LG LRTP-1231W precautio, Service Manual

Page 1: ...SERVICE MANUAL REFRIGERATOR ATTENTION Before start servicing carefully read the safety instructions in this manual MODEL S GR 382R LRTP1231W ...

Page 2: ...1 Service Parts list 42 43 Safety Precautions Read the following inst ructions before servicing your refrigerator 1 Unplug the refrigerator before servicing 2 Visually inspect for gas leakage or short circuit 3 If testing with the refrigerator plugged in wear rubber gloves to avoid electric shock 4 Do not touch frozen metal parts your hands could freeze to the surface This may cause frostbite 5 Be...

Page 3: ...a female type connector to the vacuum pump s pipe See Fig 3 System air evacuation starts as soon as the pump begins to run The system must be kept under vacuum until the low pressure gauge shows 0 absolute or 1 atm 760 mm Hg It is not recommend to run the vacuum pump for more than 30 minutes See Figure 3 In case there is a large leak and the vacuum operation must stop you must add a small amount o...

Page 4: ...ing the scale corresponding to the gas pressure indicated on the pressure indicator located on the upper part of the column To let R 134a flow into the system open the valve at the recharging cylinder s base The total amount of refrigerant should not be Service Precautions installed in one session as it could block the compressor Install 20 30 grams at a time and close the valve The compressor wil...

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Page 6: ...rigerator Door Baskets Freezer Door Baskets REFRIGERATOR FREEZER Temperature Control Fresh Meat Tray Lamp Shelves Plastic or Glass Deodorizer Absorbs Odors Multi Air Flow Air flow distributor Vegetable Tray Keeps fruits and vegetables fresh Leveling Screws MODEL S GR 382R LRTP1231W This part is only included in model LRTP1231W ...

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Page 8: ...trol Brown Red Pink Yellow Blue Violeta Whitte White Defrost and Temperature Electronic Control Orange Orange Sensor Sensor Red Black Black Brown Violet Lamp Switch Yellow Blue Defrost Resistance Red Brown CON1 Yellow Blue Blue Blue Brown Blue Yellow Black M Pink OLP Fan Motor Blue Running Capacitor Blue Pink COMPRESSOR CON2 Black AC Current 7 ...

Page 9: ... that the air ducts are not obstructed for a better cooling performance Temperature variation during defrosting time depending upon the cooling system Cold Air Warm Air Temp Refrigerator Freezer Indirect System Direct System Temp Tim e Tim e 3 4 18 3 18 3 18 16 8 ...

Page 10: ... from the door See Figure 4 from Freezer door Figure 6 Figure 5 Door Switch 1 Pull out the door switch out using a flat head screwdriver See Figure 7 2 Disconnect all switche s cables See Figure 8 Figure 7 Figure 8 Control Circuit Display PWB 1 Remove the lamp cover by inserting a screwdriver in the lower side s holes See Figure 9 2 Loosen and remove the 2 screws See Figure 10 Figure 9 Figure 10 3...

Page 11: ...ly consists of one thermistor and a fuse that melts with heat 2 The termistor s function is to sense the compartment s temperature and automatically stop the defrost The termistor is located beside of the evaporator bracket 3 The melting fuse is a safety device to prevent an overheating of the defrosting resistance when it operates 4 The fuse melts at 162 F and the resistance heater stops 5 To rep...

Page 12: ...Refrigerator Control Box Remove the lamp cover as mentioned before 1 Loosen the screws 2 Remove the entire control box See Figure 20 3 Disconnect the control box connector See Figure 21 Figure 19 Figure 20 Figure 21 ...

Page 13: ...ten and loosen the bolt 3 Be careful not to drop the refrigerator or door when assembling or disassembling lower hinge or the Adjustable Screw Assembly 4 Don t lay the refrigerator down to work on it It will cause malfunction 5 The doors may be reversed to provide left or right opening depending upon the customer s preference HOW TO REPLACE THE DOOR OPENING LEFT TO RIGHT when converting from left ...

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Page 15: ...t is bumped or forced dropping or careless handling it could damage the compressor or cause noise or undesirable operation 3 Use only exact replacement parts when repairing the compressor If the terminals become corroded it could affect operation If the replacement parts are of incorrect values operation and safety will be compromised 2 PTC 2 1 PTC Composition 1 The PTC Thermistor is a semiconduct...

Page 16: ... hot the compressor motor will overheat causing a short circuit or possibly a fire Therefore use a fail safe OLP 2 6 Note on using the starting PTC 1 Be careful not to cause an overvoltage or short circuit 2 Do not force or bump it 3 Keep the OLP dry If water or oil gets into the OLP the electrical insulation can degrade and fail 4 Do not replace the PTC at your own convenience Do not disassemble ...

