LG Electronics GR-P257/L257, GR-P227/L227 Micom, Problems Symptom Causes Checks Measures Remarks

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2-9. Micom

Problems	Symptom	Causes		Checks	Measures	Remarks

Bad PCB	All display	Bad connection	Bad connector	Visual check on connector	Reconnect
electric power.	LCD are off.	between Main PCB	connection from main	connection.	connector.
		and display circuit.	PCB to display PCB.

		Defective PCB trans.	PCB Trans winding is	Check resistance of PCB Trans	Replace PCB Trans	Applicable to
			cut.	input and output terminals with	or PCB.	model without

			PCB Trans temperature	a tester. (If resistance is infinity,		dispenser.
			fuse is burnt out.	trans winding is cut).

		DefectivePCB electric	Defective regulator IC	Check voltage at input/output	Replace regulator.	Refer to electric
		circuit 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 Main PCB	main PCB and display	connecting Main PCB and	Wire and directly
	operation	and display circuit.	PCB is cut or connector	display PCB with a tester.	connect defective
			terminal connection is		contact terminal to
			bad.		Lead Wire.

		Defective LCD.	Defective LCD.	Check if all LCD are on when	Replace display	Refer to display
				Main PCB Test switch is	PCB.	circuit in circuit
				pressed (or when both freezer		explanation.
				key and power freezer key are
				pressed at the same time for
				more than one second.)

TROUBLE DIAGNOSIS

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Contents Refrigerator Contents Page Front View SpecificationsRef No. GR-L227 Ref No. GR-P257 Ref No. GR-L257 Freezer Refrigerator compartment compartment Parts IdentificationRef No. GR-P227/GR-P257EXTERNAL Filter Parts Identification Parts Identification How to Adjust Door Height of Refrigerator HOW to Install RefrigeratorHow to Install Water Pipe Before InstallationClass Shape and Spec Nomenclature Single Lever Type Faucet general Connection of Pipe Connector a and BTwo Hands Type Faucet General TypeWhen customer uses bottled water Filter CleaningOutternal Filter Filter Fixation Replacement of water filter After installing water filterConfirm the amount of water supplied to the icemaker How to Control the Amount of Water Supplied to IcemakerDisplay Power saving Mode Door Alarm Buzzer Mute ModeMicom Function Monitor PanelDescription of Function Exhibition ModeLCD Back Light Control Outside temperature display functionLock function display button lock Filter condition display functionDispenser use selection When ice maker does not operate smoothlyAutomatic ice maker Express FreezerSuper freezing Miracle Zone functionControl of variable type of freezing room fan Control of M/C room fan motor Door opening alarmDoors of freezing Or home barSequential operation of built-in product Failure Diagnosis Function Test Function Mode Operation Contents RemarksFunction of dispenser and water dispenser built-in Test Mode 1 Status LCD Test Mode 2 Status LCDExplation for Micom Circuit Power circuitExplanation for PWB circuit GR-P227/L227Reset circuit Oscillation circuitGR-P227/L227/P257/L257 Load Driving Circuit Load/dispenser operation, door opening circuitDispenser operation circuit Lever Switch sensing circuit Measuring partDoor opening sensing circuit Short Open Temperature sensing circuitSwitch entry circuit Option designation circuit model separation functionSeparation Connection Status Application Standard Stepping motor operation circuit Fan motor driving circuit freezer, mechanical area +5 C +9F 33 k Ω 56 k Ω JCR1 Main PCB Sensor resistance characteristics table Miracle Zone Stepping Motor / Display Operation Principle Icemaking Mode Harvest ModeFill/Park Position Water supply amount TableDefect diagnosis function Stage Items Indicator RemarksCircuit Trouble Diagnosis Trouble ShootingNot performed Evaporator by heating as Refrigeration Refrigeration Residual Refrigeration No cooling air circulation Is weak Fan does not work Recess Sounds Compressor compartment operating sounds Bad soldering Bad rivet contact Short Structure Door foam Appearance Sag Power FaultsProblems Causes Checks Measures Remarks Problems Causes Checks MeasuresTemperature Cooling Disconnected from the motor Refer to fan motor disassembly Problems Causes Defrosting failureMeasures Remarks Remove the parts and replace it Icing Discharging port of cooling air Sound Click Contraction of evaporator Sources Sound Burping It happens when refrigerant expands Odor Micom Problems Symptom Causes Checks Measures RemarksDriving circuits Motor damper Replace door switch Trouble Diagnosis Items Unit Standards Purposes Remarks Cooling Cycle Heavy RepairSummary Of Heavy Repair Process Contents ToolsItems Precautions Precautions During Heavy RepairWhen replacing a compressor When replacing a drierPractical Work For Heavy Repair Inserting a capillary tubeVacuum Sequence Pipe ConnectionCharging sequence Calculation of amount of refrigerant charged12-0mm Standard Regulations For Heavy RepairBrazing Reference Drawings Asia / Middle-East AfricaEurope & CIS / America Explain the principles of temperature change Problems Checks and MeasuresSound depends on the installation location Explain general principles of soundsExplain the flow of refrigerant Explain the procedure and principles of ice maker operationExplain the characteriistics of moving parts Explain the principles of water supplied to dispenserMeasures for Symptoms on Temperature Odor and Frost Check the temperature control button and set at strongExplain the basic principles of food odor Explain the basic principles of frost formationOthers Remove a freezer door HOW to Disassemble and AssembleHandle InsertTubeLineColletClip Assembly COVER, Dispenser Exploded View Optional part Ref No. GR-P227/GR-P257Ref No. GR-L227/GR-L257 Freezer Compartment Optional part Refrigerator CompartmentMachine Compartment ICE & Water Part Dispenser Part No JD8999A