LG LBC22520SB Service Manual
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LG LBC22520SB Service Manual

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See also: Owner's Manual
REFRIGERATOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
MODELS:
LBC22520SB
LBC22520ST
LBC22520SW
LBC22520TT

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Summary of Contents for LG LBC22520SB

  • Page 1 REFRIGERATOR SERVICE MANUAL CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. MODELS: LBC22520SB LBC22520ST LBC22520SW LBC22520TT...

  • Page 2: Table Of Contents

    CONTENTS SAFETY PRECAUTIONS ..................... 1. SPECIFICATIONS ......................2. PARTS IDENTIFICATION ....................3. DISASSEMBLY ........................ 3-1 Refrigerator Door......................3-2 Freezer Door......................... 3-3 Fan and Fan Motor......................3-4 Defrost Control Assembly....................3-5 Lamp..........................3-6 Control Box Refrigerator....................3-7 Multiduct........................3-8 Cover Valve........................4.

  • Page 3: Specifications

    1. SPECIFICATIONS LBC22520SW LBC22520ST LBC22520SB LBC22520TT SPECIFICATIONS Color Super White Stainless/Light Noble Gray Black Titanium/Light Noble Gray 32.8 (W) x 32.2 (D) x 68.5 (H) in. Dimensions Net Weight 125kg Capacity 22 cuft Refrigerant R134a (120g) Climate class Temperate (N)

  • Page 4: Parts Identification

    2. PARTS IDENTIFICATION Use this section to become more familiar with the parts and features. NOTE: This guide covers several different models. The refrigerator you have purchased may have some or all of the items listed below. The locations of the features shown below may not match your model. Digital Sensor Control Dairy Bin Refrigerator Light...

  • Page 5: Disassembly

    3. DISASSEMBLY 3-1. REFRIGERATOR DOOR 3-1-1. REMOVE REFRIGERATOR DOOR 3-1-2. REVERSE REFRIGERATOR DOOR Before removing the doors, remove the Base Grille. screwdriver and remove. Fig. 5 screwdriver and remove. Fig. 1 Using 10mm or 13/32-inch socket wrench, remove the 3 bolts and lift off the T op Hinge. Set parts aside. Fig.
  • Page 6 3-1-3. HOW TO REVERSE DOOR HANDLE Lift up door slightly and remove it. NOTE: T o assist in installing the handle on the right Fig. 9 side, place a small piece of masking tape near the top of the handle before removing. Grasp the handle tightly with both hands and slide the handle up (this may require some force).

  • Page 7: Freezer Door

    Install the handle mounting screws on the 3-2. FREEZER DOOR • right side. 3-2-1. REMOVE FREEZER DOOR IMPORTANT: To avoid possible injury, product or property damage, you will need two people to perform the following instructions. Carefully lift up the door. Remove and place it on a non scratching surface.
  • Page 8 Tighten Bolts. Force-fit T op Hinge Cover over top Change the Hinge Pin from the right side to left side. Hinge. Fig. 21 Before After Fig. 25 3-2-2 REVERSE FREEZER DOOR IMPORTANT: To avoid possible injury, product or Move the Bottom Hinge to the left side keeping property damage, you will need two people to perform the same orientation and attach 2 bolts.
  • Page 9 Place screws into outer hole on right side of cabinet. Tighten Bolts. Force-fit T op Hinge Cover over top Attach cover on the right side. Cover is force-filted. Hinge. Fig.33 Fig. 29 Replace cover from left side of refrigerator top onto Flip the middle hinge bracket (flange now will be on the right of top to cover holes.

  • Page 10: Fan And Fan Motor

    3-3. FAN AND FAN MOTOR 3-5. LAMP 1. Remove the freezer shelf. (If your refrigerator has an icemaker, remove the icemaker first). 2. Remove the plastic guide for slides on left side by unscrewing phillips head screws. 3. Remove the grille by removing one screw and pulling the grille forward.

