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3SECS.

FREEZER

FREEZER

EXPRESS FRZ.

ECO MODE

FRIDGE

CHILD LOCK

DOOR ALARM

Ref.No

GC-B379S*QA 

GC-B409S*QA

Ref.No

GC-B379S*CA 

GC-B409S*CA

REFRIGERATOR 

SERVICE MANUAL

http://biz.lgservice.com

MODEL/COLOR:

Summary of Contents for GC-B379S*CA

Page 1: ...3SECS FREEZER FREEZER EXPRESS FRZ ECO MODE FRIDGE CHILD LOCK DOOR ALARM Ref No GC B379S QA GC B409S QA Ref No GC B379S CA GC B409S CA REFRIGERATOR SERVICE MANUAL http biz lgservice com MODEL COLOR ...

Page 2: ...9 DISPLAY REMOVE 10 ADJUSTMENT 10 COMPRESSOR 10 PTC STARTER 10 11 NOTE TO USE PTC STARTER 11 OLP OVER LOAD PROTECTOR 11 CIRCUIT DIAGRAM 12 TROUBLESHOOTING 13 COMPRESSOR AND ELECTRIC COMPONENTS 13 RELAY ASSEMBLY PTC AND OLP 14 ANOTHER ELECTRIC COMPONENT 15 SERVICE DIAGNOSIS CHART 16 REFRIGERATING CYCLE 17 19 MICOM FUNCTION PCB CIRCUIT EXPLANATION 20 34 EXPLODED VIEW 35 38 Contents APPENDIX FOR REFR...

Page 3: ...ion of the refrigerator with the upper door open move with care to avoid hitting the upper door 8 When tilting the set remove any materials on the set especially the thin plates ex Glass shelf or books 9 When servicing the evaporator wear cotton gloves This is to prevent injuries from the sharp evaporator fins 10 Leave the disassembly of the refrigerating cycle to a specialized service center The ...

Page 4: ...mp with the coupler And then turn the pump on for vacuum state Figure 3 Let the pump run until the low pressure gauge indicates the vacuum gauge pressure 0 absolute pressure 1atm or 760mmHg Recommended vacuum time is 30 min Charge the N2 gas in order to check for leakage from welding points and the LOKRING If leakages are found repair the defects and repeat the vacuum process After the system is c...

Page 5: ...Shelf 3EA or 2EA Magic Crisper 1EA Vegetable Container 1EA 1 Ref No GC B379 409S CA 2 Ref No GC B379 409S QA ITEMS SPECIFICATIONS DIMENSIONS mm 595 W X643 D X1737 H 595 W X643 D X1907 H NET WEIGHT kg 69 75 COOLING SYSTEM Fan Cooling TEMPERATURE CONTROL Micom Control DEFROSTING SYSTEM Full Automatic DOOR FINISH Pre Coated Metal or Vinyl Coated Metal OUT CASE Painted Steel Sheet INNER CASE ABS INSUL...

Page 6: ... Models GC 379S QA GC 379S CA GC 409S QA GC 409S CA Cover LED Multi air Flow Duct Glass Rem Shelf Vitamin Plus System Special models Vegetable Drawer Dairy Corner Special models Dairy Corner optional Guide Bottle optional Basket Door Guide optional Display optional PARTS IDENTIFICATION 6 ...

Page 7: ...k Dairy Close both doors before removing hinge pins CAUTION Do not let either door drop to the floor Doing so could damage the Door Stop 1 2 3 5 4 A 6 A 7 5 9 8 10 11 14 12 6 13 5 How to Reverse the Door 1 After unscrewing the screw 2 of cover hinge 1 on the top take off cover hinge and disconnect cable 5 Only for the exterior display type models Unscrew bolts 3 which fasten upper hinge 4 and remo...

Page 8: ...e which is fixated closer 23 of the freezer door B move closer 23 to the opposite side in appropriated place and fix it up Unscrew the screw 24 on the bottom of the case which is fixated emphasis 25 of the freezer door B move emphasis 25 to the opposite side in appropriated place and fix it up Move the upper cap 26 on the opposite side 7 Attach removed lower hinge 19 to the hole located on the opposit...

Page 9: ...stops the emission of heat from the Heater 1 Pull out the Shroud F after removing the Grille 2 Separate the connector connected with the Defrost Control Assembly and replace new one Thermister Fuse Melting 6 HEATER SHEATH In this refrigerator Heater Sheath is used for defrosting heater During heating the temperature of heater rises about 300 350 Therefore be careful not to burn while servicing 1 A...

Page 10: ...e 5 Be careful that dust humidity and flux welding don t inflow in the Compressor inside in replacing the Compressor Dust humidity and flux due to welding which inflows to Cylinder may cause lockage and noise 2 PTC STARTER 1 Composition of PTC Starter 1 PTC Positive Temperature Coefficient is a no contact semiconductor starting device which uses ceramic material and this material consists of ВаТiO...

