LG LMV1651SB, Service Manual

Page 1: ... OVEN SERVICE MANUAL MODEL LMV1651SW LMV1651SB LMV1651SS CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL P NO 3828W5S5299 August 2005 Printed in Korea Website http biz lgservice com ...

Page 2: ...ty 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 before the oven is released to the owner e A Microwave leakage check to verify compliance with the CSA Standard should be performed on each oven ...

Page 3: ...IONS 4 3 OVERALL CIRCUIT DIAGRAM 5 1 SCHEMATIC DIAGRAM 5 1 MATRIX CIRCUIT FOR TOUCH KEY BOARD 5 2 GENERAL INFORMATION FOR SERVICE 6 1 GENERAL PRECAUTIONS IN USE 6 1 TRIAL OPERATION 6 1 FEATURES AND SPECIFICATIONS FEATURES 6 1 SERVICE INFORMATION 7 1 PRECAUTIONS AND REPAIR SERVICE TIPS 7 1 MICROWAVE LEAKAGE TEST 7 2 POWER OUTPUT MEASUREMENT 7 3 DISASSEMBLY INSTRUCTIONS 7 4 INTERLOCK SYSTEM 7 12 INT...

Page 4: ...Interlock Switch Interlock Monitor Switch Magnetron 2M246 310GT Cook top Lamp 120 V 30 W Cavity Lamp 125 V 30 W or 40 W Timer Digital up to 99 min 99 sec in each cooking stage Tray Tempered Safety Glass Overall Dimensions 2915 16 W x167 16 H x153 8 D Oven Cavity Size 207 8 W x93 16 H x143 16 D Effective Capacity of Oven Cavity 1 6 Cu ft Accessories Owner s Manual Cooking Guide Installation Manual ...

Page 5: ...ng operation BEFORE TOUCHING any parts of the oven always remove the power plug from the outlet Remove your watches whenever working close to or replacing the Magnetron DO NOT touch any parts of the control panel circuit A resulting static electric discharge may damage this P C B NEVER operate the oven with no load NEVER injure the door seal and front plate of the oven cavity NEVER put iron tools ...

Page 6: ...GROUNDING INSTRUCTIONS For personal safety this appliance must be fully grounded at all times In the event of an electrical short circuit grounding reduces the risk of electrical shock The plug must be plugged into an outlet that is properly installed and grounded CAUTION This unit is equipped with a 3 prong plug for your safety If the wall outlet is a grounded 3 hole type the unit will be grounde...

Page 7: ...4 1 OPERATING INSTRUCTIONS CONTROL PANEL I For Model LMV1651SW LMV1651SB 4 9 6 8 2 5 12 21 24 23 22 15 13 10 11 20 14 26 3 19 27 16 7 1 17 18 25 ...

Page 8: ...4 2 CONTROL PANEL II For Model LMV1651SS 4 2 5 11 14 18 21 23 25 8 3 9 1 7 6 12 19 10 13 15 16 17 20 22 24 27 26 ...

Page 9: ...ogrammed into memory 9 TIME COOK Touch this pad to set a cooking time 10 POWER LEVEL Touch this pad to select a cooking power level 11 AUTO DEFROST Meat poultry fish Touch this pad to select food type and defrost food by weight 12 TIME DEFROST Touch this pad to defrost most other frozen foods 13 Q DEFROST This pad provides you with the RAPID defrosting method for 1 0 pound frozen foods 14 NUMBER T...

Page 10: ... T THERMOSTAT OVEN SWITCH SECONDARY BK O L PRIMARY SWITCH RD RD RD RD F M T T M BN MONITOR SWITCH TRANSFORMER H V FA F WH V M H V CAPACITOR C L S M HIGH C CONDENSER BL ABSOLUTE HUMIDITY SENSOR THERMISTOR YL BK RD RD RD BK BK BK BL BL BK BN YL YL YL WH YL PK BL L V TRANS FORMER CN1 RELAY POWER RY7 RY1 MAIN RELAY 1 2 3 1 3 1 2 3 5 5 4 4 5 4 6 6 7 8 9 10 11 12 6 1 2 2 1 RY2 LAMP C TOP HIGH RELAY RY3 ...

