Microwave Oven Service Manual
Contents
1. 0 WH 5 2 9 1 1 5 gt SECONDARY NOTE INTERLOCK 1 DOOR IS OPENED BK WH YL BN GN PK SWITCH BL BN 2 WIRE COLOR cue Sc 1 SYSMBOL COLOR 1 5 8 9 BK BLACK m I ER Reg BROWN 0002 uM 1 Lolo ofo BL BLUE T6665 olo 1999 Lc por M GN GREEN 000 2 Icon RY3 RY5 PINK gt CURRENT lt 4 gt Y RED TRANSFORMER 7 1 WH WHITE gt VOLTAGE YL YELLOW DETECTION BEFORE SERVICING Discharge the high voltage capacitor by shorting the negative high voltage terminal of it to chassis ground LGE Internal Use Only CIRCUIT DESCRIPTION GENERAL DETAILS The low voltage transformer supplies the necessary voltage to the micom controller when power cord is plugged in When the door is closed the primary switch is ON the secondary switch is ON and the monitor switch opens contact COM and NO WHEN SELECTING COOKING POWER LEVEL AND TIME The micom controller memorizes the function you set The time you set appears in the display window Each indicator light turns on to indicate that the stage has been set WHEN TOUCHING THE START PAD The coil of the relay is energized by the micom controller Power input is supplied to the high voltage transformer through the fuse2. Amana Microwave Oven Service Manual RFS12MPSB RFS12SW2B CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL SAFETY PRECAUTIONS This device is to be serviced only by properly qualified service personnel Consult the service manual for proper service procedures to assure continued safety operation and for precautions to be taken to avoid possible exposure to excessive microwave energy 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 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 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 microw
3. COM and normally open NO terminals of the Switch The meter should indicate a open circuit in the door open condition When the door is closed meter should 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 the door is closed meter should indicate an open circuit When the monitor switch operation is abnormal replace with the same type of switch NOTE After repairing the door or the interlock system it is necessary to do this continuity test before operating the oven RESULTS SWITCHES Wire leads removed Check for continuity of the switch with an Ohm meter Door Door open closed Primary Switch Monitor Switch ey S Switch ECL EN LGE Internal Use Only NOTE After checking for the continuity of switches make sure that they are connected correctly Copyright O 2009 LG Electronics Inc right reserved Only for training and service purposes COMPONENT TEST PROCEDURE CAUTIONS 1 DISCONNECT THE POWER SUPPLY CORD FROM THE OUTLET WHENEVER
4. Defective PCB Replace PCB nection between assembly assembly CN1 connector and PCB L No continuity Loose connection gt utt eI assembly ignty 2 Blower motor or oven lamp do not turn on Check blower T Abnormal motor porma Check oven lamp Abnormal Normal Defective blower motor Replace blower motor Defective oven lamp Replace oven lamp TROUBLE 4 Oven seems to be operating but little heat is produced in oven load CONDITION CHECK RESULT CAUSE REMEDY Output is low Check the Lower than 9096 of Decrease in power Ix Suggest customer power source rating voltage source voltage contact local voltage with load electric power utility co or Normal qualified electrician Disconnect the Defective PCB Replace PCB wire leads from assembly assembly relay 3 5 or relay 4 6 and check e N ormal on and off time with multitester X Measure the ROCHE Defective Replace output power magnetron 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
5. LGE Internal Use Only SERVICE INFORMATION TOOLS AND MEASURING INSTRUMENTS NECESSARY TOOLS Tools normally used for TV servicing are sufficient Standard tools are listed below Diagonal pliers Long nose pliers Phillips screwdriver Flat blade screwdriver Wrench size 5mm Nutdriver size 5mm Adjustable wrench Soldering iron Solder Vinyl insulation tape Polishing cloth MICROWAVE LEAKAGE TEST CAUTIONS Be sure to check microwave leakage prior to servicing the oven if the oven is operative prior to servicing The service personnel should inform the manufacturer importer or assembler of any certified oven unit found to have a microwave emission level in excess of 5 mW cm and should repair any unit found to have excessive emission levels at no cost to the owner and should ascertain the cause of the excessive leakage The service personnel should instruct the owner not to use the unit until the oven has been brought into compliance If the oven operates with the door open the service personnel should Tell the user not to operate the oven Contact the manufacturer and CDRH Center for Devices and Radiological Health immediately NOTE Address on CDRH Office of Compliance HFZ 312 Center for Devices and Radiological Healthe 1390 Piccard Drive Rockville MD 20850 The service personnel should check all surface and vent vent openings for microwave leakage Check for m
