LG LSC27950SW, LSC27950SB, LSC27950ST, LSC27960ST Service Manual

CAUTION

PLEASE READ CAREFULLY THE SAFETY PRECAUTIONS OF THIS MANUAL BEFORE CHECKING OR OPERATING THE REFRIGERATOR.

REFRIGERATOR

SERVICE MANUAL

MODEL : LSC27950SW/ LSC27950SB LSC27950ST/ LSC27960ST

COLOR : SUPER WHITE

WESTERN BLACK STAINLESS

http://aic.lgservice.com

CONTENTS

WARNINGS AND PRECAUTIONS FOR SAFETY ................................................................................................................ 3

SPECIFICATIONS................................................................................................................................................................... 4

PARTS IDENTIFICATION ........................................................................................................................................................6

HOW TO INSTALL THE REFRIGERATOR ............................................................................................................................ 8

HOW TO ADJUST DOOR HEIGHT...................................................................................................................................... 8

FILTER ................................................................................................................................................................................. 9

HOW TO CONTROL THE ICEMAKER WATER SUPPLY.................................................................................................. 10

MICOM FUNCTION............................................................................................................................................................... 11

EXPLANATION OF MICOM CIRCUIT.................................................................................................................................. 26

EXPLANATION OF PWB CIRCUIT .....................................................................................................................................26

PWB PARTS DIAGRAM AND LIST .....................................................................................................................................45

PWB CIRCUIT DIAGRAM ...................................................................................................................................................50

ICEMAKER AND DISPENSER WORKING PRINCIPLES AND REPAIR ............................................................................52

WORKING PRINCIPLES.................................................................................................................................................... 52

FUNCTION OF ICEMAKER ............................................................................................................................................... 53

CIRCUIT................................................................................................................................................................................ 55

TROUBLE DIAGNOSIS........................................................................................................................................................ 57

TROUBLESHOOTING ....................................................................................................................................................... 57

FAULTS .............................................................................................................................................................................. 67

COOLING CYCLE HEAVY REPAIR ................................................................................................................................... 84

HOW TO DEAL WITH CLAIMS.......................................................................................................................................... 91

HOW TO DISASSEMBLE AND ASSEMBLE....................................................................................................................... 96

DOOR................................................................................................................................................................................. 96

HANDLE ............................................................................................................................................................................. 97

FAN SHROUD GRILLE ...................................................................................................................................................... 97

WATER VALVE DISASSEMBLY METHOD .........................................................................................................................98

FAN and FAN MOTOR DISASSEMBLY METHOD..............................................................................................................98

DISPENSER....................................................................................................................................................................... 99

EXPLODED VIEW .............................................................................................................................................................. 101

REPLACEMENT PARTS LIST............................................................................................................................................ 113

- 2 -

WARNINGS AND PRECAUTIONS FOR SAFETY

Please observe the following safety precautions to use the refrigerator safely and correctly and to prevent accident or injury when servicing.

1. Be careful of an electric shock. Disconnect the power cord from wall outlet and wait for more than three minutes before replacing PWB parts. Shut off the power whenever replacing and repairing electric components.

2. When connecting the power cord, please wait for more than five minutes after the power cord was disconnected from the wall outlet.

3. Check if the power cord is pinched between the refrigerator and the wall. If the plug or cord is damaged, it could cause a fire or an electric shock

4. If the wall outlet is overloaded, it may cause a fire. Use a dedicated circuit for the refrigerator.

5. Make sure the outlet is properly grounded. Particularly in a wet or damp area.

6. Use standard electrical components.

7.Remove dust and foreign materials from the housing and

connecting parts.

8. Do not fray, damage, run over, kink, bend, pull out, or twist the power cord.

9. Check for evidence of moisture intrusion in the electrical components. Replace the parts or mask with insulation tape if moisture intrusion was confirmed.

10. Do not insert fingers or tools into the icemaker. The geared motor drive could cause an injury or damage to tools or the icemaker .

11. Do not suggest that customers repair their refrigerator

themselves. This work requires special tools and knowledge. Non-professionals could cause fire, injury, or damage to the product.

12. Do not store flammable materials such as ether, benzene, alcohol, chemicals, or gas.

13. Do not put anything on top of the refrigerator, especially something containing water, like a vase.

14. Do not put glass bottles with full of water into the freezer. The contents will freeze and break the glass bottles.

15. When you scrap or discard the refrigerator, remove the doors and dispose of it where children are not likely to play in or around it.

16. This is a consumer grade product. It is not intended for precise storage of medication.

- 3 -

SPECIFICATIONS

724 mm (28

in.)

