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5-14

(TROUBLE 3) Display shows all figures set, but oven does not start cooking while desired

program times are set and START pad is touched.

(TROUBLE 4) Oven seems to be operating but little heat is produced in oven load.

CONDITION

CHECK

RESULT

CAUSE

REMEDY

1.Setting time

does not count
down when
touching START
pad.

2. Fan motor or

oven lamp  do
not turn on.

No continuity.

Continuity.

Continuity

No continuity

Check the con-
nection between
CN1 connector
and PCB
assembly.

Defective
secondary switch.

Replace
secondary switch.

Defective PCB
assembly.

Replace PCB
assembly.

Check continuity
of secondary
switch (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.

Connect them
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 multitester.

Defective PCB
assembly.

Replace PCB
assembly.

Decrease in power
source voltage
with load.

Suggest customer
contact local
electric power
utility co. or
qualified
electrician.

Check the
power source
voltage.

Defective
magnetron.

Replace
magnetron.

NOTE: Simple test of power output-conducted by heating one liter water for one min. if available.

Minimum 8.5˚C temperature rise is normal condition.

LGE Internal Use Only

Copyright © 2007 LG Electronics. Inc. All right reserved. 
Only for training and service purposes

Summary of Contents for MS2647GR

Page 1: ...ICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL Website http biz lgservice com 삼 흥 정 판 MICROWAVE OVEN SERVICE MANUAL MODEL MS2647GR MS2647GRS 삼 흥 정 판 P NO MFL31039006 July 2007 Printed in Korea Internal Use Only ...

Page 2: ... 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 and microwave generation and transmission systems shall ...

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 11 EXPLODED VIEW 6 1 REPLACEMENT PARTS LIST 7 1 CONTENTS LGE Internal Use Only Copyright 2007 LG Electronics Inc All right reserved Only for training and s...

Page 4: ...iable Cooking Power level Max Full power throughout the cooking time Med High approx 80 of Full power Medium approx 60 of Full power Defrost approx 40 of Full power Low Warm approx 20 of Full power Owner s manual Glass turntable Rotating Ring 1 1 ITEM MODEL Power Requirement Power Output Microwave Frequency Magnetron Timer Outside Dimensions Cavity Dimensions Net Weight Shipping weight Control Com...

Page 5: ...ron 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 dur...

Page 6: ... 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 wires in the mains lead of this appliance may not correspond ...

Page 7: ...ower level for cooking grill and combi 7 CLOCK Used to set the time of day 8 MORE LESS Used to change the cooking time desired weight 9 COOK TIME Used to cook food for a desired time 10 STOP CLEAR Used to stop over and clear all entries except time of day 11 START Q START One tap allows over to begin functioning OPERATING INSTRUCTIONS Rotating Ring 1 2 3 4 6 5 7 9 10 8 11 LGE Internal Use Only Cop...

Page 8: ...as a CHILD LOCK feature TO SET CHILD LOCK Touch the Stop pad Touch STOP pad L appear in the display TO CANCEL CHILD LOCK Touch the Stop pad Touch STOP pad L disappears 4 Q START 5 MICROWAVE COOKING 6 AUTO WEIGHT DEFROST 7 AUTO COOK 8 ONE TOUCH AUTO MENU 9 QUICK DEFROST 10 AUTO REHEAT Stop Clock Clock Set the hour Set the minutes Clock Stop Power Start Time Stop Auto Defrost Start Weight kg Stop Au...

Page 9: ...SCHEMATIC DIAGRAM 4 3 LGE Internal Use Only Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes ...

Page 10: ...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 average output power of microwave oven as POWER LEVEL ...

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: ... 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 horizontally along the oven surface this may possibly cause probe damage REC...

Page 13: ...ture 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 on The time T for the temperature of the water to rise by a value T of 10 2 K is measured where T is the time in seconds and T is the...

Page 14: ...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 fuse board and high voltage capacitor 3 Remove the two screws holding the the suction guide ASS Y to the oven cavity and remove ...

Page 15: ...ten 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 cover is easily removed by pinching the six parts with a wire cutting 5 Disconnect the l...

Page 16: ...BLY 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 5 mm 1 64 inch Don t push the door release button while making adjustment Make sure that the latch moves smooth...

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: ...eads removed MAGNETRON Wire leads removed 1 Measure the resistance Ohm meter scale Rx1 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 Between Filament terminal 2 Measure the resistance Ohm meter scale Rx1000 Filament to chassis Approx 1 4 Ω Approx 90...

