LG Electronics LMV1625B, LMV1625W service manual Checkout Procedures for Relay Problem a

Page 30

(2)CHECKOUT PROCEDURES FOR RELAY.

-PROBLEM (A) -

TT motor and oven lamp turn on without touching START key when the door is closed.

NO

YES

GOOD

Remove the mate connector of I/O CON from the circuit board.

Does the unit still operate?

NO

YES

Replace the circuit board

Defective

RELAY3

Replace

RELAY3

- PROBLEM (B) -

TTmotor and oven lamp turn on When the door is closed and START key is touched.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

YES

 

 

 

 

 

 

NO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GOOD

Measure the voltage at pin NO.

4 of U01

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Voltage reading: 0 Vdc

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NO

 

 

 

 

 

 

 

 

 

 

 

 

 

YES

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Replace the circuit board

Defective

RELAY3 or poor

connection of

RELAY3

Replace

RELAY3 or correct

the connection.

7-19

Image 30
Contents Microwave Oven Page Table of Contents Specifications Microwave Radiation Installations Precautions on InstallationGrounding Instructions Operating Instructions Control PanelControl Panel Instructions Overall Circuit Diagram Schematic DiagramMatrix Circuit for Touch KEY Board Features and Specifications Features General Information for ServiceGeneral Precautions in USE Trial OperationService Information Precautions and Repair Service TipsPreliminary Microwave Leakage Test Measuring Microwave Energy LeakageMeasurement with a Fully Assembled Oven Power Output MeasurementMeasurement with the Outer Case Removed Record Keeping and Notification After MeasurementDisassembly Instructions Important NotesHOW to Remove the F.P.C. Connector HOW to Insert the F.P.C. ConnectorRemoving the OUT CASEFigure Removing the Door Interlock Switches Figures 9,10 Removing Magnetron Removing Door Figure Assembling Door Removing the Ventilation FanassyRemoving the Turntable Motor Interlock System Interlock MechanismTest the Latch and Switch Sequence Components Test Procedure Results Interlock Continuity TestTest and Checkout PROCEDURES, and Trouble Shooting Test Procedures HIGH-VOLTAGE Diode Top For detail matrix circuit of each model Refer to Checkout Procedures Power LevelCheckout Procedures for Relay Problem a Checkout Procedures for Circuit Board Trouble Shooting Thermostat Page Fuse Exploded View Controller Parts Oven Cavity Parts Latch Board Parts Interior Partsi Interior Parts Installation Parts Schematic Printed Circuit Board May