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MICROWAVE OVEN SERVICE MANUAL

1. touching START Continuity pad Check the con y Continuity Defective PCB Replace PCB nection between assembly assembly CN1 connector gt and PCB No continuity Loose connection connect hem assembly tightly 2 Fan motor or Check fan motor Abnormal Defective fan motor gt 7 Replace fan motor oven lamp do not turn on Check oven lamp Abnormal Defective oven lamp 39 Replace oven lamp Normal TROUBLE 4 Microwave oven seems to be operating but little heat is produced in oven load CONDITION CHECK RESULT CAUSE REMEDY Lower than 90 of Decrease in power Suggest customer Output is low gt Onde ihe rating voltage source voltage contact local EE with load electric power L Normal utility co or qualified electrician a Disconnect the ABnamal Defective PCB Replace PCB wire leads from assembly assembly relay 2 and check on and off Normal time with multitester Measure the Abnormal 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 temperatu
2. BASE PLATE PARTS LATCH BOARD PARTS DOOR PARTS TOASTER PARTS 32 DOOR PARTS 33 OVEN CAVITY PARTS 34 LATCH BOARD PARTS 35 OVEN INTERIOR PARTS 36 BASE PLATE PARTS 37 TOASTER PARTS 38 SCHEMATIC DIAGRAM OF P C B 43 E 7 5 a 8 b u 8 8 7 vor _ _ 7 u u 7 u 8 8 7 gt K i 7 INPUT 5 TMPB7CH47U 535 8110 100 9 5 44 QFD 06 111 CN1 3 96mm CN4 R20 re 22k 29 05 7 8112 7 NE 6170W1G004A col m2 em 2 1 R 1K 9 98114 9 AL 8115 10 11 RU 11 Pot OVEN 12 8117 12 8 THERMOSTAT Poo 3 8 a a p V Disp 5V 1266 Y 3202 P72 Z 20 4 SWITCH 0121 PRIMARY p73H R121 Ae 5 2K 8 7 R122 91266 RY1_3A 250V 127 3
3. CR a a a aa a N 1 Microwave Oven TOASTER AUTO FRESH FROZEN STOP STOP CLOCK DEFROST VEGETABLE ENTREE POPCORN Ez ON 19 629 659 49 659 Gras Dis mer DONNE GEVERAGE POTATO POWER 6 7 8 9 0 START LIGHTER START A CR BER A cp a 50 O gt DISPLAY The Display includes a clock and indicators that tell you time of day cooking time settings and cooking functions selected STOP CLEAR Touch this pad to stop the oven or clear entries START Touch this pad to start all entries except the Auto Cook and Add Minute function which start automatically and to turn Child Lock on or off AUTO COOK Touch this pad to select programming food items Ez ON Touch this pad to cook at 100 cook power for 1 minute to 99 minutes 59 seconds AUTO DEFROST This pad is an accurate defrosting method for frozen meat poultry and fish up to 6 0 Ibs COOK TIME Touch this pad to set a cooking time POWER Touch this pad to set a cooking power 9 CLOCK Touch this pad to set the time of day 10 KITCHEN TIMER Touch this pad to use your microwave oven as a kitchen timer 11 NUMBER PADS Touch Number Pads to enter cooking time power level quantities or weights TOASTER CONTROL AREA desee y l
4. Normal Approximately 4 7 6 4V Normal Approximately AUTO 40 00 RESET MEM READ RELD MIN MAXHOLD Figures 14 a RESET MEM READ RELD MIN MAXHOLD Figures 14 b 21 AUTO 0 RESET MEM READ RELD MIN MAXHOLD c3 c3 PWRRST RANGE Figures 14 COMPONENTS TEST PROCEDURE RESULTS RELAY 2 Power Relay 1 Measure continuity 2 Remove the lead wires and operate oven at power level 1 through power level 10 4 sec 6 sec 8 sec 10 sec 12 sec 14 sec 16 sec 18 sec 20 sec 10 22 sec FAN MOTOR 1 Remove wire leads 2 Measure resistance Normal A Approximately 95 120 ohms B Approximately 10 25 ohms Abnormal Infinite TURNTABLE MOTOR 1 Remove wire leads 2 Measure resistance Normal 2 5 3 5 Kohms Abnormal Infinite or several ohm NOTE MICROWAVE LEAKAGE 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 BE SURE TO GRASP THE CONNECTOR NOT THE WIRES 22 B CHECKOUT PROCEDURES 1 CHECKOUT PROCEDURES FOR FUSE BLOWING CAUTION REPLACE BLOWN FUSE WITH 15 AMPERE FUSE PROBLEMS CAUSES Fuse blows immediately after the door is closed
5. PRINTED CIRCUIT BOARD mm sal V V VV VV VW gt gt CD N 11615171189 VZELVIMOL89 LL 44 DESIGI u NED BY M S MOON RANGE P NO 6870W1A193A RYS 2002 06 07 E 6871415133 J102 lt 9 030705 Apr 2003 P NO 3828W5S3065 Printed in Korea
