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LG GR-J303UG Series Service Manual

LG GR-J303UG Series Service Manual

Kimchi
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KIMCHI REFRIGERATOR
SERVICE MANUAL
CAUTION
PLEASE READ CAREFULLY THE SAFETY PRECAUTIONS OF THIS MANUAL
BEFORE CHECKING OR OPERATING THE REFRIGERATOR.
MODEL : GR-J303UG*
http://www.lgservice.com

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Summary of Contents for LG GR-J303UG Series

  • Page 1 KIMCHI REFRIGERATOR SERVICE MANUAL CAUTION PLEASE READ CAREFULLY THE SAFETY PRECAUTIONS OF THIS MANUAL BEFORE CHECKING OR OPERATING THE REFRIGERATOR. MODEL : GR-J303UG*...
  • Page 2: Safety Instructions

    SAFETY INSTRUCTIONS 1. Firstly check that there is electrical leakage in the main body of the product. 2. Perform work always after removing the power plugs in handling with the part where electricity conducts through. 3. Wear a rubber gloves(insulation gloves) for preventing electrical shock accident in case of testing with power on. 4.
  • Page 3: Product Specifications

    1. PRODUCT SPECIFICATIONS 1-1. GR-J303UG* MODEL GR-J303UG ITEMS SPEC 115V/60Hz Rating 300 L Net Capacity 156 L Top Compartment Capacity Middle/Bottom 144 L Compartment 667(W) X 670.4(D) 1775(H)mm Dimensions (mm) 113 Kg Net Weight 138W Motor Power Consumption Indirect Cooling System...
  • Page 4 ITEMS SPEC P.T.C P6R8MD Overload Protector 4TM314TFB Fan Motor(Top) Ø110 Fan Fan Motor(Middle) Ø110 Fan Condenser Ø110 Fan Cooling Fan Motor Electrical 115 V 140 W Defrosting System Heater Middle 115 V 180 W(Half wave 90 W) Rating Front-C Heater 120 V(UL) 7 W Fuse-M(Top) Cutted at 70 °C...
  • Page 5: Circuit Diagram

