LG LRDN22734SB Service Manual
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LG LRDN22734SB 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:
LRDN22734SB
LRDN22734ST
LRDN22734TT
LRDN22734WW

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Summary of Contents for LG LRDN22734SB

  • Page 1 REFRIGERATOR SERVICE MANUAL CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. Models: LRDN22734SB LRDN22734ST LRDN22734TT LRDN22734WW...

  • Page 2: Table Of Contents

    CONTENTS SAFETY PRECAUTIONS ............................... 2 SPECIFICATIONS................................... 3 PARTS IDENTIFICATION ..............................4-7 DISASSEMBLY..................................8-9 DOOR....................................8 DOOR SWITCH..................................8 FAN AND FAN MOTOR................................ 9 DEFROST CONTROL ASSEMBLY............................9 LAMP....................................9 CONTROL BOX-REFRIGERATOR ............................9 MULTI DUCT ..................................9 ADJUSTMENT.................................. 10-11 COMPRESSOR.................................. 10 PTC-STARTER..................................

  • Page 3: Specifications

    1. SPECIFICATIONS 20 cu. ft. / 22 cu. ft. ITEMS SPECIFICATIONS ITEMS SPECIFICATIONS DOOR DESIGN Side Rounded VEGETABLE TRAY Opaque Drawer Type H) 20cu.ft COMPRESSOR PTC Starting Type DIMENSIONS (inches) H) 22cu.ft Dispenser EVAPORATOR Fin Tube Type H) 22cu.ft CONDENSER Wire Condenser 238.4 (20cu.ft) REFRIGERANT...

  • Page 4: Parts Identification

    2. PARTS IDENTIFICATION 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 Filter (inside)* Refrigerator Light Dairy Bin...
  • Page 5 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 Filter (inside)* Refrigerator Light Dairy Bin Shelves...
  • Page 6 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 Divider Refrigerator Light Dairy Bin Shelves...
  • Page 7 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 Design-A-Door Shelves...

  • Page 8: 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 9: 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 10: 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 11: 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 12: Circuit Diagram

    5. CIRCUIT DIAGRAM Best / Best dispenser GY: GRIS/GRAY - 12 -...
  • Page 13 Good / Better GY: GRIS/GRAY - 13 -...

  • Page 14: 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. Reconnect.

  • Page 15: Ptc And Olp

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

  • Page 16: Other Electrical Components

    6-3 OTHER ELECTRICAL COMPONENTS M 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 17: 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 18: Refrigeration Cycle

    6-5 REFRIGERATION CYCLE M 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 19 M 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 20: 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. Ice Making • Waits until water becomes cold after starting the Mode ice making operation.
  • Page 21 7-2 CONTROL METHOD ACCORDING TO 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.
  • Page 22 7-2-4 Fill / Park Position 1. When Ice-Removing control (Normal Ice-Removing control, Ice-Removing control for test) has completed, and the EJECTOR is in place, this control operates the ICE SOLENOID by time check in the compressor enclosure of the refrigerator. Then it supplies water to the ice making tray. 2.
  • Page 23 7-2-5 Function TEST 1. This is a compulsory operation for TEST, SVC, cleaning, etc. It is operated by pressing the water supply control KEY for 3 seconds. 2. It operates in the Ice Making mode, but not in the Ice-Removing mode or water supply process. (If there is an ERROR, it can only be checked in the TEST mode.) 3.

  • Page 24: Description Of Function & Circuit Of Micom (Best, Dispenser)

