LG LFC21770ST - Panorama - 0.7 cu. ft User manual

CAUTION
BEFORE SERVICING THE PRODUCT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
REFRIGERATOR
SERVICE MANUAL
COLORS: WESTERN BLACK(SB)
TITANIUM(TT)
SUPER WHITE(SW)
STAINLESS(ST)
LFC21770ST LFC25770SW
LFC25770SB LFC25770TT
LFC25770ST
MODELS:

SAFETY PRECAUTIONS....................................................................................................................................................... 2
SPECIFICATIONS................................................................................................................................................................... 3
PARTS IDENTIFICATION....................................................................................................................................................... 4
DISASSEMBLY.................................................................................................................................................................. 5-10
DOOR................................................................................................................................................................................ 5-6
DOOR ALIGNMENT..............................................................................................................................................................6
HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER.................................................................................... 7-9
ADJUSTMENT................................................................................................................................................................. 10-11
COMPRESSOR.................................................................................................................................................................. 10
PTC-STARTER................................................................................................................................................................... 10
OLP (OVERLOAD PROTECTOR)...................................................................................................................................... 11
TO REMOVE THE COVER PTC.........................................................................................................................................11
CIRCUIT DIAGRAM.............................................................................................................................................................. 12
TROUBLESHOOTING..................................................................................................................................................... 13-18
COMPRESSOR AND ELECTRIC COMPONENTS ........................................................................................................... 13
PTC AND OLP.................................................................................................................................................................... 14
OTHER ELECTRICAL COMPONENTS............................................................................................................................. 15
SERVICE DIAGNOSIS CHART.......................................................................................................................................... 16
REFRIGERATION CYCLE............................................................................................................................................ 17-18
OPERATION PRINCIPLE AND REPAIR METHOD OF ICEMAKER ............................................................................. 19-22
DESCRIPTION OF FUNCTION AND CIRCUIT OF MICOM .......................................................................................... 23-36
EXPLODED VIEW AND REPLACEMENT PARTS LIST ................................................................................................... 37-
CONTENTS
- 2 -
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

1. SPECIFICATIONS
- 3 -
ITEMS SPECIFICATIONS
DOOR DESIGN Side Rounded
COOLING SYSTEM Fan Cooling
TEMPERATURE CONTROL Micom Control
Full Automatic
DEFROSTING SYSTEM Heater Defrost
DOOR FINISH PCM, VCM, Stainless
HANDLE TYPE Bar
INNER CASE ABS Resin
INSULATION Polyurethane Foam
ITEMS SPECIFICATIONS
VEGETABLE TRAY Opaque Drawer Type
COMPRESSOR PTC Starting Type
EVAPORATOR Fin Tube Type
CONDENSER Wire Condenser
REFRIGERANT R-134a (115 g)
LUBRICATING OIL ISO10 (280 ml)
DEFROSTING DEVICE SHEATH HEATER
LAMP REFRIGERATOR 60 W (2 EA)
FREEZER 60 W (1 EA)
Description LFC21770** LFC25770**
Depth w/ Handles A 30 in. 34 1/4 in.
Depth w/o Handles B 27 1/2 in. 31 3/4 in.
Depth w/o Door C 23 5/8 in. 27 7/8 in.
Depth (Total with Door Open) D 42 1/4 in. 46 1 /2 in.
Height to Top of Case E 68 3/8 in. 68 3/8 in.
Height to Top of Door Hinge F 69 3/4 in. 69 3/4 in.
Width G 35 3/4 in. 35 3/4 in.
Width (door open 90 deg. w/o handle) H 39 1/4 in. 39/1/4 in.
Width (door open 90 deg. w/ handle) I 44 1/4 in. 44 1/4 in.
DIMENSIONS

2. PARTS IDENTIFICATION
- 4 -
Egg Box
Digital Sensor
Control
Refrigerator Light
Shelves
Optibin Crisper
Keeps fruits and
vegetable fresh
and crisp
Customcube
Icemaker
Glide'N'Serve
Ice Bin
Durabase
Divider
Pullout Drawer
Tilt- Out
Door Basket
Modular Door Bin
Modular Door Bin
Bottle Holder
Dairy Bin
Modular Door Bin
(Tilting-25770** Only)