1004 mm (391/2 in.)

908 mm (39

/16 in.)

779 mm (30

in.)

829 mm (32

in.)

897 mm (35

in.)

1261 mm (49

in.)

1741.5 mm (68

in.)

1746.5 mm (68

in.)

1771 mm (69

in.)

1771 mm (69

in.)

1. Ref No. : GR-L277SV(S)VA (LSC27950SW, LSC27950SB, LSC27950ST)

ITEMS SPECIFICATIONS

DIMENSIONS 908 X 896 X 1771 mm

X D X

H (35

NET WEIGHT 149 kg (328.5 lbs.)

COOLING SYSTEM Fan Cooling

TEMPERATURE CONTROL Micom Control

DEFROSTING SYSTEM Full Automatic

INSULATION Cyclo-Pentane

COMPRESSOR PTC Starting Type

EVAPORATOR Fin Tube Type

CONDENSER Wire Condenser

REFRIGERANT R134a (185g) (6

LUBRICATING OIL FREOL @10G (320 cc)

/16X355/16X6911/16 in.)

Heater Defrost

/2 oz.)

ITEMS SPECIFICATIONS

DRIER MOLECULAR SIEVE XH-7

CAPILLARY TUBE ID Ø0.83

FIRST DEFROST 4 - 5 Hours

DEFROST CYCLE 13 - 15 Hours

DEFROSTING DEVICE Heater, Sheath

ANTI-SWEAT HEATER Dispenser Duct Door Heater

Dispenser Heater

ANTI-FREEZING HEATER Damper Heater

FREEZER LAMP 40W (1 EA)

REFRIGERATOR LAMP 40W (4 EA)

DISPENSER LAMP 15W (1 EA)

Front View Top View

- 4 -

SPECIFICATIONS

2. Ref No. : GR-L277SSWA (LSC27960ST)

ITEMS SPECIFICATIONS

DIMENSIONS 908 X 896 X 1771 mm

X D X

H (35

NET WEIGHT 149 kg (328.5 lbs.)

COOLING SYSTEM Fan Cooling

TEMPERATURE CONTROL Micom Control

DEFROSTING SYSTEM Full Automatic

INSULATION Cyclo-Pentane

COMPRESSOR PTC Starting Type

EVAPORATOR Fin Tube Type

CONDENSER Wire Condenser

REFRIGERANT R134a (185g) (6

LUBRICATING OIL FREOL @10G (320 cc)

/16X355/16X6911/16 in.)

Heater Defrost

/2 oz.)

ITEMS SPECIFICATIONS

DRIER MOLECULAR SIEVE XH-7

CAPILLARY TUBE ID Ø0.83

FIRST DEFROST 4 - 5 Hours

DEFROST CYCLE 13 - 15 Hours

DEFROSTING DEVICE Heater, Sheath

ANTI-SWEAT HEATER Dispenser Duct Door Heater

Dispenser Heater

ANTI-FREEZING HEATER Damper Heater

FREEZER LAMP 40W (1 EA)

REFRIGERATOR LAMP 40W (4 EA)

DISPENSER LAMP 15W (1 EA)

in.)

1771 mm (69

1004 mm (391/2 in.)

908 mm (39

in.)

1741.5 mm (68

Front View Top View

in.)

1771 mm (69

1746.5 mm (68

/16 in.)

in.)

724 mm (28

779 mm (30

829 mm (32

in.)

897 mm (35

1261 mm (49

- 5 -

PARTS IDENTIFICATION

1. Ref No. : GR-L277SV(S)VA (LSC27950SW, LSC27950SB, LSC27950ST)

PWB Cover

Frame Display

Dispenser Lamp

Ice & Water

Dispenser Button

Automatic Icemaker

Freezer

Compartment

Water Tubes

Refrigerator

Compartment

Dairy Product Corner

Water Filter

Lamp Shelf

Lamp

Shelf

Drawer

Door Rack

Drawer

Door Rack

Lower Cover OptiFresh Display Humidity Switch

- 6 -

Shelf Can Server

Snack Drawer

Door Rack

Lamp

Bottle Guide

Vegetable Drawer

OptiFresh

Door Rack

PARTS IDENTIFICATION

2. Ref No. : GR-L277SSWA (LSC27960ST)

PWB Cover

Frame Display

Dispenser Lamp

Ice & Water

Dispenser Button

Automatic Icemaker

Freezer

Compartment

Water Tubes

Refrigerator

Compartment

Dairy Product Corner

Water Filter

Lamp Shelf

Lamp

Shelf

Drawer

Door Rack

Drawer

Door Rack

Lower Cover OptiFresh Display Humidity Switch

- 7 -

Shelf Can Server

Snack Drawer

Door Rack

Lamp

Bottle Guide

Vegetable Drawer

OptiFresh

Door Rack

HOW TO INSTALL REFRIGERATOR

Adjusting Screw

Driver

Height

Difference

Height Difference

Keeper nut

Down

Adjustment hinge pin

Tool for adjustment

1. How to Adjust Door Height of Refrigerator

■ Make the refrigerator level first. (If the refrigerator is not installed on a flat floor, the height of freezer and refrigerator door may not be the same.)