6. Magnetron LGE Internal Use Only G REMOVING THE BOTTOM STIRRER FAN MOTOR 1 Lay the unit down on its back 2 Remove the screw securing the base cover 3 Disconnect the leadwire from the stirrer fan motor terminals 4 Remove the screw securing the stirrer fan motor to the oven cavity ASS Y 5 After repairing the motor replace the removed base cover 6 The taptite screw shall be used when a turntable motor cover is secured with a screw NOTE 1 Remove the wire lead from the stirrer fan motor VERY CAREFULLY 2 Be sure to grasp the connector not the wires when removing Base cover Taptite Screw Wire Leads S Stirrer Fan Motor Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes HIGH VOLTAGE TRANSFORMER REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the lead wire from magnetron high voltage transformer and capacitor 3 Remove the screw holding the high voltage transformer to the baseplate BLOWER MOTOR ASSEMBLY REMOVAL 1 Discharge the leadwire from blower 2 Remove the two screws holding the blower motor bracket to the upper plate 3 Remove the screw holding the blower motor bracket to the back cover 4 Romove the screw holding the high voltage capacitor bracket 5 Remove the screw holding the duct Ass y J HIGH VOLTAGE CAPACITOR AND DIODE REMOVAL 1 Discharge the high v
7. 6 4 LGE Internal Use Only LARCH BOARD PARTS Copyright 2009 LG Electronics Inc All right reserved 6 5 LGE Internal Use Only Only for training and service purposes EV INTERIOR PARTS Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes 6 6 LGE Internal Use Only EV BASE PLATE PARTS LGE Internal Use Only 26 7 Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes P No 05869702
8. Copyright O 2009 LG Electronics Inc All right reserved Only for training and service purposes 5 14 LGE Internal Use Only TROUBLE 5 No microwave oscillation even though oven lamp and blower motor run Display operates properly CONDITION CHECK RESULT CAUSE REMEDY No microwave Disconnect the No continuit Defective PCB Replace PCB oscillation wire leads from y assembly assembly relay 3 5 or relay 4 6 and check continuity of relay 3 5 gt Continuity or relay 4 6 Operate the unit Check high vol Defective high Replace high L tage transformer pene voltage voltage transformer transformer Normal high vol vel Abnormal Defective high Replace high tage capacitor voltage capacitor voltage capacitor Normal Check high vol Defective high Replace high tage diode Abnormal voltage diode voltage diode Normal magnetron gt Abnormal Defective magnetron Replace magnetron NOTE 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 When removing the magnetron be sure to install the magnetron gasket in the correct posit
9. Display message for 24 hours every 90 days Copyright O 2009 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only SCHEMATIC DIAGRAM SCHEMATIC DIAGRAM Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes 4 7 BTM MGT BTM PRIMARY NOISE FILTER ASSEMBLY FUSE HOLDER INTERLOCK EAT WITCH 250V 15A Bie aL HV CIRCUIT 2 PLACES SET FUSE TOP PRIMARY INTERLOCK RD M SWITCH c CIRCUIT gt 250V 15A NO PROTECTOR o o BTM INTERLOCK uc A9 5 FUSE MONITOR a o lt gt 2 BK SWITCH iz gt RE gt 4 wl BK go OVEN H Zz 5 WH e m wi rS ERU j ca Hs Ed 55 55 Ze 00 a CAPACITOR Jd m TOP INTERLOCK i T MONITOR o L 0 0 WH SWITCH 2 WH NC im ig BL te ee
10. Measure the resistance Ohm meter scale Rx1000 Terminal to terminal Normal Momentarily indicates several ohms and then gradually returns to infinite Measure the resistance Ohm meter scale Rx1000 Terminal to case Normal Infinite HIGH VOLTAGE DIODE NOTE Some inexpensive meters may indicate infinite resistance in both direction LGE Internal Use Only Measure the continuity Forward Ohm meter scale Rx10000 X Normal Continuity Abnormal Infinite Measure the continuity Reverse Ohm meter scale Rx10000 5 9 Normal Infinite Abnormal Continuity Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes COMPONENTS TEST PROCEDURE RESULTS 208V RELAY 4 RELAY 6 Check for continuity of relay 3 an 220 240V RELAY 3 RELAY 5 ohm meter Remove wire leads from relay 2 and operate the unit Tn 3 sec 4 sec 5 sec 6 sec 7 sec 8 sec 9 sec 10 sec 11 sec 12 sec BLOWER MOTOR Measure the resistance Wire leads removed Ohm meter scale R x 100 Normal Approx 208V 28 31 ohm 220 240V 31 35 ohm Abnormal Infinite or several K ohm STIRRER Measure the resistance MOTOR Ohm meter scale R x 1 Wire leads removed Normal Approx 12 14 kohm Abnormal Infinite or several ohm NOTE MICROWAVE LEAKAGE TEST
11. on the exterior Put the oven on a counter table or shelf that is strong enough to hold the oven and the food and utensils you put in it The control panel side of the oven is the heavy side Use care when handling Do not block the vent and the air intake openings Blocking vent or air intake openings can cause damage to the oven and poor cooking results Make sure the microwave oven legs are in place to ensure proper air flow The oven should not be installed in any area where heat and steam are generated because they may damage the electronic or mechanical parts of the unit Do not install the oven next to a conventional surface unit or above a conventional wall oven Use microwave oven in an ambient temperature less than 104 F 40 C Place the microwave oven as far away as possible from TV RADIO COMPUTER etc to prevent interference Place the microwave oven on a stardy and flat surface A Allow at least 11 2 inches 3 81 centimeters of clearance around top and sides of equipment Proper air flow around equipment cools electrical components With restricted air flow oven may not operate properly and life of electrical parts is reduced B Allow at least 3 inches from door front to edge of Copyright O 2009 LG Electronics Inc right reserved countertop to avoid accidental tipping of oven Only for training and service purposes GROUNDING INSTRUCTIONS For persona