    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 37 °F for the Refrigerator and 0 °F for the Freezer. You can adjust the Refrigerator and the Freezer control temperature by pressing the COLDER button or the WARMER button.
  • Page 25 8-1-4 CONTROL OF FREEZER FAN MOTOR 1. Freezer fan motor has high and standard speeds. 2. High speed is used at power-up, for express freezing, and when refrigerator is overloaded. Standard speeds is used for general purposes. 3. To improve cooling speed, the RPM of the freezer fan motor change from normal speed to high. 4.
  • Page 26 8-1-8 Buzzer Sound When the button on the front Display is pushed, a Ding~ Dong~ sound is produced. (Refer to the Buzzer Circuit 8-2-4 No. 3) 8-1-9 Defrosting (removing frost) 1. Defrosting starts each time the COMPRESSOR running time reaches 7 hours. 2.
  • Page 27 8-1-13 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 28 8-1-14 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 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 G5SB-14 FREEZER DOOR SWITCH REFRIGERATOR DOOR SWITCH VALVE DEFROSTING COMP LAMP LOAD TYPE POWER MODE (DISPENSER HEATER (OPTIONAL) MDL) Measurement Location (IC6) NO.13 NO.14 NO.16 NO.12 NO.15 1V or below...
  • Page 32 3. Buzzer Drive Condition Check Condition Tone (Ding~Dong~) when the button on Alarm for open door Measure- the display is pushed. (beep-beep-beep) ment Location 0.05 s 0.2 s 0.1 s 0.5 s 0.5 s IC1 ( 2.63 kz (Ding~) 2.21 kz (Dong~) IC1 ( 2.63 kz (Beep~) 4.
  • Page 33 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. OPENING or SHORT state of each TEMPERATURE SENSOR are as follows: SENSOR CHECK POINT NORMAL (-30°C ~ 50°C)
  • 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 Dispenser Input/LED Output Circuit PUMP SWITCH - 34 -...
  • Page 35 8-2-8 Temperature Compensation & Overcooling/Undercooling Compensation Circuit 1. Refrigerator Temperature Compensation ➧ Table of Temperature Compensation by adjusting the Refrigerator resistance (difference from the current temperature) Resistance Temperature Remark e.g., If the refrigerator compensation resistance (RCR) Compensation (RCR) is changed from 10K (the current resistance) to 18K (the adjustment resistance), the temperature 180 KΩ...
  • Page 36 8-2-9 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 DISPLAY MODULE).
  • Page 37 8-3 RESISTANCE SPECIFICATION OF SENSOR TEMPERATURE DETECTED RESISTANCE OF FREEZER RESISTANCE OF REFRIGERATOR & BY SENSOR SENSOR DEFROST SENSOR & ROOM SENSOR - 20 ˚C 22.3 KΩ 77 KΩ - 15 ˚C 16.9 KΩ 60 KΩ - 10 ˚C 13.0 KΩ 47.3 KΩ...
  • Page 38 - 38 -...
  • Page 39 - 39 -...
  • Page 40 8-5 MAIN PWB ASSEMBLY AND PARTS LIST 8-5-1 Main PWB Assembly - 40 -...
  • Page 41 8-5-2 Replacement Parts List - 41 -...
  • Page 42 8-5-3 PWB Assembly, Display, And Parts List Dispenser Model Best Model SW106 - 42 -...
  • Page 43 8-6 PWB DIAGRAM 8-6-1 PWB Main Assembly G5SB-14 FREEZER DOOR SWITCH REFRIGERATOR DOOR SWITCH PWB ASSEMBLY - 43 -...
  • Page 44 220 1/2W REFRIGERATOR DOOR SWITCH FREEZER SENSOR REFRIGERATOR SENSOR DEFROST SENSOR FREEZER DOOR SWITCH - 44 -...

  • Page 45: Description Of Function & Cicuit Of Micom (Good, Better)