3-1 DOOR
● Refrigerator 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.
● 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 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.
● 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 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.
3. DISASSEMBLY
- 5 -
HINGE
HINGE COVER
Figure 1
Frame Cover Handle
Door
Frame
Gasket
Bracket Clip
Flat Tip
Screwdriver
Gasket
Bracket
Figure 2
Figure 3
Figure 4
Door
Frame
Gasket
Bracket Clip
Spring
IncorrectCorrect
Figure 5

2. Insert gasket into channel
1) Snap gasket assembly into the door bracket.
Inserting the gasket assembly into the bracket door
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 the
cover back into door.
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.)
- 6 -
Figure 7
Figure 8
Figure 9
Figure 6
Correct
Incorrect

- 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 3) Remove the two screws from the guide rails (one
from each side).
Step 2) Remove the lower basket.
Step 4) Lift the freezer door up to unhook it from the rail
support and remove.
Pull both rails to full extension.
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.

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 6) Reinstall the two screws into the guide rails
(one from each side).
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 7) Reinstall the lower basket, and close the freezer
door.
- 8 -

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.
2
3
1
Hook
- 9 -

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 repairing it.
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.
If the hermetic connector rusts out or fails, refrigerant
and oil will be expelled into the contact area, probably
resulting in smoke and fire.
(5) When replacing the compressor, be careful that dust,
humidity, and soldering flux don’t contaminate the inside
of the compressor. Contamination in the cylinder may
cause noise, improper operation or even cause it to
lock up.
4-2 TSD STARTER
4-2-3 PTC-Applied circuit diagram
● Starting method for the motor
4-2-4
4. ADJUSTMENT
- 10 -
ELECTRICAL AND DIMENSION DIAGRAM
ELECTRICAL CONNECTION DIAGRAM
SM
TSD
START
MAIN
N
CL
Ð The TSD must not be applied to refrigeration systems with
defrosting electrical resistance or any other component in
parallel to the thermostat. Systems with this configuration
can maintain a residual voltage over the compressor when
the thermostat is opened, obstructing the proper functioning
of the TSD. It is vital f or the TSD circuit and compressor t o
remain completely de-energized after opening the
thermostat.
Ð Use of the fixing clamp is essential, as this prevents
disconnection or bad TSD contact in relation to the
compressor as well as to running capacitor in relation to the
TSD. The ones that assemble it have to guarantee a
perfect connection between the parts. Bad contacts and
sparking can burn out the electronic circuit.
Ð The electronic circuit was designed taking the mandatory
use of the running capacitor into consideration.
The 115V version is rect angular box, assembling directly
onto the TSD body .
Ð The plastic box was projected to offer protection against
contamination and mechanical shock normally present in
refrigeration system production lines.
Ð The TSD's internal components may undergo degradation
when in contact with chemical elements such as CI2,H
2S,
NH3,SO
X,NO X. Some plastic isolation of cables may
release chemical elements when submitted to high
temperature conditions. Thus, check if the isolation of the
cables used on the terminal board are in accordance with
this recommendation.
Ð The TSD was designed for the operation with a run
capacitor and Embraco domestic compressor; any other
application must be previously evaluated by EmbracoÕs
technical team.
Ð Embraco reserves the right to check the customer's
handling of the manufacturing / assembly process,
indicating possible adjustments should any be required.
Ð After replacement, the compressor and itÕs accessories
must have proper processing, and the components must
be recycled according to the material group (ferrous,
non-ferrous, polymers, oils, ...) directives.
These recomendations are intended to minimize the
adverse impacts that may be caused to the environment.

