LG LSMH207ST Service Manual
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LG LSMH207ST Service Manual

LG LSMH207ST Service Manual

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삼
흥
정
판
MICROWAVE OVEN
SERVICE MANUAL
MODEL: LSMH207ST
CAUTION
BEFORE SERVICING THE UNIT, READ THE
SAFETY PRECAUTIONS IN THIS MANUAL.
P/NO : MFL06272516
Internal Use Only
Website: http://biz.lgservice.com
April, 2010
Printed in China

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  • Page 1 삼 흥 정 판 Internal Use Only Website: http://biz.lgservice.com MICROWAVE OVEN SERVICE MANUAL MODEL: LSMH207ST CAUTION BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. April, 2010 P/NO : MFL06272516 Printed in China...

  • Page 2: Safety Precautions

    CAUTION WARNING TO SERVICE TECHNICIANS PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY a. Do not operate or allow the oven to be operated with the door open. b. Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source, and make repairs as necessary;...

  • Page 3: Table Of Contents

    FOREWORD Read this Manual carefully. Failure to adhere to or observe the information in this Manual may result in exposing yourself to the Microwave Energy normally contained within the oven cavity. CONTENTS (Page) Safety Precautions .............................. 2 1. Specification ..............................4 2.

  • Page 4: Specification

    ................Fuse (20A) ................Primary Interlock Switch ................Secondary Interlock Switch ................Interlock Monitor Switch Heater ..............120 V, 400W (Sheath) Magnetron ............2M246 (LG) Cook top Lamp ...........125V, 30W (Incandescent) Warming Lamp ...........125V, 30W Timer ..............Digital,up to 99 min.(in each cooking stage) Tray ..............Tempered Safety Glass Overall Dimensions ..........29...

  • Page 5: Cautions

    2. CAUTIONS Unlike other appliances,the microwave oven is MICROWAVE RADIATION high-voltage and high-current equipment. Personnel should not be exposed to the Though it is free from danger in ordinary use, microwave energy which may radiate from the extreme care should be taken during repair. magnetron or other microwave generating device if it is improperly used or connection.

  • Page 6: Installation

    3. INSTALLATION BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY. PRECAUTIONS ON INSTALLATION A. Plug the power supply cord into a 120V AC, 60Hz, single-phase power source with a capacity of at least 20 amperes. B. Avoid placing the unit in a location where there is direct heat or splashing water.

  • Page 7: Operation

    4. OPERATION 4-1. Control Panel Features...

  • Page 8: Explanation Of Control Panel

    4-2. Explanation of Control Panel 1. DISPLAY The Display includes a clock and indicators to tell 13. EZ-ON Touch this pad to set and start quickly at 100% you time of day, cooking time setting, and cooking functions power level. selected.

  • Page 9: Wiring Diagram / Key Matrix

    5. WIRING DIAGRAM / KEY MATRIX 5-1. Wiring Diagram...

  • Page 10: Key Matrix

    5-2. Key Matrix KEY MATRIX CUSTOM TIME POWER WARMING T/T ABLE ENTER / AUTO Timer CLOCK COOK LEVEL (Hold Warm) ON/OFF START Time Set VENT TURBO MAC & STOP / Hi / Low / OFF LIGHT SOFTEN MELT MORE (Vent Speed) CHEESE CLEAR (Vent On / Off)

  • Page 11: Troubleshooting

    6. TROUBLESHOOTING 6-1. General Information for Service GENERAL PRECAUTIONS IN USE FEATURES AND SPECIFICATIONS FEATURES A. Never operate the unit when it is empty. Operating the oven with no load may shorten the A. The safety systems incorporated in this model life of the magnetron.

  • Page 12: Safety Caution

    6-2. Safety Caution A. SINCE NEARLY 4,000 VOLTS EXISTS IN (3) Do not operate the unit until it is completely SOME CIRCUITS OF THIS UNIT REPAIRS repaired, if any of the following conditions exist. SHOULD BECARRIED OUT WITH GREAT The unit must not be operated. CARE.

  • Page 13: Basic Check Summary

    6-3. Basic Check Summary 120 V Ac 120V Ac BK-L WH-N BK-CN1-3 WH-CN1-5 Symptom : Dead Check : Open/Short Symptom: Dead Check : Open/Short (It is normally recovered if the set is cooled down) Symptom: Dead Check :Open/Short Symptom #1(Door is closed): No cook, Operate F.M, S.M, T.T.M.

