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L. C-MOTOR AND SHEATH HEATER

REMOVAL

1) Remove the air guide and the air duct. 
2) Disconnect the leadwire from the circulation motor

and the sheath heater.

3) Remove four hex nuts securing the chamber guide

assembly to the oven cavity.

4) Remove a hex nut securing the circulation fan to

the shaft of the circulation motor.

5) Remove four screws securing the sheath heater

and the chamber.

6) Remove two hex nuts securing the circulation

motor to the chamber.

M. INTERLOCK SYSTEM

1) INTERLOCK MECHANISM 

The door lock mechanis m is a device which has
been s pecially des igned to eliminate completely
microwave activity when the door is opened during
cooking and thus to prevent the danger res ulting
from the microwave leakage.

2) MOUNTING OF THE PRIMARY/MONITOR/

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.

5-6

Holder Locker

Primary
Switch

Lever

Monitor Switch

Secondry
Switch

Summary of Contents for MC-3182NBR

Page 1: ...N SERVICE MANUAL MODEL MC 3182NBR CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL Website http biz lgservice com P NO MFL34215511 October 2008 Printed in Korea 삼 흥 정 판 Internal Use Only ...

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: ...ATIC 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 13 TROUBLE SHOOTING Display shows error mode 5 19 EXPLODED VIEW 6 1 REPLACEMENT PARTS LIST 7 1 CONTENTS ...

Page 4: ...Variable Cooking Power level max 1000W Full power throughout the cooking time MED HIGH 800W approx 80 of Full power MEDIUM 600W approx 60 of Full power DEFROST 400W approx 40 of Full power LOW WARM 200W approx 20 of Full power CONVECTION max 230 C GRILL COMBINATION Owner s manual Cook book Square Tray Glass turntable Square Rack Rotating ring Crisp Tray Low Rack High Rack 1 1 ITEM MODEL Power Requ...

Page 5: ...tron 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 danger in ordinary use extreme care should be taken du...

Page 6: ... the front glass during or after cooking of the Grill and Combination mode This glass is very hot during heater operating 9 Do not operate the oven at microwave and combination mode with Grill rack placed in the cavity when the oven is empty 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 b...

Page 7: ...pe and the weight of the food 6 Quick Defrost You can select the food type and the weight of the food 7 MODE You can select cooking categories 8 Display Window You can show time of day cooking time power level and cooking categories 9 TIME WEIGHT You can determine the selected cooking category You can set cooking times temperature power level and weight While cooking with auto and manual function ...

Page 8: ...ming temp 30 C 90 C Press Dial Desired Warming time Start Desired Conv temp 100 C 230 C Press Dial Desired cooking time Start Desired cooking time Start Stop Clear Select Convection Desired convection temp 40 C 100 C 230 C Start Stop Clear Select Convection Desired convection temp 40 C 100 C 230 C Press Dial Desired cooking time Start Desired cooking time Start Stop Clear Select ez clean Start Sto...

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

Page 10: ... 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 average output power of microwave oven as POWER LEVEL refer to page 1 1 One complete cycle ...

Page 11: ...ich is graduated to 600 cc and place the beaker on the center of the turntable Set the energy leakage monitor to 2 450 MHz and use it following the manufacturer s recommended test procedure to assure correct result When measuring the leakage always use the 2 inch 5cm spacer supplied with the probe Operate the oven at its maximum output Measure the microwave radiation using and electromagnetic radi...

Page 12: ...st 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 between 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 moved horizontally al...

Page 13: ...mperature after heating T0 Temperature of bowl M Weight of bowl is measured while the microwave generator is operating at full power Magnetron filament heat up time is not included The water is stirred to equalize temperature throughout the vessel prior to measuring the final water temperature Stirring devices and measuring instruments are selected in order to minimize addition or removal of heat ...