6. pu Te cA P O 2 D30 mos 9125 gt 4148 75 43 4522 k 4 2 12V 90 Ans 092 4D93 Apes Apes 31 4148 4148 4148 4148 4148 4148 5 8839 90 3891 1892 3893 3894 1095 RY4 3A 250V sv 4 74 14 7 T4 7k 4 78 4 7 14 7 Fan pe2 21 870 47K A D Option P R71 10K Model MWO Door S W P17 5 n 841 R amp l ca TES 41 4 7K 47K 127 21 20 3772 Digital Option 8 v R73 47K Simultaneous Alternative 2 R46 11 2 151 14 5 61 TOAST Door S W 1k 35 216 5v R85 stop stort clock kitchen odd auto R44 R45 I clear timer minute defrost 4 7K 47K 20 37 I 10005 7 AHH 6802 RB IK 58 he DEO ER ES E o ono 21125 881 886 LA d d a 1K R 1020 7 8 9 O derer tighter qs RIS 16 250v 0500 8 22 39 T 882 867 Bme 60 4 46 Ed 033 WT 99 4528 power toast HTR S Hm 4148 TOAST HTR 8 23 7 883 R88 ma ma wa m III C Pos et eta Ta a 5 CN3 3 96mm P13 cast ix Monitor S W 102 dinner fresh frozen E o 6 34 1 84 889 Popeorn potato plate beverage vecetabie entree Pl Dt HV Trans jd 6841 1 0000000000 Pos 12 1 a i gt E E amp i CN2 2 5mm 2235 m 1 diz 560 0141 5V 002 b 1 6105 25166 12V H I 5130 1 P50 2 2815 877 51504 Yon 26 267 876 81501 wp 2 MAGNETRON PAE
7. 3 Remove the turntable motor cover The turntable base cover is easily removed by pinching the eight parts with a wire cutting 4 Disconnect the leadwire from the turntable motor terminals 5 Remove the screw securing the turntable motor to the oven cavity ASSEMBLY 6 After repairing the motor rotate the removed turntable motor cover 7 Fit the turntable motor cover s projecting part to the base plate slit NOTE 1 Remove the wire lead from the turntable motor VERY CAREFULLY 2 Be sure to grasp the connector not the wires when removing Turntable Motor Wire Leads Figures 11 F HIGH VOLTAGE TRANSFORMER REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from magnetron high voltage transformer and capacitor 3 Remove the screw holding the high voltage transtormer to the baseplate G FAN MOTOR ASSEMBLY REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from fan motor and high voltage capacitor 3 Remove the two screws holding the the suction guide ASSEMBLY to the oven cavity 4 Remove the two screws holding the fan motor ASSEMBLY to the suction guide ASSEMBLY H HIGH VOLTAGE CAPACITOR AND DIODE REMOVAL 1 Discharge the high voltage capacitor 2 Disconnect the leadwire from fan motor and high voltage capacitor 3 Remove the screw holding the suction guide ASSEMBLY to the oven cavity 4 Remove the screw holding the high volta
8. NOTE The additional three 3 seconds is to allow the magnetron to begin generating power b When the heating is finished stir the water again with thermometer and measure the temperature of water as T2 6 Subtract T1 from T2 this will give you the temperature rise 7 The microwave power output is within specification if the temperature rise is as shown below Temperature Rise Line Voltage Degrees F Degrees C 120 V 17 1 22 5 9 5 12 5 108 V Min 12 6 Min 7 0 8 Power output will be influenced by line voltage of power supply Consequently correct power output must be measured within 120V AC 1 Volt while unit is operating SPECIAL TIP This oven used the button head screws Button Head Torx style 2 When you remove the screws using the tamper resistant Torx driver have a pin in head 13 9 DISASSEMBLY INSTRUCTIONS IMPORTANT NOTES UNIT MUST BE DISCONNECTED FROM ELECTRICAL OUTLET WHEN MAKING REPAIRS RE PLACEMENTS ADJUSTMENTS AND CONTINUITY CHECKS WAIT AT LEAST ONE MINUTE UNTIL THE HIGH VOLTAGE CAPACITOR INTHE HIGH VOLTAGE POWER SUPPLY HAS FULLY DISCHARGED THE CAPACITOR SHOULD BE DISCHARGED BY USING INSULATED WIRE I E TEST PROBE CONNECTED TO 10KOHM RESISTOR IN SERIES TO GROUND WHEN RECONNECTING THE WIRE LEADS TO ANY PART MAKE SURE THE WIRING CONNECTIONS AND LEAD COLORS ARE CORRECTLY MATCHED ACCORDING TO THE OVERALL CIRCUIT DIAGRAM ESPECIALLY SWITC
