LG LSC27918ST Service Manual Download Page 28

Page: 28 / 84

1-9. Fan motor driving circuit (freezer, mechanical area)

1. The circuit cuts all power to the fan drive IC, resulting in a standby mode.

2. This circuit changes the speed of the fan motor by varying the DC voltage between 7.5 Vdc and 16 Vdc.

3. This circuit stops the fan motor by cutting off power to the fan when it senses a lock-up condition.

a , d part

b part

e part

Motor OFF

2V or less

Motor ON

2 ~ 3V

12 ~ 14V

8 ~ 16V

4. The ground is connector 7, pin 2.

CON7

C-FAN

PIN 9, 10, 11

GY, BN, SB

CON7

F-FAN

PIN 12, 13, 14

YL, PR, BL

- 28 -

Summary of Contents for LSC27918ST

Page 1: ...CAUTION PLEASE READ CAREFULLY THE SAFETY PRECAUTIONS OF THIS MANUAL BEFORE CHECKING OR OPERATING THE REFRIGERATOR REFRIGERATOR SERVICE MANUAL PUSH PUSH MODELS LSC27918SW LSC27918ST ...

Page 2: ...RTS IDENTIFICATION 3 HOW TO INSTALL REFRIGERATOR 4 HOW TO DISASSEMBLE AND ASSEMBLE 5 MICOM FUNCTION 6 EXPLANATION FOR MICOM CIRCUIT 7 ICEMAKER AND DISPENSER WORKING PRINCIPLES AND REPAIR 8 CIRCUIT 9 TROUBLE DIAGNOSIS 10 EXPLODED VIEW 3 4 5 6 9 12 20 36 39 40 78 2 ...

Page 3: ...gaged Remove dust and foreign materials from the housing and connecting parts 8 Do not fray damage run over kink bend pull out or twist the power cord 9 Please check for evidence of moisture intrusion in the electrical components Replace the parts or mask with insulation tape if moisture intrusion was confirmed 10 Do not touch the icemaker with hands or tools to confirm the operation of geared mot...

Page 4: ...Yes 1 40W Blue 5 EA Wire Yes No Yes 4 40W Blue 1 Fix 2 S Out AUTO ICE MAKER SPACE PLUS Embo normal Vista ICE PLUS 3 full 1half Heater Sheath 13 70 Hours Fin Tube Type Lamp Shelf Tray meat Egg Bank Basket Quantity Defrosting System First Defrost Condenser Lubricanting Oil Defrost Cycle Defrosting Device Evaporator ID Ø0 85 4 Hours Capillary Tube Cooling System 36 x 33 x 70 in 328 5 lbs 27 cuft R134...

Page 5: ...f the features shown below may not match your model Refrigerator Door Rack Dairy Corner J L M K Refrigerator Shelf Freezer Door Rack Freezer Shelf Drawer B C D A E Vegetable Drawer F G I Automatic Ice Maker For storage of dairy products such as butter and cheese Freezer Lamp Base Grille Snack Pan For storage of meat or fresh food Water Filter H Refrigerator Lamp A B C B D D E F N G H I J N M K I N...

Page 6: ...frigerator door is lower than the freezer door during the installation of the refrigerator Tools you need Wrench 5 16 in 8 mm Wrench 3 4 in 19 mm AFTER LEVELING THE DOOR HEIGHT Make sure the front leveling legs are completely touching the floor difference Height difference Height difference Height difference Height difference Using a 19 mm wrench turn the keeper nut clockwise to lossen the keeper ...

Page 7: ...ound 25cc to flow out Please put up a cup under the hole to prevent it 2 Replace with a new cartridge Take the new cartridge out of it s packaging and remove protective cover from the o rings With cartridge knob in the vertical position push the new filter cartridge into the cover until it stops If you can turn the filter from side to side it isn t fully inserted Push it in firmly and twist it int...

Page 8: ... icemaker 3 If there is no problem with the operation water is supplied through the water tube up to the selected lebel of water 4 The test mode is completed after the water is supplied Note When using the test mode more than twice consecutively water can overflow When the water overflows wipe the ice storage bin It is acceptable if the adjusted level of water is a bit smaller than optimum level W...