  • Page 14: Troubleshooting

    6-4. Troubleshooting No Display or Dead -14-...
  • Page 15 Is there any beep sound in Replace the Does the display operate? continuity test between the thermostats. ends of thermostats? (Oven, Heater, Magnetron) Go to No.8 of When you push the any key, this flow chart. is there any beep sound Power Off 2 Is the connector connected Go to No.8 of...
  • Page 16 5 Is there any beep sound in 7 Is the connector connected Reconnect or Replace the continuity test between the to Main PCB assemble repair the Fuse. ends of the Fuse? disconnected or connector. disassembled? (CN10) Power ON Is the voltage of Main PCB Replace the out of the range? Main PCB...
  • Page 17 Keypad Failure MICOM • Start key or EZ-ON key works if the door is closed. -17-...
  • Page 18 3 When the door is opened, Is Replace the Does the keys operate? the voltage of door sensing (EBR64419604) part over 4V? (Pin 1 to Pin 3 of CN4) Power ON 1 Do not only START key and Check PWB EZ-ON key operate? Door Go to No.5 of should be closed?
  • Page 19 No Heat / No Cook -19-...
  • Page 20 Reconnect or Is the connector connected to After power on, does the repair product operate? Power PCB and MAIN PCB the connector. assembly disconnected or disassembled? (CN6, CN7) 1 Repeat door open and close Alternate with more than three times. explanation Does product operate? (Refer to the...
  • Page 21 Power Off 7 Is the resistance of high Replace the 5 Is there any beep sound High Voltage Adjust latch voltage Transformer out of board Transformer in continuity test between rage? (Refer to 9-1, the ends of latch board? 9-2) - primary switch (Door should be closed.) Test Point...
  • Page 22 8 Is the connector connected 11 Is the resistance of the high Reconnect or Replace the to High Voltage capacitor repair the voltage diode out of rage? high voltage assembly disconnected or connector. (Refer to 10) Diode. disassembled? 9 Is the resistance of the high 12 Is the connector connected Replace the voltage capacitor out of...
  • Page 23 4 Push the EZ-ON (Operate) Turntable Motor Does Not Work Replace the Is the voltage of both ends (EBR64419604) of the D30 over 8 V? Power ON Does the turntable motor operate? 2 Does the Fan Motor turn on when the EZ-On button is pressed? 3 When door is closed, does Adjust the...
  • Page 24 4 When the door is opened, Is Turn on automatically Replace the the voltage of door sensing (EBR64419604) part over 4V? Is the product turn on (Pin 1 to Pin 3 of CN4) automatically without pushing the start key? 1 Repeat Door Open and close Alternate with more than three times.

  • Page 25: Microwave Leakage Test

    7. MICROWAVE LEAKAGE TEST CAUTIONS EQUIPMENT- • Be sure to check microwave leakage prior to • TESTER (VOLTS-DC, AC, Ohmmeter) servicing the oven if the oven is operative prior to • Microwave survey meter servicing. - Holaday HI-1500 • The service personnel should inform the HI-1501 manufacturer, importer, or assembler of any - Narda...
  • Page 26 MEASUREMENT WITH THE OUTER NOTE WHEN MEASURING CASE REMOVED (1) Do not exceed meter full scale deflection. (2) The test probe must be removed no faster than (1) When you replace the magnetron, measure for 1 inch/sec (2.5cm/sec) along the shaded area, microwave energy leakage before the outer case otherwise a false reading may result.

  • Page 27: Power Output Measurement

    8. POWER OUTPUT MEASUREMENT (1) Microwave power output measurement is made 4.187 Mw(T2 –T1)+0.55Mc(T2 –T0) with the microwave oven supplied at its rated voltage and operated at its maximum microwave is measured while the microwave generator is power setting with a load of (1000 ± 5) g of operating at full power.

  • Page 28: Interlock System

    9. INTERLOCK SYSTEM 9-1. 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. ADJUSTMENT PROCEDURES CHECK THE DOOR LATCH AND SWITCH To avoid possible exposure to microwave energy...
  • Page 29 TEST THE LATCH AND SWITCH SEQUENCE (7) When you achieve the proper sequence of (5) Open the oven door slowly. Watch the door latch, switches in Steps 5 and 6, tighten the latch board the Secondary Switch. Release Rod and Lever screws at that point.

  • Page 30: Interlock Continuity Test

    9-2. Interlock Continuity Test A. PRIMARY INTERLOCK SWITCH TEST B.S ECONDARY INTERLOCK SWITCH TEST When the door is opened slowly,an audible click Disconnect the wire lead from the secondary should be heard at the same time or successively switch. at intervals and the latches should activate the Connect the ohmmeter leads to the common switches with an audible click.

  • Page 31: Component Testing Information

    10. COMPONENT TESTING INFORMATION CAUTIONS 1. DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER REMOVING THE OUTER CASE FROM THE UNIT. PROCEED WITH THE TEST ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE LEAD WIRES FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER.
  • Page 32 COMPONENTS TEST RESULTS 1. Remove wire leads. CAPACITOR 2. Measure resistance. (ohm meter scale: Rx1000) • Terminal to terminal Normal: Momently indicates several ohm, and then gradually returns to infinite • Terminal to case Normal: Infinite. 1. Measure continuity. Forward. Normal:Continuity.
  • Page 33 COMPONENTS TEST RESULTS 1.Remove lead wires. Normal: VENTILATION MOTOR 2.Measure resistance. Approximately (ohm meter scale: Rx1) Turbo speed: 20 to 30 ohms Turbo speed: blue & black wire High speed: 40 to 50 ohms High speed: blue & white wire Low speed: 45 to 55 ohms Low speed: blue &...
  • Page 34 COMPONENTS TEST RESULTS Measure the resistance between terminal TOUCH KEY BOARD When When not pins of connector KEY CONNECTOR. touched touched NOTE: Resistance When reconnecting the FPC connector, value More than Less than make sure that the holes on the FPC 1 megohm 400 ohms connector are properly engaged with hooks...