9. SWITCH COM CONDITIONS COM NO COM NC COM DOOR OPEN 0 DOOR CLOSED NOTE Use the above switch table with circuit diagram on page 8 oo 6 OVERALL CIRCUIT DIAGRAM A SCHEMATIC DIAGRAM CN3 AC 120V 60Hz SINGLE PHASE ONLY 1VISOMY3HL M3lV3H YALSVOL O H V TRANSFORMER TOASTER MWO DOOR SECONDARY SWITCH SWITCH NOTE 1 DOOR IS OPENED 2 WIRE COLOR CHOKE FILTER Optional CONTROL MODULE BK BL Y PK BN Y 9 PIN CONNECTOR Figure 3 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 IMPORTANT FOR PROTECTION FROM MICROWAVE RADIATION FIRE ELECTRICAL SHOCK AND IMPORTANT SAFETY NOTE THE SHADED AREAS ON THIS SCHEMATIC DIAGRAM INCORPORATE SPECIAL FEATURES NOTICE SINCE THIS IS BASIC SCHEMATIC DIAGRAM THE VALUES OF COMPONENTS AND SOME PARTIAL CONNECTIONS ARE SUBJECT TO CHANGE FOR IMPROVEMENT B MATRIX CIRCUIT FOR TOUCH KEY BOARD Md pp KITCHEN i AUTO j 4 4 4 4 STOP COOK TOAST BAGEL START CLEAR TIME POWER DINNER FROZEN E Toaster Key SI 1 I I ul Figure 4 7 OPERATING PROCEDURES A OVEN CONTROL PANEL o O ur IA N ee
10. TER toaster N em 4 5 CLEAR TOATI DANKE CER 0 START BAGEL LIGHTER START Bellen 1 1 Toast Toast bread 2 Bagel Toasts Bagels 3 Stop Clear Touch this pad to stop the toaster or clear entries 4 Start Touch this pad to start the toasting process 5 Darkness Control Adjust darkness control to desired setting before cooking foods Default 5 1 is the lightest and 9 is the darkest 6 Indicator Light When operating toaster with door closed this will be illuminated If you open the door during toasting this will blink NOTE A beep sounds when you touch a key on the control panel to indicate that you have entered a setting 10 B EASY USE TABLE MICROWAVE OVEN 1 KITCHEN TIMER 1 Touch STOP CLEAR 2 Touch KITCHEN TIMER 3 Touch correct number for time 4 Touch START 2 CHILD LOCK To set 1 Touch STOP CLEAR 2 Touch START more than 4 seconds To cancel 1 Touch STOP CLEAR 2 Touch START more than 4 seconds 3 AUTO COOK 1 Touch STOP CLEAR 2 Touch AUTO COOK Category 3 Touch START Although you don t touch start it will start after 4 seconds automatically 4 Ez ON 1 Touch STOP CLEAR 2 Touch Ez ON 5 AUTO DEFROST 1 Touch STOP CLEAR 2 Touch AUTO DEFROST Three different defrosting levels are provided Touch 1 Meat Touch 2 Poultry Touch 3 Fish 3 Enter
11. Improper operation of the primary interlock secondary interlock switches and or the interlock Fuse blows immediately after monitor switch the door is opened Fuse blows when the door is closed and START key Malfunction of the high voltage transformer the high is touched voltage capacitor including the diode the magnetron the blower motor or the circuit board NOTES If the fuse is blown by an improper switch operation replace the defective switches and the fuse at the same time After replacing the defective switches with new ones make sure that they are correctly connected Check for microwave energy leakage according to 1 ADJUSTMENT PROCEDURES on page 3 when the primary interlock secondary interlock switches and or the interlock monitor switches are adjusted or replaced 23 2 CHECKOUT PROCEDURES FOR RELAY Microwave Oven PROBLEM A FAN motor and oven lamp turn on without touching START key when the door is closed E E Toaster PROBLEM A FAN motor and indicator light turn on without touching START key when the door is closed E GOOD Remove the mate connector of I O CON from the circuit board does the unit still operate M Replace the circuit board GOOD Remove the mate connector of I O CON from the circuit board does the unit still operate Replace the circuit board PR
12. 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 TOASTER AND MICROWAVE OVEN THIS CAN ELIMINATE AN UNNECESSARY SERVICE CALL CAUTIONS 1 Check grounding and cool this unit before checking for trouble 2 Be careful of the high voltage circuit 3 Discharge the high voltage capacitor 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 panel 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 REMEDY Toaster and Microwave oven Inserting many plugs into one Avoid using other electrical does not work outlet and using them at the appliances when you use this same time unit blown fuse or breaker Plug is not inserted tightly Insert plug securely Output power is too low Low AC input voltage gt Use the this machine at adequate line voltage Food temperature