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
adjustment screw of the OLP in any way.
- 11 -
Part
Customer part
number
Lot code/
date code
330 FBYY -S1 BOX98
12345678
Physical
termination
part number
Electrical
characteristics
part number
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)
(OVERLOAD PROTECTOR cross section)
Figure 18

BETTER MODEL
5. CIRCUIT DIAGRAM
- 12 -

6. TROUBLESHOOTING
- 13 -
6-1 COMPRESSOR AND ELECTRIC COMPONENTS
1
2
3
4
5
2
5
5
3
5
1
43
YES
NO
YES
The range of resistance is between 1~50½ (ok)
Open or short
NO
Power source.
No voltage.
(Rated voltage
±10%)?
Replace OLP.
Reconnect.
Refer to page 12.
Refer to page 12.
Check connection
condition.
OLP disconnected?
Advise customer that
power supply needs to be
checked by an electrician.
Replace
compressor.
Supply
voltage rating
with ±10%.
Applied voltage isn't
in acceptable range.
(115V ±10%)
Remove TSD-Starter
from compressor and
measure voltage
between terminal C of
compressor and
terminal 5 or 6 of TSD.
Check resistance
between M-C, S-C and
M-S in motor
compressor.
Check resistance of
two terminals in
TSD-Starter.
Check resistance of two
terminals in OLP.
Check the power supply
under load.
(Compressor attempting
to re-start after being off
for 5 minutes).
Check
resistance of
motor
compressor.
Check
resistance of
TSD-Starter.
Check OLP.
Check
starting state.

- 14 -
6-2 TSD AND OLP
Shows continuity
Open
TSD-115/127V-60Hz -Y
123456789101112
513604000 000000007Z
17/JUL/06
EECON JLLE
RoHS
R
Normal operation of
compressor is
impossible or poor.
Separate TSD-Starter
from compressor and
measure resistance
between No. 5 and 6
of PTC-Starter with a
tester.
(Figure 19)
Separate OLP from
compressor and check
resistance value
between two terminals
of OLP with a tester.
(Figure 20)
Observation value is
115V/60Hz : 6.8Ω±30%
The resistance value
is 0Ω(short) or
∞(open).
Check another
electric component.
Replace OLP.
Replace TSD-
Starter.
Figure 19 Figure 20

- 15 -
▼Not cooling at all
▼Poor cooling performance
Compressor
doesn't run.
Compressor runs
poorly. Check starting
voltage.
Check for open short or
incorrect resistance readings
in the following components
a. Starting devices
b. OLP
c. Compressor coil
d. Wiring harness
Low voltage.
Short, open, or broken.
Poor contact
or shorted.
Coil open or shorted.
Poor contact
or shorted.
Poor or broken or
open contact.
Shorted.
Lack of capacity.
Replace
indicated component.
Advise customer that
the power supply
needs to be checked
by an electrician.
Replace
indicated component.
Cause
Check voltage at
starting devices.
Check current flowing
in sub-coil of
compressor.
Check rating of OLP.
Fan motor
doesn't run.
Heavy frost buildup on
evaproator.
Wire is open or
shorted.
Coil is shorted
or open.
Open.
Open. Replace
defrost heater.
Replace
indicated component.
Replace
indicated component.
Check wiring circuit.
Check fan motor.
Check current flow in
the following
components:
sensor
melting fuse
Check current flow in
the defrost heater.
6-3 OTHER ELECTRICAL COMPONENTS

