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5-9

NOTE: When testing the magnetron, be sure to install the magnetron gasket

in the correct position and be sure that the gasket is in good condition.

Antenna

Gasket

Chassis

Filament

HIGH VOLTAGE
CAPACITOR

Measure the resistance.
(Ohm-meter scale: Rx1000)
• Terminal to terminal.

Normal: Momentarily indicates

several ohms, and
then gradually returns
to infinite.

Normal: Infinite.

Normal: Continuity.
Abnormal: Infinite.

Normal: Infinite.
Abnormal: Continuity.

Measure the resistance.
(Ohm-meter scale: Rx1000)
• Terminal to case.

Measure the continuity (Forward).
(Ohm-meter scale: Rx10000)

Measure the continuity (Reverse).
(Ohm-meter scale: Rx10000)

HIGH VOLTAGE
DIODE

NOTE :
Some inexpensive meters
may indicate infinite
resistance in both direction.

COMPONENTS TEST 

PROCEDURE  RESULTS

Summary of Contents for MS-1145KYL

Page 1: ...ICROWAVE OVEN SERVICE MANUAL MODEL MS 1145KYL CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL Website http biz lgservice com P NO MFL31039201 September 2005 Printed in Korea ...

Page 2: ...r and other damage 4 damage to or loosening of hinges and latches 5 evidence of dropping or abuse C Before turning on microwave power for any service test or inspection within the microwave generating compartments check the magnetron wave guide or transmission line and cavity for proper alignment integrity and connections D Any defective or misadjusted components in the interlock monitor door seal...

Page 3: ...4 1 OPERATING SEQUENCE 4 2 SCHEMATIC DIAGRAM 4 3 CIRCUIT DESCRIPTION 4 4 SERVICE INFORMATION 5 1 TOOLS AND MEASURING INSTRUMENTS 5 1 MICROWAVE LEAKAGE TEST 5 1 MEASUREMENT OF MICROWAVE POWER OUTPUT 5 3 DISASSEMBLY AND ADJUSTMENT 5 3 INTERLOCK CONTINUITY TEST 5 7 COMPONENT TEST PROCEDURE 5 8 TROUBLE SHOOTING 5 11 EXPLODED VIEW 6 1 REPLACEMENT PARTS LIST 7 1 ...

Page 4: ...uch Control System Clock 1 00 12 59 Microwave Power for Variable Cooking Power level HIGH Full power throughout the cooking time 9 Saute approx 90 of Full power 8 Reheat approx 80 7 Med High approx 70 6 Medium approx 60 5 Med Low approx 50 4 Defrost approx 40 3 Low approx 30 2 Simmer approx 20 1 Warm approx 10 Owner s manual Glass turntable Roller Rest ITEM Model Power Requirement Power Output Mic...

Page 5: ...operation of the microwave oven requires that the magnetron be assembled to the waveguide and cavity Never operate the magnetron unless it is properly installed Be sure that the magnetron gasket is properly installed around the dome of the tube whenever installing the magnetron 2 1 CAUTIONS Unlike other appliances the microwave oven is high voltage and high current equipment Though it is free from...

Page 6: ...d flat surface at least 10 cm 4 inches from the wall 7 Place the microwave oven as far away as possible from TV RADIO COMPUTER etc to prevent interference EARTHING INSTRUCTIONS This microwave oven is designed to be used in a fully earthed condition It is imperative therefore to make sure it is properly earthed before servicing WARNING THIS APPLIANCE MUST BE EARTHED IMPORTANT As the colors of the w...

Page 7: ...ER Used to set for time of day cooking time power level or defrost weight 6 CLOCK Used to set the time of day 7 QUICK START Allows you to cook for 30 seconds at 100 power by simply touching this pad You can also extend cooking time in multiples of 30 seconds by repeatedly touching this pad during cooking 8 TIME Used to cook food for a desired time 9 CONTADOR DE TIEMPO 10 POWER Used to select power...

Page 8: ...ed or to the clock 3 ONE TOUCH COOKING NOTE Heat only 1 package at a time 4 TIME COOKING 5 MULTI STAGE COOKING 1ST STAGE 2ND STAGE 6 AUTO DEFROST COOKING 7 CHILD LOCK This oven has a CHILD LOCK feature TO SET CHILD LOCK Touch the pad Touch and hold 0 pad L appear on the display TO CANCEL CHILD LOCK Touch the pad Touch and hold 0 pad L disappear PARAR BORAR RELOJ RELOJ NUMBER PALOMITAS PARAR BORAR ...