  • Page 11: Control Box Refrigerator

    3-6. CONTROL BOX-REFRIGERATOR 1. First, remove all shelves in the refrigerator, than remove the Refrigerator control Box by loosening 2 screws. CONTROL BOX COVER LAMP Fig. 42 2. Remove the Refrigerator Control Box by pulling it downward. 3. Disconnect the lead wire on the right position and separate the lamp sockets.

  • Page 12: Cover Valve

    3-8. COVER VALVE 3-8-1. DISASSEMBLE 3-8-2. ASSEMBLE 1. Push to inside the cover valve. 1. Insert the cover valve as shown in the picture, push to insert (may need force). 2. Push to the right and release. 2. Insert hook &...

  • Page 13: Adjustment

    4. ADJUSTMENT 4-1 COMPRESSOR 4-2-3 PTC-Applied Circuit Diagram Starting Method for the Motor 4-1-1 Role The compressor intakes low temperature and low pressure gas from the evaporator of the refrigerator and compresses OVERLOAD PROTECTOR this gas to high-temperature and high-pressure gas. It then delivers the gas to the condenser.

  • Page 14: Olp (Overload Protector)

    4-3 OLP (OVERLOAD PROTECTOR) 4-4 TO REMOVE THE COVER PTC 4-3-1 Definition of OLP (1) OLP (OVERLOAD PROTECTOR) is attached to the (1) Remove the screws on the Cover Back and take it out. Compressor and protects the Motor by opening the (2) Remove the screw on Cover PTC.

  • Page 15: Circuit Diagram

    5. CIRCUIT DIAGRAM CIRCUIT DIAGRAM PWB(PCB) ASSEMBLY,DISPLAY CON101 STEPPING C-FAN F-FAN MOTOR PK WH BK YL CON5 CON6 CON4 CON8 RT-SENSOR PWB(PCB) ASSEMBLY, MAIN R-DOOR PERCEPTION S/W CON7 F-DOOR PERCEPTION S/W DEF-SENSOR R-SENSOR F-SENSOR POWER SUPPLY CON2 CON1 CON3 CORD GN/YL (GN) ICE MAKER PART...

  • Page 16: Troubleshooting

    6. TROUBLESHOOTING 6-1 COMPRESSOR AND ELECTRIC COMPONENTS (Rated voltage Remove PTC-Starter Power Source. ± 10%)? from compressor and measure voltage between T erminal C of compressor and terminal 5 or 6 of PTC. OLP disconnected? No voltage. Reconnect. Check connection condition.

  • Page 17: Ptc And Olp

    6-2 PTC AND OLP Separate PTC-Starter Observation value is Normal operation of compressor is impossible from Compressor and 115V/60Hz : 6.8 ±20% or poor. measure resistance between No. 5 and 6 of PTC-Starter with a T ester. (Figure 1) Replace PTC- The resistance value Starter.

  • Page 18: Other Electrical Components

    6-3 OTHER ELECTRICAL COMPONENTS • Not cooling at all Check for open short or Compressor Cause doesn't run. incorrect resistance readings in the following components a. Starting devices Short, open, or broken. Poor contact b. OLP or shorted. Coil open or shorted. c.

  • Page 19: Service Diagnosis Chart

    6-4 SERVICE DIAGNOSIS CHART COMPLAINT POINTS TO BE CHECKED REMEDY No Cooling. • Is the power cord unplugged from the outlet? • Plug into the outlet. • Check if the power switch is set to OFF . • Set the switch to ON. •...