Page 19: ... Ohm meter scale Rx10000 Measure the continuity Reverse Ohm meter scale Rx10000 Normal Momentarily indicates several ohms and then gradually returns to infinite Normal Normal Continuity Abnormal Normal 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 Chassis Filament T...

Page 20: ...ION WHEN REMOVING THE WIRE LEADS FROM THE PARTS BE SURE TO GRASP THE CONNECTOR NOT THE WIRES 20 40 60 80 100 6 sec 10 sec 14 sec 18 sec 22 sec 16 sec 12 sec 8 sec 4 sec 0 sec POWER LEVEL Relay 1 Relay 2 Power Transformer A B 230V 21V COM Measure the resistance Ohm meter scale R x 100 Check for continuity of relay 2 with an ohm meter Remove wire leads from relay 2 and operate the unit Measure the r...

Page 21: ...ITION Microwave oven does not work Inserting many plug into one plug outlet and using them at the same time blown fuse or breaker 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 occur Inconsistent intensity of microwave by their characteristics 1 Wrap the thinner p...

Page 22: ...r when cooking is finished 12 Beep sound is not heard when correct key is touched 5 12 TROUBLE 1 The following visual conditions indicate a probable defective control circuit CONDITION CHECK RESULT CAUSE REMEDY Everything works as specified Continuity No continuity Still have trouble Defective key membrane assembly Defective PCB assembly Loose connection Defective PCB assembly Replace key membrane...

Page 23: ...ct at the primary switch Replace fuse primary monitor switches and RELAY RY2 of P C B Assembly No continuity Normal Defective high voltage capacitor Replace high voltage capacitor Fuse blows again Defective high volt age transformer Replace high volt age transformer Malfunction of the monitor switch Replace fuse primary monitor switches and RELAY RY2 of P C B Assembly Check continuity of monitor s...

Page 24: ...al Abnormal Normal Defective fan motor Defective oven lamp Replace fan motor Replace oven lamp Loose connection Connect them 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 multitester Defective PCB assembly Replace PCB assembly De...

Page 25: ...rotector Replace circuit protector Check circuit protector Normal Normal Abnormal Defective high voltage capacitor Replace high voltage capacitor Check high vol tage capacitor Abnormal Defective high voltage transformer Replace high voltage transformer Check high vol tage transformer Abnormal Defective high voltage diode Replace high voltage diode Check high vol tage diode Normal Abnormal Defectiv...

Page 26: ...Removing the wire leads from the parts be sure to grasp the connector not the wires When removing the magnetron be sure to install the magnetron gasket in the correct position and in good condition TROUBLE 5 No microwave oscillation even though oven lamp and fan motor run Display operates properly CONDITION CHECK RESULT CAUSE REMEDY LGE Internal Use Only Copyright 2007 LG Electronics Inc All right...

Page 27: ...L PANEL PARTS INTERIOR PARTS BASE PLATE PARTS OVEN CAVITY PARTS 6 1 EXPLODED VIEW INTRODUCTION EV MODEL MS2647GR MS2647GRS LGE Internal Use Only Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes ...

Page 28: ... 6 2 13213A 13552A 15006A 13581A 13536A 14026A 14970A 13720D 14890A DOOR PARTS EV LGE Internal Use Only Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes ...

Page 29: ...6 3 23572A 24781M WTP018 268711 24510L 250201 24970A 23506A 23790D CONTROL PANEL PARTS EV LGE Internal Use Only Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes ...

Page 30: ... 6 4 WTT010 WTP013 WTT021 33390G 34370T 35889A 36549S 33112U 33052A OVEN CAVITY PARTS EV LGE Internal Use Only Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes ...

Page 31: ... 6 5 466001 466003 466001 43500A WSZ085 43501A LATCH BOARD PARTS EV LGE Internal Use Only Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes ...

Page 32: ...0A 50CZZH WEB001 WEB001 WTT028 WSZ062 WSZ002 WTT037 WTT028 54810C 56930V 56324A WSZ002 34930W WSZ002 56912B 55262A 948501 56901A INTERIOR PARTS EV LGE Internal Use Only Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes ...

Page 33: ... 6 7 56170D 63303A WSZ002 WTT021 WTT030 647781 63302A BASE PLATE PARTS EV LGE Internal Use Only Copyright 2007 LG Electronics Inc All right reserved Only for training and service purposes ...

Page 34: ......

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