  • Page 35: Disassembly Instructions

    11. DISASSEMBLY INSTRUCTIONS IMPORTANT NOTES: (4) Remove 3 screws securing the circuit board. UNIT MUST BE DISCONNECTED FROM ELEC- TRICAL OUTLET WHEN MAKING REPAIRS, RE- PLACEMENTS, ADJUSTMENTS AND CONTIN- UITY CHECKS. Circuit Board WHEN RECONNECTING THE WIRE LEADS TO ANY PART, MAKE SURE THE WIRING CONNE- CTIONS AND LEAD COLORS ARE CORRECTLY MATCHED ACCORDING TO THE OVERALL CIR- CUIT DIAGRAM.
  • Page 36 HOW TO REMOVE THE F.P.C. CONNECTOR HOW TO INSERT THE F.P.C. CONNECTOR Follow the steps below as illustrated in Figures 4 Follow the steps below as illustrated in Figures 6 and 5 to remove the F.P.C. connector. and 7 to insert the F.P.C. connector. (1) Insert the F.P.C.
  • Page 37 B. REMOVING THE OUT CASE(Figure 8) (1) Remove the vent grille by removing one screw securing it to the outer case. (2) Remove three screws securing it to the air duct. (3) Remove one screw securing it to the front cavity. (4) Remove the mounting plate by turning two screwssecuring it to the outer case.
  • Page 38 C REMOVING THE DOOR INTERLOCK SWITCHES (Figures 9,10) (1) Disconnect the wire leads from the interlock switches. (2) Remove two screws securing the Latch Board. (3) Make necessary replacements and check microwave energy leakage according to ADJUSTMENT PROCEDURES on page 28. WIRE COLOR SYMBOL COLOR...
  • Page 39 D. REMOVING MAGNETRON E. REMOVING STIRRER FAN (Figures 11 Through 12) (Figures 13 and 14) (1) Remove the vent grille by loosening two screws. (1) Remove one rivet assembly securing it to the (Figure 11) oven upper plate by using knife blade. (2) Remove the outcase.
  • Page 40 F. REMOVING DOOR (Figure 15) H. ASSEMBLING DOOR (1) Remove the vent grille by two screws securing it (1) When mounting the door assembly to the oven to the outcase loosening. assembly, be sure to adjust the door assembly parallel (2) Lift up and draw the door.
  • Page 41 (3) Carefully pull the ventilation motor assembly out of J. REMOVING THE TURNTABLE MOTOR the microwave oven. (See Figure 18-b) (1) Remove the glass tray and rotating ring. (2) Remove the turntable shaft VERY CAREFULLY with a hand. (Figure 19) (3) Remove the base plate by removing 8 screws securing it to the oven cavity.
  • Page 42 K. REPLACING THE HUMIDITY SENSOR L. REMOVING CONVECTION HEATER (1) Remove the sensor by removing two screws in AND THERMISTOR (Figure 23) front of the lamp cover & removing one screw (1) Remove the out case. securing it to the air duct. (See Figure 22) (2) Remove the air duct by removing six screws (2) Mount the new humidity sensor to the air duct.

  • Page 43: Exploded View

    #EV# 12. EXPLODED VIEW DOOR PARTS FOR MODELS 1005 1004 1002 1000 W136 1381 W136 1006 2041 1007 W301 2009 1015 W109 1009 -43-...
  • Page 44 #EV# CONTROLLER PARTS 2004 2006 2015 W130 2008 MBM2 -44-...
  • Page 45 #EV# OVEN CAVITY PARTS 3010 W142 W138 W138 W109 W142 W142 3024 W109 3031 3005 3001 3061 3032 5063 5138 3032 5015 W297 5015 3053 W298 3107 3401 5138 3230 3053 W109 3109 W297 4100 3402 3107 3093 W298 3036 3240 W109 3034...
  • Page 46 #EV# LATCH BOARD PARTS 4000 4002 W102 4001 4003 4004 4002 -46-...
  • Page 47 #EV# INTERIOR PARTS (I) W177 5404 5400 5441 5402 W109 W177 5401 5041 5012 W110 W108 5001 5073 W109 5512 W108 5403 5010 W109 5405 5412 5407 5075 3002 W108 W109 W124 W105 W246 5216 3008 5069 5007 3012 W265 5049 W109 5009...
  • Page 48 #EV# INTERIOR PARTS (II) 5460 W107 5011 5074 5021 5206 W109 W109 3027 5006 5014 5117 W109 5019 5117 3047 5037 -48-...
  • Page 49 #EV# INSTALLATION PARTS 6011 6008 6010 6009 COOKING MFL1 MFL3 MEZ1 MBM4 MBM5 UPPER WALL INSTALLATION & GUIDE TEMPLATE TEMPLATE MANUAL CARE LABEL -49-...

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