Page 11: ...5 2 MATRIX CIRCUIT FOR TOUCH KEY BOARD KEY MATRIX ...

Page 12: ...l show the time counting down by seconds D After about 5 minutes make sure the primary interlock switch the secondary interlock switch and the interlock monitor switch operate properly by opening and closing the door several times Touch the START key each time the door is closed E Continue operating the unit Two short and a long beep sound signal is heard when the time is up The unit will shut off...

Page 13: ...w the limit of 5 mW cm2 All service adjustments should be made for minimum microwave energy leakage readings 3 Do not operate the unit until it is completely repaired if any of the following conditions exist The unit must not be operated a The door does not close firmly b The hinge is broken c The door seal is damaged d The door is bent or warped or there is any other visible damage on the unit th...

Page 14: ...rvicing The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 1mW cm2 sq And always start measuring of an unknown field to assure safety for operating personnel from radiation leakage NOTE The standard is 5mW cm2 sq while in the customer s home 1mW cm2 sq stated here is manufacturer s own voluntary standard for units in customer s home EQUIPMENT TESTE...

Page 15: ...l have been used 3 At least once a year have the electromagnetic energy leakage monitor checked for calibration by its manufacturer POWER OUTPUT MEASUREMENT 1 Microwave power output measurement is made with the microwave oven supplied at its rated voltage and operated at its maximum microwave power setting with a load of 1000 5 g of potable water 2 The water is contained in a cylindrical borosilic...

Page 16: ... CIRCUIT BOARD Figures 1 2 and 3 1 Remove a screw securing the control panel assembly to the oven cavity 2 Remove the control panel with pushing it upward 3 Remove the connectors CN1 CN3 and wire leads RY7 from the circuit board 4 Remove 5 screws securing the circuit board Power Transformer Control Panel Screw Circuit Board RY7 CN3 CN1 Circuit Board Control Bracket Circuit Board FPC Connector S1 5...

Page 17: ...sert the F P C connector into the terminal socket securely with the fingers 2 Hold the plastic fastener with thumb and forefinger of the other hand and push it slowly into the terminal socket Figure 6 NOTE When reconnecting the F P C connector make sure that the holes on the F P C connector are properly engaged with the hooks on the plastic fastener 3 Lock the level of the plastic fastener into th...

Page 18: ...urning the screws 1 or 2 screws securing it to the out case 4 Remove two screws on the left central edge and one screw on the right central edge of Base plate Remove the Mount All from the out case by removing one screw securing it to the out case 5 Remove six screws of the rear cavity 6 Remove the outcase Door Mount All Vent Grille Out Case Mounting Plate Power cord cover Controller Figure 8 ...

Page 19: ...2 Latch Board Primary Interlock Switch RD from H V T RD from Fan Motor BK from Cooktop lamp WH from RY7 PK from P C B BL from P C B RD from Turntable Motor RD from H V T BK from MGT THERMOSTAT Monitor Interlock Switch Secondary Interlock Switch Latch Board Primary Interlock Switch Monitor Interlock Switch Secondary Interlock Switch Figure 9 Figure 10 WIRE COLOR SYMBOL COLOR WH WHITE BK BLACK BR BR...

Page 20: ...agnetron be sure to install the magnetron gasket in the correct position and be sure that the gasket is in good condition After replacing the magnetron check for microwave energy leakage with a survey meter Check microwave energy leakage must be below the limit of 5 mW cm2 All service adjustments should be made for minimum microwave energy leakage readings E REMOVING STIRRER FAN Figures 13 and 14 ...

Page 21: ...iver etc 2 Remove two screws securing it to the door handle CAUTION Be careful not to damage door seal plate with the screwdriver H ASSEMBLING DOOR 1 When mounting the door assembly to the oven assembly be sure to adjust the door assembly parallel to the chassis Also adjust so the door has no play between the inner door surface and oven frame assemblyIf the door assembly is not mounted properly mi...

