LG LRM1230B Service Manual Download Page 4

1-1

This microwave oven is designed for household use only.

It is not recommended for commercial purposes.

ITEM

MODEL

Power Requirement

Power Output

Microwave Frequency

Magnetron

Timer

Outside Dimensions

Cavity Dimensions

Net Weight

Shipping weight

Control Complement

Nameplate Location

Accessories

DESCRIPTION

LRM1230W/LRM1230B

120 Volts AC 60 Hz

1,650 Watts (13.8 A)

Single phase, 3 wire grounded

1,200 Watts full microwave power (IEC705)

2,450 MHz

2M246

0 ~ 99 min. 99 sec.

21

7/8

(W) x 12

1/2

(H) x 17

1/8

(D) 

14

11/16

(W) x 9

5/8

(H) x 15

5/8

(D) 

36.5 lbs (approx.)

41.5 lbs (approx.)

Touch 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 & cooking guide

Glass turntable

Rotating ring

Back Side

SPECIFICATIONS

Summary of Contents for LRM1230B

Page 1: ...CROWAVE OVEN SERVICE MANUAL MODEL LRM1230W LRM1230B CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL website http www lgservice com e mail http www lgeservice com techsup html ...

Page 2: ...1 interlock operation 2 proper door closing 3 seal and sealing surfaces arcing wear 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 connec...

Page 3: ...EASURING 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 DOOR PARTS 6 2 CONTROLLER PARTS 6 3 OVEN CAVITY PARTS 6 4 LATCH BOARD PARTS 6 5 INTERIOR PARTS 6 6 BASE PLATE PARTS 6 7 REPLACEMENT PARTS LIST 7 1 SCHEMATIC DIAGRAM OF P C B 8 ...

Page 4: ...se 3 wire grounded 1 200 Watts full microwave power IEC705 2 450 MHz 2M246 0 99 min 99 sec 217 8 W x 121 2 H x 171 8 D 1411 16 W x 95 8 H x 155 8 D 36 5 lbs approx 41 5 lbs approx Touch 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 6...

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 fro...

Page 6: ...nal surface unit or above a conventional wall oven 5 Use microwave oven in an ambient temperature less than 104 F 40 C 6 Place the microwave oven on a sturdy and 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 GROUNDING INSTRUCTIONS For personal safety this appliance must be fully grounded at a...

Page 7: ... TIMER Touch this pad to use your microwave oven as a kitchen timer 12 CUSTOM SET Touch this pad to select sound control time of day clock Off or On scroll speed lbs kg choice 13 MORE LESS All of the one touch cook and Timed Cook can be adjusted to cook food for a longer or shorter time MORE Press MORE will add 10 seconds to the cooking time LESS Press LESS will subtract 10 seconds to the cooking ...

Page 8: ...display TO CANCEL CHILD LOCK Touch and hold pad LOCKED disappears 8 MORE LESS The cook time is adjustable by MORE pad or LESS pad 9 AUTO REHEAT NOTE Then the oven will start automatically 10 Q DEFROST 11 KITCHEN TIMER 12 FAST BREAKFAST NOTE Then the oven will start automatically 13 CHICKEN CHOICES NOTE Then the oven will start automatically 4 2 STOP CLEAR POPCORN NUMBER OF TABLE STOP CLEAR Ez On S...

Page 9: ...en will start automatically 16 AUTO COOK NOTE Then the oven will start automatically 17 CUSTOM SET NOTE Then the oven will start automatically STOP CLEAR MELT NUMBER OF TABLE NUMBER OF TABLE NUMBER OF TABLE NUMBER OF TABLE STOP CLEAR SOFTEN STOP CLEAR AUTO COOK STOP CLEAR CUSTOM SET ...

Page 10: ... MICROWAVE RADIATION FIRE L E LECTRICAL SHOCK AND HAZARDS WHEN SERVICING IT IS ESSENTIAL THAT ONLY MANUFACTURER S SPECIFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SHADED AREAS OF THE SCHEMATIC DIAGRAM NOTICE SINCE THIS IS BASIC SCHEMATIC DIAGRAM THE VALUES OF COMPONENTS AND SOME PARTIAL CONNECTIONS ARE SUBJECT TO CHANGE FOR IMPROVEMENT ...

Page 11: ...roximately 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...

Page 12: ...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 13: ...wise a false reading may result The test probe must be held by 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 Hold vertically when testing the top and bottom and horizontally along RECORD K...