Page 9: ...SCHEMATIC DIAGRAM 4 3 ...

Page 10: ...ximately 2100 volts AC is generated in the secondary of the high voltage transformer which is increased by the action of the high voltage diode and charging of the high voltage capacitor The negative 4 000 Volts DC is applied to the filament of the magnetron WHEN THE OVEN IS SET AT ANY LEVEL EXCEPT MAXIMUM The micom controller controls the ON OFF time of relay 2 by the applied signal to vary the a...

Page 11: ...nt openings for microwave leakage Check for microwave leakage after every servicing The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 4 mW cm2 Always start measuring of an unknown field to assure safety for operating personnel from radiation leakage NECESSARY MEASURING INSTRUMENTS TESTER VOLTS DC AC Ohmmeter Microwave survey meter Holaday HI 1500 ...

Page 12: ... deflection The test probe must be removed no faster than 1 inch sec 2 5 cm sec along the shaded area otherwise a false reading may result The test probe must be held with the grip portion of the handle A false reading may result if the operator s hand is befween the handle and the probe When testing near a corner of the door keep the probe perpendicular to the surface making sure the probe is mov...

Page 13: ...er of approximately 190 mm The oven and the empty vessel are at ambient temperature prior to the start of the test The initial temperature T1 of the water is 10 2 C It is measured immediately before the water is added to the vessel After addition of the water to the vessel the load is immediately placed on the center of the turntable which is in the lowest position and the microwave power switched...

Page 14: ...ance between the door and the oven E HIGH VOLTAGE TRANSFORMER REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from magnetron high voltage transformer and capacitor 3 Remove the screw holding the high voltage transformer to the baseplate F FAN MOTOR ASSEMBLY REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from fan motor and high voltage capacitor 3 ...

Page 15: ...sure that gasket is rigidly attached to the magnetron To prevent microwave leakage tighten the mounting screws properly making sure there is no gap between the waveguide and the magnetron J REMOVING THE TURNTABLE MOTOR 1 Remove the turntable 2 Remove the turntable shaft VERY CAREFULLY with a slotted screwdriver 3 Lay the unit down on its back 4 Remove the turntable motor cover The turntable base c...

Page 16: ...ONITOR SECONDARY SWITCHES TO THE LATCH BOARD 3 INSTALLATION AND ADJUSTMENT OF THE LATCH BOARD TO THE OVEN ASSEMBLY Mount the latch board to the oven assembly Adjust the latch board in the arrow direction so that oven door will not have any play in it when the door is closed Tighten the mounting screw Check for play in the door by pushing the door release button Door movement should be less than 0 ...

Page 17: ...tion When the door is closed meter should indicate an closed circuit When the secondary switch operation is abnormal make the necessary adjustment or replace the switch only with the same type of switch C MONITOR SWITCH TEST Disconnect the wire lead from the monitor switch Connect the ohmmeter leads to the common COM and normally closed NC terminals of the switch The meter should indicate closed c...

Page 18: ...VOLTAGE TRANSFORMER Wire leads removed MAGNETRON Wire leads removed Approx 0 3 0 8 ohm Approx 100 200 ohm Less than 1 ohm Normal Infinite Normal Infinite Normal Less than 1 ohm Normal Infinite PRIMARY TERMINAL SECONDARY TERMINAL WINDING FILAMENT TERMINAL COMPONENTS TEST PROCEDURE RESULTS 1 Measure the resistance Ohm meter scale Rx1 and Rx100 Primary winding Secondary winding Filament winding 2 Mea...

Page 19: ...ormal Momentarily indicates several ohms and then gradually returns to infinite Normal Infinite Normal Continuity Abnormal Infinite Normal Infinite Abnormal Continuity Measure the resistance Ohm meter scale Rx1000 Terminal to case Measure the continuity Forward Ohm meter scale Rx10000 Measure the continuity Reverse Ohm meter scale Rx10000 HIGH VOLTAGE DIODE NOTE Some inexpensive meters may indicat...