Page 22: ...19 3 Remove the base plate by removing 8 screws securing it to the oven cavity Figure 20 4 Disconnect the leadwire from the turntable motor terminals 5 Remove the 1 screws securing the turntable motorto the oven cavity ASS Y Figure 21 NOTES Remove the leadwire from the turntable motor VERY CAREFULLY Be sure to grasp the connector not the wires when removing Figure 18 b Figure 19 Figure 20 Figure 2...

Page 23: ...7 11 K REPLACING THE HUMIDITY SENSOR 1 Remove the sensor by removing two screws securing it to the air duct See Figure 22 2 Mount the new humidity sensor to the air duct Figure 22 ...

Page 24: ...rd and the switches as shown in Figure 23 a 2 Close the door tightly and check gaps A and B to be sure they are no more than 1 64 0 5 mm See Figure 23 b for close up view of gaps A and B door latches If all gaps are less than 1 64 0 5 mm adjustment of the latch board may not be necessary Go to Steps 5 and 6 to check the sequence of the switches NOTE To correct sequence of the Primary Interlock Swi...

Page 25: ...ro to the body of the switches in the following sequence Interlock Monitor Switch Primary Interlock Switch Secondary Interlock Switch NOTE The Interlock Monitor Switch is an added safety check on the Primary and Secondary Interlock Switches If the Primary and Secondary Interlock Switches allow the oven to operate with the door open the Monitor Switch will blow the fuse 7 When you achieve the prope...

Page 26: ...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 is closed meter shoul...

Page 27: ... 1 Remove wire leads 2 Measure resistance ohm meter scale Rx1 Primary winding Secondary winding Filament winding 3 Measure resistance ohm meter scale Rx1000 Primary winding to ground Filament winding to ground 1 Remove wire leads Install the magnetron seal in the correct position Check that the seal is in good condition 2 Measure resistance ohm meter scale Rx1 Filament terminal 3 Measure resistanc...

Page 28: ...e Rx1000 CAPACITOR DIODE Some inexpensive ohm meters may indicate infinite resistance in both directions 1 Measure continuity ohm meter scale Rx1 2 Remove the lead wires and operate oven at power level 1 through power level 10 RELAY 7 1 Remove wire leads 2 Measure resistance ohm meter scale Rx1 Normal Approximately Terminal 85 to 105 ohms Terminal 15 to 25 ohms Abnormal Infinite or several A B C F...

Page 29: ...lead wires 2 Measure resistance ohm meter scale Rx1 1 Remove wire leads 2 Measure resistance ohm meter scale Rx1000 VENTILATION MOTOR TURNTABLE MOTOR 1 Disconnect sensor connector from micom computer board 2 Measure resistance terminal to terminal ohm meter scale R X 1000 RD BK WH 1 2 3 ABSOLUTE HUMIDITY SENSOR FOR SENSOR MODEL 1 Remove lead wires 2 Measure resistance ohm meter scale Rx1000 Normal...

Page 30: ...r MATRIX CIRCUIT FOR TOUCH KEY BOARD CONNECTOR KEY CON TOUCH KEY BOARD Resistance value When touched Less than 400 ohms When not touched More than 1 mega ohm FPC CONNECTOR Top 1 2 3 4 5 6 7 8 9 10 11 12 13 NOTES A MICROWAVE ENERGY 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 B...

Page 31: ... ADJUSTMENT PROCEDURES on page 7 12 when the primary interlock secondary interlock switches and or the interlock monitor switches are adjusted or replaced Fuse blows immediately after the door is closed Fuse blows immediately after the door is opened Fuse blows when the door is closed and START key is touched Improper operation of the primary interlock secondary interlock switches and or the inter...

Page 32: ...without touching START key when the door is closed GOOD Remove the mate connector of I O CON from the circuit board Does the unit still operate Defective Wire Assembly Replace the circuit board Replace Wire Assembly NO NO YES YES GOOD Measure the voltage at pin NO 1 4 of CN1 Voltage reading 120 V AC Replace the circuit board Defective FAN motor YES NO NO YES Replace FAN motor PROBLEM B Oven lamp t...