Page 14: ... in watts is calculated from the following formula 4187 x T T is measured while the microwave generator is operating at full power Magnetron filament heat up time is not included about 3 sec 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 remova...

Page 15: ...g the door be sure to check that the primary switch monitor switch and secondary switch operate normally 2 After replacing the door check for microwave energy leakage with a survey meter Microwave energy must be below the limit of 4 mW cm with a 275 ml water load 3 When mounting the door assembly to the oven assembly be sure to adjust the door assembly parallel to the chassis Also adjust so the do...

Page 16: ...5 ml water load Make 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 H REMOVING THE TURNTABLE MOTOR 1 Remove the turntable and rotating ring 2 Lay the unit down on its back 3 Remove the turntable motor cover The turntable base cover is easily removed by pinchi...

Page 17: ...SYSTEM 1 INTERLOCK MECHANISM The door lock mechanism is a device which has been specially designed to eliminate completely 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 SECONDARY SWITCHES TO THE LATCH BOARD 3 INSTALLATION AND ADJUSTMENT OF THE LATCH BOARD TO THE OVEN ASSEMBLY Mount the...

Page 18: ...d 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 circuit in the door open condition When t...

Page 19: ... PROCEDURE 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 sca...

Page 20: ... Terminal 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 ...

Page 21: ...ec 2 6 sec 16 sec 3 8 sec 14 sec 4 10 sec 12 sec 5 12 sec 10 sec 6 14 sec 8 sec 7 16 sec 6 sec 8 18 sec 4 sec 9 20 sec 2 sec 10 22 sec 0 sec Normal A Approx 85 100 ohm B Approx 10 25 ohm Abnormal Infinite or several ohm Normal Approx 100 150 ohm 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 ...

Page 22: ...s panel to discharge any static charge built up in your body Micom model only CONDITION Microwave oven does not work Inserting many plugs into one 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 Inc...

Page 23: ... does not turn on after setting cooking cycle 11 Display time of day does not reappear when cooking is finished 5 12 TROUBLE 1 The following visual conditions indicate a probable defective control circuit CONDITION CHECK RESULT CAUSE REMEDY 1 No input can be programmed Continuity No continuity Defective PCB assembly Loose connection Replace PCB assembly Connect them tightly Check the conn ection b...

Page 24: ...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 Continuity Malfunction of secondary switch Replace fuse primary monitor secondary switches and RELAY RY2 of P C B Assembly No continuity Check continuity of secondary switch with door opened 2 Fuse does not blow No continuity Continuity ...

Page 25: ...ws 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 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 CONDITION CHECK RESULT CAUSE REMEDY Output is low Lower than 90 ...

Page 26: ... relay 2 and check continuity relay 2 Operate the unit Abnormal Defective high voltage capacitor Replace high voltage capacitor Normal Check high vol tage capacitor Abnormal Defective high voltage diode Replace high voltage diode Normal Check high vol tage diode Abnormal Defective magnetron Replace magnetron Check magnetron TROUBLE 5 No microwave oscillation even though oven lamp and fan motor run...

Page 27: ...DOOR CONTROL PANEL BASE PLATE OUTER CASE LATCH BOARD INTERIOR 6 1 EXPLODED VIEW INTRODUCTION ...

Page 28: ...6 2 13552A 13213A 13581A 14970A 14026A 13536A 15006A 13720D 13352A DOOR PARTS ...

Page 29: ...6 3 24781M 23506A 23572A 24510L 24970A 250201 268711 WTP018 CONTROLLER PARTS ...

Page 30: ...6 4 33390G WTT010 WTT020 WSZ185 33112U 35889A 36549S WTP013 33052A 948502 OVEN CAVITY PARTS ...

Page 31: ...6 5 WSZ085 466001 466003 466001 43500A LATCH BOARD PARTS ...

Page 32: ...6 6 568771 WSZ002 WSZ002 WSZ187 WSZ002 WSZ085 WTT028 56411A 56930V 50FZZA 55006F 56549F 54974S WTT037 55900A 54810C WTT028 50CZZH 56851D 34930W 56324A 55262A 56912B 948501 948503 INTERIOR PARTS ...

Page 33: ...6 7 56170D WSZ002 WTT021 63302A 65006B 63303A BASE PLATE PARTS ...