6-4 SERVICE DIAGNOSIS CHART
- 16 -
COMPLAINT POINTS TO BE CHECKED REMEDY
●Other possible problems:
Check if frost forms in
the freezer. Check components of
the defrosting circuit.
Check the
refrigeration system.
Check the
thermistor.
Not
defrosting
The system
is faulty. Perform sealed
system repair.
Replace the
thermistor.
The operation of
the thermistor is
incorrect.
No Cooling.
Cools poorly.
Food in the
Refrigerator
is frozen.
Condensation or ice
forms inside
the unit.
Condensation forms
in the Exterior Case.
There is abnormal
noise.
Door does not
close well.
Ice and foods
smell unpleasant.
• Is the power cord unplugged from the outlet?
• Check if the power switch is set to OFF.
• Check if the fuse of the power switch is shorted.
• Measure the voltage of the power outlet.
• Check if the unit is placed too close to the wall.
• Check if the unit is placed too close to the stove,
gas cooker, or in direct sunlight.
• Is the ambient temperature too high or
the room door closed?
• Check if food put in the refrigerator is hot.
• Did you open the door of the unit too often
or check if the door is sealed properly?
• Check if the Control is set to warm position.
• Is food placed in the cooling air outlet?
• Check if the control is set to colder position.
• Is the ambient temperature below 5°C?
• Is liquid food sealed?
• Check if food put in the refrigerator is hot.
• Did you open the door of the unit too
often or check if the door is sealed properly?
• Check if the ambient temperature and humidity
of the surrounding air are high.
• Is there a gap in the door gasket?
• Is the unit positioned in a firm and even place?
• Are any unnecessary objects placed
behind of the unit?
• Check if the drip tray is not firmly attached.
• Check if the cover of the compressor enclosure
in the lower front side is taken out.
• Check if the door gasket is dirty with
an item like juice.
• Is the refrigerator level?
• Is there too much food in the refrigerator?
• Check if the inside of the unit is dirty.
• Are foods with a strong odor unwrapped?
• The unit smells of plastic.
• Plug into the outlet.
• Set the switch to ON.
• Replace the fuse.
• If the voltage is low, correct the wiring.
• Place the unit about 4 inches (10 cm) from the wall.
• Place the unit away from these heat sources.
• Lower the ambient temperature.
• Put in foods after they have cooled down.
• Don't open the door too often and close
it firmly.
• Set the control to recommended position.
• Place foods in the high-temperature section.
(front part)
• Set the control to recommended position.
• Set the control to warm position.
• Seal liquid foods with wrap.
• Put in foods after they have cooled down.
• Don't open the door too often and close
it firmly.
• Wipe moisture with a dry cloth. It will disappear
in low temperature and humidity.
• Fill up the gap.
• Adjust the leveling screw, and position the
refrigerator in a firm place.
• Remove the objects.
• Fix the drip tray firmly in the original position.
• Place the cover in its original position.
• Clean the door gasket.
• Position in a firm place and level the
leveling screw.
• Make sure food stored in shelves does not prevent
the door from closing.
• Clean the inside of the unit.
• Wrap foods that have a strong odor.
• New products smell of plastic, but this
will go away after 1-2 weeks.

6-5 REFRIGERATION CYCLE
- 17 -
▼Troubleshooting Chart
PARTIAL Freezer Low flowing sound of A little higher • Refrigerant level is low due
LEAKAGE compartment and refrigerant is heard and than ambient • to a leak.
refrigerator don't frost forms in inlet only. temperature. • Normal cooling is possible by
cool normally. • restoring the normal amount of
•refrigerant and repairing the leak.
COMPLETE Freezer Flowing sound of refrigerant Equal to ambient • No discharging of refrigerant.
LEAKAGE compartment and is not heard and frost isn't temperature. • Normal cooling is possible by
refrigerator don't formed. • restoring the normal amount of
cool normally. • refrigerant and repairing the leak.
PARTIAL Freezer Flowing sound of refrigerant A little higher • Normal discharging of the
CLOG compartment and is heard and frost forms than ambient • refrigerant.
refrigerator don't in inlet only. temperature. • The capillary tube is faulty.
cool normally.
WHOLE
Freezer Flowing sound of refrigerant Equal to ambient • Normal discharging of the
CLOG compartment and is not heard and frost isn't temperature. • refrigerant.
refrigerator don't cool. formed.
MOISTURE Cooling operation Flowing sound of refrigerant Lower than • Cooling operation restarts
CLOG stops periodically. is not heard and frost melts. ambient • when heating the inlet of the
temperature. • capillary tube.
COMP- Freezer and Low flowing sound of A little higher • Low pressure at high side
RESSION refrigerator refrigerant is heard and than ambient • of compressor due to low
don't cool. frost forms in inlet only. temperature. • refrigerant level.
NO COMP- No compressing Flowing sound of refrigerant Equal to ambient • No pressure in the high
RESSION operation. is not heard and there is temperature. • pressure part of the
no frost. • compressor.
CAUSE TEMPERATURE
OF THE
COMPRESSOR REMARKS
STATE OF
THE UNIT STATE OF THE EVAPORATOR
LEAKAGE
CLOGGED BY DUST
DEFECTIVE
COMPRESSION

