LG B712Y*B, Service Manual

Page 1: ...E SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL MODEL GR M562Y X M602Y X GR M562Y Y M602Y Y GR B562Y Y B602Y Y GR B562Y Q B602Y Q GR B562Y C B602Y C REFRIGERATOR SERVICE MANUAL http biz lgservice com ...

Page 2: ...electric shock unplug prior to servicing 3 In case of testing with power on wear rubber gloves to prevent electric shock 4 If you use any appliances check regular current voltage and capacity 5 Don t touch metal products in cold freezer with wet hand It may cause frostbite 6 Prevent water flowing to electric elements in mechanical parts 7 When you stand up during observing the lower part with the ...

Page 3: ...ration is over add the quantity in grams of R 134a to the refrigerant system Remember that every system has an exact quantity of R 134a 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 refilling tube are closed to keep the Freon for adding to th...

Page 4: ... 79 81 FREEZER Knob Dial REFRIGERATOR Micom Control DEFROSTING SYSTEM Full Automatic Heater Defrost OUT CASE Pre Coated Metal INNER CASE A B S INSULATION Cyclo Pentane Foam FREEZER 1 EA REFRIGERATOR 2 EA 3EA Option VEGETABLE TRAY Drawer Type EGG TRAY 1 Piece ICE TRAY 2 Pieces ICE BANK 1 Piece COMPRESSOR P T C Starting Type EVAPORATOR Fin Tube Type CONDENSER Wire Condenser Screw Condenser REFRIGERA...

Page 5: ... or all of the features shown above FREEZER COMPARTMENT Lamp Shelf Shelves Convertible Room Vegetable Drawer Vita Light optional Freezer Temperature Control Dial Deodorizer Optional Lamp REFRIGERATOR COMPARTMENT In Door Ice Maker Optional Freezer Door Rack Egg Storage Rack Dairy Corner Refrigerator Door Rack Levelling Screw Vegetable Partitioner Base Cover Optional ...

Page 6: ...the features shown above FREEZER COMPARTMENT Lamp Shelf Shelves Convertible Room Vegetable Drawer Vitamin Kit optional Freezer Temperature Control Dial Deodorizer Optional Lamp REFRIGERATOR COMPARTMENT Twisting Ice Serve Optional or In Door Ice Maker Optional Freezer Door Rack Egg Storage Rack Optional Dairy Corner Optional Refrigerator Door Rack Levelling Screw Base Cover ...

Page 7: ...n Kit optional Shelf Deodorizer Optional Lamp REFRIGERATOR COMPARTMENT Freezer Temperature Control Dial Freezer Door Rack Egg Storage Rack Refrigerator Door Rack Levelling Screw Base Cover NOTE This guide covers several different models The refrigerator you have purchased may have some or all of the features shown above ...

Page 8: ...CH 1 T o remove the door switch pull out it with a Ñ type Ass y driver as shown in figure 9 2 Disconnect the lead wire from the switch 3 3 FAN AND FAN MOTOR 1 Remove the freezer shelf 2 Remove the Cover Lamp F by loosening 1 screw fixed to ceiling of Inner Liner 3 Remove the Grille by pulling it out 4 Pull out the Shroud and remove the Fan Motor Assy by loosening 2 screws 5 Pull out the fan and se...

Page 9: ...Wrap Figure 14 3 5 LAMP 1 Unplug the power cord from the outlet 2 Remove the room lamp lid by loosening 1screw and take down while pulling it forward with both hands as shown in figure 3 Remove the lamp by turning it counterclockwise 3 5 2 Refrigerator room lamp 1 Unplug the power cord from the outlet 2 Remove refrigerator shelves 3 Remove the room lamp lid by pulling it forward 4 Make sure the bu...

Page 10: ...For normal operation of single phase induction motor in the starting operation flows in both main coil and sub coil After the starting is over the current is cut off in subcoil The proper features of PTC play the above all roles So PTC is used as a starting device of motor 4 2 3 PTC Applied Circuit Diagram l According to Starting Method of Motor 4 2 4 Motor Restarting and PTC Cooling 1 For restart...

Page 11: ...s by heating the heater inside OLP and OLP protects Motor by cutting off current which flows to Compressor Motor 4 3 2 Role of OLP 1 OLP is attached to Hermetic Compressor used to Refrigerator and Show Case and prevents Motor Coil from being started in the Compressor 2 Do not turn the Adjust Screw of OLP in any way for normal operation of OLP Composition and connection Diagram of OLP 11 CONTACTING...

Page 12: ...u u GR M562Y X M602Y X GR M562Y Y M602Y Y GR B562Y Y B602Y Y GR B562Y Q B602Y Q u u u GR B562Y C B602Y C NOTE 1 This is a basic diagram and specifications vary in different localities 5 CIRCUIT DIAGRAM 12 ...

Page 13: ...cted 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 at voltage 10 of rated voltage 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 a regular...

