LG GR-S642 Service Manual
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LG GR-S642 Service Manual

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REFRIGERATOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT, READ THE "SAFETY
PRECAUTIONS" IN THIS MANUAL.
MODEL: GR-S642/GR-S702
http://biz.lgservice.com

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Summary of Contents for LG GR-S642

  • Page 1 REFRIGERATOR SERVICE MANUAL CAUTION BEFORE SERVICING THE UNIT, READ THE "SAFETY PRECAUTIONS" IN THIS MANUAL. MODEL: GR-S642/GR-S702...

  • Page 2: Table Of Contents

    CONTENTS CONTENTS..................................... 2 SERVICING PRECAUTIONS..............................3 SPECIFICATIONS................................... 4 PARTS IDENTIFICATION ............................... 5 DISASSEMBLY..................................6-7 DOOR....................................6 DOOR SWITCH..................................6 FAN AND FAN MOTOR................................ 6 DEF' CONTROL ASM ................................7 LAMP....................................7 CONTROL BOX-R................................7 ADJUSTMENT..................................8-9 COMPRESSOR..................................8 PTC-STARTER..................................8 OLP (OVER LOAD PROTECTOR)............................

  • Page 3: Servicing Precautions

    SERVICING PRECAUTIONS Air Recharging in Compressor vacuum operation is over, add the quantity in grams of R-134a to the refrigerant system. Remember that every Test the refrigeration by connecting it electrically before system has an exact quantity of R-134a with a tolerance of refilling operation.

  • Page 4: Specifications

    1. SPECIFICATIONS 1-1. GR-S642 ITEMS SPECIFICATIONS ITEMS SPECIFICATIONS FREEZER FREEZER 1 EA SHELF NET CAPACITY REFRIGERATOR REFRIGERATOR 2 EA ( l ) TOTAL VEGETABLE TRAY Drawer Type DIMENSIONS (mm) 860(W) 709(D) 1794(H) EGG TRAY 2 Pieces NET WEIGHT (kg) ICE TRAY...

  • Page 5: Parts Identification

    2. PARTS IDENTIFICATION 2-1. FEATURE CHART FREEZER COMPARTMENT Lamp Shelf Freezer Temperature Control Dial Twisting Ice Serve(Option) Freezer Door Rack General Type Ice Making REFRIGERATOR Egg Storage Rack COMPARTMENT Deodorizer Fresh Meat Lamp Shelves Vegetable Drawer Used to keep fruits and vegetables, etc.

  • Page 6: Disassembly

    3. DISASSEMBLY 3-1 DOOR 3-2 DOOR SWITCH Freezer Door 1. To remove the door switch, pull out it with a '—' type 1. Remove the hinge cover by pulling it upwards. driver as shown in (figure 9). 2. Loosen hexagonal bolts fixing the upper hinge to the 2.

  • Page 7: Def' Control Asm

    3-4 DEF' CONTROL ASSY 3-5-1 Freezer room lamp 1. Unplug the power cord from the outlet. Def control ASM consists of Defrost Sensor and FUSE–M. 2. Remove the room lamp lid by taking down while pulling Defrost Sensor functions to defrost automatically and it is it forward with your hand after inserting finger into the attached to the Evaporator and the metal side of the case inside hole as shown in (figure 16).

  • Page 8: Adjustment

    4. ADJUSTMENT 4-1 COMPRESSOR 4-2-3 PTC-Applied Circuit Diagram According to Starting Method of Motor 4-1-1 Role The compressor inhales low temperature and low pressure gas evaporated from Evaporator of the Refrigerator, and OVERLOAD PROTECTOR condenses this gas to high temperature and high pressure gas, and then plays delivering role to Condenser.

  • Page 9: Olp (Over Load Protector)

    4-3 OLP (OVER LOAD PROTECTOR) CONTACTING 4-3-1 Definition of OLP POINT COVER (1) OLP (OVER LOAD PROTECTOR) is attached to Hermetic Compressor and protects Motor by cutting off BIMETAL current in Compressor Motor by Bimetal in the OLP in case of over-rising temperature. (2) When over-voltage flows to Compressor motor, Bimetal CONTACTING POINT...

  • Page 10: Troubleshooting

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

  • Page 11: Ptc And Olp

    6-2 PTC AND OLP Check another Normal operation of Separate the PTC from Observation value is electric components. Compressor is 220V/50Hz : 47Ω ± 30% Compressor and impossible or poor. 220 - 240V/50Hz : 47Ω ± 30% measure the resistance 110 -115V/60Hz : 6.8Ω...

  • Page 12: Another Electric Component

    6-3 ANOTHER ELECTRIC COMPONENTS M Cooling is impossible Compressor Check if current flows to Cause. doesn't run. the following components. a. Thermistor Poor contacting. b. Starting devices Shorted or broken. Poor contacting c. OLP or shorted. d. Compressor coil Coil shorted. Replace Poor contacting e.