Page 11: ...out fail 3 Note to Use PTC Starter 1 Be careful not to allow over voltage and over current 2 No Strike Don t apply a forcible power or strike 3 Keep apart from any liquid If liquid such as oil or water away enter the PTC PTC materials it may break due to insulation breakdown of the material itself 4 Don t change PTC at your convenience Don t disassemble PTC and mold If the exterior to the PTC star...

Page 12: ...12 CIRCUIT DIAGRAM P No MEZ62581565 ...

Page 13: ...ressor Replace Compressor 3 Check the resistance of PTC Starter Check the resistance of two terminals in PTC Starter 4 Check OLP Check if applying a regular OLP OLP works within 30 sec in forcible OLP operation by turning instant power on and off 5 Check starting state Measure minimum starting voltage after 5 min for balancing cycle pressure and cooling the PTC Components start in the voltage of R...

Page 14: ...a Tester or Whistone Bridge Figure 22 Separate the OLP from Compressor and check resistance value between two terminals of OLP with a Tester Figure 23 Check another electric components Replace PTC Observation value is 20 Ohm 220 240V 50Hz The resistance value is 0 or several hundreds The value is Check another electric components YES NO Replace OLP 33 TROUBLESHOOTING Mechanical Part 14 ...

Page 15: ... current flowing in sub coil of Compressor Shorted Check capacity of OLP Lack of capacity The items described above are normal Coil of motor Compressor Running state of Compressor is poor Poor contacting Replace each component Fan motor doesn t run Check current flowing in the MOTOR MECH FAN Coil is shorted Check current flowing of the following components THERMISTOR FUSE MELTING Check current flowing...

Page 16: ...ing air are high Is there gap in the door packed Wipe dew with a dry cloth This occurrence is solved naturally in low temperature and humidity Fill up the gap Abnormal noise generates Are the set positioned in a firm and even place Are any unnecessary objects set in the back side of the set Check if the Tray Drip is not firmly fixed Check if the cover of mechanical room in below and front side is tak...

Page 17: ...mperature Equal to ambient temperature Normal discharging of refrigerant The capillary tube is faulty Normal discharging of Refrigerant MOISTURE CLOG Cooling operation stops periodically Flowing sound of Refrigerant is not heard and frost melts Low than ambient temperature Cooling operation restarts when heating the inlet of capillary tube DEFECTIVE COMPRESSION COMPRESSION NO COMPRESSION Freezer a...

Page 18: ...in 3Omin after unpacking 2 Keep the unpacked drier at the temperature of80 100 C Don t keep the drier in a outdoors because humidity damages to it VACUUM 1 When measuring with pirant Vacuum gauge the charging М С vacuum degree is within 1 Torr 2 If the vacuum degree of the cycle inside is 10 Torr below for low pressure and 20 Torr for high pressure it says no vacuum leakage state 3 Vacuum degree o...

Page 19: ...Figure 23 LOKRING Figure 24 LOKRING TOOL TOOL ASSEMBLY JAWS BOLT TUBE LOKRING LOKRING JOINT TROUBLESHOOTING Mechanical Part 19 ...

Page 20: ...ON Quick freeze Economy mode Economy mode Temperature control in freezing compartment Temperature control in refrigeration compartment LED display lock button Loose fitting door alarm Quick freeze Temperature control in freezing compartment Temperature control in refrigeration compartment ...

Page 21: ...0 20 21 5 23 23 15 15 17 5 20 20 unit temperature GC B379S QA GC B409S QA GC B379S CA GC B409S CA Setting temp GC B379S CA GC B409S CA classification First Power On 1time press 2times press 3times press 4times press 5times press 6times press 7times press 8times press 9times press NOTCH Setting temp classification First Power On 1time press 2times press 3times press 4times press 5times press NOTCH ...

Page 22: ...on status during Eco Friendly freezer and fridge display is controlled by the minimal Notch control temperature of freezer refrigerator has to be at minimal Notch You can use this function for quick freezing This function is used when you want to freeze the food quickly Express Freezing on off method Press the Express Frz Button once The Express Frz Lamp turns on and the quick freezing starts If y...

Page 23: ...Buzzer signal Display Micom gets the information about door open started from Main Micom the function of Door Alarm starts For stopping the signal you have to close the door LOCK function Display button lock LOCK on off method on press continuously the Lock Alarm button for 3 seconds or more off press continuously the Lock Alarm button for 3 seconds or more DISPLAY operation of LOCK function befor...

Page 24: ...ot operate but the tones such as ding will sound 3 When the defect CODE removes the sign it returns to normal operation RESET 4 The defect CODE shows on the Refrigerator and Freezer Display PIC 2 3 GC B379S CA GC B409S CA 1 Defrosting starts each time the COMPRESSOR running time limit 50 hours s t r a t s g n i t s o r f e d n o r e w o p when the compressor running time reaches 4 hours 4 Defrosti...

