LG Electronics LMV1825SBQ, MV1825SW service manual Checkout Procedures for Circuit Board

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(3) CHECKOUT PROCEDURES FOR CIRCUIT

 

 

BOARD

 

 

The following symptoms indicate a defective circuit

6)

Wrong figures appear.

board.

7)

The figures of all digits.

1) The start function fails to operate but the high

8)

Some of the indicators do no flicker light up.

voltage Systems, the interlock switches, the door

9)

The clock does not keep time properly.

sensing and the relay check good.

 

 

2)The unit with a normal relay continuously operates.

3)Proper temperature measurement is not obtained.

4)The buzzer does not sound or continues to sound.

5)Some segments of one or more digits do not light up, or they continue to light up, or segments light when they should not.

NOTE: A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON.

7-20

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Contents Microwave Oven Safety Precautions in this ManualPage Table of Contents Specifications Microwave Radiation Grounding Instructions InstallationControl Panel Operating InstructionsControl Panel Instructions Schematic Diagram Overall Circuit DiagramMatrix Circuit for Touch KEY Board Features and Specifications Features General Precautions in USETrial Operation Preliminary Precautions and Repair Service TipsEquipment Microwave Leakage TestMeasurement with the Outer Case Removed Power Output MeasurementImportant Notes Disassembly InstructionsHOW to Insert the F.P.C. Connector HOW to Remove the F.P.C. ConnectorRemoving the OUT CASEFigure Removing the Door Interlock Switches Figures 9,10 Removing Magnetron Removing Door Figure Removing Stirrer FANRemoving the Ventilation Motor Assembling DoorReplacing the Humidity Sensor Removing the Turntable Motor Interlock Mechanism Interlock SystemTest the Latch and Switch Sequence Interlock Continuity Test Components Test Procedure ResultsTest Procedures Test and Checkout PROCEDURES, and Trouble ShootingHIGH-VOLTAGE Diode FPC Connector Power Level Checkout ProceduresCheckout Procedures for Relay Problem a Checkout Procedures for Circuit Board Trouble Shooting Circuit board Poor Check the contact of relay 2see Normal Operation Circuit board Fuse Exploded View Control Panel Oven Cavity Latch Board Interior 50FZZA Installation Schematic Diagram of P.C.B Printed Circuit Board May