13. grounded 3 hole type the unit will be grounded automatically Properly Polarized and Grounded Outlet hree Pronged Grounding Plug Figure 2 3 GENERAL PRECAUTIONS IN USE Microwave Oven A Never operate the unit when it is empty Operating the oven with no load may shorten the life of the magnetron Whenever cooking dry foods dried fish bread etc or a small amount of food be sure to put a glass of water into the cooking compartment The turntable tray may become hot after operating be careful when touching it B Aluminum foil should be avoided because it will disrupt cooking and may cause arcing However small pieces may be used to cover some parts of food to slow the cooking Any aluminum foil used should never be closer than 2 5 cm to any side wall of the oven Toaster A Never operate the toaster when it is empty Operating the toaster with no load may overheat this appliance B Oversized food metal foil packages or utensils must not be inserted in this toaster as they may create a fire or electrical hazards 4 TRIAL OPERATION After installation the following sequences and results should be checked carefully Microwave Oven A Put a container filled with water about 1 liter into the oven and close the door tightly B Touch the STOP CLEAR and the COOK TIME keys C Set cooking time for 10 minutes by touching 1 and then 0 three times 1000 appears in the displ
14. in mV Will be seen 20 COMPONENTS TEST PROCEDURE RESULTS H V Diode rectifer c NS STEP 1 Test the diode to see if it is shorted Procedure 1 Select the O scale on the meter 2 Place the meter leads across the diode as pictured in Figure 14 a The reading should be 40MO OL or a reading of infinity 3 Reverse the meter leads The reading should again indicate a reading of infinity If the diode shows infinity in BOTH directions itis NOT shorted 4 If the diode is not shorted proceed to step 2 STEP 2 Test the diode for forward biasing Procedure 1 Select the DCV scale on the meter 2 Using the meter battery and jumper wire connect the items as illustrated in Figure 14 b This has the positive side of the battery connected to the cathode of the diode 3 The diode should be forward biased therefore a voltage reading of approximately 4 7 VDC to 6 4 VDC will be read depending on meter battery strength etc Note If the meter leads were reversed a negative voltage of the same amount would be seen STEP 3 Test the diode for reverse biasing Procedure 1 Using the same scale on the meter connect the positive side of the battery to the anode of the diode as illustrated in Figure 14 c 2 The diode should be reverse biased therefore a reading of O volt or a value displayed in mV will be seen The display will be erratic changing values rapidly in the mV scale
15. of P C B Assembly Check continuity of primary switch with door opened Continuity No continuity Shorted contact at the primary switch Replace fuse primary monitor Switches and RELAY RY2 of P C B Assembly Disconnect one side of the wire lead connected from transformer to the high voltage capacitor and operate the unit Normal Defective high voltage capacitor Replace high voltage capacitor Fuse blows again Defective high volt age transformer Replace high volt age transformer 2 Fuse does not blow Check continuity gt No continuity Defective gt Replace of thermostat thermostat thermostat Continuity Check continuity No continuity Defective power Replace power of power supply supply cord supply cord cord 28 program times are set and START pad is touched TROUBLE 3 Display shows all figures set but microwave oven does not start cooking while desired CONDITION CHECK RESULT CAUSE REMEDY 1 Setting time Check continuity No continuity Defective Replace does not count of secondary secondary switch secondary switch down when switch with door closed
16. 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 itis 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 Primary Switch Monitor Switch Secondary Switch NOTE After checking for the continuity of switches make sure that they are connected correctly 18 11 TEST AND CHECKOUT PROCEDURES AND TROUBLESHOOTING 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 WIRE LEADS FROM THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORMER 2 ALL OPERATIONAL CHECKS WITH MICROWAVE ENERGY MUST BE DONE WITH A LOAD 1 LITER OF WATER IN CONTAINER IN THE OVEN A TEST PROCEDURES COMPONENTS TEST PROCEDURE RESULTS HIGH VOLTAGE TRANSFORMER Wire leads