Page 33: ...usly operates 3 Proper temperature measurement is not obtained 4 The buzzer does not sound or continues to sound 5 Some segments of one or more digits do not light up or they continue to light up or segments light when they should not 6 Wrong figures appear 7 The figures of all digits 8 Some of the indicators do no flicker light up 9 The clock does not keep time properly NOTE A MICROWAVE ENERGY LE...

Page 34: ... 2 FUSE See CHECKOUT PROCEDURES FOR FUSE BLOWING on page 7 19 3 OVEN CAVITY THERMOSTAT 1 1 Measure voltage between pin 1 and pin 3 of connector CN1 0 120 120V Replace circuit board Normal circuit board Normal resistance Voltage incorrect Correct connections 0 120 BL WH Runs Runs Measure resistance of touch key board after removing connector S1 See page 7 5 and 7 18 Normal resistance Resistance inc...

Page 35: ...t board Contact OK Normal contact Correct seating Check contact of connector S1 Check the contact of relay 7 see page 7 16 Runs Runs Resistance incorrect Check the continuity of H V C see page 7 16 Normal H V T Resistance incorrect Normal H V C Abnormal Replace H V D Normal Magnetron Replace Magnetron Normal Normal H V D Check the continuity of H V D see page 7 16 Replace H V C Normal resistance R...

Page 36: ...7 24 PROBLEM F No buzzing when touching the key between stages or at end of cooking 1 Normal circuit board Check normal operation circuit board Replace circuit board Runs ...

Page 37: ...ace magnetron thermostat and oven thermostat Poor contact Replace circuit board Normal circuit board Contact OK Normal contact Correct seating Check contact of connector S1 see page 7 5 NO runs Check the contact of magnetron thermostat and oven thermostat Runs Runs Runs Runs Check 1 POWER SUPPLY 2 FUSE ...

Page 38: ...PLODED VIEW DOOR PARTS FOR MODEL FOR MODEL LMV1651SS 13581A 13213A 13536A 13552A 14026A 14970A 13581A 13551A 13213A 13536A 13552A 14026A 14970A 14890A 13720D WTT028 WTT028 13651A LMV1651SW LMV1651SB 13651A EV ...

Page 39: ...8 2 CONTROLLER PARTS FOR MODEL LMV1651SW LMV1651SB FOR MODEL LMV1651SS 24781M 23572A 23506A TECHNICAL CARD TECHNICAL CARD 24810P 24810P 23551A 24781M 268711 WTP018 268711 WTP018 EV ...

Page 40: ...EN CAVITY PARTS 34960A WTT028 33112U 34810Q 368771 66804A 63303A 63302A 34890C 34810T WTT010 35230A 36912C WTT010 35026G 34930R 33530A WTT027 WTT029 33550L For Model LMV1651SS LMV1651SB For Model LMV1651SW EV ...

Page 41: ...8 4 LATCH BOARD PARTS 43501A WSZ085 43500A 466001 466003 466001 44510A EV ...

Page 42: ...8 5 INTERIOR PARTS I WSZ002 56930M 33390G 34351A 35889A 56324A WTT021 55238A WSZ002 50CZZH 54810C 56851D WSZ002 WTP013 36549S WTT021 WTT021 33740A 54810A WTP004 56170D 53300B 56201B EV ...

Page 43: ...8 6 INTERIOR PARTS II WTP005 56912B 53550L 55231C 56804A WTT028 56411A 568771 56501A WTP013 552622 53550F 340511 36549V 55901A 568773 56549B WSZ002 WTT037 56549F 55900A 552621 50FZZA 56201A WTP015 EV ...

Page 44: ...8 7 INSTALLATION PARTS 63300M WTT028 65862D 65862B VINYL BAG 63861A 01 OWNERS MANUAL 05 COOKING GUIDE LABEL 06 TEMPLATE 04 INSTALLATION MANUAL EV ...

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