Page 9: ...ed tube while pressing area Figure 1 as shown in the figure below If a tube end is deformed or abraded trim the part away Disconnecting the tube under the door causes about 0 5 liters water to flow out Put a large container at end of tube to prevent water from draining onto the floor NOTE Figure 1 1 Open the door Remove the top hinge cover screw 1 2 Use a flat blade screwdriver to pry back the hoo...

Page 10: ...h 7 and into place Rotate lever 5 clockwise to secure hinge 3 Install the grounding screw 4 and connect all the wire harnesses 3 4 Hook tab on door switch side of cover 2 under edge of wire opening in cabinet top Position cover into place Insert and tighten cover screw 1 1 Feed the water tubes through the lower hinge pin and place the door onto the lower hinge pin 5 Reconnect the water tubes by in...

Page 11: ...de 2 Disassembly of an upper grille fan Hold upper part of an upper grille fan U and pull forward carefully 3 Disassembly of a lower grille fan Hold upper part of a lower grille fan and pull forward carefully 4 Disassembly of an upper freezer shroud Hold lower part oull forward and disconnect housing A and B 5 Check foam sticking conditions around a shroud upper freezer and lower freezer during as...

Page 12: ...er selection button Temperature adjustment button for refrigerator compartment Lamp On Off button Filter status display RESET button Temperature adjustment button for freezer compartment Ice Plus function selection button Alarm button and Lock button 12 ...

Page 13: ... will show the word OFF 4 In this mode all loads are turn off Compressor Heater Fans etc 5 Lamps and Dispenser Functions works normally even in demonstration mode the refrigerator Lamp automatic off function works normally 6 To exit Demonstration mode open any Door then press and hold ICE PLUS and REFRIGERATOR button over 5 seconds Display return to normal mode 1 When the appliance is plugged in i...

Page 14: ...e is a replacement indicator for the filter cartridge on the dispenser 2 Water filter needs replacement once six months or of using water filter 3 Water filter icon turn on to tell you need to replace the filter soon 4 After replacing the filter press and hold the FILTER RESET button more than 3 seconds HOLD 3 SECS icon turn off with reset status 14 1 7 ICE PLUS selection 1 8 Dispenser Light Dispe...

Page 15: ...tes in the input of initial power or ICE PLUS operation or load response operation for the high speed of RPM and operates in the standard RPM in other general operation 3 If opening doors of freezing cold storage room or home bar while fan motor in the freezing room operates the freezing room fan motor normally operates If being operated in the high speed of RPM it converts operation to the standa...

Page 16: ...ically off 1 Refrigerator room lamp turn on and off by refrigerator door switch 2 If refrigerator room lamp continuously turns on more than 7 minutes the refrigerator room lamp turns off automatically by compulsion 1 Defrost is cycled whenever the compressor s runtime reaches at least 7 7 hours 2 In providing initial power or returning power failure defrost starts whenever total operation time of ...

Page 17: ...more than 5 c it returns to the test mode for initial operation comp operates after 7 minutes Def sensor TEST MODE 1 TEST MODE 2 POWER ON COMP ON F FAN C FAN ON STEPPING MOTOR ON DEF HTR OFF DEF HTR ON DISP HTRON DISP HTROFF 0 3 sec 0 3 0 3 sec sec 10 sec 5 sec POWER ON 5 sec PIPE ON 0 3 sec COMP ON 0 3 sec F FAN C FAN ON 0 3 sec STEPPING MOTOR ON DUCT HTR ON TEST SW PRESS Once OTHER LOADS OFF COM...

Page 18: ...EZER and ICE PLUS buttons at the same time for more than 1 second to activate the LED check function R2 Sensor Error ICE PLUS LED turns OFF Fig 3 Ambient Sensor Error LOCK LED turns OFF Fig 9 Water Tank Sensor Error Display show Er rt Fig 10 FULL OPENING FOR 10MIN FULL CLOSING FOR 15MIN Error1 Error2 Error3 Error4 Error5 Error6 Error7 Error8 Error9 Error10 ...