12. to enter desired cooking time For example to heat for 2 minutes 30 seconds press 2 3 and 0 pads 5 Press desired power level pad to change power level f a power level pad is not pressed oven defaults to 100 power For example pressing MEDIUM 50 pad sets oven to 50 power Display shows current power level if other than 100 power 6 Press START pad to save new heating time and power level in oven memory Repeat step 3 6 to program additional pads 7 Press STOP RESET pad or close oven door to exit programming mode LGE Internal Use Only Multiple Heating Stages Follow instructions below to program oven to perform 3 consecutive heating cycles without interruption 1 Open oven door f door is closed or STOP RESET pad is pressed before finishing programming sequence oven exits programming mode 2 Press pad 1 for approximately 5 seconds After 5 seconds signal sounds 3 Press desired number pad Display shows heating time and preprogrammed number 4 Press number pads to enter desired cooking time For example to heat for 2 minutes 30 seconds 5 Press desired power level pad to change power level f a power level pad is not pressed oven defaults to 100 power For example pressing MEDIUM 50 pad sets oven to 50 power Display shows current power level if other than 100 percent power 6 Press TIME ENTRY pad Display briefly shows STAGE 2 Then cook time and powe
13. to top primary switch and relay 3 208V relay 4 and the btm primary switch and realy 5 208V relay 6 Stirrer fan rotates BTM PRIMARY INTERLOCK SWITCH 0 0 FUSE 0 0 9 7 TOP PRIMARY 731 INTERLOCK SWITCH BIM INTERLOCK 7 HV INTERLOCK MONITOR TRANSFORMER MONITOR TRANSFORMER SWITCH 9 19 PIE e SECONDARY TY INTERLOCK RELAY 3 RELAY 5 SWITCH MICOM CONTROLLER The fan motor rotates and cools the magnetron by blowing the air coming from the intake on the base plate The air is also directed into the oven to exhaust the vapor in the oven through the upper plate Cooking time starts counting down 3 3 volts AC is generated from the filament winding of the high voltage transformer This 3 3 volts is applied to the magnetron to heat the magnetron filament through two noise preventing choke coils Copyright O 2009 LG Electronics Inc right reserved Only for training and service purposes A high voltage of approximately 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 contro
14. ENT DIRECTION MONITOR SWITCH PRIMARY SWITCH SECONDARY SWITCH LGE Internal Use Only INTERLOCK CONTINUITY TEST WARNING FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION EMISSION REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS TYPE NO SZM V 16 FD 63 OR V 16 3C 25 FOR PRIMARY SWITCH TYPE NO SZM V 16 FD 62 OR V 16 2C 25 FOR MONITOR SWITCH TYPE NO SZM V 16 FD 63 OR V 16 3C 25 FOR SECONDARY SWITCH PRIMARY INTERLOCK SWITCH TEST When the door release button is depressed slowly with the door closed an audible click should be heard at the same time or successively at intervals When the button is released slowly the latches should activate the switches with an audible click If the latches do not activate the switches when the door is closed the switches should be a adjusted in accordance with the adjustment procedure Disconnect the wire lead from the primary switch Connect the ohmmeter leads to the common COM and normally open NO terminal of the switch The meter should indicate an open circuit in the door open condition When the door is closed the meter should indicate a closed circuit When the primary switch operation is abnormal make the necessary adjustment or replace the switch only with the same type of switch COMPONENTS TEST PROCEDURE B SECONDARY INTERLOCK SWITCH TEST Disconnect the wire lead from the secondary Switch Connect the ohmmeter leads to the common
15. Full power throughout the cooking time 7096 Med High 5096 Med Low 2096 Low approx 7096 of Full power approx 5096 of Full power approx 2096 of Full power Rating Label Location Back Side Accessories Time chart This microwave oven is designed for commercial use only It is not recommended for buelt in Installation Copyright 2009 LG Electronics Inc All right reserved 1 1 LGE Internal Use Only Only for training and service purposes 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 DO NOT operate on a 2 wire extension cord during repair and use NEVER TOUCH any oven components or wiring during operation BEFORE TOUCHING any parts of the oven always remove the power plug from the outlet For about 30 seconds after the oven stops an electric charge remains in the high voltage capacitor When replacing or checking you must discharge the high voltage capacitor by shorting across the two terminals with an insulated screwdriver 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 cavit
16. Interrupting Operation 20 sec Open oven door to interrupt operation Oven fan continues to operate Close door and press START pad to resume oven operation Press STOP RESET pad to interrupt operation Display continues to show countdown time Press START pad to resume oven operation and countdown timing k 40 sec 1 min 1 30 min 2 min 3 min Canceling Mistakes 4 min f oven is operating press STOP RESET pad once to stop oven then again to clear display f oven door is open and time shows in display close oven door and press pad to clear display 6 min I 8 2 3 4 5 6 7 8 9 0 10 Operating Preprogrammed Pads Manual Time Entry Oven has 10 20 preprogrammed number pads Manual Time Entry feature allows the operator to Instructions are written for factory programmed ovens enter time and power levels and heat without Ovens that are reprogrammed can respond differently changing the preprogrammed pads than described below 1 Open oven door place food in oven and close 1 Open oven door place food in oven and close door oven door Display shows READY If pad is not pressed in 30 seconds open and f pad is not pressed in 30 seconds open and close oven door again close oven door again 2 Press desired number pad 2 Press TIME ENTRY pad Oven operates
