LG LRBP1031T, Service Manual

Page 1: ...N PLEASE READ CAREFULLY THE SAFETY PRECAUTIONS OF THIS BOOK BEFORE CHECKING OR OPERATING THE REFRIGERATOR REFRIGERATOR SERVICE MANUAL http biz lgservice com MODEL LRBP1031W LRBP1031T Color Euro White Titanium ...

Page 2: ...to prevent electric shock 3 Whenever testing with power on wear rubber gloves to prevent electric shock 4 If you use any kind of appliance check regular current voltage and capacity 5 Don t touch metal products in the freezer with wet hands This may cause frostbite 6 Prevent water from following onto electric elements in the mechanical parts 7 When standing up after having checked the lower sectio...

Page 3: ... operation is over add the quantity in grams of R134a to the refrigeration system Remember that every system has an exact quantity of R134a with a tolerance of 5 grams that can be added Figure 4 Before performing this operation if the vacuum pump and refilling cylinder are connected make sure that the valve placed between the vacuum pump and the refilling tube are closed in order to keep the Freon...

Page 4: ...pe EVAPORATOR Fin Tube Type CONDENSER Side Wire Condenser SPECIFICATIONS 4 Optional Parts ITEMS SPECIFICATIONS DIMENSIONS mm 595 W X626 D X1710 H NET WEIGHT kg 69 COOLING SYSTEM Fan Cooling REFRIGERATOR Knob Dial FREEZER Button Full Automatic DEFROSTING SYSTEM Heater Defrost DOOR FINISH Pre Coated Metal OUT CASE Painted Steel Sheet INNER CASE ABS INSULATION Polyurethane Foam DEFROSTING DEVICE Heat...

Page 5: ...r movable Bottle Holder 2LBottle Door Basket Leveling Screw Egg Tray 1 or 2 Freezer Temperature Control Removable Glass Shelf 2 or 3 Lamp Multi air Flow Duct Fresh Meat Keeper Optional Refrigerator Temperature Control Vegetable Drawer Used to keep fruits and vegetables etc fresh and crisp Ice Cube Tray Freezer Compartment Removable Plinth ...

Page 6: ...lower cover And seperate screw lower hinge and remove pin Separating the freezer door in opening and more the position the cap Move the position of bracket door and screw 2 Separating screw and remove the center hinge and the refrigerator door Move the position of cap Move the position of bracket door and screw 3 Move the position of upper hinge pin and cap Assemble the refrigerator door Assemble ...

Page 7: ... C to the body to remove the refrigerator door only 2 Pull out the Door Gasket to remove from the Door Foam Assy R 2 DOOR SWITCH 1 Loosen four screws in upper part and disconnect top cover 2 Disconnect Lead Wire from switch 3 Disengage hook behind the switch by pressing it with hands 3 REFRIGERATOR ROOM LAMP 1 Remove the Cover Lamp R by pulling with a Ð type driver 2 Remove the Lamp by turning Bol...

Page 8: ...y and replace new one 6 DAMPER CONTROL 1 Remove the Cover Lamp R and loosen 2 screw 2 Pull the Control Box R and separate the lead wire housing 3 Remove the Cover Lamp R 4 Separate the Insulation Multi Duct and Control Box R 5 Disassemble the Knob 6 Separate the Damper Control and Control Box R 7 Separate the Damper Control and Resistor 8 Disconnect the lead wire 7 HEATER SHEATH In this refrigerat...

Page 9: ...e phase induction motor in the starting operation flows in both main coil and sub coil After the starting is over the current in subcoil is cut off The proper features of PTC play all the above roles So PTC is used as a motor starting device 3 PTC Applied Circuit Diagram According to Starting Method for the Motor 4 Motor Restarting and PTC Cooling 1 For restarting after power off during normal Com...

Page 10: ...or 2 Role of the OLP 1 The OLP is attached to the Hermetic Compressor used for the Refrigerator and Show Case and prevents the Motor Coil from being started in the Compressor 2 Do not turn the Adjust Screw of the OLP in any way for normal operation of the OLP Composition and connection Diagram of OLP CIRCUIT DIAGRAM CONTACTING POINT COVER BIMETAL CONTACTING POINT HEATER TERMINALS ADJUST SCREW HEAT...

Page 11: ...ed Advise the customer to use a regular Trans Replace Compressor OLP works within 30 sec in forcible OLP operation by turning instant power on and off Components start in the voltage of Rating Voltage 10 below Applied voltage isn t in the range of Rating Voltage 10 Check the resistance among M C S C and M S in Motor Compressor Check the resistance of two terminals in PTC Starter Check if applying ...

Page 12: ...ester or Whistone Bridge Figure 21 Separate the OLP from the Compressor and check the resistance value between two terminals of OLP with a Tester Figure 22 Observation value is 220V 50Hz 22 30 115V 60Hz 6 8 30 240V 50Hz 33 30 127 220V 60Hz 22 30 The resistance value is 0 or serveral hundreds The value is Check another electric components Replace OLP Check another electric components Replace PTC St...