Page 19: ...t door is opened this will remain opened 5 second after release dispenser pad 5 While using dispenser Ice or Water function and the door is opened the operation will be stoped 6 If the water or ice Pad exceeds 3 minutes this will turn OFF automatically but the duct door will remain opened 5 seconds after this interruption 7 While pressing a water pad the water will be dispensed and then water pad ...

Page 20: ...circuit IC3 and IC4 Caution Since high voltage 160 Vdc is maintained at the power terminal wait at least 3 minutes after unplugging the appliance to check the voltages to allow the current to dissipate Voltage of every part is as follows 6 EXPLANATION FOR MICOM CIRCUIT Part VA1 CE1 CE2 CE3 CE4 CE5 Voltage 120 Vac 160 Vdc 14 Vdc 12 Vdc 15 5 Vdc 5 Vdc The part highlighted in green are the components...

Page 21: ... of the MICOM will be affected and it might not work at all 1 3 Reset circuit The RESET circuit allows various parts of the MICOM such as RAM defrosting etc to be restarted from the initial state when power is interrupted or restored A LOW signal applied to the reset terminal for 10 ms causes the MICOM to reset itself During normal operation the voltage at the reset terminal is 5 Vdc If the reset ...

Page 22: ... Solenoid Dispenser Pilot Water Solenoid Cube Geared Motor Dispenser Heater Refrigerator LAMP Defrost Heater Compressor Type of Load 0 VAC 0 VAC 0 VAC 0 VAC 0 VAC 0 VAC 0 VAC 0 VAC 0 VAC OFF 110 127VAC 110 127VAC 110 127VAC 110 127VAC 110 127V AC 110 127VAC 110 127VAC 110 127VA C 110 127VAC ON STATUS CON5 PIN 5 7 CON4 PIN 1 CON5 PIN 5 CON4 PIN 3 CON5 PIN 5 CON4 PIN 5 CON5 PIN 5 CON4 PIN 7 CON5 PIN...

Page 23: ... 23 ...

Page 24: ...pond properly If either switch fails the light will not come on Closing 5 V A B C D Switch at both ends are at Off status Opening 0 V A B C D Switch at both ends are at On status Measuring part Door of Freezer Refrigerator CONNECTOR 7 F DOOR S W 2 RD PIN 5 6 CONNECTOR 9 R DOOR S W BO PK PIN 3 4 IC1 MICOM PIN 39 40 24 ...

Page 25: ... 5 Temperature sensing circuit B C D E F A 1 6 Switch entry circuit The following circuits are sensing signal form the test switch damper motor reed switch for testing and diagnosing the refrigerator 25 ...

Page 26: ...el separation function The circuit configuration is OP1 open and OP2 in short these circuits are preset at the factory and can not be altered 1 8 Stepping motor operation circuit CONNECTOR 9 STEPPING MOTOR PIN 9 10 11 12 RD YL BK BL 26 ...

Page 27: ...y sending signals of 3 33 mSEC via MICOM pins 33 34 and 35 as shown in the chart below These signals are output via terminals 10 11 14 and 15 via input terminals 3 6 and 8 of IC10 TA7774P the motor drive chip The output signals allow the coils wound on each phase of the stator to form a magnetic field which causes rotation Input to the terminals INA and INB of IC10 as shown in the chart below driv...

Page 28: ...eed of the fan motor by varying the DC voltage between 7 5 Vdc and 16 Vdc 3 This circuit stops the fan motor by cutting off power to the fan when it senses a lock up condition a d part b part e part Motor OFF 5V 2V or less 2V or less Motor ON 2 3V 12 14V 8 16V 4 The ground is connector 7 pin 2 CON7 C FAN PIN 9 10 11 GY BN SB CON7 F FAN PIN 12 13 14 YL PR BL 28 ...