17. 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 Copyright O 2009 LG Electronics Inc right reserved Only for training and service purposes 5 10 LGE Internal Use Only TROUBLE SHOOTING WHEN YOU GET A COMPLAINT FROM YOUR CUSTOMER EVALUATE THE COMPLAINT CAREFULLY IF THE FOLLOWING SYMPTOMS APPLY PLEASE INSTRUCT THE CUSTOMER IN THE PROPER USE OF THE MICROWAVE OVEN THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL CAUTIONS panel 1 Check grounding before checking for trouble 2 Be careful of the high voltage circuit 3 Discharge the high voltage capacitor See page 2 1 4 When checking the continuity of the switches or of the high voltage transformer disconnect one lead wire from these parts and then check continuity with the AC plug removed To do otherwise may result in a false reading or damage to your meter 5 Do not touch any part of the circuit on the PCB since static electric discharge may damage this control Always touch yourself to ground while working on this panel to discharge any static charge built up in your body Micom model only CONDITION CAUSE Microwave oven does not work Inserting many plugs into one outlet and using them at the same time blown fuse or breaker
18. Microwave oven plug is not inserted tightly Output power is too low Low AC input voltage gt REMEDY Avoid using other electrical appliances when you use the microwave oven Insert microwave oven plug securely Use the microwave oven at adequate line voltage Food temperature is too low gt Sparks occur This may not be a defect It is possible that the food should be cooked for a longer time period Using metallic ware and __ allowing it to touch the oven wall Do not use metallic ware for cooking except that noted in the cooking guide Ceramic ware trimmed in Uneven cooking Do not use any type of cookware with metallic trimming LGE Internal Use Only gt gold or silver powder is used Inconsistent intensity of gt microwave by their characteristics 1 Use plastic wrap or lid 2 Stir once or twice while cooking soup cocoa or milk etc Display CALL SERVICE This may be cause incomplete connect to H V transformer 5 11 Copyright O 2009 LG Electronics Inc All right reserved Only for training and service purposes TROUBLE 1 The following visual conditions indicate a probable defective control circuit Incomplete segments Segment missi
19. REMOVING THE OUTER CASE FROM THE UNIT PROCEED WITH THE TEST ONLY AFTER DISCHARGING THE HIGH VOLTAGE CAPACITOR AND REMOVING THE WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER SEE PAGE 2 1 2 ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD 1 LITER OF WATER IN CONTAINER IN THE OVEN COMPONENTS TEST PROCEDURE RESULTS HIGH VOLTAGE TRANSFORMER Wire leads removed FILAMENT WINDING SECONDARY TERMINAL PRIMARY TERMINAL 1 Measure the resistance Ohm meter scale Rx1 and Rx100 208V 220 240 V Primary winding Approx 0 8 1 0 0 9 1 1 ohm Secondary winding Approx 70 800hm 70 80 ohm Filament winding Less than 1 ohm Measure the resistance Ohm meter scale Rx1000 Primary winding to ground Normal Infinite Filament winding to ground Normal Infinite MAGNETRON Wire leads removed Measure the resistance Ohm meter scale Rx1 Normal Less than 1 ohm Filament terminal Measure the resistance Ohm meter scale Rx1000 Normal Infinite Filament to chassis Copyright 2009 LG Electronics Inc All right reserved 5 8 LGE Internal Use Only Only for training and service purposes COMPONENTS TEST PROCEDURE RESULTS 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 HIGH VOLTAGE CAPACITOR
20. TEST ded tnnt ibd 5 1 MEASUREMENT OF MICROWAVE POWER OUTPUT e nnn een 5 3 DISASSEMBLY AND ADJUSTMENT tanen tto rt int teat testante dana 5 3 INTERLOCK CONTINUITY 5 7 COMPONENT TEST PROCEDURE 5 8 TROUBLE SHOOTING 5 11 EXPLODED VIEW TESE EE ESE ESE EE OASE TE 6 1 Replacement Parts 7 1 LGE Internal Use Only Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes SPECIFICATIONS ITEM DESCRIPTION MODEL RFS12MPSB RFS12SW2B Power Requiremen 120 V 60 Hz 2000 watt 18 A Single phase 3 wire grounded Power Output 1200 watt full microwave power IEC60705 Microwave Frequency 2450 MHz Magnetron 2M246 Timer 0 60 min Outside Dimensions 213 4 W x 141 4 x 177 e D Cavity Dimensions 141 4 W x 87 2 x 163 8 D Net Weight 64 Ibs approx Shipping weight 71 Ibs approx Control Complement Touch Control System Clock 00 60 Microwave Power for Variable Cooking Power level