Page 14: ... and the oven F AIR DUCT ASSEMBLY REMOVAL 1 Disconnect the leadwire from lamp 2 Remove the mounting screw to the cavity G MAGNETRON REMOVAL 1 Disconnect the leadwire from the high voltage transformer and high voltage capacitor 2 Carefully remove the mounting screws holding the magnetron and the waveguide 3 Remove the magnetron ASS Y until the tube is clear from the waveguide NOTE 1 When removing t...

Page 15: ... capacitor 2 Disconnect the leadwire from magnetron high voltage transformer and capacitor 3 Remove the screw holding the high voltage transformer to the baseplate K THE TURNTABLE MOTOR REMOVAL 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 cover is easily removed by...

Page 16: ...LOCK SYSTEM 1 INTERLOCK MECHANISM The door lock mechanis m is a device which has been s pecially des igned to eliminate completely microwave activity when the door is opened during cooking and thus to prevent the danger res ulting from the microwave leakage 2 MOUNTING OF THE PRIMARY MONITOR SECONDARY SWITCHES TO THE LATCH BOARD 3 INSTALLATION AND ADJUSTMENT OF THE LATCH BOARD TO THE OVEN ASSEMBLY ...

Page 17: ...te 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 circuit in the door open condition When the door ...

Page 18: ...RESULTS HIGH VOLTAGE TRANSFORMER Wire leads removed MAGNETRON Wire leads removed 1 Measure the resistance Ohm meter scale Rx1 and Rx100 Primary winding Secondary winding Filament winding 2 Measure the resistance Ohm meter scale Rx1000 Primary winding to ground Filament winding to ground 1 Measure the resistance Ohm meter scale Rx1 Filament terminal 2 Measure the resistance Ohm meter scale Rx1000 F...

Page 19: ...inal to case Measure the continuity Forward Ohm meter scale Rx10000 Measure the continuity Reverse Ohm meter scale Rx10000 Normal Momentarily indicates several ohms and then gradually returns to infinite Normal Infinite Normal Continuity Abnormal Infinite Normal Infinite Abnormal Continuity NOTE When testing the magnetron be sure to install the magnetron gasket in the correct position and be sure ...

Page 20: ... by improper switch operation replace the defective switch and the fuse at the same time Replace just the fuse if the switches operate normally NOTE Make sure heater is fully cooled when tested Measure the resistance Multi meter scale Rx1 Normal Grill heater Approx 40 ohm at 20 30o C Convection heater Approx 70 ohm at 20 30o C Normal more than 0 5 Mohm Normal Abnormal Measure the resistance with 5...

Page 21: ...ill Relay 5 Convection FAN MOTOR Wire leads removed TURNTABLE MOTOR Wire leads removed Measure the resistance Ohm meter scale R x 1 Measure the resistance Ohm meter scale R x 1000 Check for P C B connector Normal Approx 60 ohm Abnormal Infinite or several ohm Normal Approx 15 kohm Abnormal Infinite or several ohm B Cooking Start OFF Relay 2 Relay 3 Relay 5 1 2 3 4 5 6 7 Cooking Start OFF ...

Page 22: ...ROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON MAKE SURE THE WIRE LEADS ARE CORRECT POSITION WHEN REMOVING THE WIRE LEAD FROM THE PARTS BE SURE TO GRASP THE CONNECTOR NOT THE WIRES Normal COM 230V Approx 180 Ω Abnormal Infinite or several ohm ...

Page 23: ...el to discharge any static charge built up in your body CONDITION Microwave oven does not work Inserting many plug into one plug outlet and using them at the same time causes overloading Microwave oven plug is not inserted tightly Output power is too low Low AC input voltage Food temperature is too low Using metallic ware and allowing it to touch the oven wall Sparks occurring Inconsistent intensi...

Page 24: ... 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 12 Beep sound is not heard when correct key is touched 5 14 TROUBLE 1 The following visual conditions indicate a probable defective control circuit CONDITION CHECK RESULT CAUSE REMEDY Everything works as specified Still h...

Page 25: ...ch with door closed Check continuity of primary switch with door opened Disconnect one side of the wire lead connected from transformer to the high voltage capacitor and operate the unit Replace fuse TROUBLE 2 Oven does not operate at all Display window does not display any figures and no input is accepted NOTE All these switches must be replaced at the same time Refer to page 5 6 5 7 2 Fuse does ...