17. 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 15 not mounted properly microwaves may leak from the clearance between the door and the oven Remove Door Figure 9 15 D MAGNETRON REMOVAL Figure 10 1 Disconnect the wire lead from the magnetron 2 Carefully remove the mounting screws holding the magnetron and the waveguide 3 Remove the magnetron assembly until the tube is clear from the waveguide NOTE 1 When removing the magnetron make sure its dome does nat 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 Waveguide Bracket Magnetron Gasket Magnetron Figures 10 E REMOVING THE TURNTABLE MOTOR Figure 11 1 Remove the turntable and rotating ring 2 Lay the unit down on its back
18. 3 OR VP 533A OF OR 52300 FOR PRIMARY SWITCH TYPE NO SZM V 16 FA 62 VP 532A OF OR V 5220Q FOR MONITOR SWITCH TYPE NO SZM V 16 FA 63 OR VP 533A OF OR V 5230Q FOR SECONDARY SWITCH A 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 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
19. HES AND HIGH VOLTAGE CIRCUIT A REMOVING OUT CASE Figures 7 1 Remove four screws from the rear section 2 Remove one screw from the side section 3 Push the outer case back about 1 inch 3cm 4 Lift the case from the set 2 IL YH Figure 7 B REMOVING TOASTER ASSEMBL Y Figure 8 CAUTION BE CAREFUL HOT SURFACE AFTER TOASTING ENTIRE TOASTER S SURFACES ARE VERY HOT BEFORE SERVICING COOL DOWN THE TOASTER PARTS ENOUGH NOT TO GET BURNT 1 Open the door 2 Remove 2 screws holding the toaster 3 Disconnect the 2 lead wires from connectors CN2 CN3 4 Disconnect the wires at the secondary interlock switch and wires at the toaster door switch 5 Disconnect the wires from the toaster thermostat and wires at the Toaster Assembly 6 Lift up and pull out Toaster Assembly carefully from the cavity 14 Remove screw Securing Figures 8 C DOOR GROSS ASSEMBLY REMOVAL 1 Open the door Remove choke cover cap 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 limit of 5 mW cm sq with a 275 ml water load
20. OBLEM B FAN motor and oven lamp turn on When the door is PROBLEM B FAN motor and indicator light turn on When the door is closed and START key 15 touched closed and START key 15 touched 16 M F Check the interlock switches GOOD je Replace the Defective micro switches RELAY or poor connection of relay Replace RELAY or correct the connection GOOD Check the interlock switches Es pe Replace the Defective micro switches RELAY or poor connection of relay Replace RELAY or correct the connection 3 CHECKOUT PROCEDURES FOR CIRCUIT BOARD The following symptoms indicate a defective circuit board 1 The start function fails to operate but the high voltage Systems the interlock switches the door sensing and the relay check good 2 The unit with a normal relay continuously operates 3 The buzzer does not sound or continues to sound 4 Some segments of one or more digits do not light up or they continue to light up or segments light when they should not Wrong figures appear The figures of all digits flicker Some of the indicators do no light up 6 7 8 9 The clock does not keep time properly I VS a NOTE A MICROWAVE ENERGY LEAKAGE TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON 25 C TROUBLE
21. PCB when you set lower wire leads from assembly assembly power level relay 2 and check continuity relay 2 Operate the unit 30 TROUBLE 6 When toaster operates strange code can be seen on the display and stop with beep sound 31 CONDITION CHECK RESULT CAUSE REMEDY 1 1 code eus 200800 No continuity veloc m Replace thermistor of thermistor thermistor Continuity Check the No continuity Defective heater Replace toaster continuity of Assembly heater Continuity Check the Continuity Defective PCB Replace PCB connection assembly Assembly between CN3 SONRSEIDEANG No continuit Loose connection connect Mem PCB assembly y tightly 2 F 9 code Check the CN3 sel Aftached 2 wire leads are Apart 2 wire leads connector shorted contact as far as possible whether 2 wire leads are L gt Seperated Defective PCB Replace PCB attached assembly assembly 3 HOT code Internal Allow the toaster to temperature 15 cool down over 220 deg c Automatically fan will blow for 3 minutes to cool this unit EXPLODED VIEW INTRODUCTION OVEN CAVITY PARTS