21. and time counts down Display shows 00 00 3 Oven stops heating and oven signal sounds when 3 Press number pads to nter desired cooking time heating timing elapses For example to heat for 2 minutes 30 seconds press 2 3 and 0 pads 4 Press desired power level pad to change power level f a power level pad is not pressed oven defaults to 100 power Operating QTY 2X Pads For xample pressing MEDIUM 50 pad sets oven to 50 power 1 Press Ea Pad Display shows current power level if other than 100 percent power 2 Press desired number pad 5 Press STAHT pad E Oven operates and time counts down krampar press P zb 6 Oven stops heating and oven signal sounds when heating timing elapses Copyright 2009 LG Electronics Inc All right reserved 4 4 LGE Internal Use Only Only for training and service purposes PROGRAMMING Preprogrammed Number Pads Oven has 10 preprogrammed number pads Follow instructions below to program heating times and power levels for customized cooking 1 Open oven door f door is closed or STOP RESET pad is pressed before finishing programming sequence oven exits programming mode 2 Press and hold pad 1 for approximately 5 seconds After 5 seconds signal sounds Display shows PROGRAM indicating program mode 3 Press desired number pad Display shows heating time COOK LEVEL and power level if other than 100 percent power 4 Press number pads
22. ave leakage check to verify compliance with the Federal Performance Standard should be performed on each oven prior to release to the owner Copyright 2009 LG Electronics Inc All right reserved LGE Internal Use Only Only for training and service purposes CONTENTS Page SAFETY PRECAUTIONS Leere Inside front cover GRE CIFIC A TIONG eniro ken Eon UXOR uxXEUEREn MER EpRSR YER 1 1 CAUTIONS O P A 4 4 A A 4 4 A A 4 A4 46A4AA A 4 4 4A4A 4A A 2 1 INSTALLATIONS wa tein Ie a Sd tutu Ea Et M n ut MEI UI ADM DEN DM CES 3 1 OPERATING INSTRUCTIONS vibes e vipera estes usada 4 1 FEATURES n 4 1 CONTROL tetti etant tine tanta kann b tna ha ee ir aka abide enant etena t ha tags 4 1 COOKING DISPLAYS engan 4 3 OPERATION M 4 4 PROGRAMMING etate tenetur tna than tta rh nata tal td phase eara tat detta a darte aeta tana tnl 4 5 SCHEMATIC DIAGRAM 4 7 CIRCUIT DESCRIPTION 2ni un cuneata tnnt rate 4 8 SERVICE INFORMATION enu Mud E NU XEM En CUPS UU 5 1 TOOLS AND MEASURING INSTRUMENTS tinent tata te theta 5 1 MICROWAVE LEAKAGE
23. brane as specified membrane membrane programmed assembly and assembly assembly check operation 3 Display shows a Ly Still have trouble Defective PCB Replace PCB number or figure assembly assembly 5 12 LGE Internal Use Only and no input is accepted TROUBLE 2 Oven does not operate at all Display window does not display any figures NOTE All these switches must be replaced at the same time voltage capacitor CONDITION CHECK RESULT CAUSE REMEDY gt Check continuit T Malfunction of the Replace fuse of monitor Continuity monitor switch primary monitor dary switch with ar door closed No continuity RELAY RY3 5 or RY4 6 of P C B Replace fuse Assembly _ Check continuity Continuity L Shoned contactat Replace Of primary the primary switch ed switch with door opened No continuity RELAY RY3 5 or RY4 6 of P C B Assembly L Check continuity Continuity l Malfunction of Replace fuse bee inni secondary switch nca and door opened No continuity RELAY RY3 5 or RY4 6 of P C B Assembly Disconnect one Defective high volt Replace high volt side of th
24. e wire Pence Plows again age transformer age transformer lead connected from transformer to the high voltage Normal capacitor and operate the unit Measure to Normal Set is good condition resistance high defective fuse only voltage capacitor refer to page 5 9 Abnormal Defective high Replace high voltage capacitor Refer to page 5 7 5 8 2 Fuse does not blow LGE Internal Use Only cord Defective thermostat Replace thermostat Check continuity No continuity gt of thermostat Continuity Check continuity ate o of power supply No continuity 5 13 Defective power supply cord Replace power supply cord Copyright O 2009 LG Electronics Inc right reserved Only for training and service purposes program times are set and START pad is touched TROUBLE 3 Display shows all figures set but oven does not start cooking while desired CONDITION CHECK RESULT CAUSE REMEDY 1 Setting time gt Check continuity No continuity Defective Replace does not count of secondary secondary switch secondary switch down when switch with touching START door closed L Continuity pad L Check the con Continuity gt
25. icrowave leakage after every servicing The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 4 mW cm Always start measuring of an unknown field to assure safety for operating personnel from radiation leakage LGE Internal Use Only NECESSARY MEASURING INSTRUMENTS TESTER VOLTS DC AC Ohmmeter Microwave survey meter Holaday HI 1500 HI 1501 Narda 8100 8200 Inch scale 600 cc non conductive material beaker glass or plastic inside diameter approx 8 5 cm 3 2 in Cylindrical and made of borosilicate glass vessel max thickness 3 mm outside diameter approx 190mm height approx 90mm Glass thermometer 100 C or 212 F 1 deg scale MEASURING MICROWAVE ENERGY LEAKAGE Pour 275 15 of 20 5 C 68 9 F water in a beaker which 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 bcm 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 surface being measured Move probe along shaded area Probe scanning speed Less than 2 5 cm sec 1 in sec Copyright O 2009 LG E
26. ion and in good condition Output is full power when you set lower power level LGE Internal Use Only Disconnect the wire leads from relay 3 5 or relay 4 6 and check continuity of relay 3 5 or relay 4 6 Operate the unit Abnormal Defective PCB assembly Replace PCB assembly 5 15 Copyright O 2009 LG Electronics Inc right reserved Only for training and service purposes EV EXPLODED VIEW INTRODUCTION MODEL RFS12MPSB RFS12SW2B OVEN CAVITY PARTS INTERIOR PARTS BASE PLATE PARTS DOOR PARTS LATCH BOARD PARTS CONTROL PANEL PARTS Copyright 2009 LG Electronics Inc All right reserved 6 1 LGE Internal Use Only Only for training and service purposes EV DOOR PARTS A Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes 6 2 LGE Internal Use Only EV CONTROL PANEL PARTS Copyright 2009 LG Electronics Inc All right reserved 6 3 LGE Internal Use Only Only for training and service purposes EV OVEN CAVITY PARTS Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes
