LG LMC25780 Series User manual

MODEL : LMC25780**
COLOR : WESTERN BLACK(SB)
ILLUMINA(AL)
SUPER WHITE(SW)
REFRIGERATOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CONTENTS
- 2 -
SAFETY PRECAUTIONS ....................................................................................................................................................... 2
1. SPECIFICATIONS .............................................................................................................................................................. 3
2. PARTS IDENTIFICATION .................................................................................................................................................. 4
3. DISASSEMBLY ............................................................................................................................................................. 5-11
REMOVING AND REPLACING REFRIGERATOR DOORS ............................................................................................... 5
DOOR .............................................................................................................................................................................. 6-7
DOOR ALIGNMENT ........................................................................................................................................................... 7
LAMP .................................................................................................................................................................................. 8
MULTI DUCT ...................................................................................................................................................................... 8
MAIN PWB ........................................................................................................................................................................... 8
HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER ................................................................................ 9-10
TOP DRAWER................................................................................................................................................................... 11
BOTTOM DRAWER........................................................................................................................................................... 11
4. ADJUSTMENT ............................................................................................................................................................ 12-13
COMPRESSOR ................................................................................................................................................................ 12
TSD STARTER ................................................................................................................................................................. 12
OLP(OVERLOAD PROTECTOR) ..................................................................................................................................... 13
5. CIRCUIT DIAGRAM ......................................................................................................................................................... 14
6. TROUBLESHOOTING ................................................................................................................................................ 15-19
COMPRESSOR AND ELECTRIC COMPONENTS .......................................................................................................... 15
OTHER ELECTRICAL COMPONENTS............................................................................................................................. 16
SERVICE DIAGNOSIS CHART ........................................................................................................................................ 17
REFRIGERATION CYCLE .......................................................................................................................................... 18-19
7. OPERATION PRINCIPLE AND REPAIR METHOD OF ICEMAKER .......................................................................... 20-23
OPERATION PRINCIPLE ................................................................................................................................................. 20
ICE MAKER FUNCTIONS ........................................................................................................................................... 21-23
8. DESCRIPTION OF FUNCTION & CIRCUITS OF MICOM........................................................................................... 25-38
FUNCTION .................................................................................................................................................................. 24-28
9. PCB Picture .................................................................................................................................................................29-30
Main PCB .......................................................................................................................................................................... 29
Display PCB ...................................................................................................................................................................... 30
10. Troubleshooting with Error display ........................................................................................................................ 31-51
Freezer Sensor Error ....................................................................................................................................................31-32
Refrigerator Sensor Error ............................................................................................................................................. 33-34
Defrost Sensor Error .................................................................................................................................................... 35-36
Ice Maker Sensor Error ................................................................................................................................................ 37-38
Defrost Heater Error ..................................................................................................................................................... 39-43
Freezer Fan Error ......................................................................................................................................................... 44-46
Condenser Fan Error .................................................................................................................................................... 47-48
Communication Error(display LED off) ......................................................................................................................... 49-50
11. Troubleshooting Without Error Display ................................................................................................................. 51-58
Freezer Room Lamp does not work. .............................................................................................................................51-52
REFRIGERATOR Room LAMP does not work ............................................................................................................ 53-54
POOR COOLING in the refrigerator compartment ...................................................................................................... 55-56
OVER-COOLING in the refrigerator compartment ....................................................................................................... 57-58
12. Reference .................................................................................................................................................................. 59-61
TEST MODE and Removing TPA ......................................................................................................................................59
TEMPERATRUE CHART - FRZ AND ICING SENSOR .................................................................................................... 60
TEMPERATRUE CHART - REF AND DEF SENSOR ....................................................................................................... 61
13. EXPLODED VIEW & REPLACEMENT PARTS LIST ................................................................................................ 62-66
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.

1. SPECIFICATIONS
- 3 -
Opaque Drawer Type
Recipro
Fin Tube Type
Wire Condenser
R-134a (130 g)
ISO10 (280 ml)
SHEATH HEATER
60W (2EA)
60W (1EA)
VEGETABLE TRAY
COMPRESSOR
EVAPORATOR
CONDENSER
REFRIGERANT
LUBRICATING OIL
DEFROSTING DEVICE
REFRIGERATOR
FREEZER
LAMP
ITEMS SPECIFICATIONS
Side Rounded
35 3/4X 34 1/4X 69 3/4(WXDXH) 25cu.ft
324.18 (25cu.ft)
Fan Cooling
Micom Control
Full Automatic
Heater Defrost
Embossed Metal, 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 SPECIFICATIONS
Description LMC25780**
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 1/4 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
25 cu. ft

2. PARTS IDENTIFICATION
- 4 -
ADJUSTABLE REFRIGERATOR SHELVING
The refrigerator compartment shelves are adjustable to
allow flexibility for storage needs.
MODULAR DOOR 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.
INTERIOR LAMP
Digital Sensor Control
FIXED DOOR BIN
AUTOMATIC ICEMAKER
1
2
3
4
5
6
7
3
2
7
4
6
1
2
5

Removing Refrigerator Door
CAUTION : Before you begin, unplug the refrigerator. Remove food and bins from doors.
Left Door -FIG. 2
1. 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.
2. Disconnect door switch wire harness. Remove cover.
3. Disconnect the three wire harnesses (4). Remove the grounding screw (5).
4. 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.
5. 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. Disconnect wire harness (3).
4. Remove the grounding screw ( 4).
5. Rotate hinge lever (5) clockwise. Lift top hinge (6) free of hinge lever latch (7).
CAUTION : When lifting hinge free of latch, be careful that door does not fall forward.
6. Lift door up from middle hinge pin door.
7. Place door, inside facing up, down onto a non-scratching surface.
3. DISASSEMBLY
- 5 -
3-1 REMOVING AND REPLACING REFRIGERATOR DOORS
Figure 2 Figure 3

- 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.
2. Insert gasket into channel
1) Snap gasket assembly into the door bracket.
<Inserting the Gasket Assembly into the Bracket Door>
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. 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.
3. Remove gasket
Pull gasket free from gasket channel on the three
remaining sides of door.
Figure 1
Frame Cover
Handle
Figure 4
Figure 5
Door
Frame
Correct
Correct
Incorrect
Incorrect
Figure 2
Door
Frame
Gasket
Bracket Clip
Gasket
Bracket
Flat Tip
Screwdriver
Figure 3
Spring
Gasket
Bracket Clip

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

- 8 -
Figure 15
3-4 LAMP
Unplug Refrigerator, or disconnect power at the circuit
breaker.
If necessary, remove top shelf or shelves.
1. Using a flat instrument, gently pry the lamp cover loose
in the front as shown. Rotate downward to remove rear
tabs.
2. Make sure the bulbs are cool to the touch. Turn bulbs
counterclockwise to remove. Insert new bulb(s).
3. Replace with a new 60-watt appliance bulb.
4. Assemble in reverse order by snapping the Lamp Cover
in, engaging the rear tabs followed by the front tabs.
3-4-1 Refrigerator Compartment Lamp
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. 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.
3-6 MAIN PWB
1) Loosen the 3 screws on the PWB cover.
Figure 16
2) Remove the PWB cover
3) Disconnect wire harness and replace the main PWB in
the reverse order of removal.

- 9 -
3-7 HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER
3-7-1 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.

- 10 -
3-7-2 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.