Manuals / LG Electronics / Kitchen Appliance / Microwave Oven

LG Electronics LMV1625W, LMV1625B service manual Checkout Procedures For Circuit Board, 7-20

Models: LMV1625W LMV1625B

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(3)CHECKOUT PROCEDURES FOR CIRCUIT BOARD

The following symptoms indicate a defective circuit board.

1)The start function fails to operate but the high voltage Systems, the interlock switches, the door 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.

6)Wrong figures appear.

7)The figures of all digits.

8)Some of the indicators do no flicker light up.

9)The clock does not keep time properly.

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

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LG Electronics LMV1625W Checkout Procedures For Circuit Board, The following symptoms indicate a defective circuit board

Contents

MODEL LMV1625B LMV1625W SERVICE MANUALSAFETY PRECAUTIONS IN THIS MANUAL MICROWAVE OVENDURING SERVICING TO AVOID POSSIBLE EXPOSURE SAFETY PRECAUTIONS PRECAUTIONS TO BE OBSERVED BEFORE ANDTO EXCESSIVE MICROWAVE ENERGY TABLE OF CONTENTS FOREWORD1,500W maximum Microwave oven+Cook top lamp+Ventilation fan SPECIFICATIONSGasket CAUTIONSMICROWAVE RADIATION MAGNETRONPRECAUTIONS ON INSTALLATION INSTALLATIONSGROUNDING INSTRUCTIONS CONTROL PANEL OPERATING INSTRUCTIONSCONTROL PANEL INSTRUCTIONS SCHEMATIC DIAGRAM OVERALL CIRCUIT DIAGRAMMATRIX CIRCUIT FOR TOUCH KEY BOARD TRIAL OPERATION GENERAL INFORMATION FOR SERVICEGENERAL PRECAUTIONS IN USE FEATURES AND SPECIFICATIONS FEATURESPRECAUTIONS AND REPAIR SERVICE TIPS SERVICE INFORMATIONTell the user not to operate the oven MICROWAVE LEAKAGE TESTEQUIPMENT If the oven operates with the door open, the service personnel shouldMEASUREMENT WITH A FULLY ASSEMBLED OVEN NOTE WHEN MEASURINGPOWER OUTPUT MEASUREMENT MEASUREMENT WITH THE OUTER CASE REMOVEDA. REMOVING POWER AND CONTROL CIRCUIT BOARD Figures 1, 2 and DISASSEMBLY INSTRUCTIONSIMPORTANT NOTES HOW TO INSERT THE F.P.C. CONNECTOR HOW TO REMOVE THE F.P.C. CONNECTORB. REMOVING THE OUT CASEFigure C REMOVING THE DOOR INTERLOCK SWITCHES Figures 9,10 D. REMOVING MAGNETRON G. DISASSEMBLING DOOR Figure F. REMOVING DOOR FigureCAUTION Be careful not to damage door seal plate with the screwdriver I. REMOVING THE VENTILATION FANASSY H. ASSEMBLING DOORK. REMOVING THE TURNTABLE MOTOR ADJUST THE LATCH AND SWITCH CLOSING INTERLOCK SYSTEMADJUSTMENT PROCEDURES CHECK THE DOOR LATCH AND SWITCH CLOSINGTEST THE MICROWAVE ENERGY LEAKAGE TEST THE LATCH AND SWITCH SEQUENCEC. MONITOR SWITCH TEST INTERLOCK CONTINUITY TESTA. PRIMARY INTERLOCK SWITCH TEST B. SECONDARY INTERLOCK SWITCH TESTRESULTS TEST AND CHECKOUT PROCEDURES, AND TROUBLE SHOOTINGTEST PROCEDURES COMPONENTSFigure 25-a TEST PROCEDURESCOMPONENTS RESULTSMeasure the resistance between terminal TEST PROCEDURESCOMPONENTS RESULTSThese two connectors are not Inter 1 CHECKOUT PROCEDURES FOR FUSE BLOWINGTEST PROCEDURES wCAUTION The relay connector 2WhiteGOOD 2 CHECKOUT PROCEDURES FOR RELAY PROBLEM ARemove the mate connector of I/O CON from the circuit board Defective RELAY3 Replace RELAY3 PROBLEM B2 The unit with a normal relay continuously operates 3 CHECKOUT PROCEDURES FOR CIRCUIT BOARDThe following symptoms indicate a defective circuit board 8 Some of the indicators do no flicker light upRuns PROBLEM - C Unit does not heat up even if display counts down when PROBLEM - D No buzzing when touching the key, between Check 1. POWER SUPPLY DOOR PARTS EXPLODED VIEW13552A 13581A 13536A 13213A 13720D WTT021 14890A 14026A 14970A 13650A 268711 24781M 24810P WTP018 23572A WTT029 CONTROLLER PARTS23506A WTT021 OVEN CAVITY PARTS33530A 34930R 35026G 33052A 33550L 36912C WTT022 35230AWSZ084 LATCH BOARD PARTS43500A 46600135889A INTERIOR PARTSI33390G 34370T WSZ00255231C 53550L 56804A INTERIOR PARTS56912B 36549VWSZ204 INSTALLATION PARTSWSZ203 44360A WSZ098 WSZ133DIAGRAM SCHEMATICPRINTED CIRCUIT BOARD Printed in Korea P/NO. 3828W5S3242