Page 25: ...re Freezer and Refigerator temperature setting Normal Setup temperature indication Normal Display Switch Failure of freezer sensor FS E Freezer sensor disconnection or short circuit Failure of Refigerator sensor rS E Refrigerator sensor disconnection or short circuit Check sensor wiring Failure of defrost sensor dS F Defrost sensor short circuit or disconnection Ambient sensor failure rt E Ambient...

Page 26: ...FF Recycle ON OFF Recycle NO Classification Operation control COMP Fan of Engine section FAN of freezer Defrost heater Damper of refrigerator Normal 1 Freezer sensor failure Fridge sensor failure Defrost sensor failure Ambient sensor failure Defrost failure Main PCB Connection failure 2 3 4 5 6 7 15min ON 15min OFF No defrost Return immediately Sensor failure time 10min OPEN 15min CLOSE No compens...

Page 27: ...n the display after reset the MICOM Return to normal mode Attention If Short made in TEST terminal the TEST 1 condition will maintain TEST function If the temperature is above than 45 C when the first time defrost sensor is power on the primary defrost conditions are proceed In case of temperature is lower than 45 C LQC heater check mode starts Attention If the sensor becomes above 45 C within 10 ...

Page 28: ...uits for RELAY driving electricity 12Vdc and for supplying electricity to MICOM and IC 5Vdc The voltage in each part is as follows 7 If Short made in TEST terminal the TEST 1 condition will maintain Internal display Test 2 Mode PARTS VA1 CE2 CE3 VOLTAGE 230Vac 12Vdc 5Vdc 28 MICOM FUNCTION PCB CIRCUIT EXPLANATION ...

Page 29: ... RESET CIRCUIT All the internal parts of MICOM IC1 return to the initial condition when the early power ON or apply power again in MICOM after temporary power failure As a result all the functions operate according to the early condition At the early period of power ON the LOW voltage is applied in the RESET terminal of MICOM for the fixed time The RESET terminal is 5V during the general operation...

Page 30: ...4 LOAD BUZZER OPERATION 1 LOAD OPERATION CHECK 2 BUZZER OPERATION CHECK 51 50 MICOM FUNCTION PCB CIRCUIT EXPLANATION 30 ...

Page 31: ...of each SENSOR is as follows SENSOR REFRIGERATOR SENSOR FREEZER SENSOR DEFROST SENSOR RT SENSOR CHECK POINT POINT A Voltage POINT B Voltage POINT C Voltage POINT D Voltage NORMAL 30 C 50 C SHORT OPEN 0 5V 4 5V 0V 5V Measure point CLOSE OPEN Refrigerator door NO 25 OF IC 1 MICOM 5V S W of 2 1 is OFF state 0V S W of 2 1 is ON state MICOM FUNCTION PCB CIRCUIT EXPLANATION 31 ...

Page 32: ...SWITCH INPUT CIRCUIT The following circuit is a test switch input circuit for checking the refrigerator TEMPERATURE COMPENSATION P20 25 P65 MICOM FUNCTION PCB CIRCUIT EXPLANATION 32 ...

Page 33: ...Inner MICOM DISPLAY GC B379S CA GC B409S CA GC B379S QA GC B409S QA 33 MICOM FUNCTION PCB CIRCUIT EXPLANATION ...

Page 34: ...1D 108A 108A 281F 281B 501A 407B 102A 503A 402A 102C 102B 103B 281E 281A 610E 282B 283B EXPLODED VIEW REPLACEMENT PARTS LIST 610E GC B379S CA GC B409S CA 103A 109A 233A 231A 210A 281H 230A 239A 203A 230B 210B 128D 128C ...

Page 35: ... 405C 301A EXPLODED VIEW REPLACEMENT PARTS LIST 401A 405A 329A 332A 315A 315B 315C 319A 319C 420A 329C 106B 104A 104C 420A 317A 318A 120E 120A 120B 401B 120D 323B 328A 327A 604F GC B379S CA GC B409S CA GC B379S QA GC B409S QA 310A 308A 309A 303D 319B ...

Page 36: ...103E 241A 241C 235A 136E 155A 154G 151B 154D 154B 136A 136B 136C 136D GC B379S CA GC B409S CA GC B379S QA GC B409S QA 125A EXPLODED VIEW REPLACEMENT PARTS LIST ...

Page 37: ...must withstand at least 20atm Connect a hose from the balloon to manometric rail and a hose from manometric rail high pressure side to suction pipe of refrigerator Open the nitrogen bottle The pressure over 13 atmospheres for refrigerators with tube on sheet evaporator and the pressure over 20 atmospheres for refrigerators with tubular evaporator are not recommended Close balloon and block valve o...

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