    2. CIRCUIT DIAGRAM - 5 -...
  • Page 6: Micom Function And Explanations Of Circuits

    3. MICOM FUNCTION AND EXPLANATIONS OF CIRCUITS 3-1. EXPLANATION OF FUNCTION 3-1-1. DISPLAY PART Cabbage/Radish/ Mul Kimchi Vegetble/ Fruit Light Freezing Frozen Food Chilled Food NOTCH Max Max Temperature 1.0°C -0.5°C -2.0°C 4.5°C 3.5°C 2.5°C -4.0°C -5.0°C -6.0°C -15°C -18°C -21°C -25°C 5.0°C 2.0°C 0.0°C setting 1.
  • Page 7 3-1-2. Food storage/seasoning function (1) When selecting food type and storage temperature 1. Press the “Lock/Unlock” button for more than 2 seconds to “Unlock” the refrigerator. 2. When you press the “Uppper compartment”, ”Store” button in this condition, the storage temperature level changes from “Mid”...
  • Page 8 3-1-3. Rhythm fermenting control pattern diagram 1. The fermenting control pattern varies, depending on the temperature of the Kimchi when it is placed into the storage, the type of Kimchi being made and the degree of the seasoning selected. 2. In the 1st seasoning cycle, if the Kimchi is at room temperature, the cold control operates. 3.
  • Page 9 3-1-4. TEMPERATURE CONTROL AT UPPER, MIDDLE AND LOWER COMPARTMENT (1) Temperature control at upper compartment 1. Turn COMP, upper compartment fan motor depending on temperature of the upper compartment sensor and cool them by opening the 3-way valve to the upper compartment. 2.
  • Page 10 3-1-7. FRONT-C HEATER CONTROL 1. A heater for prevention of dewing is installed on the FRONT-C part between the middle compartment and the lower compartment, and turns on at the time of COMP ON and for 20 minutes after COMP OFF. 2.
  • Page 11 3-1-12. SEQUENTIAL OPERATION OF ELECTRICAL PARTS Electrical parts such as COMP, defrosting heater at the upper & middle compartment, fan motor at the upper & middle compartment, single motor damper and FRONT-C heater sequentially operate as followers for preventing noise and damage of parts occurred by that various parts operate at the same time in input of initial power on and after test closing (including temporary power failure, either): Function...
  • Page 12 3-1-13. FAILURE DIAGNOSIS FUNCTION (1) Failure Mode 1. Failure diagnosis function is intended in order that service is easily done when failure to affect performance of the product during use occurs. 2. Function is neither done, nor buzzer sound rings even when pressing the button in occurrence of failure. 3.
  • Page 13 (2) Load Operation in Failure Classification DEFROSTING DEFROSTING UPPER MIDDLE STEPPING SINGLE ITEM HEATER OF HEATER OF 3-WAY FRONT-C COMP COMPARTMENT COMPARTMENT MOTOR MOTOR UPPER MIDDLE VALVE HEATER DAMPER DAMPER COMPARTMENT COMPARTMENT Normal Failure of 15 min Upper compartment 15 min (K1) sensor Failure of 15 min...
  • Page 14 3-1-14. TEST FUNCTION 1. Test function is intended to check function of PCB and the product and find a failure part with failure status. 2. The test S/W exists on the main PCB, and ends the test mode after 2 hours irrespective of the test mode, and then returns to normal status.
  • Page 15 3-2. EXPLANATION OF CIRCUITS 3-2-1. POWER CIRCUIT Power circuits consist of SMPS (Switching Mode Power Supply) power, and the SMPS consists of the rectification part (BD1, CE1) to convert AC voltage to DC voltage, the switching part (IC3) to switch the converted DC voltage, a transformer to transfer energy of the primary side on the switching terminal, secondary side power to supply power to the MICOM and IC and the feed back part (IC4, IC5) to feedback the secondary side voltage to the primary side of transformer in order to maintain it uniformly.
  • Page 16 3-2-4. LOAD/BUZZER DRIVE CRICUIT (1) Load Drive Circuit COMP, UPPER UPPER MIDDLE MIDDLE MIDDLE LOWER SINGLE FRONT-C Type of Load Mechanical DEFROST DEFROST FERMENT FERMENT MOTOR HEATER Area FAN MOTOR HEATER MOTOR HEATER HEATER HEATER DAMPER Measuring Point(IC7) No.10 No.16 No.12 Q1 Collector No.11...
  • Page 17 (2) Buzzer driving circuit (located on display PCB) g Only the buzzer sound for the Lock/Unlock operation is shown in this SVC technical manual. Status Ex) Lock: "Ding-D-Dong" sound Ex) Lock: "Ding-D-Dong" sound Measuring point 45ms 45ms 45ms 45ms 70ms 750ms 45ms 45ms 45ms 45ms 70ms...
  • Page 18 3-2-6. TEMPERATURE SENSING CIRCUIT Above circuits consist of the upper sensor, middle sensor, lower sensor for adjusting setup temperature at the upper, middle and lower compartment, the ambient temperature sensor to detect ambient air temperature, the upper defrost sensor and the middle defrost sensor attached to the evaporator at the upper, middle compartment to detect the defrost return temperature.
  • Page 19 3-2-7. TEMPERATURE SENSING CIRCUIT 1.Temperature adjustment at the lower compartment consists of the circuit part for driving the damper, as electronic single motor damper, to open or close the baffle and the reed switch part to detect open/close status of the damper. 2.
  • Page 20 3-2-8. STEPPING MOTOR DAMPER DRIVE CIRCUIT (FOR TEMPERATURE CONTROL AT MIDDLE COMPARTMENT) As for motor drive, the motor rotates since rotation magnetic force is formed at coils wound around each phase of the motor and the stator if outputting “High” “Low” signal as much as the fixed step numbers through the MICOM pin 51 and pin 52 after applying “High”...
  • Page 21 3-2-9. 3-WAY VALVE STEPPING MOTOR DRIVE CIRCUIT (FOR SWITCHING UPPER/MIDDLE/LOWER COMPARTMENT CYCLE) As for motor drive, the motor rotates since rotation magnetic force is formed at coils wound around each phase of the motor and the stator via the IC11 (TD62308AP) as IC for motor drive if outputting “High” “Low” signal as much as the fixed step numbers from the MICOM pin 50, 47 and 48.
  • Page 22 3-2-10. KEEPING TEMPERATURE COMPENSATION AND TOO COLD/ TOO WARM CUT COMPENSATION CIRCUIT (1) Keeping Temperature Compensation Circuit u This circuit is used for entering the required level of temperature compensation into MICOM to adjust keeping temperature at the upper, middle and lower compartment. Upper Compartment Middle/Lower Compartment Resistance Value...
  • Page 23 u Temperature compensation table at the upper compartment is as follows: Modification RCF1:620 Ω RCF1:3 KΩ RCF1:2.4 KΩ RCF1:1.8 KΩ RCF1:1.2 KΩ RCF1: RCF1: RCF1: RCF1: RCF1: RCF1: Division RCF2: RCF2: RCF2: RCF2: RCF2: RCF2: RCF2:1.2 KΩ RCF2:2.4 KΩ RCF2:3 KΩ RCF2:5.1 KΩ...
  • Page 24 (2) Too Cold/Too Warm Cut Compensation Circuit. Upper compartment Upper Middle compartment Lower compartment compartment cut compensation cut compensation cut compensation Middle Lower temperature compartment compartment Too cold Too warm Too cold Too warm Too cold Too warm compensation temperature temperature compensation compensation...
  • Page 25: Main Pcb

