LG LDC22720 Service Manual
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LG LDC22720 Service Manual

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See also: Owner's Manual , User Manual
REFRIGERATOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
MODELS: LDC22720**

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Summary of Contents for LG LDC22720

  • Page 1 REFRIGERATOR SERVICE MANUAL CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. MODELS: LDC22720**...

  • Page 2: Table Of Contents

    CONTENTS SAFETY PRECAUTIONS ..................... 1. SPECIFICATIONS ......................2. PARTS IDENTIFICATION ....................3. DISASSEMBLY ......................... 3.1 Door ..........................3.2 Door switch ........................3.3 Fan and fan motor ......................3.4 Defrost control assembly ....................3.5 Lamp ..........................3.6 Control Box-Refrigerator ....................3.7 Multi Duct........................4.

  • Page 3: Specifications

    1. SPECIFICATIONS MODELS LDC22720** SPECIFICATIONS CAPACITY 22CUFT HANDLE TYPE VISTA HANDLE REVERSIBLE DOOR DOOR FINISH REFRIGERANT R134a 115±3 ICE TRAY & BANK I/B(1EA) SHELF WIRE(1) BASKET DOOR LAMP YES(1) 40W/blue TRAY MEAT SHELF 4EA(FIXED) MAGIC CRISPER LAMP YES(2) 40W/blue GUIDE BOTTLE...

  • 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. Divider Digital Sensor Control Dairy Bin...
  • Page 5 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 6: Disassembly

    3. DISASSEMBLY 3-1 DOOR Freezer Door 1. Loosen the hexagonal bolts attaching the lower hinge to Refrigerator Door the body to remove the refrigerator door only. 1. Remove the hinge cover by pulling it upwards. 2. Loosen the hexagonal bolts attaching the upper hinge to the body and lift the freezer door.

  • Page 7: Fan And Fan Motor

    3-3 FAN AND FAN MOTOR 3-5-1 Refrigerator Compartment Lamp 1. Unplug the power cord from the outlet. 1. Remove the freezer shelf. (If your refrigerator has an icemaker, remove the icemaker first) 2. Remove refrigerator shelves. 2. Remove the grille by pulling it out and by loosening a 3.

  • Page 8: 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 9: 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 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...

  • Page 10: Circuit Diagram

    5. 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 CON3 CON1 CORD GN/YL (GN) ICE MAKER PART GN/YL (GN)

  • Page 11: Troubleshooting

    6. TROUBLESHOOTING 6-1 COMPRESSOR AND ELECTRIC COMPONENTS (Reated Voltage Remove PTC-Starter Power Source. ±10%)? from Compressor and measure voltage between Terminal C of Compressor and Terminals 5 or 6 of PTC. OLP disconnected? No Voltage. Replace OLP . Check connection condition.

  • Page 12: Ptc And Olp

    6-2 PTC AND OLP Normal operation of Separate PTC-Starter Observation value is Compressor is from Compressor and 115V/60Hz : 6.8 ±30% measure resistance impossible or poor. between No. 5 and 6 of PTC-Starter with a Tester. (Figure 14) Replace PTC- The resistance value Starter.

  • Page 13: Other Electrical Components

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

  • Page 14: 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 15: Refrigeration Cycle

    6-5 REFRIGERATION CYCLE Troubleshooting Chart TEMPERATURE STATE OF STATE OF THE CAUSE REMARKS OF THE THE UNIT EVAPORATOR COMPRESSOR PARTIAL Freezer Low flowing sound of A little higher • Refrigerant level is low due LEAKAGE compartment and Refrigerant is heard and than ambient •...

  • Page 16: Description Of Function & Circuit Of Micom

    7. DESCRIPTION OF FUNCTION & CIRCUIT OF MICOM 7-1 FUNCTION 7-1-1 Function 1. When the appliance is plugged in, it is set to for Refrigerator and “4” for freezer. You can adjust the Refrigerator and the Freezer control temperature by pressing the ADJUST button. 2.
  • Page 17 7-1-5 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 18 7-1-9 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 the defect CODE removes the sign, it returns to normal operation (RESET). 4.
  • Page 19 7-1-10 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. While in the test mode, the function control button is not recognized, but the recognition tone (beep - ) sounds. 3.

  • Page 20: Pcb Function

    7-2 PCB FUNCTION 7-2-1 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 21 7-2-2 Oscillation Circuit This circuit generates the base clock for calculating time and the synchro clock for transmitting data from and to t he inside logic elements of the IC1 (MICOM). Be sure to use specific replacement parts, since calculating time by the IC1 may be changed.
  • Page 22 7-2-4 Load / Buzzer Drive & Open Door Detection Circuit 1. Load Drive Condition Check DEFROSTING COMP LOAD TYPE LAMP POWER MODE HEATER (OPTIONAL) Measurement Location (IC6) NO.14 NO.12 NO.11 NO.13 1V or below Condition 2. Fan motor driving circuit (freezing compartment fan) 1.
  • Page 23 2.2 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 circuit 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 24 4. Open Door Detection Circuit Check Measurement Pin No. 15 (Freezer Door) Location Freezer/ Pin No. 14 (Refrigerator Door) Refrigerator Door Closed Open 7-2-5 T emperature Sensor Circuit The upper CIRCUIT reads REFRIGERA TOR temperature, FREEZER T e mperature, and DEFROST-SENSOR temperature for defrosting and the indoor temperature for compensating for the surrounding temperature into MICOM.
  • Page 25 7-2-6 Refrigeration Compartment Stepping Motor Damper Circuit * The circuit shown below is the damper circuit to regulate the refrigerator temperature. 7-2-7 Temperature Compensation & Overcooling/Undercooling Compensation Circuit 1. Refrigerator Temperature Compensation - 25 -...
  • Page 26 7-2-8 Key Button Input & Display Light-On Circuit The circuit shown below determines whether a function control key on the operation display is pushed. It also tu rns on the corresponding function indication LED (LED Module) SEVEN SEGMENT DISPLAY (SEVEN SEGMENT DISPLA Y MODULE).