Page 20: ...T POSITION WHEN REMOVING THE WIRE LEADS FROM THE PARTS BE SURE TO GRASP THE CONNECTOR NOT THE WIRES Relay 1 Relay 2 A RD B BK C WH Measure the resistance Ohm meter scale R x 1000 Normal A B Approx 65 80 ohm B C Approx 10 30 ohm A C Approx 85 105 ohm Abnormal Infinite or several ohm Normal Approx 100 150 ohm Abnormal Infinite or several ohm POWER LEVEL 1 2 3 4 5 6 7 8 9 10 4 sec 6 sec 8 sec 10 sec ...

Page 21: ...tallic ware for cooking except where noted in the cooking guide Do not use any type of cookware with metallic trimming CAUSE REMEDY TROUBLE SHOOTING CAUTIONS 1 Check grounding before checking for trouble 2 Be careful of the high voltage circuit 3 Discharge the high voltage capacitor See page 2 1 4 When checking the continuity of the switches or of the high voltage transformer disconnect one lead w...

Page 22: ...ce key membrane assembly Defective PCB assembly Replace PCB assembly 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 t...

Page 23: ...ntinuity No continuity Malfunction of the monitor switch Replace fuse primary monitor secondary switches and RELAY RY2 of P C B Assembly Check continuity of monitor switch with door closed Continuity No continuity Shorted contact at the primary switch Replace fuse primary monitor secondary switches and RELAY RY2 of P C B Assembly Check continuity of primary switch with door opened Normal Replace f...

Page 24: ... Defective PCB assembly Loose connection Output is low Lower than 90 of rating voltage Normal Decrease in power source voltage with load Suggest customer contact local electric power utility co or qualified electrician Check the power source voltage Disconnect the wire leads from relay 2 and check on and off time with multitester Measure the output power Abnormal Abnormal Normal Defective PCB asse...

Page 25: ...relay 2 Operate the unit Defective PCB assembly Replace PCB assembly Replace high voltage transformer Defective high voltage capacitor Replace high voltage capacitor Abnormal normal Check high vol tage transformer Abnormal normal Check high vol tage capacitor Defective high voltage diode Replace high voltage diode Abnormal normal Check high vol tage diode Defective magnetron Replace magnetron Abno...

Page 26: ...OVEN CAVITY PARTS INTERIOR PARTS BASE PLATE PARTS LATCH BOARD PARTS CONTROL PANEL PARTS DOOR PARTS 6 1 EXPLODED VIEW INTRODUCTION MODEL MS 1145KYL EV ...

Page 27: ...6 2 DOOR PARTS 13581A 14970A 14026A 13650A WTT028 13552A 13213A 14890A 13551A 13536A EV ...

Page 28: ...6 3 CONTROLLER PARTS 23551A 268711 WTT028 24781M EV ...

Page 29: ...6 4 OVEN CAVITY PARTS 33390G 35889A WTT021 33112U WTP013 36549S 33052A WTT010 EV ...

Page 30: ...6 5 LATCH BOARD PARTS 466001 466003 WSZ085 466001 43500A 43501A EV ...

Page 31: ...INTERIOR PARTS 568771 56930V 56411A WTT028 56324A WSZ002 WEB001 WTT037 50CZZH 54810C 56851D 55900A 56549F 54974S WEB001 WEB001 WSZ002 50FZZA 56201A 54980A 56912B 948503 WSZ002 948501 55262A 948502 948502 EV ...

Page 32: ...6 7 BASE PLATE PARTS 63302A WTT021 WSZ002 56170D EV ...

Page 33: ... 6600W1K004F Switch Micro R 6600W1K003D 466003 6600W1K004E Switch Micro R 6600W1K003C 466003 6600W1K004E Switch Micro R 6600W1K001C 50CZZH 0CZZW1H004B Capacitor AL Radial R 0CZZW1H004G 50CZZH 0CZZW1H004B Capacitor AL Radial R 0CZZW1H001Q 50FZZA 3B74133Q Fuse Time Delay R 3B74133K 54810C 4810W4C003B Bracket Capacitor R 54974S 4974W1S052A Guide Suction R 54980A 4980W3A038A Supporter R 55262A 5262W2A...

Page 34: ... 4B70188C Screw Customzied R WTP013 1TPL0402418 Screw Tapping R WTT010 1TTG0402422 Screw Tapping R WTT021 1TTL0402418 Screw Tapping R WTT028 1TTL0402818 Screw Tapping R WTT037 1TTL0403818 Screw Tapping R PART NO DESCRIPTION SVC ALTERNATE R SERVICE PARTS ...

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