Page 29: ...Up Up Up 2 C 1 5 C 1 C 0 5 C No 0 5 C 1 C 1 5 C 2 C 2 5 C 3 C 8 2 k 3 6 F 2 7 F 1 8 F 0 9 F 0 9 F 1 8 F 2 7 F 3 6 F 4 5 F 5 4 F Refrigerator Down Down Down Drop change Up Up Up Up Up Up RCR1 2 5 C 2 C 1 5 C 1 C 0 5 C No 0 5 C 1 C 1 5 C 2 C 2 5 C 10 k 4 5 F 3 6 F 2 7 F 1 8 F 0 9 F 0 9 F 1 8 F 2 7 F 3 6 F 4 5 F Down Down Down Down Down change Up Up Up Up Up 3 C 2 5 C 2 C 1 5 C 1 C 0 5 C No 0 5 C 1 C...

Page 30: ... compensation value Remarks JCR3 JCR4 JCR1 JCR2 at refrigerator 0 C In shipment from factory CUT 1 C 1 8 F CUT 1 C 1 8 F CUT 1 C 1 8 F CUT 1 C 1 8 F CUT CUT 2 C 3 6 F CUT CUT 2 C 3 6 F CUT CUT 0 C 0 F CUT CUT 0 C 0 F CUT CUT 0 C 0 F CUT CUT 0 C 0 F CUT CUT CUT 1 C 1 8 F CUT CUT CUT 1 C 1 8 F CUT CUT CUT CUT 0 C 0 F T emperature compensation in CUT JCR1 1 C 1 8 F 2 C 3 6 F JCR2 1 C 1 8 F JCR3 1 C 1...

Page 31: ...B A bi directional lead wire assembly between the two boards is required for the display to function properly Poor communication occurs if a continuous information exchange fail to continue for more than 2 minutes between main MICOM of main PCB and LED dedicated MICOM for LED control of display PCB Main MICOM LCD LED dedicated MICOM DC 12V GND Transmission error status Reception notch status Main ...

Page 32: ... a margin of error Resistance of the cold storage sensor 1 and 2 shall be measured with a digital tester Resistance of the freezing sensor shall be measured with a digital tester after separating CON7 of the PWB ASSEMBLY and the MAIN part Measuring Temperature C Freezing Sensor Cold storage sensor 1 2 Frost removal sensor Outside sensor 20 C 22 3 k 77 k 15 C 16 9 k 60 k 15 C 13 0 k 47 3 k 5 C 10 1...

Page 33: ... 33 ...

Page 34: ... 34 ...

Page 35: ... 35 ...

Page 36: ...ld after starting the Adjust EJECTOR to Start Position with power on icemaking operation Runs MOTOR to drop ice from the tray into the ICE BIN During harvest mode check if the ice bin is full Performs Ice Making Mode after supplying water by operating the SOLENOID in ICE VALVE To operate LINE and SERVICE press and hold the Fill Key for 3 seconds The icemaker will run through 3 stages Harvest Fill ...

Page 37: ...TE After Icemaker Power is ON the Icemaker heater will be on for test for 6 sec 2 3 Harvest Mode 1 Harvest Ice removing refers to the operation of dropping ices into the ice bin from the tray when icemaking has completed 2 Harvest mode 1 The Heater is ON for 30 seconds then the motor starts 2 The feeler arm senses the quantity of ice in the ice storage bin while rotating with the EJECTOR A Ice sto...

Page 38: ...gnosis TABLE 3 DEFECT DIAGNOSIS FUNCTION 3 1 ERROR CODES shown on Icemaker water supply control panel ERROR indicators in table can be checked only in TEST mode STAGE ITEMS INDICATOR REMARKS 1 2 3 4 5 6 HEATER MOTOR HALL IC I detection of position HALL IC II detection of position VALVE Reset Five seconds after heater starts a heater will go off if the temperature by sensor is higher than 10 C Five...

Page 39: ...8 CIRCUIT DIAGRAM PCB ASSEMBLY S W CON10 PWB ASSEMBLY LAMP CON2 PWB ASSEMBLY LAMP CON2 39 ...