Page 14: ...Wheat stone bridge Figure 22 Separate the OLP from Compressor and check resistance value between two terminals of OLP with a T ester Figure 23 Observation value at 220V 50Hz 47 30 220 240V 50Hz 47 30 110 115V 60Hz 6 8 30 220V 60Hz 47 30 127V 60Hz 22 30 The resistance value is 0 or several hundreds or infinity Check another electric components Replace OLP Check another electric components Replace P...

Page 15: ... Replace 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 t Cooling ability is poor Fan motor doesn t run Much frost are sticked to the EVAPORATOR Poor contacting Coil is shorted Shorted Replace each component Repl...

Page 16: ...n 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 happening in the Out Case of surrounding air are high is solved in low temperature and humidity naturally Is the gap in the door packed Fill up the gap Abnormal Is the set positioned in a firm and even place Adjust the Leveling screw and position noise generates in the f...

Page 17: ...re Normal cooling is possible don t get cold formed when injecting Refrigerant at all of regular amount PARTIAL Freezer room and Flowing sound of Refrigerant A little higher Normal discharging of CLOG Refrigerator is heard and frost forms than refrigerant don t get cold in inlet only ambient The capillary tube is faulty normally temperature WHOLE Freezer and Flowing sound of Refrigerant Equal to a...

Page 18: ...ithout fail 1 gauge of charging M C vacuum Perform vacuum operation until a proper 1 degree is within 1 T orr 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 T orr below for low pressure and 20 T orr 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 19: ...der and Interior display is set to ÔR2Õ ÕÕR3Õ ÕÕR4Õ ÕÕR0Õ ÕÕR1Õ 2 When the power is initially applied or restored after a power failure it is automatically set to Ô3Õ against the interruption of electric power 7 DESCRIPTION OF FUNCTION CIRCUIT OF MICOM 19 u GR M562Y X M602Y X GR M562Y Y M602Y Y GR B562Y Y B602Y Y GR B562Y Q B602Y Q u GR B562Y C B602Y C MIN MAX REF TEMP CONTROL Temp Medium Medium C...

Page 20: ... RPM 7 1 3 CONTROL OF VARIABLE SPEED FAN IN THE FREEZER COMPARTMENT 1 Fan motor in the freezer compartment shall change from standard to high speed rpm in order to increase cooling speed and load corresponding speed 2 Hign speed rpm is only used for the initial power application super cool mode and load corresponding operation But standard rpm is used in the general working conditions 3 When the d...

Page 21: ... will not be performed 7 1 7 SEQUENTIAL OPERATION OF ELECTRIC COMPONENTS The electric components such as the comp defrosting heater and cooling fan start sequentially to avoid the noise and damage to the part which may result from the simultaneous start of various components on turning the power on or after the completion of a test Condition of Operation Operating Sequence If the temp of the defro...

Page 22: ... Y M602Y Y GR B562Y Y B602Y Y GR B562Y Q B602Y Q NO Error Error Code Cause State of Operation with Error Display Comp Cooling fan Defrosting heater 1 2 3 4 Faulty refrigerator R sensor Faulty defrosting sensor Faulty Room temperature sensor in the main PCB Defrosting failure r d when super cool and refrigerator key pressed together display will be all off Cut or short circuited wire of H refrigera...

Page 23: ...off 23 u GR B562Y C B602Y C MIN MAX REF TEMP CONTROL NO Error Error Code Display Cause R0 R1 R2 R3 R4 Comp Cooling fan Defrosting heater OFF ON 1 2 3 4 Faulty refrigerator sensor on the control box of the refrigerator Faulty defrosting sensor Faulty room temp sensor in the main PCB Defrosting failure Cut or short circuited wire of refrigerator sensor Cut or short circuited wire of defrosting senso...

Page 24: ...eater OFF 4 Every display LED ON 5 F lamp can be switch on off by door open close TEST 2 Push the test button 1 Comp OFF Reset if the temp of once while in the 2 Freezer fan OFF the defrosting sensor TEST MODE 1 3 Defrosting heater ON is 13 C or above 4 Every display LED OFF except the refrigerator temp status keys displaying Ô2Õ 5 H lamp can be switch on off by door open close for 5 secÕs Reset P...

Page 25: ... voltage transformer to transmit energy of the first side of the switching end to the second side the secondary power to supply power to MICOM and IC and the feedback part IC3 to feedback the secondary voltage to the first side of the transformer in order to maintain the secondary voltage constant Caution High voltage DC 310V is maintained in this circuit Wait at least 3 minutes after unplugging t...

Page 26: ... is changed 7 2 3 RESET CIRCUIT The RESET circuit is for allowing all the functions to start at the initial conditions by initializing various parts includingthe RAM inside the MICOM IC1 when the power is initially supplied or the power supply to the MICOM is restored after a momentary power failure For the initial 10ms of power supply ÔLOWÕ voltage is applied to the MICOM RESET terminal During a ...

Page 27: ...refrigerator is left open for 7 minutes or longer the lamp of the freezer refrigerator turns of f automatically 27 Load Type COMP NO 16 NO 12 NO 10 NO 15 NO 14 NO 13 NO 11 1V or below 12V Defrosting Lamp Heater Fan Motor Low RPM Home Bar Heater R Lamp Fan Motor HIGH RPM Measurement Location IC6 Condition ON OFF ...