    3-2-11. COMMUNICATION CIRCUIT BETWEEN MAIN PCB AND DISPLAY PCB Following circuits as communication circuits are circuits for changing necessary information between the main MICOM of the main PCB and the MICOM for LED control of the display PCB. DC12V for driving the display PCB, transmit/receive circuits are required. Poor communication occurs where continuing information change between the main MICOM of the main PCB and the MICOM for LED control of the display PCB is not done for more than 30 seconds.
  • Page 26 3-3. SENSOR RESISTANCE CHARACTERISTICS TABLE Measuring Temperature(°C) Upper/Middle/Lower sensors, RT sensor, Upper/Middle defrosting sensors -20 °C 77 KΩ -15 °C 60 KΩ -10 °C 47.3 KΩ -5 °C 38.4 KΩ 0 °C 30 KΩ +5 °C 24.1 KΩ +10 °C 19.5 KΩ...
  • Page 27 3-4. PCB PARTS DIAGRAM AND LIST 3-4-1. PWB(PCB) ASSEMBLY, MAIN (1) Parts diagram 6871JB1129 "S" - 27 -...
  • Page 28 (2) Parts List - 28 -...
  • Page 29 - 29 -...
  • Page 30 3-4-2. PWB(PCB) ASSEMBLY, DISPLAY [STANDARD] (1) Parts diagram (2) Parts List - 30 -...
  • Page 31 3-5. PCB CIRCUIT DIAGRAM – PCB CIRCUIT DIAGRAM MAY CHANGE DEPENDING ON SITUATION. 3-5-1. PWB (PCB) ASSEMBLY, MAIN CIRCUIT DIAGRAM (LED MODULE TYPE) - 31 -...
  • Page 32 - 32 -...
  • Page 33 3-5-2. PWB (PCB) ASSEMBLY, DISPLAY CIRCUIT DIAGRAM - 33 -...
  • Page 34: Exploded View And Service Parts List

    4. EXPLODED VIEW AND SERVICE PARTS LIST 4-1. EXPLODED VIEW u u GR-J303UG 501F 281A 281B 103A 411A 410H 103B 316B 501A 410G 332A 619B 401A 404A 501K 301A 405C 405A 329A 418A 304A 108A 282B 406B 330B 316C 332D...
  • Page 35 GR-J303UG 150J 150G 150K 155C 150H 155A 150F 150E 155B 200A 150A 201A 150C 157A 203A 150G 206A 150D 150B 157B 157C 157D 150F 212G 150E 207A 155C 155A 205Q 155B 205L 205G 150A 150C 150G 150D 150B...
  • Page 36 GR-J303UG 604E 241A 604G 200C 203B 253C 251A 248A 253B 149B 160C 149B 201B 252C 252A 604G 604E 241B 252B 253C 253A 200D 203C 253B 149B 160C 248B 149B 253C 254A 254B 201C - 36 -...
  • Page 37 P/No. 3828JD8947C FEB., 2008 Printed in Korea...