Page 13: ...lace the compressor Replace each component Raise the voltage Replace each component Cause Check if current flows to starting devices Check current flowing in sub coil of Compressor Check capacity of OLP The items described above are normal Cooling ability is poor Fan motor doesn t run Much frost are sticked to the EVAPORATOR Poor contacting Coil is shorted Shorted Replace the Heater Sheath Replace...

Page 14: ...en and close the set often or check if the door is closed up it firmly Dew forms Check if ambient temperature and humidity Wipe dew with a dry cloth This occurrence in the Exterior Case of surroumcling air are high is solved naturally in low temperature and humidity Is there gap in the door packed Fill up the gap Abnormal Are the set positioned in a firm and even place Adjust the Adjust Screw and ...

Page 15: ...ature Normal cooling is possible don t cool formed when injecting of Refrigerant normally the regular amount PARTIAL Freeze room and Flowing sound of Refrigerant A little high Normal discharging of CLOG Refrigerator is heard and frost forms more than refrigerant don t cool in inlet only ambient The capillary tube is faulty normally temperature WHOLE Freezer room and Flowing sound of Refrigerant Eq...

Page 16: ... without fail 1 gauge the charging M C vacuum Perform vacuum operation until a proper 1 degree is within 1 Torr vacuum degree is built up 2 If the vacuum degree of the cycle inside is If a proper vacuum degree isn t built up 2 10 Torr below for low pressure and 20 Torr check the leakage from 2 for high pressure it says no vacuum the Cycle Pipe line part and 2 leakage state Quick Coupler Connecting...

Page 17: ...ING time is below 90 minutes defrost and then operate the QUICK FREEZING for the remaining time When the QUICK FREEZING time is over 90 minutes defrost and then operate the QUICK FREEZING for 2 hours 3 If QUICK FREEZE button is pressed during defrosting the QUICK FREEZE LED is lit up But the QUICK FREEZING operates for 3 hours after 7 minutes from the end of defrosting 4 If VACATION button is pres...

Page 18: ...r 7 minutes the operation for the freezing is started But if DEFROST SENSOR is not reach to 7 C after 2 hours operation of the defrosting heater it represents a defrosting trouble See the TROUBLE REPRESENTING FUNCTION 4 If DEFROST SENSOR is short or open defrosting is not performed 7 ORDERLY OPERATION OF ELECTRIC PARTS To avoid NOISE and DAMAGE the items containing an electric parts such as COMP D...

Page 19: ...ROST HEATER 1 FREEZER FREEZER SENSOR open SENSOR abnormal or short O O 2 DEFROST DEFROST SENSOR open SENSOR abnormal or short O O No defrosting 3 DEFROSTING DEFROST HEATER FUNCTION TEMP FUSE open or is abnormal disconnection Displayed after at least 4 hours O O O from the trouble s occurring 4 RT SENSOR NOTE 1 Room Temperature abnormal SENSOR open or short O O O 19 VACATION FREEZE TEMP QUICK FREEZ...

Page 20: ...hed during ERROR CODE TEST FUNCTION is not operated MODE OPERATION CONTENTS REMARKS TEST 1 Press TEST button 1 COMP OPERATES SUCCESSIVELY once 2 FAN OPERATES SUCCESSIVELY 3 DEFROSTING HEATER OFF 4 ALL DISPLAY LEDS ON TEST 2 Press TEST button 1 COMP OFF If DEFROST HEATER once in the state of 2 FAN OFF is over 7 C it returns TEST MODE 1 3 DEFROST HEATER ON to the NORMAL STATE 4 ALL THE DISPLAY LEDS ...

Page 21: ...1 to transmit and receive an information and BASIC TIME for calculating time Use a proper form for OSC 1 Because in case that SPECIFICATION is changed the calculated time in IC1 is changed or IC1 isn t able to operate 3 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 al...

Page 22: ...pe DOOR S W R of NOT MICOM MODEL it s logic of the A B of DOOR S W R is reversed Even though LAMP R is operated a normal ON OFF according to DOOR S W R but the MICOM couldn t detect a DOOR R opened or closed of lead wire of the A B is abnormal or S W of the A B of DOOR S W R is abnormal When DOOR R open isn t detected Even though DOOR R is opened FAN MOTOR couldn t stop When DOOR R close isn t det...

Page 23: ...K 23 DISPLAY FUNCTION BUTTON RING DOOR OPEN ALARM DING DONG SCREECHING OFF IC1 No 14 Pin ov IC1 No 13 Pin ov MEASURING POINT CONDITIONS 0 05s 0 2s 0 1s 1s 0V 5V 0V 5V 0V 5V 0V 5V 0 5s 0 5s 2 66khz DING 2 232khz DONG 3 1khz OFF ...