22. a aet aee 18 11 Test and Checkout Procedures and Troubleshooting __ ___2 lt _ __ _ _ _ _ _ _3 2 lt 3 _ _ 19 22 B Checkout 23 25 C Troubleshooting 5 5 26 31 12 Exploded View 32 38 13 Replacement 39 42 14Schem tic diagram of P G B iae ai idas 43 A Primed circul board entera t t 44 45 EA EISE tiet ets ctt etd 46 48 1 ADJUSTMENT PROCEDURES To avoid possible exposure to microwave energy leakage adjust the door latches and interlock switches using the following procedure ONLY AUTHORIZED SERVICE PERSONNEL SHOULD MAKE THIS ADJUSTMENT The Interlock Monitor and Primary Interlock Switch acts as the final safety switch protecting the user from microwave energy The terminals between COM and NC of the Interlock Monitor must close when the door is opened After adjusting the Interlock Monitor Switch make sure that it is correctly connected See Figures 1 and 1 b throughout this procedure CHECK THE DOOR LATCH AND SWITCH CLOSING NOTE The outer cover of the microwave oven is removed 1 Set the microwave oven on its side so that you can see the latch board and the switches as sh
23. 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 Health 1390 Piccard Drive Rockville Maryland 20850 4 The service personnel should check all surface and vent openings for microwave emission testing 5 Check for microwave energy leakage after every servicing The power density of the microwave radiation leakage emitted by the microwave oven should not exceed 1mW cm sq And always start measuring of an unknown field to assure safety for operating personnel from radiation leakage NOTE The standard is 5mW cm sq while in the customer s home 1mW cm sq stated here is manufacturer s own voluntary standard for units in customer s home Electromagnetic energy leakage monitor NARDA 81008 HOLADAY HI 1501 600cc glass beaker Glass thermometer 100 C Figure 5 B MEASURING MICROWAVE ENERGY LEAKAGE 1 Pour 275 15cc of 20 5 water in a beaker which is graduated to 600 cc and place the beaker in the center of the oven 2 Set the energy leakage monitor to 2 450 MHz a
24. ay window D Touch the START key Make sure the cavity light comes on The unit will begin cooking and the display window will show the time counting down by seconds E After about 5 minutes make sure the primary interlock Switch the secondary interlock switch and the interlock monitor and oven lamp switch operate properly by opening and closing the door several times Touch the START key each time the door is closed F Continue operating the unit Four long beep sound signal is heard when the time is up The unit will shut off automatically G Confirm the water is hot H Finally measure the output power according to POWER OUTPUT MEASUREMENT on page 13 Toaster A Make sure the crumb tray is pushed all the way in place plugging in B Remove all protective wrappings from food before placing into toasting slots Then place bread into slots and close the door Select one mode Toast Bagel Press the Darkness Control to the desired setting Press the Start button Make sure indicator light comes on The unit will begin cooking and the display will show the browning level you selected F After 1 minute make sure the toaster door switch and indicator light operate properly by opening and closing the door several times In normal state indicator light blinks when door is opened Continue operating the unit by pressing the Start button Beep sound signal is heard when the time is up The unit will shut off automati