    9. DESCRIPTION OF FUNCTION & CIRCUIT OF MICOM 9-1 FUNCTION 9-1-1 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 46 9-1-5 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 1/2 seconds. These tones repeat every 30 seconds.
  • Page 47 9-1-9 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 48 9-1-10 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 49 9-2 PCB FUNCTION 9-2-1 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: CE 2 CE 1...
  • Page 50 9-2-2 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 51 9-2-4 Load / Buzzer Drive & Open Door Detection Circuit 1. Load Drive Condition Check G5SB-14 FREEZER FREEZER DEFROSTING COMP LAMP LOAD TYPE FAN MOTOR FAN MOTOR HEATER (HIG RPM) (LOW RPM) Measurement Location (IC4) NO.11 NO.14 NO.15 NO.12 NO.13 1V or below Condition - 51 -...
  • Page 52 2. Buzzer Drive Condition Check Condition Tone (Ding~Dong~) when the button on Alarm for open door Measure- the display is pushed. (beep-beep-beep) ment Location 0.05 s 0.2 s 0.1 s 0.5 s 0.5 s IC1 ( 2.63 kz (Ding~) 2.21 kz (Dong~) IC1 ( 2.63 kz (Beep~) 3.
  • Page 53 9-2-5 Temperature Sensor Circuit 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. OPENING or SHORT state of each TEMPERATURE SENSOR are as follows: SENSOR CHECK POINT NORMAL (-30°C ~ 50°C)
  • Page 54 9-2-6 Refrigeration Compartment Stepping Motor Damper Circuit * The circuit shown below is the damper circuit to regulate the refrigerator temperature. - 54 -...
  • Page 55 9-2-7 Temperature Compensation & Overcooling/Undercooling Compensation Circuit 1. Refrigerator Temperature Compensation ➧ Table of Temperature Compensation by adjusting the Refrigerator resistance (difference from the current temperature) Resistance Temperature Remark e.g., If the refrigerator compensation resistance (RCR) is changed from 10K (the current resistance) (RCR) Compensation to 18K (the adjustment resistance), the temperature...
  • Page 56 9-2-8 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 DISPLAY. The drive type is the scan type. 150J - 56 -...
  • Page 57 9-3 RESISTANCE SPECIFICATION OF SENSOR TEMPERATURE DETECTED RESISTANCE OF FREEZER RESISTANCE OF REFRIGERATOR & BY SENSOR SENSOR DEFROST SENSOR & ROOM SENSOR - 20 ˚C 22.3 KΩ 77 KΩ - 15 ˚C 16.9 KΩ 60 KΩ - 10 ˚C 13.0 KΩ 47.3 KΩ...
  • Page 58 - 58 -...
  • Page 59 - 59 -...
  • Page 60 9-5 MAIN PWB ASSEMBLY AND PARTS LIST 9-5-1 Main PWB Assembly - 60 -...
  • Page 61 9-5-2 Replacement Parts List - 61 -...
  • Page 62 9-5-3 PWB Assembly, Display, And Parts List - 62 -...
  • Page 63 9-6 PWB DIAGRAM 9-6-1 PWB Main Assembly G5S-1A - 63 -...
  • Page 64 - 64 -...

  • Page 65: Exploded View

    #EV# EXPLODED VIEW CASE PARTS CASE PARTS CAUTION: Use the part number to order part, not the position number. CAUTION : Use th e par t number t o order part , no t th e positio n number. 103B 281A 281B 103A...
  • Page 66 #EV# FREEZER PARTS CAUTION: Use the part number to order part, not the position number. 285A 136F 136B 125A 145G 248E 248F 249G 131A 237C 145D 136A -66-...
  • Page 67 #EV# REFRIGERATOR PARTS CAUTION: Use the part number to order part, not the position number. 140A 140B 147C 147B 147A 140F 103E 128A 142A 142D 103E 142B 128B 142E 146A 103E 128A 170A 141D 128M 128G 103E 278C 149C 128C 141A 149E 141E...

  • Page 68: Door Parts

    #EV# DOOR PARTS CAUTION: Use the part number to order part, not the position number. 241F 230A 241A Models: 233A LRDN22734WW 231A 241B 286A 212G 281E 212J 241C 244E 241E 212F 237A 2 2 44H 212F 286A 241D 212J 243A 248N 700C 313A...
  • Page 69 #EV# DOOR PARTS CAUTION: Use the part number to order part, not the position number. 230A 241F 147D 241A Models: 233A LRDN22734SB 231A 241B LRDN22734ST LRDN22734TT 212G 244B 241C 241E 237A 244A 212J 700B 241D 244C 248N 313A 281H 281D...
  • Page 70 June, 2009...

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