Page 40: ...ion between plug and adapter faulty plug The distance between pins Pin outer diameter No power on power cord COMBO is off No electric power on compressor Faulty compressor Faulty COMBO Disconnected copper wire Internal electrical short Faulty terminal contact Disconnected Capacity of COMBO is small Characteristics of COMBO is wrong Bad connection Power is disconnected Inner Ni Cr wire blows out Ba...

Page 41: ...igeration oil Caps are missed Air blowing During transportation During work Not performed Performed T oo short time Low air pressure Less dry air Air Blowing Leave it in the air Caps are missed Short pipe insert Pipe gaps T oo much solder T oo large Damaged pipes Not dried in the compressor Elapsed more than 6 months after drying Caps are missed No pressure when it is open During rest time After w...

Page 42: ...ugh the hole Seal with drain Adiabatics lump input Damage by a screw or clamp Other foreign materials input Parts disconnected Wire is cut Heating wire Contact point between heating and electric wire Dent by fin evaporator Poor terminal contacts Wire is cut Lead wire Heating wire Contact point between heating and electric wire Heating wire is corroded Water penetration Bad terminal connection Chec...

Page 43: ...tion of case door Sheath Heater rated Heater plate Heater cord L Gap Bad attachment Contraction Bad adhesion Weak binding force at hinge Fan motor Door switch Self locked Wire is cut Bad terminal contact Contact distance Button pressure Melted contact Contact Poor door attachment Door liner dimension Contraction inner liner Misalignment Bad terminal connection Adiabatics liquid leak Faults Refrige...

Page 44: ...als on rotating parts Fan shroud contact Clearance Damping evaporator contact Accumulated residual frost Fan misuse Bad shape Loose connection Not tightly connected Insert depth Rating misuse Small capacity Low valtage Malfunction of charging cylinder Wrong setting of refrigerant Insufficient compressor Faulty compressor Fan overload Fan misuse Bad low termperature RPM characteristics Rated power ...

Page 45: ...ty contact Faulty temperature characteristics External air inflow Bushing installed incorrectly Door opens but not closes Gap around gasket Contraction distortion loose door twisted corner not fully inserted Food vapor Storing hot food Unsealed food Door opens but not closes Gasket gap Cool air leak and transmitted High ambient temperature Space is secluded Different rating Small capacity Store ho...

Page 46: ... 1 Compressor compartment operating sounds Compressor sound Sound from machine itself inserted Sound from vibration Restrainer Bushing T oo hard seat Distorted Aged Burnt Stopper Bad Stopper Not fit assembly inner diameter of stopper Tilted Not Compressor base not connected Bad welding compressor stand fallen Foreign materials in the compressor compartment COMBO sound Chattering sound Insulation p...

Page 47: ...screw connection Bad assembly Distortion Foreign materials inside Bad connection Partly damaged Not connected Bad pipe caulking Normal operating sound Vibration sound Aged rubber seat Bad torque for assembling motor bracket Fan guide contact Shroud burr contact Damping evaporator contact Residual frost contact Unbalance Ice on the fan Air intake opposite to motor bushing assembly Supporter disorte...

Page 48: ...d connection Bad terminal contact Adiabatics liquid leak 1 Lead wire is damaged Wire damage when assembling Bracket Cover Outlet burr in the bottom plate Pressed by cord heater lead wire evaporator pipe 2 Exposed terminal Compressor Compartment terminal T ouching other components Freezer compartment terminal T ouching evaporator pipe 3 Faulty parts Transformer Coil contacts cover Welded terminal p...

Page 49: ...er High Faulty damper control Button is set atweak Door is open interference by food No deodorizer Poor capacity Seal condition Storage of fragrant foods Long term storage Odors from cleaners or items which shroud not be stored in a refrigerator Bigger door foam Hinge Pin tilted Poor flatness No washer No grease Stopper worn out Bad freezer compartment door assembly No stopper Bolt is loosened dur...

Page 50: ...ts Replace with rated fuse Electricity leakage Check the resistance of power cord If fuse blowns out High voltage with tester if it is 0 it is shorted frequently confirm Short circuit of components the cause and prevent tracking due to moisture and dust penetration Problems Causes Checks Measures Remarks Compressor Faulty Combo Check the resistance If resistance is infinite replace it does not Vla...