1) If the freezer door is lower than the refrigerator door:

2) If the freezer door is higher than the refrigerator door:

Insert a driver  into the groove  of the adjusting screw and turn in the direction of the arrow (clockwise) until the refrigerator is level.

3) When the refrigerator door is lower than the freezer door

Adjust the level when the refrigerator door is lower than the freezer door during

the use of the refrigerator. (1) Using the wide side of the tool for adjustment , turn the

keeper nut  ( ) clockwise to loosen the keeper nut.

(2) Using the narrow side of the tool for adjustment, turn the

adjustment hinge pin  ( ) clockwise or ( ) counterclockwise to level the refrigerator and freezer door.

(3) After setting the level of the door, turn the keeper nut ( )

counterclockwise to tighten.

Caution : Do not force too hard to level the height. The hinge

pin can be pulled out (Adjustable range of height: Maximum of 2/10

- 8 -

Insert a driver  into the groove  if the adjusting screw and turn in the direction of the arrow (clockwise) until the refrigerator is level.

HOW TO INSTALL REFRIGERATOR

2. Filter

Replace the filter when the indicator light comes on or the performance of the icemker or water dispenser decreases noticeably.

After changing the water filter cartridge, reset the water filter status display and indicator light by pressing and holding the FILTER Button for 3 seconds. (page 13)

1) Remove the old cartridge.

Twist the knob of the cartridge counterclockwise.

2) Replace with a new cartridge.

Take the new cartridge out of its packaging and remove protective cover from the o-rings.

With cartridge knob in the vertical position, push the new filter cartridge into the cover until it stops.

If you can’t turn the filter from side to side, it isn’t fully inserted. Push it in firmly and twist it into place. You will hear the snap when it clicks into place.

Using the handle, twist the cartridge clockwise about 1/4 turn.

When the cartridge is removed, you will feel it click .

Pull out the cartridge.

NOTE: There will be some water (25cc) in the filter

cartridge. Some spilling may occur. Catch it in a bowl or towel.

3) Flush the Water System After Replacing Filter

Dispense water through the water dispenser for 3 minutes to purge the system. There may be a little air in the line, causing noise or hissing. Run the water at the dispenser until the hissing stops to purge the air from the system.

NOTE: - To purchase replacement water filter cartridges,

visit your local appliance dealer or part distributor.

- You can also visit our website : www.lgappliances.com or call 1-877-714-7481.

LG MDL PART NO MAKER GR-L277SV(S)VA LSC27950 SW/SB/ST

GR-L277SSWA

LSC27960ST

5231JA2006A CUNO

- 9 -

HOW TO INSTALL REFRIGERATOR

Water Amount Indicator Light

Power Switch

Water Amount Selection Button

Feeler Arm

Check water level

3. How to Control the Amount of Water Supplied to Icemaker.

3-1. Confirm the amount of water supplied to the icemaker.

1) Confirm the amount of water supplied to the icemaker

(1) Press the button (Figure 1) to selsct the level of water (Optimum level

2) Icemaker Operation Test (Test mode)

(1) Press the button (Figure 1) for more than 3 seconds and It will start the Test mode.

(2) Test the operation of the operating part of the icemaker.

(3) If there is no problem with the operation, water is supplied through the water tube (up to the

selected lebel of water).

(4) The test mode is completed after the water is supplied.

Note : When using the test mode more than twice consecutively, water can overflow.

When the water overflows, wipe the ice storage bin.

Large Small.)

* It is acceptable if the adjusted level of water is a bit smaller than optimum level.

Figure 1.