Page 24: ...ate of each SENSOR is as follows 6 SWITCH INPUT CIRCUIT The following circuit is a test switch input circuit for checking the refrigerator 24 RTÐ SENSOR DEFROST SENSOR FREEZER COMPARTMENT SENSOR SENSOR CHECK POINT NORMAL 30 C 50 C SHORT OPEN ROOM TEMPERATURE SENSOR POINT A Voltage DEFROST SENSOR POINT B Voltage 0 5V 4 5V 0V 5V FREEZER SENSOR POINT C Voltage ...

Page 25: ...artment is changed from 10K present resistance to 18K revised resistance the temp of freezer compartment goes up by 2 C 25 FREEZER TEMPERATURE COMPENSATION FREEZER ROOM RESISTANCE VALUES R1 TEMPERATURE COMPENSATION REMARKS 180 k 5 0 C COMPENSATE WARMLY 56 k 4 0 C 33 k 3 0 C 18 k 2 0 C 12 k 1 0 C 10 k 0 C STANDARD 8 2 k 1 0 C 5 6 k 2 0 C 3 3 k 3 0 C 2 k 4 0 C 470 5 0 C COMPENSATE COOLLY ...

Page 26: ... C 6 C 7 C 8 C 9 C 2k COMPENSATE 2 C 1 C NOT 1 C 2 C 3 C 4 C 5 C 6 C 7 C 8 C 3 3k COMPENSATE 3 C 2 C 1 C NOT 1 C 2 C 3 C 4 C 5 C 6 C 7 C 5 6k COMPENSATE 4 C 3 C 2 C 1 C NOT 1 C 2 C 3 C 4 C 5 C 6 C 8 2k COMPENSATE FREEZER 5 C 4 C 3 C 2 C 1 C NOT 1 C 2 C 3 C 4 C 5 C ROOM 10k COMPENSATE R1 6 C 5 C 4 C 3 C 2 C 1 C NOT 1 C 2 C 3 C 4 C 12k COMPENSATE 7 C 6 C 5 C 4 C 3 C 2 C 1 C NOT 1 C 2 C 3 C 18k COMPE...

Page 27: ...OF KEY BUTTON INPUT AND DISPLAY PARTS The above circuit is to judge the operation conditions of function key and to light each function indicating LED It is operated by SCAN method 27 FREEZER TEMP CONTROL KEY DISPLAY PART ...

Page 28: ...to sensor speed Measure the resistances of SENSORs with a digital tester after disconnecting CON 4 of MAIN PWB ASSY 28 MEASUREDTEMPERATURE RESISTANCE OF FREEZER SENSOR RESISTANCE OF DEFROST SENSOR ROOM TEMPERATURE SENSOR 20 C 22 3k 77k 15 C 16 9k 60k 10 C 13 0k 47 3k 5 C 10 1k 38 4k 0 C 7 8k 30k 5 C 6 2k 24 1k 10 C 4 9k 19 5k 15 C 3 9k 15 9k 20 C 3 1k 13k 25 C 2 5k 11k 30 C 2 0k 8 9k 40 C 1 4k 6 2...

Page 29: ...20 CC4 R6 CC10 R19 J05 J10 J11 J02 R7 J04 RF3 R10 R1 CC8 CC7 R16 R15 R17 RF2 RF1 TEST R13 R12 R11 IC4 J09 IC1 CC3 J08 6871JB1037 STICKER J12 Q1 J13 Q2 J14 Q3 R14 CC6 CC5 OSC1 R8 R9 CC9 1 D 6 R DOOR F CON3 RT SENSOR 9 1 CON2 98 12 COMP F FAN D HEATER CON1 VA1 RY2 RY3 RY1 D8 D7 J15 D6 R4 R18 R3 BUZZER Q4 IC6 TRANS D1 D3 D4 D2 IC2 ...

Page 30: ...2 REPLACEMENT PARTS LIST 30 ...

Page 31: ...3 PWB ASS Y DISPLAY AND PARTS LIST 31 ...

Page 32: ... 5 PWB circuit drawing The PWB circuit drawing may change without notice ...

Page 33: ... 33 ...

Page 34: ...D 120B 120E 501A 120C 120A 282B 283B 104C 106B 104A 109A 109B 103C 301A 418A 401A 104C 106B 104A 315A 315B 315C 315B 315C 319A 319C 328A 420A 329C 323B 310A 308A 309A 314A 312A 317A 307A 318A 105A 304A 411A 404A 405A 329A 332A 409B 330B 405C 281B 281F 610E 108A 604F 120H 410G 303D ...

Page 35: ...EXPLODED VIEW 136E 136F 155A 140A 151A 151B 241A 235A 249C 241A 249A 237A 241C 136A 125A 136B 136C 136D 233A 231A 210A 210A 249B 230A 203A 201A 200A 281D 145C ...

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