Page 34: ...HOLDER WIRE R 35889A 5889W1A003B ROTATING RING ASSEMBLY R 36549S 6549W1S011B MOTOR CIRC SYNCHRONOUS R 6549W1S015A 43500A 3500W1A018A BOARD LATCH R 466001 6600W1K003D SWITCH MICRO R 6600W1K001D 466001 6600W1K003D SWITCH MICRO R 6600W1K004C 466003 6600W1K003C SWITCH MICRO R 6600W1K001C 466003 6600W1K003C SWITCH MICRO R 6600W1K004B 50CZZH 0CZZW1H005A CAPACITOR DRAWING HIGH VOLTAGE R 0CZZW1H004C 50FZZ...

Page 35: ... 1SBF0402418 SCREW TAP TITE S BINDING HEAD R WSZ085 4B70188C SCREW DRAWING R WSZ185 1SZZW2A002A SCREW DRAWING R WSZ187 1SZZW2A002B SCREW DRAWING R WTP013 1TPL0402418 SCREW TAPPING PAN HEAD R WTP018 1TPL0402818 SCREW TAPPING PAN HEAD R WTT010 1TTG0402422 SCREW TAPPING TRUSS HEAD R WTT021 1TTL0402418 SCREW TAPPING TRUSS HEAD R WTT028 1TTL0402818 SCREW TAPPING TRUSS HEAD R WTT037 1TTL0403818 SCREW TA...

Page 36: ...B029A HOLDER WIRE R 35889A 5889W1A003B ROTATING RING ASSEMBLY R 36549S 6549W1S011B MOTOR CIRC SYNCHRONOUS R 6549W1S015A 36549S 6549W1S011B MOTOR CIRC SYNCHRONOUS R 6549W1S017A 43500A 3500W1A018A BOARD LATCH R 466001 6600W1K003D SWITCH MICRO R 6600W1K001D 466001 6600W1K003D SWITCH MICRO R 6600W1K004C 466003 6600W1K003C SWITCH MICRO R 6600W1K001C 466003 6600W1K003C SWITCH MICRO R 6600W1K004B 50CZZH ...

Page 37: ...SHION R 948503 3B72246B CUSHION R WSZ002 1SBF0402418 SCREW TAP TITE S BINDING HEAD R WSZ085 4B70188C SCREW DRAWING R WSZ185 1SZZW2A002A SCREW DRAWING R WSZ187 1SZZW2A002B SCREW DRAWING R WTP013 1TPL0402418 SCREW TAPPING PAN HEAD R WTP018 1TPL0402818 SCREW TAPPING PAN HEAD R WTT021 1TTL0402418 SCREW TAPPING TRUSS HEAD R WTT028 1TTL0402818 SCREW TAPPING TRUSS HEAD R WTT037 1TTL0403818 SCREW TAPPING ...

Page 38: ...8 1 SCHEMATIC DIAGRAM OF P C B ...

Page 39: ...8 2 PRINTED CIRCUIT BOARD ...

Page 40: ...N4002 PYUNG CHANG TP52 DO41 100V 1A 30A R D02 0DD400209AD DIODE 1N4002 PYUNG CHANG TP52 DO41 100V 1A 30A R D03 0DD400209AD DIODE 1N4002 PYUNG CHANG TP52 DO41 100V 1A 30A R D04 0RD1002F609 RESISTOR FIXED CARBON FILM 10K OHM 1 6 W 5 TA52 R D10 0DD400209AD DIODE 1N4002 PYUNG CHANG TP52 DO41 100V 1A 30A R D20 0DD414809AD DIODE 1N4148 PYUNG CHANG TP52 DO35 100V 0 5A 0 R D30 0DD414809AE DIODE 1N4148M PY...

Page 41: ...1000G609 RESISTOR FIXED CARBON FILM 100 OHM 1 4 W 5 TA52 R R54 0RH1001L622 RESISTOR METAL GLAZED CHIP 1K OHM 1 8 W 5 2012 R TP R R55 0RH1004L622 RESISTOR METAL GLAZED CHIP 1MOHM 1 8 W 5 2012 R TP R R80 0RD2202F609 RESISTOR FIXED CARBON FILM 22K OHM 1 6 W 5 TA52 R R81 0RH2202L622 RESISTOR METAL GLAZED CHIP 22K OHM 1 8 W 5 2012 R TP R R82 0RH2202L622 RESISTOR METAL GLAZED CHIP 22K OHM 1 8 W 5 2012 R...

Page 42: ...P NO 3828W5S3026 Mar 2002 Printed in China ...

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