- 10 -

MICOM FUNCTION

Dispenser Selection Button

Ice Plus Freezer Selection Button

Door Alarm Button/

Dispenser Lock Button

Dispenser Light On/Off Button/

Filter Status Display RESET Button

Temperature Adjust Button

For Refrigerator Compartment

Temperature Adjust Button For Freezer Compartment

Dispenser Selection Button

Ice Plus Freezer/Jet Freezer Function Selection Button

Door Alarm Button/

Dispenser Lock Button

Dispenser Light Auto On/Off Button/

Filter Status Display RESET Button

Temperature Adjust Button

For Refrigerator Compartment

Temperature Adjust Button For Freezer Compartment

1. Monitor Panel

1-1. GR-L277SV(S)VA (LSC27950SW, LSC27950SB, LSC27950ST)

1-2. GR-L277SSWA (LSC27960ST)

- 11 -

MICOM FUNCTION

Display Power Saving Mode

Demo Mode

Change Display Degree from Fahrenheit to Centigrade Mode

Buzzer Mute Mode

1-3. Display Second Function

1. Door Alarm Buzzer Mute Mode

Press ALARM/LOCK to turn the buzzer on or off.

2. Display Power saving Mode

It places display in standby mode until door is opened. Press FREEZER and ICE PLUS/JET buttons simultaneously to turn all LEDs ON and then OFF with the recognition sound of Ding~ after 5 seconds. (Be sure not to press only one button to work.) Once the mode activates, the display is always OFF. Until door is opened or display button is pressed. When 20 seconds has elapsed after closing door or pressing button, the display turns OFF. To deactivate this mode is same as the activation methods. The mode inactivates when resetting the power.

3. Change Display Degree to Centigrade Mode from Fahrenheit Mode

To change temperature display from Fahrenheit to Celsius press and hold FREEZER and REFRIGERATOR buttons simultaneously for more than 5 seconds. Do the same to convert back to Celsius.

4. Exhibition Mode

Demo mode is available for displaying the refrigerator in a sales setting or similar condition. It allows the display, dispenser, lights, and fan to operate without running the compressor. To enter the DEMO mode, press and hold the REFRIGERATOR and ICE PULS/JET buttons simultaneously for 5 seconds until the Ding~ sounds. To exit the DEMO mode and return to normal operation, press and hold the REFRIGERATOR and ICE PULS/JET buttons simultaneously for 5 seconds until the Ding~ sounds again. The refrigerator will default to the NORMAL mode (DEMO mode OFF) if the power fails.

- 12 -

MICOM FUNCTION

2. Description of Function

2-1-1. Function of Temperature Selection

Division Power Initially On 1st Press 2st Press 3th Press 4th Press

Temperature Control

Freezer Control

Refrigeration Control

* The temperature can vary ±5°F (±3°C) depending on the load condition.

❉ Whenever pressing button, setting is repeated in the order of COLD ➝ COLDER ➝ COLDEST ➝ COOL ➝ COLDER.

• The actual inner temperature varies depending on the food status, as the indicated setting temperature is a target temperature, not actual temperature within refrigerator.

• Refrigeration function is weak in the initial time. Please adjust temperature as above after using refrigerator for minimum 2~3 days.

• Freezer Notch is fixed COLDER unconcerned with display Notch during Icemaking Control Mode and Icemaker Stop switch is selected with ON.

2-1-2. Outside temperature display function

1. The ambient temperature sensor is located under the upper right hinge cover. This sensor reads the temperature of the room and displays it in the upper right corner of the display.

2. The ambient temperature is displayed between 16 °F and 120 °F. Outside of that range, the display will show Er.

3. Since the ambient temperature sensor is located at the hinge, its reading may differ from other thermometers in the room.

COLD COLDER COLDEST COOL COOLER

-2 °F -5 °F -8 °F 7 °F 1 °F

37 °F 34 °F 32 °F 46 °F 41 °F

- 13 -

MICOM FUNCTION

LOCK

DISPENSER & BUTTON

3 SECS

LOCK

DISPENSER & BUTTON

3 SECS

LOCK LOCK again

2-1-3. Lock function (dispenser and display button lock)

1. In power application of refrigerator, the LOCK text is turned off at the right side of lock graphic of display with the lock replease status.

2. If desiring to lock the dislay the dispenser and control panel, push on the LOCK button more than 3 seconds. LOCK is turned on at the right side of lock graphic of display with lock status.

3. The buzzer sound and control panel and dispenser function is not performed even if pressing display button other than lock key in the lock status.

4. If desiring to release the lock status and pressing the lock button more than 3 seconds. LOCK text is turned off at the right side of lock graphic of display with the lock release status.

LED

2-1-4. Filter condition display function

1. There is a replacement indicator light for the water filter cartridge on the dispenser.

2. Water filter needs replacement once six months.

3. Water filter light and FILTER RESET HOLD 3SECS text turn on to tell you need to replace the filter soon.

4. After replacing the filter, press and hold the lock button more than 3seconds. Then water filter light and FILTER RESET HOLD 3SECS text turn off with reset status.