Page 17: ...Check the resistance among M C S C and M S in Motor Compressor Replace Compressor Go to Step 3 Go to Step 3 Go to Step 4 Go to Step 5 3 Check the resistance of PTC Starter Check the resistance of two terminals in PTC Starter Go to Step 4 Replacce PTC Starter Go to Step 5 NO NO YES 4 Check OLP Check if applying a regular OLP OLP works within 30 seconds In forcible OLP operation by turning against p...

Page 18: ... ter or Wheatstone Bridge Figure 22 Observation value is 220V 50Hz 22 W 30 115V 60Hz 6 8 W 30 240V 50Hz 33 W 30 127 220V 60Hz 22 W 30 Check the other electric components Separate the OLP from Compressor and check resistance value between two terminals of OLP with a Tester Figure 23 Replace PTC The Resistance value is 0 or several hundreds W The value is Check other electric components Replace OLP ...

Page 19: ... sub coil of Compressor Check if current flows to starting devices Check starting voltage Replace the defective component Raise the voltage Replace the Compressor Compressor Motor Coil Lack of Capacity Shorted Poor contacting and broken Low Voltage Fan Motor doesn t run Checker current flow of the door switch Check current flowing in the fan motor Poor contact Coil is shorted Replace the defective...

Page 20: ...Don t open the door too often and close it firmly Moisture forms on the outside 13 Check if ambient temperature and humidity are high 14 Is there a gap in the door gasket 15 Wipe moisture with a dry cloth 16 This does not occur if the temperature and humidity are in the normal range 17 Fix the gap Abnormal Noise 18 Is the refrigerator positioned in a firm and even place 19 Is something in the way ...

Page 21: ...rmed Equal to ambient temperature 7 Normal discharging of refrigerant MOISTURE CLOG Cooling operation stops periodically Flowing sound of refrigerant is not heard and frost melts Lower than ambient temperature 8 Cooling operation restarts when heating the inlet of capillary tube COMPRESSION Freezer and refrigerator don t get cold Low flowing sound of refrigerant is heard and frost forms in inlet o...

Page 22: ... for low pressure and 20 Torr For high pressure indicates no vacuum leakage state 3 Vacuum degree of vacuum pump must be 0 05 Torr below after 5 minutes 4 Vacuum degree must be the same of the value described on item 2 above for more than 20 min 3 Apply M C Vacuum Gauge withou fail 4 Perform vacuum operation until a proper vacuum degree is built up 5 If a proper vacuum degree is not built up check...

Page 23: ...e the button is pushed it cycles through Medium Medium High High Low Medium Low Medium 2 When the power is initially applied or restored after a power failure it is automatically set to Medium Temperature Control Low Medium Low Medium Medium High High TEMP F C 46 4 8 39 2 4 37 4 3 34 7 1 5 30 2 1 ROOM REFRIGERATOR 22 ...

Page 24: ... temperature does not reach 13 C in 2 hours after the defrosting starts the defrosting error code is displayed Refer to 7 1 4 Error Diagnostic Mode 4 With the defective defrosting sensor cut or short circuited wire the defrosting will not be performed 7 1 3 SEQUENTIAL OPERATION OF ELECTRIC COMPONENTS The electric components such as the compressor defrosting heater and cooling fan starts sequential...

Page 25: ...function control button is pushed when an error occurs the function will not be performed 3 When the error is cleared while the error code is displayed due to a fault the refrigerator returns to the normal condition Reset 4 The error code is displayed by the refrigerator temperature indication LED on the display of the refrigerator while the remaining LEDs are off 24 ...

Page 26: ...elay drive 12 Vdc and for the MICOM and IC 5 Vdc The voltage for each part is as follows VA1 prevents overvoltage and noise When 175 V or higher power is a pplied the inside elements are short circuited and broken resulting in the blowout of the fuse in order to protect the elements of the secondary part of the Transformer 25 ...

Page 27: ...C1 SPEC 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 including the 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 10 ms of power supply LOW voltage is applied to the MICOM RESET terminal Du...

Page 28: ...AD DRIVE CIRCUIT 1 Load Drive Condition Check FEEZER FAN COOLING FAN MELTING FUSE DEFROST HEATER Load Type Compressor Freeze Fan Motor Defrosting Heater Measurement Location A B ON 1 V or below Condition OFF 12 V ...