  • Page 13: Service Diagnosis Chart

    6-4 SERVICE DIAGNOSIS CHART COMPLAINT POINTS TO BE CHECKED REMEDY Cooling is • Is the power cord unplugged from the outlet? • Plug to the outlet. impossible. • Check if the power S/W is set to OFF. • Set the switch to ON. •...

  • Page 14: Refrigerating Cycle

    6-5 REFRIGERATING CYCLE M Troubleshooting Chart TEMPERATURE STATE OF STATE OF THE CAUSE REMARKS OF THE THE SET EVAPORATOR COMPRESSOR PARTIAL Freezer and Low flowing sound of A little high • A little Refrigerant LEAKAGE Refrigerator Refrigerant is heard and more than •...
  • Page 15 M General Control of Refrigerating Cycle ITEMS CONTENTS AND SPECIFICATIONS REMARKS WELDING (1) H 30 • Chemical Ingredients • Recommend H34 containing 34% Ag in the (1) • Ag: 30%, Cu: 27%, Zn: 23%, Cd: 20% • Service Center. • Brazing Temperature: 710~840°C (2) Bcup-2 •...

  • Page 16: Description Of Function & Circuit Of Micom

    7. DESCRIPTION OF FUNCTION & CIRCUIT OF MICOM The following description is basically for GR-S642/GR-S702. For the other models, refer to the diagram of the entire PCB circuit. 7-1 FUNCTION 7-1-1 FUNCTION 1. When the appliance is plugged in, it is set to ‘Medium’. Each time the button is pushed, it is set to ‘Medium’¡’Medium/High’¡’High’¡’Low’¡’Medium/Low’¡’Medium’...
  • Page 17 7-1-2 SUPER COOL 1. This feature is to shorten the cooling time of the refrigerator by keeping the comp, fan running for a while. When the Super Cool button is pushed, the Super Cool LED turns on in order and the comp keeps on running. In 2 hours, the Super Cool mode will be cleared.
  • Page 18 7-1-6 BUZZER SOUND 1. When the button on the front Display is pushed, “Ding-” sound is produced and it works as follows. 7-1-7 CONTROL OF DOUBLE COOLING FAN IN THE REFRIGERATOR COMPARTMENT. 1. To raise the refrigerating speed, fan motor in the refrigerator compartment is operated when the door of freezer room or refrigerator room is opened and then closed.
  • Page 19 7-1-10 ERROR DIAGNOSTIC MODE 1. The error diagnostic mode allows the SVC when a fault that may affect the performance of the product occurs while operating the product. 2. Even if the function control button is pushed when an error occurs, the function will not be performed. However, the recognition tone (beep~) sounds.
  • Page 20 7-1-11 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 button is on the main PCB of the refrigerator (Test S/W). The test mode will be cleared in 2 hours regardless of the type of the test mode and then reset.
  • Page 21 7-2 PCB FUNCTION 7-2-1 POWER CIRCUIT The secondary part of the TRANS is composed of the power supply for the display and relay drive (12Vdc) and that for the MICOM and IC (5Vdc). The voltage for each part is as follows. PART VA 1 CE 1...
  • Page 22 7-2-2 OSCILLATION CIRCUIT This circuit is to generate 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 the authentic parts since the calculating time by the IC1 may be changed or it will not work if the OSC1 SPEC is changed.
  • Page 23 7-2-4 LOAD/BUZZER DRIVE & OPEN DOOR DETECTION CIRCUIT 1. Load Drive Condition Check Double cooling Freezer Fan Freezer Fan Defrosting COMP Lamp Fan Motor R-Lamp Load Type Motor HIGH Motor Heater (R-FAN) Standard RPM Measurement Location (IC5) NO.16 NO.12 NO.10 NO.15 NO.14 NO.13...
  • Page 24 2. Buzzer Drive Condition Check Tone (Beep~) when the button on the display is pushed Alarm for open door (beep-beep-beep) Measure- Condition ment Location 0.1 s 0.5 s 0.5 s 0.5 s IC1 ( 1.9 kH (Beep~) IC1 ( 1.9 kH (Beep~) 3.