- 14 -

MICOM FUNCTION

DISPENSER

Pressing

Switch

LED (GR-L277SV(S)VA) (LSC27950SW, LSC27950SB, LSC27950ST)

LCD (GR-L277SSWA) (LSC27960ST)

ON ON OFF

LED (GR-L277SV(S)VA) LCD (GR-L277SSWA)

(LSC27960ST)

(LSC27950SW, LSC27950SB, LSC27950ST)

DISPENSER

2-2. Dispenser use selection

You can select water or ice.

❉ Select WATER, CRUSHED ICE, or CUBED ICE by pressing the button as

you desire.

❉ Use your cup to press lightly on the actuator.

• Each graphic is indicated for the selected function.

• You’ll hear a CLICK when the ice door closes 5 seconds after ice is dispensed.

REFERENCE : Hold your cup in the dispenser for a few seconds after dispensing

ice or water to catch the last few drops or pieces of ice.

2-3. ICE PLUS Freezing/JET Freezing Selection

Select this function to expedite freezing.

• Press the button to cycle to toggle between the settings.

• The arrow mark graphic remains at the ON status after flickering 4 times when selecting Special Refrigeration ICE PLUS

FRZ or JET FRZ.

• ICE PLUS freezer or JET freezer function automatically turns off after a set time.

• Jet Freezing : Not applicable to all models.

2-4. Dispenser Light

• The dispenser light function is repeated following below whenever pressing LIGHT/FILTER button.

• Auto mode is automatic control of the dispender light by using the light sensor.

- 15 -

MICOM FUNCTION

2-5. ICE PLUS freezing

1. ICE PLUS freezing is a function to increase the cooling speed of the freezer compartment by running both the compressor and the fan simultaneously.

2. ICE PLUS is cancelled and the refrigerator returns to its default setting in the event of a power interruption.

3. Selecting ICE PLUS changes only the speed of the cooling without affecting the set temperature.

4. The temperature can be adjusted even when ICE PLUS has been selected and is in progress.

5. The freezer operates at whatever temperature was set at the time ICE PLUS was selected.

6. If you select ICE PLUS, the compressor and fan will run until it is deselected or the cycle time has elapsed. (3 hours : compressor and fan run / 3 ~ 24 hours : COLDEST operation)

7. If a defrost cycle occurs while an ICE PLUS is already running, ICE PLUS runs for its remaining cycle time after the defrost cycle is completed. If the defrost cycle takes longer than 30 minutes, ICE PLUS will run for only 2 hours at the end of the defrost cycle.

8. If you press ICE PLUS during a defrost cycle, the ICE PLUS indicator (LCD or LED, depending upon the model) will illuminate but the compressor will not operate until the defrost cycle is complete.

9. If you press ICE PLUS within 7 minutes of compressor cut-off, the compressor will not operate until the 7-minute delay has passed.

10. The freezer fan motor runs at high speed during the ICE PLUS cycle.

2-6. JET FREEZING (GR-L277SSWA / LSC27960ST)

1. JET FREEZING is a function to increase the cooling speed of the JET FREEZING compartment within the freezer by running both the compressor and the JET FREEZING fan simultaneously.

2. JET FREEZING is cancelled and the refrigerator returns to its default setting in the event of a power interruption.

3. The display temperature is not changed by selecting JET FREEZING.

4. If JET FREEZING is selected, the compressor (after the 7-minute compressor delay time passes) and the freezer fan motor will operate. The temperature in the refrigerator will drop and the fan motor will be off while the JET FREEZING cycle runs, a maximum of 2 hours. The JET FREEZING indicator will go off at the end of the JET FREEZE cycle.

5. To prevent icing up, the JET FREEZING fan motor will cycle for 10 seconds every hour when JET FREEZING is not selected.

6. If the JET FREEZING fan motor fails, this failure will not be detected because it is a 12-volt DC operation.

7. To check the JET FREEZING function, press and hold the FREEZER button or ICE PLUS/JET button for more than one second. The JET FREEZE fan will operate.

- 16 -

MICOM FUNCTION

2-7. OptiFresh Function

1. The OptiFresh bin is positioned at the bottom of the refrigerator compartment and has a separate temperature control to allow perfect storage of fruits and vegetables.

2. OptiFresh comprises of OptiFresh sensor at the rear of OptiFresh and a damper between OptiFresh and Freezer compartment and a temperature adjusting display at the top of it.

3. When powered on, the initial NOTCH of OptiFresh display will be on OptiFresh Crisper. If only the refrigerator door is opened, the OptiFresh LED will be ON.

