinge (1) over the hinge lever
latch (2) and into place. Rotate the lever (3)
counterclockwise to secure the hinge.
• Insert and tighten the cover screw (4).
2
(1) (2)
(3)
(4)
-6-
-6-

-6-
- 7 -
1. Remove gasket
Pull gasket free from gasket channel on the four
remaining sides of door.
3-2 DOOR
Mullion Removal
1. Remove 2 screws.
Door Gasket Removal
2. Lift Mullion 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.
2. Insert mullion into the channel.
Insert the cover assembly into bracket, door.
Mullion Replacement
1. Connect wire harness.
3. Assemble 2 screws.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
- 7 -

- 8 -
- 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.)
3-6 MAIN PWB
1) Loosen 3 screws on the PWB cover.
2) Remove the PWB cover
3) Disconnect wire harness and replace the main PWB in
the reverse order of removal.
Figure 15
Figure 16
Figure 13
1. Unplug refrigerator power cord form outlet.
2. Remove screw with driver.
3. Grasp the cover Lamp, pull the cover downward.
3-4-2 Freezer Compartment Lamp
3-5 MULTI DUCT
1. Romove the upper and
lower caps with a flat
screwdriver and remove
2 screws.
(Figure 19)
2. Disconnect the lead wire
on the bottom position.
Figure 14
Figure 10
3-4 LAMP
Unplug, or disconnect power at the circuit breaker.
If necessary, remove top shelf or shelves.
1) Release 2 screws.
2) Hold both ends and pull down to remove.
3-4-1 Refrigerator Compartment Lamp
4) Use a flat tool as shown below to remove the lamp
cover.
5) To remove the LED assembly, pull apart the cover.
3) To remove the lamp case and cover, release 2 screws
as shown.
Figure 9
Figure 11
Figure 12
Cover, lamp
Case, lamp
LED, Assembly
Figure 17

- 8 -
- 9 -
- -
3-7HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER
3-7-1 FOLLOW STEPS TO REMOVE
Step 1) Open the freezer door.
Step 3) Remove the two screws from the guide rails (one
from each side).
Step 2) Remove the lower basket.
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.
Step 5) Remove only 1 screw of gearice, and disassemble
the bar and gearice

3-7-2 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 4) Insert opposite gear ice into connector rail and
screw them
Step 6) Reinstall the freezer door by inserting the rail tabs
into the guide rail.
Step 8) Reinstall the lower basket, and close the freezer
door.
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 7) Reinstall the two screws into the guide rails
(one from each side).
Step 2) ①Assemble a bar and gear ice with screw.
②Push the otherside of the gear to inside of the
bar.
* Assemble them like as pictures
-10 -

3-8WATER VALVE DISASSEMBLY METHOD
1) Turn off the water to unit. Remove the waterline from the
valve.
3-9FAN AND FAN MOTOR DISASSEMBLY
METHOD
1) Remove screws for the Drain Pipe Assembly and the 1
connected to the Motor Cover.
2) Remove cover and 1 screw from the valve.
3) Separate the housing and remove the valve.
4) Remove the clip, and press the collet to separate the
tube from the connector. Note: there maybe some water
in the line.
Mechanical Cover
Housing
MOTOR COVER
2) Separate the Fan Assembly and Motor, turn counter
clockwise to remove from the motor shaft.
FAN ASSEMBLY MOTOR
Assemble in reverse order. Taking care to avoid.
1. Do not to bend the tube during assembly.
2. Press the Water Dispenser button letting water pour out,
this checks for any leaks in the tube connection, this may
vary depending on the water pressure
( about 2 minutes.).
- 11 -

3-10 PULL OUT DRAWER
- 12
-
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.

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).
- 13 -

- 8 -
5. CIRCUIT DIAGRAM
- 14 -

- 8 -
- 15 -
6. TROUBLESHOOTING
6-1 Error Code Summary
NO Error Detection
Category
1Normal 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
9
10
11
12
Communication
Error Er
Er
Er
CO
Communication Error
between Micom of Main
PWB and Display Micom
Poor Communication
connection,Poor TR of
Transmitter and Receiver
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 HS”,“Er IS”, “Er It” error, are displayed.
Normality None
Humidity
Sensor Error HS
rt
Er rt
Short or Disconnection
Of Humidity
Short or Disconnection
of Room temp. sensor
Check Each sensor and its
Connector
Check Each sensor and its
Connector
Room Temp
Sensor Error
Ice maker kit
defect
Other Electric system error
such as mother,gear,Hall IC,
operation circuit within I/M kit
When the ice does not drop
even when the I/M Test S/W
is pressed
(same as model applied
Twisting Ice Maker before)

- 8 -
- 16 -
7. PCB Picture
7-1 Main PCB
P/No & MFG Picture
CON7
CON5
CON201
CON4
CON3 CON2
CON1
EBR74796405
(2013.03~)

- 8 -
7-2 Display PCB & Sub PCB
P/No
Display PCB
Picture
CON01
-17 -
EBR42479314
(2013.03~)

- 8 -
8. Troubleshooting With Error Display
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
-18-
0 Short
Open
Normal
Change the sensor
Replace the refrigerator
Check the Temp and
resistance (Table-1)
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.

- 8 -
0 Ω
OFF
Other
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
-19-
<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>

- 8 -
8-3 Icing Sensor Error (Er IS)
0 Ω
OFF
Other
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 KΩ
30.5 ~ 28.5 KΩ
23 ~ 21.5 KΩ
17.5 ~ 16.5 KΩ
13.5 ~ 12.5 KΩ
10.5 ~ 9.5 KΩ
8 ~7.5 KΩ
※The sensor is determined by
the temperature.
For example, 23 KΩ indicates -4°F.
<CON4>
-20-