LG MC3283FMPG, Service Manual

Page 1: ...MODEL MC3283FMPG CAUTION BEFORESERVICINGTHEUNIT READTHESAFETYPRECAUTIONSINTHISMANUAL August 2014 PrintedinIndia 삼 흥 정 판 ...

Page 2: ...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 and microwave generation and transmission systems shall be repaired replaced or adjusted by procedures described in this manual...

Page 3: ...ON 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 EXPLODED VIEW 6 1 REPLACEMENT PARTS LIST 7 1 CONTENTS LGE Internal Use Only Copyright 2009 LG Electronics Inc All right reserved Only for training and s...

Page 4: ...ing time MED HIGH 720W approx 80 of Full power MEDIUM 540W approx 60 of Full power DEFROST 360W approx 40 of Full power LOW WARM 180W approx 20 of Full power CONVECTION max 230 C GRILL COMBINATION Owner s manual Recipe Manual and Recipe Booklet Glass Tray Rotating ring High rack Low rack Single Rotisserie and Rotisserie Handle ITEM MODEL Power Requirement Power Output Microwave Frequency Magnetron...

Page 5: ...te 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 during repair THE OVEN IS TO BE SERVICED ONLY BY PROPERLY Q...

Page 6: ...uring 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 before servicing WA...

Page 7: ...ass tray MULTICOOK TAWA LGE Internal Use Only Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes Safety Door Lock System Oven Front Plate Window Door Screen Door Seal Control Panel Milk Pasteurisation Kit 3 13 Energy Saving This feature allows to save energy STOP CLEAR ...

Page 8: ...o cook 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 4 GRILL COMBINATION COOKING Stop Clear Select Grill combi Desired cooking level Desired cooking time Start Press Dial 5 CONVECTION COMBINATION COOKING Stop Clear Select Conv combi Desired cooking level Press D...

Page 9: ...SCHEMATIC DIAGRAM LGE Internal Use Only Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes MC3283FMPG AMPG AMG ...

Page 10: ...IMUM 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 of relay 2 is 22 seconds WHEN THE DOOR IS OPENED DURING COOKING Both the primary switch and relay 2 are cut off primary winding voltage of the high voltage transformer ON OFF of relay 2 is coupled electrically wit...

Page 11: ...nter 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 radiation monitor by holding the probe perpendicular to the s...

Page 12: ... 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 along the oven surface RECORD KEEPING AND...

Page 13: ... is calculated from the following formula 4187 x T 0 55 X T2 T0 X M T T2 Temperature 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...

Page 14: ...t the leadwire from lamp and MGT thermostat 2 Remove the mounting screw to the magnetron 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 the magnetron make sure its dome...

Page 15: ... 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 cover is easily removed by pinching the six parts with a wire cutting 5 Disconnect the leadwire from the turntable motor terminals 6 Remove the screw securing the turntable motor to the oven cavity ASS Y...

Page 16: ...SS Y to the control panel 3 Disconnect the flat cable from the PCB SUB ASS Y and take off the PCB SUB ASS Y M INTERLOCK SYSTEM 1 INTERLOCK MECHANISM The door lock mechanism is a device which has been specially designed to eliminate microwave activity when the door is opened during cooking and thus to prevent the danger resulting from the microwave leakage 2 MOUNTING OF THE PRIMARY MONITOR SECONDAR...

Page 17: ...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 is closed meter should indicat...

Page 18: ...R 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 Filament to chassis Approx 1 9 o...

Page 19: ...r 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 that the gasket is in good condition Antenna Gasket ...

Page 20: ... 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 42 ohm at 20 30o C Normal more than 0 5 Mohm Normal Abnormal Measure the resistance with 500V 100M ohm insulation resistance meter 0 C Approx 145 ...

Page 21: ...r P C B connector Normal Approx 200 400 ohm Abnormal Infinite or several ohm Normal Approx 10 20 kohm Abnormal Infinite or several ohm NOTE A MICROWAVE LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION WHEN REMOVING THE WIRE LEADS FROM THE PARTS BE SURE TO GRASP THE CONNECTOR NOT THE WIRES A B Cooking Start OFF Relay...

Page 22: ...KAGE 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 Relay 2 Relay 3 Relay 5 Cooking Start OFF CN2 1 3 4 5 9 6 8 Relay 6 Relay 4 COM YL 230V BL Cooking Start OFF Normal COM 230V Approx 150 Ω Abnormal Infinite or several ohm LGE Internal Use On...

Page 23: ...put volatge supply Multi outlet Use Check Multi outlet Fuse Measure the voltage across the outlet Voltage Fuse is OK Check the current capacity of the outlet Using many Replace the Multi Outlet Avoid using other electrical after disconnecting power cord AC 230V AC 230V Is outlet connected to other products plugs in one outlet appliances when you use the microwave oven Unplug the power cord Misuse ...

Page 24: ...Measure resistance across the ends of magnetron Thermostat with a multimeter Normal Replace the magnetron Normal Replacing the oven Thermo stat at both ends Abnormal Normal Abnormal Normal thermostat Measure resistance across the ends of oven Thermostat with a multimeter Abnormal Normal ...

Page 25: ...eter Check the continuity between power cord terminals and PCB connector 1 Measure Power Cord terminal connection with CN1 Pin 1 2 Measure Power Cord terminal connection with CN1 Pin 13 Normal Visually check the connection status of Replace Harness Loose Adjust the PCB Abnormal Normal PCB connecotr CN2 connection connector Replace PCB ...