4. The OptiFresh sensor opens and closes the damper based on the temperature.

5. The OptiFresh damper will cycle every hour to prevent icing up.

• Press the button to toggle between ON and OFF.

- 17 -

MICOM FUNCTION

Doors of freezer, refrigerator, or home bar.

BUZZER

Closing

Opening

Less than

one minute

One minute

seconds30seconds30seconds

Opening

Closing Closing

3 Times 3 Times 3 Times 3 Times

2-8. Control of variable type freezing fan

1. To increase cooling speed and response to load, the MICOM will vary the speed of the freezer fan between low and high.

2. The MICOM runs the fan at high speed only at power-up and for ICE PLUS or JET FREEZING cycles, and runs at low speed for all other settings.

3. If you open the freezer door, the refrigerator door, or the home bar door, and the freezer fan was running at high speed, it will reduce to low speed. If it was running at low speed when a door was opened, it will turn off.

4. If the MICOM determines the BLDC fan motor is locked up, (no signal for 115 seconds) it will show a failure code on the display and cut power to the fan. To power the fan again, unplug the refrigerator for a few seconds and plug it in again.

2-9. Control of cooling fan motor

1. The cooling fan motor performs ON/OFF control by linking with the COMPRESSOR.

2. It controls at the single RPM without varying RPM.

3. Failure sensing method is same as in fan motor of freezing fan motor (refer to failure diagnosis function table for failure display).

2-10. Door opening alarm

1. The buzzer sounds when any door is held open for more than one minute.

2. After any door has been open for one minute, the buzzer sounds three times for times for

3. When all open doors have been closed, the buzzer stops.

second each every thirty seconds until the door is closed.

second each, then it sounds three

2-11. Ringing of button selection buzzer

1. If pressing the front display button, Ding ~ sound rings.

- 18 -

MICOM FUNCTION

2-12. Ringing of manual operation, manual frost defrost buzzer

1. The buzzer sounds briefly when the test button on the main PCB is pressed.

2. If you select manual operation, the buzzer sounds three times for second each every thirty seconds until the door is closed.

3. If you select manual defrost, the buzzer sounds three times for each every thirty seconds until the door is closed.

2-13. Defrost function

1. Defrost is cycled whenever the compressor’s runtime reaches 7 ~ 7 hours.

2. In providing initial power (or returning power failure), defrost starts whenever total operation time of compressor becomes 4 ~ 4

3. Defrost is completed if temperature of a frost removal sensor becomes more than 5°C after starting frost removal. Poor frost removal is not displaced if it does not arrive at 5°C even if two hours have passed after starting frost removal.

4. No defrost cycle is run if the defrost sensor fails.

hour.

2-14. Refrigerator room lamp automatic off

• Refrigerator room lamp turn on and off by refrigerator door switch.

• If refrigerator room lamp continuously turns on more than 7 minutes, the refrigerator room lamp turns off automatically.

/10second each, then it sounds three times for 2/

second

- 19 -

MICOM FUNCTION

POWER

COMP

F-FAN

C-FAN

R-STEP

MOTOR

DAMPER

OPTICHILL

STEP

DAMPER

MOTOR

FROST

REMOVAL

HEATER

OFF

FROST

REMOVAL

HEATER

DAMPER

DUCT DOOR

OPTICHILL

HEATER ON

DAMPER

DUCT DOOR

OPTICHILL

HEATER OFF

0.3

sec.

6.0

sec.

0.3

sec.

0.3

sec.

0.3

sec.

0.3

sec.

PIPE

DISP'

HEATER

OFF

0.3

sec.

COMP

0.3

sec.

F-FAN

C-FAN

0.3

sec.

R-STEP MOTOR

DAMPER

0.3

sec.

OPTICHILL

STEP

DAMPER

MOTOR

PIPE

DISP'

HEATER

TEST

SWITCH

(PRESS

Once)

OTHER

LOAD

OFF

COMP

F-FAN

C-FAN

R-STEP MOTOR

DAMPER

OPTICHILL

STEP

DAMPER

MOTOR

TEST

SWITCH

(PRESS

2 Times)

COMP

OFF

F-FAN

C-FAN

OFF

FROST

REMOVAL

HEATER

R-STEP MOTOR

DAMPER

0.3

sec.

0.3

sec.

0.3

sec.

0.3

sec.

0.3

sec.

0.3

sec.

0.3

sec.

0.3

sec.

0.3

sec.

0.3

sec.

0.3

sec.