  • Page 25 7-2-5 TEMPERATURE SENSOR CIRCUIT <LED MODEL> <LCD MODEL> The upper CIRCUIT reads REFRIGERATOR temperature, and DEF-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 26 7-2-6 SWITCH INPUT CIRCUIT * The circuit shown below is the input circuit to detect the signals of the test S/W for checking the refrigerator. <LED MODEL> <LCD MODEL> - 26 -...
  • Page 27 7-2-7 TEMPERATURE COMPENSATION & OVERCOOLING/UNDERCOOLING COMPENSATION CIRCUIT 1. Refrigerator Temperature Compensation <LCD MODEL> ➧ Table of Temperature Compensation by adjusting the Refrigerator resistance (Difference with the current temperature) Resistance Temperature Remark E.g.) If the refrigerator compensation resistance (RCR) (RCR) Compensation is changed from 10K (the current resistance) to 18K (the adjustment resistance), the temperature 180 KΩ...
  • Page 28 3. The circuits for less cooling and overcooling compensation in a refrigerator compartment <LED MODEL> <LCD MODEL> OVER COOLING LESS COOLING REFRIGERATOR TEMPERATURE COMPENSATION COMPENSATION REMARKS COMPENSATION VALUES JCR1 JCR2 JCR3 JCR4 +1°C +2°C -1°C -2°C 0°C 0°C +1°C -1°C 0°C(AT FACTORY) •...
  • Page 29 7-2-9 COMMUNICATION CIRCUIT AND CONNECTION L/WIRE BETWEEN MAIN PCB AND DISPLAY PCB The following circuit is a communiction cirtuit used for exchanging the necessary information between main MICOM of main PCB and LCD dedicated MICOM for LCD control of display PCB. Transmission/receipt L/Wire together with the necessary display PCB for driving the display PCB is required.
  • Page 30 7-3. RESISTANCE SPECIFICATION OF SENSOR TEMPERATURE SENSOR RESISTANCE OF FREEZER RESISTANCE OF REFRIGERATOR SENSOR (DEFROST) SENSOR - 20 ˚C 22.3 KΩ 77 KΩ - 15 ˚C 16.9 KΩ 60 KΩ - 10 ˚C 13.0 KΩ 47.3 KΩ - 5 ˚C 10.1 KΩ...
  • Page 31 7-4. TRUBLE SHOOTING • Replace PCB when no trouble after checking the contents of trouble. CLASSIFICATION STATE OF TROUBLE POINT BE CHECKED CHECKING METHOD CONTENT REMEDY POWER SOURCE 1. All the DISPLAY 1. FREEZER/ FREEZER/REFRIGERATOR POWER SOURCE is poor Certify Fuse. is poor LED OFF REFRIGERATOR...
  • Page 32 CLASSIFICATION STATE OF TROUBLE POINT BE CHECKED CHECKING METHOD CONTENT REMEDY COOLING is poor. REFRIGERATOR 1. FREEZER TEMPERATURE See "FREEZER Certify the attaching state TEMPERATURE is is normal? TEMPERATURE is poor". of DOOR. poor. 2. Cool air of FAN MOTOR is Certify the amount of cool air FAN MOTOR is poor.
  • Page 33 7-5 MAIN PWB ASS'Y AND PARTS LIST 7-5-1 MAIN PWB ASS'Y - 33 -...
  • Page 34 7-5-2 REPLACEMENT PARTS LIST <LED MODEL> - 34 -...
  • Page 35 <LCD MODEL> - 35 -...
  • Page 36 7-5-3 PWB ASS'Y, DISPLAY AND PARTS LIST <LED MODEL> - 36 -...
  • Page 37 <LCD MODEL> - 37 -...
  • Page 38 7-6 PWB DIAGRAM 7-6-1 PWB ASSEMBLY, MAIN(LED MODEL) - 38 -...
  • Page 39 - 39 -...
  • Page 40 7-6-2 PWB ASSEMBLY, MAIN(LCD MODEL) - 40 -...
  • Page 41 - 41 -...
  • Page 42 7-6-3 PWB ASSEMBLY, DISPLAY(LCD DISPLAY) - 42 -...
  • Page 43 - 43 -...

  • Page 44: Exploded View & Replacement Parts List

    8. EXPLODED VIEW & REPLACEMENT PARTS LIST 8-1. M The parts of refrigerator and the shape of each part are subject to change in different localities. M Capacitors and fuse are optional parts. 501F 281A 103B 410G 301A 401A 281B 411A (501B,C) 501A...
  • Page 45 405C 200A 405A 203A 201A 404A 205A 329A 330B 212G 332A 212A 503B 205A 212C 503C 131C 149A 210B 131A 210A 230A 235A 125A 234B 233A 231A 149A 233B 125A 125H 241A 131A 149B 244A 140A 244C 149C 241B 154A 241A 151A 241D...
  • Page 46 405C 200A 405A 203A 201A 404A 205A 329A 330B 212G 332A 212B 503B 205A 212A 503C 131C 149A 212D 210B 131A 210A 212C 230A 235A 234B 125A 233A 231A 149A 233B 125A 125H 241A 131A 149B 244C 140A 149C 241B 244D 154A 244A...

This manual is also suitable for:

Gr-s702

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