Page 26: ...s Malfunction Check whether the button is stuck when you press any button A good working switch makes Only the Start button malfunction Button Stuck Adjust the stucked buttons on control Adjust or replace moulding No cooking start Unplug the power cord and then again insert some sound on press Replace PCB panel by loosening screws ...

Page 27: ...ntacts Primary Switch is located on the top of Check contact adjustment Check contacts Check contacts Adjust Latch Spacing door 2 3 times Unplug power cord latch board Check that the contact is pressed after the door is closed Primary Switch is located on the top of latch board Check that the contact is pressed after the door is closed ...

Page 28: ... whether PCB Unplug the connector Close the Door Measure the resistance between both ends Abnormal Replace PCB its two terminals Abnormal Normal switch connector CN1 connected Check whether PCB connector CN1 connected connector CN8 connected Unplug the connector Abnormal Normal Replace Harness ...

Page 29: ...nnector and Micro Switch is pressed when is closed No Heating Unplug the power cord When the contact is closed adjust gap Normal Adjust latch Check start button operation by opening and closing the door 2 3 times Unplug the power cord Check latch contacts Primary Switch is located on the top of latch board Check that the contact is pressed after the door is closed Check latch contacts Primary Swit...

Page 30: ...ltage transformer and measure the Normal Replace the high voltage transformer Primary Switch is located on the top of Abnormal Normal Normal Less than 1 Ohm Magnetron resistance with a multimeter measure the resistance across both ends of high voltage fuse with a multimeter safety Switch B W Primary Core Normal Infinity B W Filament Core Normal Infinity B W Filament Terminals B W Filament Case Nor...

Page 31: ...and then check the Normal Replace PCB Replace Check the connection status of high voltage diode and measure the resistance across the terminals with a clamp meter housing connected across the relays RY1 RY2 resistance across terminals of relay RY1 RY2 Abnormal Normal Harness Terminal Resistance Normal Abnormal 0 Ohm gradually return to infinity Filament Case Resistance Momentarily shows Normal Inf...

Page 32: ...the power cord That normal operation guide Explains how to use Measure the resistance across the terminals of upper Normal Normal Convection thermostat and lower quartz heater with a multimeter as shown below Abnormal Normal Measure the resistance across the terminals of convection thermostat with a multimeter Abnormal Normal Replace the ...

Page 33: ...ate the oven and measure the resistance across the terminals of each relay Normal Normal Replace Heater Replace Harness Replace PCB Abnormal Normal the relay RY1 RY5 of upper quartz heater with a multimeter Abnormal Normal heater Measure the resistance across the terminals of lower quartz heater with a multimeter Abnormal Normal Replace Quartz heater connecting harness ...

Page 34: ... No Heating Failure symptoms Raw uncooked food No heat inside cavity unplug the power cord That normal operation guide Explains how to use grill heaters with a multimeter as shown in fig Normal Check the resistance across the ends of two Abnormal Normal ...

Page 35: ... the resistance of each relay Normal Normal Connect the heater bracket Replace Replace PCB Pull the Blue and Yellow housing the relay RY1 RY3 connected across with a multimeter Abnormal Normal Left Grill Heater Measure the resistance of the right grill heater with a multimeter Abnormal Normal Replace Right Grill Heater Harness Abnormal Normal ...

Page 36: ...p and Turn table No heating unplug the power cord turn table are not working at the same time is in correct place and position Adjust table position as shown below Check start button operation by opening and closing the door 2 3 times Unplug the Power Cord When the contact is closed adjust gap Check latch contacts Primary Switch is located on the top of latch board ...

Page 37: ...located on the top of the board Across the resistance measurement Normal Replace Harness Normal adjust latch Replace Primary Safety Switch latch board Measure the resistance across the Primary Switch is located on the top of switch ends Normal Abnormal Terminal Resistance Normal 10 20 KOhm Abnormal infinity 0 Ohm Terminal Case Resistance Normal Infinity Abnormal 0 Ohm Terminal Resistance ...

Page 38: ...e does 1 Check whether controller connector CN9 2 Check whether Thermistor is Open 3 Check whether convection heater working Thermistor check conducted at room temperature measured Normal approximately 214 KOhm Abnormal infinity or short circuited F 01 not reached above 100 C in 10 min then error is displayed came out F 02 short then Error F 02 displayed Check whether Thermistor is Short ...

Page 39: ...DOOR PARTS CONTROL PANEL PARTS LATCH BOARD PARTS BASE PLATE PARTS INTERIOR PARTS OVEN CAVITY PARTS OWNERS MANUAL COOK BOOK 6 1 EXPLODED VIEW INTRODUCTION EV MODEL ...

Page 40: ... 6 2 DOOR PARTS EV 13581A ...

Page 41: ... 6 3 CONTROL PANEL PARTS EV 23572A 23806C 268712 268711 250204 250203 249401 23550C 24930M SUB MAIN ...

Page 42: ... 6 4 35026C 33112U 35026G 34370T 35889A 33390G 36549S 33390M 35300A 35300A 335021 33550S 33651A OVEN CAVITY PARTS EV 445101 33301R 33390C 43500A 44980A 445102 348102 330522 55238B 55238A ...

Page 43: ... 6 5 43500B LATCH BOARD PARTS EV 568771 466003 466003 466001 14510L ...

Page 44: ... 6 6 56411A 56912B 56324A 56930V INTERIOR PARTS EV 54974S 56930G 55300A 56322A 535041 535042 55900N 55900C 568774 56930H 36549C 568772 56851D 56901A 56851F 56851E 56892 56201A 56549F ...

Page 45: ... 6 7 BASE PLATE PARTS EV 56170D 64970A ...

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