27. it of 4 mW cm with a 275 ml water LI TIT 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 door has no play between the inner door surface and oven frame assembly If the door assembly is not mounted properly microwaves may leak from the clearance between the door and the oven Copyright O 2009 LG Electronics Inc All right reserved 5 4 LGE Internal Use Only Only for training and service purposes MAGNETRON REMOVAL 1 Disconnect the lead wire from the magnetron 2 Remove the duct ASS Y 3 Carefully remove the mounting screws holding the magnetron and the waveguide 4 Remove the magnetron ASS Y until the tube is clear from the waveguide NOTE 1 When removing the magnetron make sure its dome does not hit any adjacent parts or it may be damaged 2 When replacing the magnetron be sure to install the magnetron gasket in the correct position and be sure that the gasket is in good condition 3 After replacing the magnetron check for microwave leakage with a survey meter around the magnetron Microwave energy must be below the limit of 5 mW cm With a 275 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
28. l 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 WARNING Improper use of the grounding plug can result in a risk of electric shock Do not under any circumstances cut or remove the third ground prong from the power cord plug PREFERRED METHOD ENSURE PROPER GROUND EXISTS BEFORE USE LGE Internal Use Only OPERATING INSTRUCTIONS FEATURES Window Door Screen Electronic Control Safety Door Lock System CONTROL PANEL Display Some items in display can be seen but will not glow COOK 02 HEATER T table OFF Pads TIME ENTRY Use to enter heating time without changing preprogrammed number pads Pads 1 0 Use to begin heating with preprogrammed times and power levels or to enter times for Manual Time Entry cooking HOLD 096 Use to select power level Oven can heat at DEFROST 20 full or reduced power If oven power level is 50 set to 0 oven does not heat for MED HI 70 programmed time If no power level is selected oven operates 100 power STOP RESET Use to exit programming mode and stop cooking during cooking cycle START Use to start Manual Time Entry program or resta
29. lectronics Inc right reserved Only for training and service purposes MEASUREMENT WITH OUTER CASE REMOVED When you replace the magnetron measure for microwave energy leakage before the outer case is installed and after all necessary components are replaced or adjusted Special care should be taken in measuring the following parts Circled area of Fig below Around the magnetron The waveguide WARNING AVOID CONTACTING ANY HIGH VOLTAGE PARTS MEASUREMENT WITH A FULLY ASSEMBLED OVEN After all components including the outer case are fully assembled measure for microwave energy leakage around the door viewing window the exhaust opening and air inlet openings Microwave energy leakage must not exceed the values prescribed below NOTE Leakage with the outer case removed less than 5 mW cm sq Leakage for a fully assembled oven Before the latch switch primary is interrupted with the door in a slightly opened position less than 2 mW cm sq Copyright O 2009 LG Electronics Inc All right reserved 5 2 Only for training and service purposes NOTES WHEN MEASURING Do not exceed meter full scale deflection The test probe must be moved no faster than 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 ha
30. ller controls the ON OFF time of relay 3 and relay 5 208V relay 4 amp relay 6 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 3 is 12 WHEN THE DOOR IS OPENED DURING COOKING Between the btm primary switch and relay 5 208V relay 6 and top primary switch and relay 3 208V relay 4 cut off the primary winding voltage of the high voltage transformer ON OFF of relay 3 relay 5 208V relay 4 and relay 5 is coupled electrically with opening and closing of the secondary switch When the door is opened the secondary switch is opened and when the door is closed the secondary switch is closed The cooking time stops counting down Relay stops functioning As the door is opened if the contact of top primary switch and relay 3 208V relay 4 and the btm primary switch and relay 5 208V relay 6 and or secondary switch fail to open the fuse opens due to the large current surge caused by the monitor switch activation which in turn stops magnetron oscillation BTM PRIMARY INTERLOCK FUSE SWITCH O O FUSE 0 06 TOP PRIMARY INTERLOCK SWITCH BIM INTERLOCK TOP HV INTERLOCK BTM MONITOR TRANSFORMER MONITOR TRANSFORMER SWITCH D SWITCH e OT oO e SECONDARY INTERLOCK RELAY 3 RELAY 5 SWITCH MICOM CONTROLLER
31. ndle 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 NOTIFICATION AFTER MEASUREMENT After adjustment and repair of any microwave energy interruption or microwave energy blocking device record the measured values for future reference Also enter the information on the service invoice The microwave energy leakage should not be more than 4 mW cm sq after determining that all parts are in good condition functioning properly and genuine replacement parts which are listed in this manual have been used At least once a year have the electromagnetic energy leakage monitor checked for calibration by its manufacturer LGE Internal Use Only MEASUREMENT OF MICROWAVE POWER OUTPUT 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 The water is contained in a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm and an outside diameter of approximately 190 mm The oven and the empty vessel are at ambient temperature prior to the start of the test The initial temperature 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 i