6-5-1 SEALED SYSTEM DIAGNOSIS
- 18 -
Not Cooling Complaint
All components operating, No airflow problems, Not frosted up as a defrost problem
problem has been isolated to sealed system area
Frost
Pattern?
Equalization
Test
Partial
Very Fast
Inefficient
Compressor Partial Restriction Complete Restriction
Equalization
Test
Condenser
Temperature
None
Very Fast
Very SlowVery Slow
Hotter than Normal
Air/Low Side
Leak Loss of Change
Compressor Not
Pumping
CapTube
Sound
RoomTemperature
Trace of Oil
Undercharge
Leak
Yes
No
Faint
Fast
None toWeak
(The equalization test is trying to restart a compressor using a start kit after it has been operating.)

7-1 OPERATION PRINCIPLE
7-1-1 Operation Principle of Icemaker
7. OPERATION PRINCIPLE AND REPAIR METHOD OF ICEMAKER
- 19 -
1. Turning the Icemaker stop switch off (O) stops the icemaking function.
2. Setting the Icemaker switch to OFF and then turning it back on will reset the icemaker control.
¥ Adjusts EJECTOR to Start Position with power on.
Power On
Start Position
Icemaking
Mode
Harvest
Mode
Park Position
Fill
Test Mode
¥ Waits until water becomes cold after starting the
icemaking operation.
¥ Runs MOTOR to drop ice from the tray into the ICE BIN.
¥ Performs Icemaking Mode after supplying water by operating
the SOLENOID in ICE VALVE.
¥ To operate LINE and SERVICE, press and hold the Fill Key 
for 3 seconds. The icemaker will run through 3 stages:
Harvest Fill Icemaking .
¥ With the detect lever, checks if the ICE BIN is full.
Automatic
Shut off Arm
Icemaker
Cube Size
Indicator Light Cube Size
Select Button
Power Switch

7-2 ICE MAKER FUNCTIONS
7-2-1 Start Position
1. After POWER OFF or power outage, check the EJECTOR's position with MICOM initialization to restart.
2. How to check if it is in place:
- Check HIGH/LOW signals from HALL SENSOR in MICOM PIN.
3. Control method to check if it is in place:
(1) EJECTOR is in place,
- It is an initialized control, so the mode can be changed to ice making control.
(2) EJECTOR isn't in place:
A. If EJECTOR is back in place within 2 minutes with the motor on, it is being initialized. If not, go to step B.
B. If the heater does not return to operate by turning on and off five times for 5 minutes in one cycle, it is being
initialized. If not, it is not functioning. Repeat step B with heater and motor off.
7-2-2 Ice Making Mode
1. Icemaking refers to the freezing of supplied water in the ice trays. Complete freezing is assured by measuring the
temperature of the Tray with icemaking SENSOR.
2. Icemaking starts after completion of the water fill operation.
3. The icemaking function is completed when the sensor reaches -7°C, 60 minutes after starting.
NOTE : After icemaker power is ON, the icemaker heater will be on for test for 9 sec.
7-2-3 Harvest Mode
1. Harvest (Ice removing) refers to the operation of dropping ices into the ice bin from the tray when icemaking has
completed.
2. Harvest mode:
(1) The Heater is ON for 30 seconds, then the motor starts.
(2) Harvest mode is completed if it reaches start position again while Heater & Motor are on at the same time.
A. ice bin is full : the motor, the heater and the ejector will not operate.
B. ice bin is not full : The EJECTOR rotates once to open for ice.
NOTE : If the EJECTOR does not rotate once within 5 minutes in status (2), separate heater control mode starts
operating to prevent the EJECTOR from being constrained. (It is recommended that the user open for ice to
return to normal mode.)
- 20 -
G/Y
G/YG/Y
G/Y BK
BKBK
BK BL
BLBL
BL RD
RDRD
RD