25. cally and fan will blow for 1 minute to cool this toaster H Confirm the bread is cooked moo NOTE If you operate this toaster for the first time you will notice an odor that is a characteristic of burning off residues on the new heating elements This is normal 5 FEATURES AND SPECIFICATIONS Microwave Oven A The safety systems incorporated in this oven are Toaster A The safety systems incorporated in this toaster are 1 Primary interlock switch 2 Secondary interlock switch 3 Interlock monitor switch 4 Choke system 5 Oven cavity thermostat Note This thermostat located on the oven cavity will open and stop the unit from operation only if a high temperature is reached such as a fire created by overcooking food Any one of 10 power output levels ranging 100W to 900W can be selected by the touch control and electronic computer system Cooking time can be displayed on the digital readout And MWO mode and Toaster mode can be displayed to avoid confusion Three different cooking stages can be set The oven remembers three cooking stages and changes from one cooking stage to another This is made possible with the memory function of the microprocessor 1 Toaster door switch 2 Toaster thermostat Note This thermostat located on the air tunnel will open and stop the unit from operation only if a high temperature is reached such as a fire created by overcooking food Cooking mode Toast Bage
26. e assembled to the wave guide 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 Routine service safety procedures should be exercised at all times Untrained personnel should not attempt service without a thorough review of the test procedures and safety information contained in this manual 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 MECHANICAL SERVICE INFORMATION TABLE OF CONTENTS 1 AdjustMent PTOCOGUIGS 3 2 Precautions on InstallatlOn 1 a 5 General Precautions in Use teet Rn Rinde 5 4 Trial occ ettet rite ero Be arbitra 5 5 Features and SpecifICatioris 2 b ee teda e Ue c o P s 6 7 6 Overall Circuit Diagram rs ii 8 9 Y iii ci 10 11 8 Procedure for Measuring Microwave Energy nnne 12 13 9 Disassembly Instructions srra idee bee ine T dene 14 17 10 Interlock G nhtinuity Testa since re DE ettet re
27. ge capacitor bracket and remove the high voltage diode earth screw Fan Motor HN 7 Capacitor Diode Figures 12 17 I 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 board to the oven assembly Adjust the latch board in the arrow direction so that oven door will not have any play in it when the door is closed Tighten the mounting screw Check for play in the door by pushing the door release button Door movement should be less than 0 5 mm 1 64 inch Don t push the door release button while making 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 ADJUSTMENT DIRECTION SECONDARY SWITCH MONITOR SWITCH PRIMARY SWITCH Figures 13 10 INTERLOCK CONTINUITY TEST WARNING FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION EMISSION REPLACE ONLY WITH IDENTICAL REPLACEMENT PARTS TYPE SZM V 16 FA 6
28. http www LGEservice com l G E mail Techsupport LGEservice com MICROWAVE OVEN MODEL LTM9000W LTM9000B CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL 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 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 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 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 Federal performance standard should be performed on each oven prior to release to the owner Proper operation of the microwave ovens requires that the magnetron b
29. is too low gt This may not be a defect It is possible that the food should be cooked for a longer time period Sparks occur in oven Using metallic ware and Do not use metallic ware for allowing it to touch the oven cooking except where noted wall in the cooking guide Ceramic ware trimmed in Do not use any type of gold or silver powder is used cookware with metallic trimming Uneven microwave cooking Inconsistent intensity of gt 1 Use plastic wrap or lid microwave by their 2 Stir once or twice while characteristics cooking soup cocoa or milk etc 26 TROUBLE 1 The following visual conditions indicate a probable defective control circuit mk Incomplete segments Segment missing 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 do