32. ng Partial segment missing Digit flickering NOTE Slight flickering is normal Colon does not turn on or blink A distinct change in the brightness of one or more numbers in display One or more digits in the display are not lighting Display indicates a number different from one touched for example key in 5 and 3 appears in the display Specific numbers for example 7 or 9 will not display when key pad is touched Display does not count down with time blinking or up with clock operation Display obviously jumps in time while counting down Display counts down too fast while cooking Each indicator light does not turn on after setting cooking cycle Display time of day does not reappear when cooking is finished different from one touched 4 Random programming when touching other pads 5 Display is fixed at some figure and can not accept any input Copyright O 2009 LG Electronics Inc right reserved Only for training and service purposes CONDITION CHECK RESULT CAUSE REMEDY 1 No input can be Check the conn confit Defective PCB Replace PCB programmed ection between y assembly assembly membrane key assembly and ad Loose Connect them PCB assembly see connection tightly 2 Some inputs Replace key Everything works Defective key Replace key cannot be mem
33. oltage capacitor 2 Disconnect the leadwire from high voltage capacitor 3 Remove the screw holding the high voltage diode earth screw 4 Remove the screw holding the high voltage capacitor bracket H V capacitor bracket H V Transformer Copyright O 2009 LG Electronics Inc right reserved Only for training and service purposes 5 6 K INTERLOCK 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 latch b oard 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 this adjustment Make sure that the latch moves smoothly after adjustment is completed and that the screws are tight Make sure the primary monitor and secondary switches operate properly by following the continuity test procedure following the continuity test procedure ADJUSTM
34. r level for stage show in display Repeat steps 5 6 to create additional stages 7 Press START pad to save new heating time and power level in oven memory 8 Press STOP RESET pad or close oven door to exit programming mode Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes User Options Follow the instructions below to customized the microwave oven s operation End of cycle signal maximum heating time and other options can be changed to meeting your cooking needs 1 Open oven door f door is closed or STOP RESET pad is pressed before finishing programming sequence oven exits programming mode 2 Press and hold pad 2 for approximately 5 seconds After 5 seconds signal sounds Display shows OPTION 3 Press number pad that matches desired option OP represents optional program mode first number represents option number and second number represents functions currently selected for option Numbered Pads Display 4 Press START pad to advance to next option See table for options 5 Press number pad 0 1 3 to change option 6 Press START pad to save changes Repeat steps 4 6 to change additional options 7 Press STOP RESET pad or close oven door to exit programming mode Pad Option Number Selected Optional Program Indicator Options Factory Settings in Bold 1 OP 10 3 second beep End of Cycle Beep OP 11 Continuo
35. rt interrupted cooking cycle Use to advance to next user option Use to save times and power levels when programming pads RFS12MPSB LGE Internal Use Only QTY2x Use to automatically increase the programmed time for double quantities 4 1 Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes OPERATING INSTRUCTIONS FEATURES Window Door Screen Electronic Control Safety Door Lock System CONTROL PANEL T DEFROST 20 MEDIUM 50 95 Heat 2 5 ths meatballs sauce 2 3 pouch Display Some items in display can be seen but will not glow RFS12SW2B Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes Pads TIME ENTRY Use to enter heating time without changing preprogrammed number pads Pads 1 0 Use to begin heating with preprogrammed times and power levels or to enter times for Manual Time Entry cooking HOLD 0 Use to select power level Oven can heat at DEFROST 20 full or reduced power If oven power level is MEDUIM 50 set to 0 oven does not heat for MED HI 70 programmed time If no power level is selected oven operates at 100 power STOP RESET _ Use to exit programming mode and stop cooking during cooking cycle START Use to start Manual Time En