Page 51: ...operation Confirm icing causes and repair switch operation Press button to check Replace door switch Faulty button pressure and contact Press button to check operation Door cannot press door switch Door sag fix door button Check visually Door liner bent replace door or attach sheets Bad radiation conditions in Check the clearance between the Keep clearance between The fan may be compressor compart...

Page 52: ...de 3 Check silver soldered parts Cu Fe Fe Fe 4 Check bending area of wire condenser pipe in compressor compartment cracks can happen during bending 5 Check other parts compressor compartment and evaporators in freezer compartment Shortage of refrigerant Check frost formation on the surface Find out the leaking area repair Drier must be replaced of evaporator in the freezer evacuate and recharge th...

Page 53: ... warm OK joints might be clogged If it is not condenser outlet weld Disconnect with torch remove the joints might be colgged causes evacuate and recharge seal refrigerant Leak at loop pipe weld joint Check sequence Replace the compressor weld Drier must be replaced discharge in compressor 1 Manually check whether evacuate and recharge refrigerant condenser is warm It is not warm and the frost form...

Page 54: ...inserting 1 Impurities of ice insert the copper line copper wire Turn off more than 2 Ice through the hole to check 3 hours and pour in hot water if 2 Put hot water into the drain frost is severe check drains outside 2 Put in hot water to melt down frost 3 Check the water outlet 4 Push the heater plate to suction duct manually and assemble the disconnected parts Gap between Suction duct and 1 Conf...

Page 55: ...g soft copper 3 Reassemble the heater plate wire into the duct soft and thin copper not to impair heating wire Bad cool air inflow and discharge 1 Turn on power open or close the 1 Check the faulty connector of and bad defrosting due to faulty door check that motor fan housing and reassemble wrongly contact and insertion bad connector operates If it operates motor fan assembled parts insertion int...

Page 56: ...placement should compartment Check door assembly conditions conditions and replace it be done when it Faulty gasket Door assembly and replacement cannot be repaired Faulty assembly 3 Overcooling in the refrigerator Check refrigerator compartment Replace faulty parts compartment is overcooled when button Faulty damper in the refrigerator pressed on weak compartment Check parts are faulty Faulty MIC...

Page 57: ...heck gasket attachment Correct the gasket attachement Replace when it can not Icing in the Faulty gasket conditions conditions and replace it be repaired shute Faulty assembly Check door assembly conditions Door assembly and replacement 3 Over freezing in the freezer Refrigerator operates pull down Replace defective parts compartment Check if it is operated Faulty MICOM intermittently The Temperat...

Page 58: ...place defective fan and fan conditions in pipes motor 2 3 Touch pipes with hands or screw 6 Adjust fan to be in the center of driver check the change of the fan guide sound 7 Leave a clearance between interfering parts and seal gaps in 3 Fan operation sound in the freezer 3 1 Check fan insertion depth and the structures compartment blade damage 8 Reassemble the parts which make 3 2 Check the inter...

Page 59: ...ing 4 Moving wheel vibration 2 2 Check capillary tube touches and restrainer if it is severe 5 Other structure and parts cover back especially compressor and pipe vibration 3 1 Check compressor stopper 4 Replace compressor stopper if it Vibration vibrates severely 4 1 Check vibration of front and rear moving wheels 5 1 Touch other structures and parts Irregular sound 1 It is caused by heat expansi...

Page 60: ...ciples of freezing cycles Water boiling or It happens when refrigerant passes Check the sound when compressor is Explain the principles of freezing cycles flowing sound orifice in accumulator internal pipes by turned on and refrigerant flowing phenomenon by the pressure difference between Check the sound when compressor is internal pressure difference condenser and evaporator turned off If sound i...

Page 61: ...th plastic wrap Clean the refrigerator and set Chedk food cleanliness button at strong Plastic Odor Odors of mixed food and plastic Check wet food is wrapped with Clean the refrigerator odors plastic bowl and bag Persuade customers not to use It happens in the new refrigerator plastic bag or wraps with wet food or odorous foods Odor from the Odor from the old deodorizer Check the deodorizer odors ...