Page 28: ...the button on the display is pushed Alarm for open door beep beep beep OFF IC1 0 V IC1 0 V Measure ment Location Condition 0 V 5 V 0 V 5 V 0 5 s 0 5 s 1 9 kHz Beep OFF 0 1 s 0 5 s 0 V 5 V 0 V 5 V 1 9 kHz Beep PIN NO 34 Closed 0 V Open 5 V Freezer Measurement Refrigerat Door Location A B ...

Page 29: ...is shown below The upper CIRCUIT reads FREEZER and 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 29 SENSOR CHECK POINT NORMAL 30 C 50 C SHORT CIRCUITED OPEN Room Temperature Sensor POINT Voltage Refrigeration Sensor POINT Volta...

Page 30: ... circuits for less cooling and overcooling compensation in a refrigerator compartment The above OPTION circuit is to compensate refrigerator temperature by simply cutting during service 30 OVER COOLING LESS COOLING COMPENSATION COMPENSATION REFRIGERATOR TEMPERATURE REMARKS JCR1 JCR2 JCR3 JCR4 COMPENSATION VALUES CUT 1 C CUT CUT 2 C CUT 1 C CUT CUT 2 C CUT CUT 0 C CUT CUT 0 C CUT CUT CUT 1 C CUT CU...

Page 31: ...AY LIGHT ON CIRCUIT ç The circuit shown above is to determine whether a function control key on the operation display is pushed and to turn on the corresponding function indication LED LED Module The drive type is the scan type 31 ...

Page 32: ...iving speed Measure the F SENSOR SUPER FROST SENSOR R1 R2 SENSOR after disconnect CON5 of PWB ASSY MAIN TEMPERATURE SENSOR RESISTANCE OF FREEZER RESISTANCE OF REFRIGERATOR SENSOR DEFROST SENSOR 20 ßC 22 3 K 77 K 15 ßC 16 9 K 60 K 10 ßC 13 0 K 47 3 K 5 ßC 10 1 K 38 4 K 0 ßC 7 8 K 30 K 5 ßC 6 2 K 24 1 K 10 ßC 4 9 K 19 5 K 15 ßC 3 9 K 15 9 K 20 ßC 3 1 K 13 K 25 ßC 2 5 K 11 K 30 ßC 2 0 K 8 9 K 40 ßC 1...

Page 33: ...d COOLING blocked If pass less than 7 minutes OLP PTC is poor Replace OLP PTC after stop of COMP don t COMPRESSOR RELAY is Replace MAIN PWB RY1 press it and stand by poor THE CONNECTING WIRE Certify the black wire of MAIN is poor PWB CONNECTOR CON2 2 Whether refrigerant leaks or Measure the amount of frost Refrigerant leakage Remedy the leaking part not sticking on EVA and the and reaching Refrige...

Page 34: ...NG is NO DEFROSTING 1 HEATER emit heat PRESS TEST KEY on MAIN HEATER disconnection Replace HEATER poor PWB three times forced DEFROSTING TEMPERATURE FUSE Replace TEMPERATURE disconnection FUSE Connection is poor Certify EVA connection and wire of MAIN PWB CONNECTOR DEF SENSOR is poor Replace DEF SENSOR HEATER RELAY is poor Replace RY5 of MAIN PWB 2 DRAIN PIPE blocking Certify DRAIN PIPE DRAIN PIPE...

Page 35: ...7 5 MAIN PWB ASS Y AND PARTS LIST 7 5 1 MAIN PWB ASS Y In the case of GR M652 M712 203V model P No of main ASSÕY is used as EBR327903 35 ...

Page 36: ...7 5 2 REPLACEMENT PARTS LIST 36 ...

Page 37: ... 37 ...

Page 38: ...7 5 3 PWB ASS Y DISPLAY AND PARTS LIST 38 ...

Page 39: ... 39 7 5 4 PWB ASS Y DISPLAY I MICOM AND PARTS LIST ...

Page 40: ... 40 7 5 5 V LED DISPLAY PART LIST ...

Page 41: ...7 6 PWB DIAGRAM 41 ...

Page 42: ... 42 ...

Page 43: ...o change in different localities t Capacitors and fuse are optional parts 8 EXPLODED VIEW REPLACEMENT PARTS LIST 43 182 121 164 183 166 501F 318A 148 312A 40 129A 109 103 604G 501K 150 165 115 109 418A 323B 329A 171 116 108 411A 139 178 181 146 106A 29 145 179 404B 142 158 ...

Page 44: ... 44 149D 155J 149B 120 118 119 138 120 110 111 149B 405A 140A 133 405C 405C 404A ...

Page 45: ... 45 101 122 241D 244C 244A 162 212C 212A 205A 241A 279A 123 102 241C 235A 205A 210A 173 172 241E ...

Page 46: ...P No MFL38971701 MAR 2007 Printed in Korea ...