36. s immediately placed on the center of the ceramic plate 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 A T of 10 2 K is measured where T is the time in seconds and AT is the temperature rise The initial and final water temperatures are selected so that the maximum difference between the final water temperature and the ambient temperature is 5 K The microwave power output P in watts is calculated from the following formula 4187 x AT 0 55 X T2 To XM T Tz Temperature after heating To 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 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 removal of heat P CERAMIC PLATE ow WATER LOAD DISASSEMBLY AND ADJUSTMENT A OUTER CASE REMOVAL 1 Disconnect the power supply cord from the outlet 2 Remove the screws from the rear of the case The outer case must be moved backward to be lifted off B POWER SUPPLY CORD 1 Remove the outer case 2 Disconnect two terminals and remove one screw of the ground terminal C CONTROL PANEL ASSEMBLY 1 Open the door 2 Remove
37. the screw for securing the control panel 3 Disconnect the leadwire from RELAY of the PCB SUB ASS Y 4 Disconnect the leadwire from connector CN1 of the PCB SUB ASS Y 5 Lift up and pull out control panel assembly carefully from the cavity CAUTION DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE SERVICING refer to page 2 1 LGE Internal Use Only 5 3 Remove the screw securing screw Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes PCB ASSEMBLY REMOVAL Remove choke cover 1 Remove the control panel assembly from the cavity Refer to control panel assembly removal on previous page 2 Remove screws which hold the PCB SUB ASS Y to the control panel 3 Disconnect the flat cable from the PCB SUB ASS Y and take off the PCB SUB ASS Y PCB Sub Asm Control Panel Remove door assembly Door seal plate E DOOR ASSEMBLY REMOVAL 1 Open the door 2 Remove the choke cover cap very carefully with a flat blade screwdriver CAUTION Be careful not to damage door seal plate by screwdriver 3 Lift up and push the door NOTE 1 After replacing 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 lim
38. try program or restart interrupted cooking cycle Use to advance to next user option Use to save times and power levels when programming pads 4 2 LGE Internal Use Only Cooking Cooking Displays Shows when power is connected to oven Open and close door to clear READY shows when oven control will accept entries Appears after oven door is opened and closed 20 CI 33 33 shows heating time When more than 1 heating stage is 7 7 71 71 71 programmed total time for all stages displays 7 7 shows when oven is operating MELLE am 20 indicates the microwave power level used If power level does not show oven is heating at 100 power Programming Displays L1 L1 Indicates programming mode See Programming section of LI LI manual for programming procedure Indicates programming user options mode See User Options section of manual for programming procedure LGE Internal Use Only 4 3 Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes Operation Preprogrammed Times and Cook Level A CAUTION All preprogrammed pads arrive set at full power To avoid fire do not dry newspapers or clothes in Option Single Digit Option Double Digit microwave oven Heating Pads Heating Pads Heating Times Times Times
39. us beep until door is opened OP 12 5 beep bursts until door is opened 2 OP 20 Eliminates beep Speaker Volume OP 21 Sets volume to low OP 22 Sets volume to medium OP 23 Sets volume to high 3 OP 30 Prevents beep when pad is pressed Key Beep OP 31 Allows beep when pad is pressed 4 OP 40 15 seconds after oven door is opened keyboard disabled Keyboard Enable OP 41 30 seconds after oven door is opened keyboard disabled Window OP 42 1 minute after oven door is opened keyboard disabled OP 43 2 minutes after oven door is opened keyboard disabled 5 OP 50 Prevents adding heating time while oven is heating Add Time During OP 51 Allows heating time to be changed while oven is heating when a memory pad Heating is pressed 6 OP 60 Allows oven to resume heating time countdown after door is opened during Reset Door Open cycle OP 61 Cancels heating time count down after door is opened during cycle 7 OP 70 Allows 60 minutes of heating time some models some models OP 71 Allows 10 minutes of heating time Maximum Heating Time 8 OP 80 Allows use of preprogrammed pads only Manual Operation OP 81 Allows use of manual time entry and preprogrammed pads 9 OP 90 Allows 10 0 9 preprogrammed pads some models OP 91 Allows 100 00 99 preprogrammed pads Double Digit Operation 0 OP 00 Do not display message Clean Filter Message OP 01 Display message for 24 hours every 7 days OP 02 Display message for 24 hours every 30 days OP 03
40. y NEVER put iron tools on the magnetron NEVER put anything into the latch hole and the interlock switches area LGE Internal Use Only MICROWAVE RADIATION Personnel should not be exposed to the microwave energy which may radiate from the magnetron or other microwave generating device if it is improperly used or connection All input and output microwave connections waveguide flange and gasket must be secure never operate the device without a microwave energy absorbing load attached Never look into an open waveguide or antenna while the device is energized Proper 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 ANTENNA Gasket COOLING FIN FILAMENT MAGNETRON TERMINALS CHASSIS GROUND MAGNETRON THE OVEN IS TO BE SERVICED ONLY BY PROPERLY QUALIFIED SERVICE PERSONNEL Copyright 2009 LG Electronics Inc All right reserved Only for training and service purposes INSTALLATION BEFORE YOU BEGIN READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY INSTALLING 1 Empty the microwave oven and clean inside it with a soft damp cloth Check for damage such as misaligned door damage around the door or dents inside the cavity or
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