Page 62: ... parts 7812 7805 terminals circuit in circuit explanation PCB electric terminal Check fuse in PCB electric Replace PCB fuse fuse is burnt out terminal with a tester STR Parts are Check if STR No 2 and 3 pins Replace parts Applicable to damaged are cut when power is off model with dispenser Abnormal Bad connection Lead Wire connecting Check Lead Wire terminals Reconnect Lead display LCD between Mai...

Page 63: ...o tables to page 29 The wrong sensor Confirm the color of sensor in Repair main PCB explanation has been installed circuits main PCB sensor sensor housing Order by model number housing and part number Defective freezer fan Fan motor lead wire Check fan motor lead wire Reconnect lead motor is cut with a tester wire Defective door switch Measure the voltage between Replace door Refer to load freezer...

Page 64: ... Foreign materials in Step Check Step Motor damper Remove foreign Motor damper baffles baffle visually materials Ice formation on Check if Step Motor damper Replace Step Motor Step Motor damper Heater wire is cut with a damper or refrigerator baffles tester control Box Assembly Defective refrigerator Defective refrigerator Check the resistance of Replace refrigerator Refer to sensor sensor sensor ...

Page 65: ...lanation Defective Buzzer Defective connecting lead wire from Check lead wire related to door Repair lead wire buzzer continuously main PCB to door switch switch with a tester rings or door Defective door switch parts Refer to door switch in parts repair Replace door switch opening alarm guide does not work Defective Buzzer does Key input wire is cut or bad connector Check input wire with a tester...

Page 66: ... lever Repair lead wire dispenser are not Main PCB to lever switch switch with a tester dispensed Defective lever switch parts Refer to door switch in parts repair guide Replace lever switch Defective photo coupler IC parts Check voltage change at photo coupler Replace photo output terminals with lever switch coupler IC or PCB pressed It is OK if voltage change is between 0V 5V Defective relay ass...

Page 67: ...r operates electronic scales pinch off Weld carefully after pinching off the inlet pipe plier gas welding machine Check leak at weld joints Electronic Leak Detector Minute leak Use electronic leak detector Driver Ruler Big leak Check visually Note Do not use soapy water for check Check cooling capacity 1 Check radiator manually to see if warm 2 Check hot line pipe manually to see if warm 3 Check f...

Page 68: ... OIL FROM BEING FORCED OUT The use of piercing type valves will allow future servicing and eliminates the possibility of a defective pinch off 3 Replacement of drier 1 Be sure to replace drier with R134a only when repairing pipes and injecting refrigerant 4 Nitrogen blowing 1 Use pressurized nitrogen to prevent oxidation inside the piping welding Nitrogen pressure 0 1 0 2 kg cm2 5 Others 1 Only ni...

Page 69: ...When replacing a compressor Weld 1 And 2 parts by blowing nitrogen to the low pressure side Note For other parts nitrogen blowing is not necessary because it does not produce oxidized scales inside pipe because of its short welding time 3 Replacement of drier Inserting a capillary tube Measure distance with a ruler and put a mark on the capillary tube Insert tube to the mark and weld it KEY POINT ...

Page 70: ...measure the weight Calculate the weight of refrigerant charged into the charging canister by subtracting the weight of an evacuated charging canister KEY POINT If power is applied during vacuum degassing vacuum degassing shall be more effective Run the compressor while charging the system It is easier and works better KEY POINT Be sure to charge the refrigerant at around 25 C 77 F Be sure to keep ...

Page 71: ...cover of the mechanical area Compressor Condenser Drier Hot Line Evaporator Charging Canister Bushing 1 Observe the safety precautions for gas handling 2 Use JIG or a wet towel in order to prevent electric wires from burning during welding In order to prevent insulation break and accident 3 The inner case will melt and the insulation will burn 4 The copper piping will oxidize 5 Do not allow alumin...

Page 72: ...r Brazing Silver Brazing Pipe Assembly Hot Line Freezer Capi tube Drier assembly Pipe assembly suction Copper Brazing Pipe Assembly Joint Copper Brazing Copper Brazing Copper Brazing Pipe assembly joint Silver Brazing Condenser Assembly wire Silver Brazing ...

