Goldstar MA-2005ST service manual Defective PCB assembly Defective high voltage transformer

Page 37

(TROUBLE 5) No microwave oscillation even though oven lamp and fan motor run. (Display operates properly)

CONDITION

No microwave oscillation.

	CHECK	RESULT
	Disconnect the	No continuity.
	wire leads from	No continuity.
	wire leads from
	relay 2 and
	check continuity	Continuity.
	of relay 2.	Continuity.
	of relay 2.
	(Operate the unit)
	Check high vol-	Abnormal
	tage transformer	Abnormal
	tage transformer

Normal

CAUSE

Defective PCB assembly.

Defective high voltage transformer.

REMEDY

Replace PCB assembly.

Replace high voltage transformer.

	Check high vol-	Abnormal
	tage capacitor.	Abnormal
	tage capacitor.

Normal

	Check high vol-	Abnormal
	tage diode.	Abnormal
	tage diode.

Defective high voltage capacitor.

Defective high voltage diode.

Replace high voltage capacitor.

Replace high voltage diode.

Normal

Check magnetron.

Abnormal

Defective magnetron.

Replace magnetron.

NOTE : ¥ Make sure the wire leads correct position.

¥When Removing the wire leads from the parts, be sure to grasp the connector, not the wires.

¥When removing the magnetron, be sure to install the magnetron gasket in the correct position and in good condition.

Output is full power when you set lower power level.

Disconnect the wire leads from

relay 2 and check continuity relay 2. (Operate the unit)

Abnormal.

Defective PCB assembly.

Replace PCB assembly.

5-15

Image 37

Contents Microwave Oven Safety Precautions How a Microwave Oven Works Function & Type 1/2Type of Microwave Oven Grill Cooking Function & Type 2/2Installation Installation & Utensils 1/2Cooking Utensils Installation & Utensils 2/2History of dielectric heating What’s the microwave? 1/2Principle of dielectric heating What’s the microwave? 2/2 Safety of microwave ovenDefinition of electric wave Conventional heating Conventional heating vs. dielectric heatingCavity Construction of microwave ovenDoor ControllerHow does the microwave oven operate? Input Senondary Winding AT Microwave generation systemMagnetron 1/2 Microwave generation systemMagnetron 2/2 Testing Magnetron TubeMultiwave system What is Multi-WaveWhat’s the infrared sensor? Infrared sensorWhat’s does move automatically? Auto moving heaterConventional Heater LG’s Auto Moving HeaterSpecifications Control Panel FeaturesOperating Sequence Schematic Circuit Description Microwave Leakage Test Tools and Measuring InstrumentsNecessary Tools Necessary Measuring InstrumentsMeasurement with a Fully Assembled Oven Measurement with Outer Case RemovedRecord Keeping and Notification After Measurement Disassembly and Adjustment Measurement of Microwave Power OutputPower Supply Cord Control Panel AssemblyDoor Main Assembly Removal PCB Assembly RemovalMagnetron Removal AIR Duct Assembly RemovalRemoving the Turntable Motor High Voltage Transformer Removal FAN Motor Assembly RemovalHigh Voltage Capacitor and Diode Removal Interlock SystemSecondary Interlock Switch Test Primary Interlock Switch TestMonitor Switch Test Interlock Continuity TestComponents Test Procedure Component Test ProcedureComponents Test Procedure Results Relay Condition Cause Remedy Trouble ShootingResult Result Condition Check Defective PCB assembly Defective high voltage transformer Introduction Exploded ViewDoor Parts Controller Parts Oven Cavity Parts Latch Board Parts Interior Parts Base Plate Parts Schematic Diagram of P.C.B Printed Circuit Board