POWER

2-15. Sequential operation of components

Component products such as compressor, frost removal heater, freezing room fan, cooling fan, and step motor damper are

sequentially operated as follows for preventing noise and part damage occurred due to simultaneous operation of many

parts in applying initial power and completing test.

Function Load Operation Sequence Remark

When temperature of a frost removal

sensor becomes more than 45°C

If error occurs during operation, initial operation is not done.

(At purchase,

shipping)

In applying Initial power TEST MODE

When temperature of a

frost removal sensor becomes less than 45°C (In power failure,

■

Sequence of load operation when closing FREEZER and REFRIGERATOR.

service)

Test mode 1 (Manual function)

If you press the switch in the again test mode 2 or temperature of a frost removal sensor is more

Test mode 2 (Manual frost

removal)

than 5°C, it immediately returns to the test mode for initial operation (COMPRESSOR operates after 7 minutes).

- 20 -

MICOM FUNCTION

2-16. Failure Diagnosis Function

1. Failure diagnosis facilitates service when a failure code shows during product operation.

2. When a failure is detected, the buttons are deactivated.

3. If a failure code is released, the MICOM resets and normal operation continues.

4. The failure code is displayed on the FRZ TEMP display. All display graphics that are not part of the failure code are turned off

(1) GR-L277SV(S)VA (LSC27950SW, LSC27950SB, LSC27950ST)

- 21 -

MICOM FUNCTION

(2) GR-L277SSWA (LSC27960ST)

- 22 -

MICOM FUNCTION

Note1) Freezer room notch temperature display and refrigerator room notch temperature display (failure code indication

part) are normally indicated in abnormal ambient sensor, and “Er” indicated on the ambient temperature dispaly (except for the ambient temperature display, other display parts are indicated normally)

Note 2) R2-sensor, water-tank sensor and opti-fresh sensor is not indicated on the failure indicating part but indIicated in

checking all displaly parts (when pressing for more than the button of freezing temperature and quick rfeezing button for more than 1 second).

R2-sensor (middle room)

Water-tank sensor

Opti-fresh sensor

Note 3) Freezer room notch temperature display and refrigerator room notch temperature display (Failure code indication

part) are normally indicated in abnormal ambient sensor, and Er indicated on the amvient temperature display (except for the ambient temperature display, other LEDs or LCDs are indicated normally)

✻ LCD (LED) check function: If simultaneously pressing express freezer button and freezing temperature adjustment button

Normal: Abnormal:

for a second, a back light is turned on and all display LCD (LED) graphics on. If releasing the button, the LCD (LED) graphic displays the previous status, the back light is turned off (LCD graphic and back light ON/OFF check).

display part graphic on the (C) part turns on

display part graphic on the (C) part turns off

display part graphic on the (D) part turns on

display part graphic on the (D) part turns off

display part graphic on the (E) part turns on

display part graphic on the (E) part turns off

The other display graphics turn on

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MICOM FUNCTION

2-17. Test Function

1. The test function assists in diagnosing the PWB and determining the exact mode of failure.

2. The test button is on the main PCB. When test mode is engaged, it will complete its test cycle and default to normal operation within 2 hours.

3. The buttons are disabled while the test mode is in effect.

4. When you have finished running test mode, unplug the refrigerator to reset it to normal operation.

5. If a failure is detected during test mode, release the test mode to display the failure code.

6. If a failure code is displayed, the test mode cannot be started.

Mode Operation Contents Remarks

Test 1

Test 2

Normal

Status

Press test button once (strong cold mode)

Press test button once at the test mode 1 status (forced defrost mode)

Press test button once at the test mode 2 status

1. Continuous operation of compressor

2. Continuous operation of freezing BLDC motor (high-speed RPM) and cooling BLDC motor

3. Defrost heater turns off

4. Stepping motor damper is completely opened (baffle is closed)

5. OptiFresh stepping motor damper is completely closed.

6. All display LEDs or LCD graphics turn on.

1. Compressor OFF

2. Freezing BLDC motor and cooling BLDC motor turn off

3. Defrost heater turns on

4. Stepping motor damper is completely closed (baffle is closed)

5. OptiFresh stepping motor damper is completely closed.

Return to the initial status.

Freezer fan turns off when door is opened.

Return to the normal mode when the defrost sensor is above +5°C (+41°F)

Compressor will operate after delay for 7 minutes

TEST MODE 1 STATUS DISPLAY

TEST MODE 2 STATUS DISPLAY

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MICOM FUNCTION

2-18. Dispenser Function

1. The dispenser allows serving ice and water without opening the door.

2. Pressing the dispenser switch dispenses crushed or cubed ice or water. If ice is selected, the switch operates the door solenoid also. The door will close 5 seconds after the ice is dispensed.