Page 73: ...the refrigerator compartment expand and contract as the temperature changes during the refrigerator operation This sound also happens during defrosting twice a day when the ice on the evaporator melts Clunk sound Explain that it comes from the compressor when the refrigerator starts When the refrigerator operates the piston and motor in the compressor rotate at 3600 RPM This sound is caused by the...

Page 74: ...wing also makes sound When water Noise from motor sounds Hiss freezes clicking sounds are heard When ice is being ejected sounds like Hiss produced by a motor to rotate an ice tray and ice dropping and hitting ice bin sounds are also heard Noise when supplying water Explain the principles of water supplied to dispenser When the water supply button in the dispenser is pressed the water supply valve...

Page 75: ...ream The freezing point of ice cream is below 15 C 5 F Therefore ice cream may melt if it is stored in the door rack Store ice cream in a cold place or set the temperature control button of a freezer at strong position Refrigeration is too strong Check the position of temperature control button Check if refrigeration is strong in whole area of the refrigerator or partly near the outlet of the cool...

Page 76: ...ng Frost in the freezer compartment Explain the basic principles of frost formation The main causes for frosting Door was left open Air penetration through the gasket T oo frequent door opening parties etc Hot foods are stored before they are cooled down The temperature of freezer is 19 C 2 2 F if temperature is set at MID If hot air comes into the refrigerator fine frost forms as cold air mixes w...

Page 77: ...ent and the cover of frequently opened and wet foods are not stored in the air tight container or properly vegetable drawer wrapped Be sure to store wet foods in airtight containers or securely covered in plastic wrap When is the power connected When should the power be connected You can connect the power immediately after installation However if the refrigerator was laid flat before or during ins...

Page 78: ...FREEZER DOOR PART 10 EXPLODED VIEW 203A 201A 200A 243A 241E 241G 241G 212J 244A 131C 600A 606A 614A 131A 131B 131D 78 EV 606B SVC KIT BUCKET ICE ...

Page 79: ...REFRIGERATOR DOOR 241H 233A 231A 241D 243B 230A 212G 241B 241C 241A 237A 241H 241H 237A 212J 244A EV 79 ...

Page 80: ...EEZER COMPARTMENT 271B 281C 271A 106A 319B 610E 128D 128F 128C 128E 103C 281G 332B 330B 405G 329A 332A 902B 120D 405A 405D 409A 418A 301A 316B 158C 136B 136A 281A 406A 401A 404A 149B 149A 149C 903E EV 80 ...

Page 81: ...RATOR COMPARTMENT 170A 271B 271C 106A 128J 161A 151A 281H 146A 128K 161B 158B 409A 120B 409A 120A 158A 128A 128B 281D 406A 281B 604H 611C 611E 154A 141A 128H 128G 610E 610E 140A 140B 151B 903D 903D EV 81 281K ...

Page 82: ...ER PART 412A 625A 619A 616G 616F 627A 627D 621D 621B 616K DISPENSER PARTS 405H 282G 113E 617A 113F 276C 280F 276B 402C 281J 501B 281F 278G 279B 279A 279C 280A 500E S18 Only STS model 607A 500D 501D EV 623A 82 ...

Page 83: ...2A 419A S38 318A 317A 304A 323B 314A 105A S15 328A 501A 501K 411A 103B 103A 319A 319E 319C 405C 404B 405F 329C 501F 410G 305C 305B 305C 305B 315A 316A 412D 105F S15 EV 83 314A 309B 309B 307B 328A 307A 419B 412D 310A SVC KIT COMPRESSOR 410G ...

Page 84: ...OCTOBER 2009 MFL62215910 ...

Search results

Summary of Contents for LSC27918ST

Reviews:

Related manuals for LSC27918ST

Brands by name

Popular brands

LG LSC27918ST, Service Manual

Search results

Summary of Contents for LSC27918ST

Reviews:

Related manuals for LSC27918ST

Brands by name

Popular brands