Page 29: ...FROST SENSOR temperature for defrosting into MICOM OPENING or SHORT state of each TEMPERATURE SENSOR are as follows REFRIGERATOR SENSOR DEFROST SENSOR SENSOR CHECK POINT NORMAL 30 50 SHORT CIRCUITED OPEN Refrigerator Sensor POINT A Voltage Defrosting Sensor POINT B Voltage 0 5 V 4 5 V 0 V 5 V ...

Page 30: ...Compensation by raising the temperature 10 KW 32 0 Standard Temperature 8 2 KW 30 2 1 0 5 6 KW 28 4 2 0 3 3 KW 26 6 3 0 2 KW 24 8 4 0 470 KW 23 5 0 Compensation by lowering the temperature Table of Temperature Compensation by adjusting the resistance Difference with the current temperature Example If the refrigerator compensation resistance RCR1 is changed from 10 K the current resistance to 18 K ...

Page 31: ...PUT DISPLAY LIGHT ON CIRCUIT 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 The drive type is the scan type ...

Page 32: ...47 3 KW 23 5 38 4 KW 32 0 30 KW 41 5 24 1 KW 50 10 19 5 KW 59 15 15 9 KW 68 20 13 KW 77 25 11 KW 86 30 8 9 KW 104 40 6 2 KW 122 50 4 3 KW 1 The resistance of SENSOR HAS 5 common difference 2 Measure the resistance of SENSOR after leaving it over 3 minutes in measuring temperature This postponing is necessary because of perceiving speed ...

Page 33: ...SOR RELAY is defective CONNECTING WIRE is defective Refrigerant leakage FAN MOTOR is defective DOOR LINER contact CONNECTING WIRE is defective Poor DEFROSTING SENSOR RESISTANCE is incorrect CHECKING METHOD FREEZER REFRIGE RATOR door open Verify the correct bulb is used Check the connector Check the main PWB Measure the amount of frost on Evaporator and the surface temperature of condenser pipe Che...

Page 34: ...R is defective HEATER RELAY is defective DRAIN PIPE is blocked Attachment is incorrect DOOR sealing is incorrect CHECKING METHOD See if FREEZER TEMPERATURE Iis too warm Check the amount and speed of cool air being supplied inside the refrogerator Check the main PWB Check DRAIN PIPE Check the attachin of DEFROST SENSOR Check the gap in the door gasket POINTS TO CHECK 1 Is FREEZER TEMPERATURE normal...

Page 35: ...7 4 MAIN PWB ASSEMBLY AND PARTS LIST 7 4 1 MAIN PWB ASSEMBLY 34 ...

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Page 39: ...7 5 PWB DIAGRAM 38 REFRIGERATOR LAMP FREEZER FAN MOTOR COOLING FAN MOTOR MELTING FUSE DEFROST HEATER ...

Page 40: ...39 DEFROST SENSOR REFRIGERATOR SENSOR ...

Page 41: ...40 8 Exploded View The parts of refrigerator and the shape of each part may vary by market area Capacitors and fuse are optional parts Optional parts ...

Page 42: ...41 D A ...

Page 43: ...ZER SHELF 5026JJ1001B 5026JJ1001B 149B MEAT TRAY 3390JJ1002A 3390JJ1002A 149C REFRIGERATOR SHELFASSEMBLY 5027JJ2001A 5027JJ2003A 149E REFRIGERATOR SHELFASSEMBLY 5027JJ2002A 5026JJ1002A 151A VEGETABLE TRAY 3390JJ1001A 3390JJ1001A 154A VEGETABLE TRAY COVER 3550JJ1003B 3550JJ1003B 158C LAMP COVER 3550JJ1004B 3550JJ1004A 200A FREEZER DOOR ASSEMBLY 3581JJ8009B 3581JJ8001D 201A FREEZER DOOR FOAM ASSEMBL...

Page 44: ...IDE 4974JJ1002A 4974JJ1002A 323B CONDENSER ASSY WIRE 5403JA1039A 5403JA1039A 327A BUSHING 5040JJ3003A 5040JJ3003A 328A BUSHING 5040JJ3002A 5040JJ3002A 329A FAN ASSEMBLY 5901JJ1001A 5901JJ1001A 329C FAN ASSEMBLY 5901JJ1001B 5901JJ1001B 330B FREEZER SHROUD ASSEMBLY 4999JJ1001A 4999JJ1001A 332A FAN GRILLE ASSEMBLY 3531JJ1001A 3531JJ1001A 401A DEFROST CONTROL ASSEMBLY 6615JB2005C 6615JB2005A 404A FAN ...

Page 45: ...Electronics Inc P No 3828J8331B ...