Goldstar MA-2005ST service manual Result

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(TROUBLE 1) The following visual conditions indicate a probable defective control circuit.

1.Incomplete segments.

¥Segment missing.

¥Partial segment missing.

¥Digit flickering (NOTE: Slight flickering is normal.)

2.Colon does not turn on or blink.

3.A distinct change in the brightness of one or more numbers in display.

4.One or more digits in the display are not lighting.

5.Display indicates a number different from one touched, for example, key in 5 and 3 appears in the display.

6.Specific numbers (for example 7 or 9) will not display when key pad is touched.

7.Display does not count down with time blinking or up with clock operation.

8.Display obviously jumps in time while counting down.

9.Display counts down too fast while cooking.

10.Each indicator light does not turn on after setting cooking cycle.

11.Display time of day does not reappear when cooking is finished.

CONDITION

1.No input can be programmed.

2.Some inputs cannot be programmed.

3.Display shows a number or figure different from one touched.

4.Random programming when touching other pads.

5.Display is fixed at some figure and can not accept any input.

CHECK

Check the conn- ection between membrane key assembly and PCB assembly.

Replace key membrane assembly and check operation.

RESULT

Continuity

No continuity

Everything works as specified.

Still have trouble.

CAUSE

Defective PCB assembly.

Loose connection.

Defective key membrane assembly.

Defective PCB assembly.

REMEDY

Replace PCB assembly.

Connect them tightly.

Replace key membrane assembly.

Replace PCB assembly.

5-12

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Contents Microwave Oven Safety Precautions How a Microwave Oven Works Function & Type 1/2Type of Microwave Oven Function & Type 2/2 Grill CookingInstallation & Utensils 1/2 InstallationInstallation & Utensils 2/2 Cooking UtensilsHistory 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 vs. dielectric heating Conventional heatingDoor Construction of microwave ovenCavity ControllerHow does the microwave oven operate? Input Senondary Winding AT Microwave generation systemMagnetron 1/2 Testing Magnetron Tube Microwave generation systemMagnetron 2/2What is Multi-Wave Multiwave systemInfrared sensor What’s the infrared sensor?Conventional Heater Auto moving heaterWhat’s does move automatically? LG’s Auto Moving HeaterSpecifications Features Control PanelOperating Sequence Schematic Circuit Description Necessary Tools Tools and Measuring InstrumentsMicrowave Leakage Test Necessary Measuring InstrumentsMeasurement with a Fully Assembled Oven Measurement with Outer Case RemovedRecord Keeping and Notification After Measurement Power Supply Cord Measurement of Microwave Power OutputDisassembly and Adjustment Control Panel AssemblyPCB Assembly Removal Door Main Assembly RemovalMagnetron Removal AIR Duct Assembly RemovalRemoving the Turntable Motor High Voltage Capacitor and Diode Removal FAN Motor Assembly RemovalHigh Voltage Transformer Removal Interlock SystemMonitor Switch Test Primary Interlock Switch TestSecondary Interlock Switch Test Interlock Continuity TestComponent Test Procedure Components Test ProcedureComponents Test Procedure Results Relay Trouble Shooting Condition Cause RemedyResult Result Condition Check Defective PCB assembly Defective high voltage transformer Exploded View IntroductionDoor Parts Controller Parts Oven Cavity Parts Latch Board Parts Interior Parts Base Plate Parts Schematic Diagram of P.C.B Printed Circuit Board