  • Page 20: Refrigeration Cycle

    6-5 REFRIGERATION CYCLE • Troubleshooting Chart TEMPERATURE STATE OF STATE OF THE CAUSE REMARKS OF THE THE UNIT EVAPORATOR COMPRESSOR - Refrigerant level is low due to a Freezer Low flowing sound of A little higher than PARTIAL leak. ¥ compartment and refrigerant is heard and frost ambient...
  • Page 21 General Control of Refrigerating Cycle ITEMS UNIT STANDARDS PURPOSES REMARKS Pipe and Min. Pipe: within 1 hour. To protect The opening time should be reduced piping system Comp: within 10 minutes. moisture to a half of the standards during rain opening time Drier: within 20 minutes.

  • Page 22: Operation Principle And Repair Method Of Icemaker

    7. OPERATION PRINCIPLE AND REPAIR METHOD OF ICEMAKER 7-1 OPERATION PRINCIPLE 7-1-1 Operation Principle of Icemaker Power On Start Position • Adjusts Ejector to Start Position with power on. Icemaking • Waits until water becomes cold after starting the Mode Icemaking operation.

  • Page 23: Ice Maker Functions

    7-2 ICE MAKER FUNCTIONS 7-2-1 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.

  • Page 24: Defect Diagnosis Function

    7-2-4 Function TEST 1. This is a compulsory operation for test, service, cleaning, etc. It is operated by pressing and holding the Cube Size button for 3 seconds. 2. The test works only in the Icemaking Mode. It cannot be entered from the Harvest or Fill mode. (If there is an ERROR, it can only be checked in the TEST mode.) 3.

  • Page 25: Description Of Function & Circuit Of Micom

    8. DESCRIPTION OF FUNCTION & CIRCUIT OF MICOM 8-1 FUNCTION 8-1-1 Function 1. When the appliance is plugged in, it is set to “4” for Refrigerator and “4” for freezer. You can adjust the Refrigerator and the Freezer control temperature by pressing the ADJUST button, 2.
  • Page 26 8-1-5 Alarm for Open Door 1. This feature sounds a buzzer when the freezer or refrigerator door is not closed within 1 minute after it is opened. 2. One minute after the door is opened, the buzzer sounds three times each for ½ seconds. These tones repeat every 30 seconds.
  • Page 27 8-1-9 Defect Diagnosis Function 1. Automatic diagnosis makes servicing the refrigerator easy. 2. When a defect occurs, the buttons will not operate; but the tones. such as ding. will sound. 3. When defect is repaired the defect code is removed and refrigerator returns to normal operation (RESET) 4.
  • Page 28 8-1-10 TEST Mode 1. The Test mode allows checking the PCB and the function of the product as well as finding out the defective part in case of an error. 2. The test mode is operated by pressing two buttons at Display panel. 3.

  • Page 29: Pcb Function

    8-2 PCB FUNCTION 8-2-1 Power Circuit The secondary part of the TRANSFORMER is composed of the power supply for the display, the BLDC FAN Motor drive (15.5 V), the relay drive (12 Vdc) and the MICOM and IC (5 Vdc). The voltage for each part is as follows: PART VA 1...
  • Page 30 8-2-2 Oscillation Circuit This circuit generates the base clock for calculating time and the synchro clock for transmitting data from and to the inside logic elements of the IC1 (MICOM). Be sure to use specific replacement parts, since calculating time by the IC1 may be changed.
  • Page 31 8-2-4 Load / Buzzer Drive & Open Door Detection Circuit 1. Load Drive Condition Check DEFROSTING COMP LAMP LOAD TYPE POWER MODE HEATER (OPTIONAL) Measurement Location (IC6) NO.14 NO.12 NO.11 NO.12 1V or below Condition 2. Fan motor driving circuit (freezing compartment fan) 1.
  • Page 32 3. Cooling motor driving circuit (machine room) 1. This circuit makes standby power 0 by cutting off power supplied to Iss inside of the fan motor in the fan motor OFF. 2. This circuir prevents over-driving the fan motor by cutting off power applied to the fan motor in the lock of fan motor by sensing the operation RPM of the fan motor.
  • Page 33 5. Open Door Detection Circuit Check REFRIGERATOR DOOR SWITCH FREEZER DOOR SWITCH Measurement Location Freezer/ (PIN NO.15 & PIN NO.14) Refrigerator Door Closed Open 8-2-5 Temperature Sensor Circuit FREEZER-SENSOR REFRIGERATOR-SENSOR DEFROST-SENSOR The upper CIRCUIT reads REFRIGERATOR temperature, FREEZER Temperature, and DEFROST-SENSOR temperature for defrosting and the indoor temperature for compensating for the surrounding temperature into MICOM.
  • Page 34 8-2-6 Refrigeration Compartment Stepping Motor Damper Circuit * The circuit shown below is the damper circuit to regulate the refrigerator temperature. 8-2-7 Temperature Compensation & Overcooling/Undercooling Compensation Circuit 1. Refrigerator Temperature Compensation Table of Refrigerator temperature compensation. OPTION CUTTING REMARK Warmer JCR1 R+ 1.0 deg compensation...
  • Page 35 8-2-8 Key Button Input & Display Light-On Circuit ? The circuit shown above determines whether a function control key on the operation display is pushed. It also turns on the corresponding function indication LED (LED Module) SEVEN SEGMENT DISPLAY (SEVEN SEGMENT DISPLA Y MODULE).