  • Page 27: Resistance Specification Of Sensor

    7-3 RESISTANCE SPECIFICATION OF SENSOR TEMPERATURE DETECTED RESISTANCE OF FREEZER RESISTANCE OF REFRIGERATOR & BY SENSOR SENSOR DEFROST SENSOR & ROOM SENSOR - 20 C 22.3 K 77 K ° - 15 C 16.9 K 60 K ° - 10 C °...

  • Page 28: Troubleshooting

    - 28 -...
  • Page 29 - 29 -...

  • Page 30: Main Pwb Assembly And Parts List

    7-5 MAIN PWB ASSEMBLY AND PARTS LIST 7-5-1 Main PWB Assembly - 30 -...
  • Page 31 7-5-2 Replacement Parts List - 31 -...
  • Page 32 7-5-3 PWB Assembly Display and Parts List Best Model SW106 - 32 -...

  • Page 33: Pwb Diagram

    7-6 PWB DIAGRAM 7-6-1 PWB Main Assembly - 33 -...
  • Page 34 - 34 -...

  • Page 35: Exploded View And Replacement Part List

    #EV# 8. EXPLODED VIEW & REPLACEMENT PARTS LIST CASE PARTS CAUTION: Use the part number to order part, not the position number CAUTION :Use th epar tnumber t oorder part ,no tth epositio nnumber 103B 281A 281B 103A 410A 409D 406B 501F 503G...
  • Page 36 #EV# FREEZER PARTS CAUTION: Use the part number to order part, not the position number 136B 131A 145C 248E 248F 237C 145F 136A - 36 -...
  • Page 37 #EV# REFRIGERATOR PARTS CAUTION: Use the part number to order part, not the position number 143E 140B 140D 143E 140E 140B 140D 140E 143E 140B 140D 140E 143F 142D 140B 142E 103E 128A 170A 128B 167B 154A 151A 103E 155B 151A 151C - 37 -...
  • Page 38 #EV# DOOR PARTS CAUTION: Use the part number to order part, not the position number 286A 230A 212G 241A 233A 231A 241B 244E 241E 241C 244A 212J 286A 243A 249A 241D 249E 250B 249J 205C 621B 250A 200A 621C 203A 201A 250B 212J...
  • Page 39 #EV# ICE MAKER PARTS CAUTION: Use the part number to order part, not the position number 602A 600C 600A 622B 618A 619C 616E 627A 623C 619A 262D - 39 -...
  • Page 40 #EV# LDC22720ST LOC NO PART NO DESCRIPTION LOC NO PART NO DESCRIPTION 103A 3650JJ2003H Handle,Rear 286A 4984JJ3003A BUSH 103B 3650JJ2003D Handle,Rear 301A 5421JJ1001B Evaporator Assembly 103C 3551JJ1015H Cover Assembly,Lower 304A 3551JJ2008B Cover Assembly,Machinery(Rear) 103E 5218JJ3001A Rail,Slide 305B 4580JJ3001A Roller 105A 5250JA2009B Tube,Drain 305C...
  • Page 41 #EV# LDC22720SW LOC NO PART NO DESCRIPTION LOC NO PART NO DESCRIPTION 103A 3650JJ2003E Handle,Rear 286A 4984JJ3003A BUSH 103B 3650JJ2003A Handle,Rear 301A 5421JJ1001B Evaporator Assembly 103C 3551JJ1015B Cover Assembly,Lower 304A 3551JJ2008B Cover Assembly,Machinery(Rear) 103E 5218JJ3001A Rail,Slide 305B 4580JJ3001A Roller 105A 5250JA2009B Tube,Drain 305C...
  • Page 42 #EV# LDC22720TT LOC NO PART NO DESCRIPTION LOC NO PART NO DESCRIPTION 103A 3650JJ2003H Handle,Rear 286A 4984JJ3003A BUSH 103B 3650JJ2003D Handle,Rear 301A 5421JJ1001B Evaporator Assembly 103C 3551JJ1015H Cover Assembly,Lower 304A 3551JJ2008B Cover Assembly,Machinery(Rear) 103E 5218JJ3001A Rail,Slide 305B 4580JJ3001A Roller 105A 5250JA2009B Tube,Drain 305C...
  • Page 43 P/No. MFL49482601 March, 2008...

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Ldc22720 series

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