3. If the freezer door is opened, the dispenser is deactivated.

4. If there is no OFF signal 3 minutes after the ice dispenser is activated, the auger and door solenoid are turned off. The auger will stop immediately, but the door will not close for another 5 seconds.

5. The dispenser lamp turns on automatically if the crushed/cubed/water button is pressed or if the dispenser button is pressed. It will turn off automatically shortly thereafter.

6. Selection function of water/crushed/cube ice

1) Select crushed/cubed/water. The display will show your selection.

2) If you select cubed ice, the auger is rotated to dispense cubes.

3) If you select crushed ice, the auger is rotated in the opposite direction to direct the cubes through the crusher.

7. Water dispenser function

1) If you select water, the display will indicate water.

2) The water dispenser uses a solenoid connected directly to the water pipe. Pressing the dispenser switch operates the solenoid, which is at the right side of the back plate.

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EXPLANATION FOR MICOM CIRCUIT

1. Explanation for PWB circuit

1-1. Power circuit

The power circuit includes a Switched Mode Power Supply (SMPS). It consists of a rectifier (BD1 and CE1) converting AC to DC, a switch (IC2) switching the DC voltage, a transformer, and a feedback circuit (IC3 and IC4).

Caution : Since high voltage (160 Vdc) is maintained at the power terminal, wait at least 3 minutes after unplugging the

appliance to check the voltages to allow the current to dissipate.

Voltage of every part is as follows:

Part VA1 CE1 CE2 CE3 CE4 CE5

Voltage 120 Vac 160 Vdc 14 Vdc 12 Vdc 15.5 Vdc 5 Vdc

(1) GR-L277SV(S)VA, SSWA (LSC27950SW, LSC27950SB, LSC27950ST, LSC27960ST)

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EXPLANATION FOR MICOM CIRCUIT

1-2. Oscillation circuit

The oscillation circuit generates a basic clock signal for synchronization and time calculation related to the transmission of data and calculations made by the MICOM (IC1). The oscillator (OSC1) must always be replaced with an exact replacement part. If this specification is changed, the change will affect the time calculations of the MICOM and it might not work at all.

(1) GR-L277SV(S)VA, SSWA (LSC27950SW, LSC27950SB, LSC27950ST, LSC27960ST)

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EXPLANATION FOR MICOM CIRCUIT

1-3. Reset circuit

The RESET circuit allows various parts of the MICOM, such as RAM, defrosting, etc., to be restarted from the initial state when power is interrupted or restored. A LOW signal applied to the reset terminal for 10 ms causes the MICOM to reset itself. During normal operation, the voltage at the reset terminal is 5 Vdc. If the reset fails, the MICOM will not operate.

(1) GR-L277SV(S)VA, SSWA (LSC27950SW, LSC27950SB, LSC27950ST, LSC27960ST)

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EXPLANATION FOR MICOM CIRCUIT

1-4. Load/dispenser operation, door opening circuit

1. LOAD DRIVING CIRCUIT

✽ The fan operates at the regular speed even if the door of the refrigerator or freezer is opened. When the doors are closed,

the fan reverts to its original speed.

✽ (A), (B), (C), and (D) of door switch for the freezer or refrigerator are connected to the door open sensing circuit in parallel

toward both ends of switch to determine door open at MICOM.

✽ In the TEST mode, the fan will stop if any door is opened. It will resume operation when the door is closed.

Type of Load Compressor

Measuring part (IC6) IC6-16 IC6-13 IC6-12 IC6-15 IC6-14

Status

ON Within 1 V

OFF 12 V

Defrost

Heater

AC Converting

Relay

Refrigerator

LAMP

Dispenser

Heater

(1) GR-L277SV(S)VA, SSWA (LSC27950SW, LSC27950SB, LSC27950ST, LSC27960ST)

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EXPLANATION FOR MICOM CIRCUIT

1-5. Dispenser operation circuit

(1) GR-L277SV(S)VA, SSWA (LSC27950SW, LSC27950SB, LSC27950ST, LSC27960ST)

1) Check load driving status

Type of Load

Measuring part IC7-15 IC7-14 IC7-13 IC7-12 IC7-11

Status

2) Lever Switch sensing circuit

Measuring part

Lever S/W

OFF 5V

ON Within 1 V

OFF 12 V

GEARED

MOTOR

SOLENOID

CUBE

5 V

0 V

WATER VALVE

WATER

IC1(Micom) (No. 16)

PILOT

VALVE

(60 Hz)

DISPENSER

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SOLENOID

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