Page 26: ...with door closed Check fan motor Check oven lamp Abnormal Abnormal Normal Defective fan motor Defective oven lamp Replace fan motor Replace oven lamp Loose connection Connection then tightly CONDITION CHECK RESULT CAUSE REMEDY Output is low Lower than 90 of rating voltage Normal Normal Abnormal Abnormal Measure the output power Disconnect the wire leads from relay 2 and check on and off time with ...

Page 27: ... Defective high voltage transformer Replace high voltage transformer Check H V transformer normal normal Abnormal Defective high voltage Diode Replace high voltage Diode Check H V diode Abnormal Defective high voltage capacitor Replace high voltage capacitor Check H V capacitor Abnormal Defective magnetron Replace magnetron Check Magnetron TROUBLE 5 No microwave oscillation even though oven lamp a...

Page 28: ...ion the heater Replace Replace TROUBLE 6 Oven does not cook properly when programmed for the set power level Operates properly on HIGH CONDITION CHECK RESULT CAUSE REMEDY Output is full when you set lower power level Abnormal Disconnect the wire leads from relay 2 and check continuity relay 2 Operate the unit Defective P C B assembly Replace P C B assembly NOTE Make sure the wire leads are in the ...

Page 29: ...ermistor and P C B assembly Defective P C B Assembly Replace the P C B assembly CONDITION CHECK RESULT CAUSE REMEDY Display shows E02 No continuity Continuity Normal Abnormal Check the thermistor Defective thermistor Thermistor opened Replace the thermistor Loose connection Connect them tightly Check the connnection between Thermistor and P C B assembly Normal Abnormal Check the heater Defective h...

Page 30: ...H BOARD PARTS INTERIOR PARTS BASE PLATE PARTS OVEN CAVITY PARTS DOOR PARTS CONTROL PANEL PARTS MAY000 MFL552 OWNERS MANUAL MAX171 COOK BOOK MEZ173 COOKING GUIDE LABEL 6 1 EXPLODED VIEW INTRODUCTION EV MODEL ...

Page 31: ... 6 2 13551A 13581A 13650A 14810L 14810R 14270A WNZ027 13213A 14026A 13552A WSZ085 WTP005 WTP037 DOOR PARTS EV ...

Page 32: ... 6 3 24781S 23572A 268711 268712 24980A 24810C WTP018 250202 249401 250201 23550D 23790D WTT024 WTP004 WTT024 CONTROL PANEL PARTS EV ...

Page 33: ... 6 4 33112U 63302A 65238A 647781 WTT028 WTT021 647781 WTT028 33052M 34930R 368771 63303A 36549S 35889A 35026A 33390G 33390M 35026G 35026C 33391M WTP013 34370T WTT021 OVEN CAVITY PARTS EV ...

Page 34: ... 6 5 466001 43501L 43500L 44510A 466003 466001 449701 449701 449702 449702 43500R 43501R WSZ236 44510A WSZ236 LATCH BOARD PARTS EV ...

Page 35: ...384 54810H WNH003 WWS005 548103 559004 WTT021 WTT021 548102 559003 559001 559002 54810H 55300S WSZ232 WSZ232 WTT021 WNH200 55012A WTT021 53052M 56930M WNH002 568772 568771 56411A 54620A WSZ062 WSZ185 565492 565491 548101 INTERIOR PARTS EV ...

Page 36: ...9V 33550V WSZ002 WTT028 56170D 552382 WTT030 WTT021 WTT021 WTT021 WTT021 WTT021 WSZ002 WSZ002 WTP007 WSZ248 WSZ228 466002 55262A 54810U 56549S 53550L 34890C 56912B 56930G 54811A 36549W 56324A 54980N 56201A 50FZZ1 35300S WNH002 WTP004 56322A WTT021 WTT021 WTT021 WTT021 WSZ062 WTT021 INSULATOR PARTS EV ...

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