  • Page 36: Resistance Specification Of Sensor

    8-3 RESISTANCE SPECIFICATION OF SENSOR RESISTANCE OF REFRIGERATOR & TEMPERATURE DETECTED RESISTANCE OF FREEZER DEFROST SENSOR & ROOM SENSOR BY SENSOR SENSOR 22.3K -20°C -15°C 16.9K 13.0K 47.3K -10°C 38.4K -5°C 10.1K 0°C 7.8K 24.1K +5°C 6.2K 4.9K +10°C 19.5K +15°C 3.9K 15.9K...

  • Page 37: Troubleshooting

    - 37 -...
  • Page 38 - 38 -...

  • Page 39: Main Pwb Assembly And Parts List

    8-5 MAIN PWB ASSEMBLY AND PARTS LIST 8-5-1 Main PWB Assembly - 39 -...
  • Page 40 8-5-2 Replacement Parts List - 40 -...
  • Page 41 8-5-3 PWB Assembly, Display and Parts List - 41 -...

  • Page 42: Pwb Diagram

    8-6 PWB DIAGRAM 8-6-1 PWB Main Assembly - 42 -...
  • Page 43 - 43 -...

  • Page 44: Exploded View And Replacement Part List

    #EV# 10. EXPLODED VIEW CASE PARTS CAUTION: Use the part number to order part, not the position number. 103A 281A 281B 103B 410A 409D 406B 503G 501F 282E 503F 282F 903D 503D 145A 610A 503C 503E 501A 409B 619B 120B 411A 304A 125D*...
  • Page 45 #EV# FREEZER PARTS CAUTION: Use the part number to order part, not the position number. 131A 149A 136C - 45 -...
  • Page 46 #EV# REFRIGERATOR PARTS CAUTION: Use the part number to order part, not the position number. 143E 140D 140B 140E 143E 140D 140B 143E 140E 140D 140B 140E 143F 142D 140B 142E 128A 103E 170A 128B 167B 154A 151A 103E 155B 151A 151C - 46 -...
  • Page 47 #EV# DOOR PARTS CAUTION: Use the part number to order part, not the position number. 230A 241A 233A 231A 241B 286A 212G 241C 244E 241E 244A 286A 241D 243A 205D 200A 203A 201A 281E 212A 286A 243A 283F - 47 -...
  • Page 48 #EV# WATER & ICE MAKER PARTS CAUTION: Use the part number to order part, not the position number. 600C 602A 600A 622B 618A 623C 616E 627A 619C 619A 262D - 48 -...
  • Page 49 MFL62526004 September, 2009...

This manual is also suitable for:

Lbc22520swLbc22520ttLbc22520st

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