30. l and browning level can be displayed on the digital readout Thermister controls the toasting time by detecting the internal temperature This makes it possible to cook bread evenly S Rated Power Consumption Output Microwave oven Toaster Frequency Power Supply Rated Current Magnetron 8 Heater Cooling Microwave Stirring Rectification Door Sealing Safety Devices Microwave oven ine Magnetron High Voltage Capacitor High Voltage Diode Cavity Lamp Crumb Tray Overall Dimensions Oven Cavity Size Effective Capacity of Oven Accessories PRIMARY INTERLOCK SWITCH SWITCH MODE SECONDARY PECIFICATIONS 900W IEC 60705 Rating standard Adjustable 100W through 900W 10 steps Rectification Voltage Doubler Half Wave Choke System Thermostat Open at 110 C 5 C Close at 60 5 C Fuse 15A Primary Interlock Switch Secondary Interlock Switch Interlock Monitor Toaster Door Switch Thermostat Open at 145 5 Close at 60 5 C Capacitor 0 95LL 2 1KV Ac 350mA 9 0KV 125V 20W Digital up to 99 mm 99 sec in each cooking stage Tempered Safety Glass 150 C 3 Crumbs of bread lay on it 21516 W x 123 16 H x 16 16 D 131 2 W x 811 16 H x 14316 D 0 9 Cu ft Use and Care Manual Turntable Rotating Ring Assembly SWITCH TABLE TOASTER DOOR SWITCH INTERLOCK MONITOR SWITCH INTERLOCK
31. nd use it following the manufacturer s recommended test procedure to assure correct result 3 When measuring the leakage always use the 2 inch bcm spacer supplied with the probe 4 Operate the oven at its maximum output b Measure the microwave radiation using and electromagnetic radiation monitor by holding the probe perpendicular to the surface being measured See Figure 6 Move probe along shaded area Probe scanning speed less than 2 5 cm sec Figure 6 C MEASUREMENT WITH THE OUTER CASE REMOVED 1 When you replace the magnetron measure for microwave energy leakage before the outer case 15 installed and after all necessary components are replaced or adjusted Special care should be taken in measuring the following parts Around the magnetron The waveguide WARNING AVOID CONTACTING ANY HIGH VOLTAGE PARTS 12 D MEASUREMENT WITH A FULLY ASSEMBLED OVEN 1 After all components including the outer panels are fully assembled measure for microwave energy leakage around the door viewing window the exhaust opening and air inlet openings 2 Microwave energy leakage must not exceed the values prescribed below NOTES Leakage with the outer panels removed less than 5mW 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 1 mW cm sq E NOTE WHEN MEASURING 1 Do n
32. ot exceed meter full scale deflection 2 The test probe must be removed no faster than 1 inch sec 2 5cm sec along the shaded area otherwise a false reading may result 3 The test probe must be held with the grip portion of the handle A false reading may result if the operator s hand is between the handle and the probe 4 When testing near a corner of the door keep the probe perpendicular to the surface making sure the probe horizontally along the oven surface this may possibly cause probe damage F RECORD KEEPING AND NOTIFICATION AFTER MEASUREMENT 1 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 Should the microwave energy leakage not be more than 1mW 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 13 POWER OUTPUT MEASUREMENT 1 Fill the test beaker with 59 15 C 75 F 24 C 1 liter tap water 2 Stir the water in the beaker with thermometer F or and measure temperature as T1 3 Place the beaker on the center of turntable 4 Set for one 1 minute and three 3 seconds and operate the oven at high power
33. own in Figure 1 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 1 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 Switch Secondary Interlock Switch and the Interlock Monitor Switch is very important If any gap is larger than 1 64 0 5 mm you will need to adjust the latch board U L Go to step 3 and follow all steps in order ADJUST THE LATCH AND SWITCH CLOSING 3 Loosen the two screws holding the plastic latch board as shown 4 With the oven door closed tightly move the latch board upward toward the top of the oven and or away from the door latch until the gaps are less than 1 64 0 5 mm Hold the latch board tightly in this position until you check the sequence of the switches in steps 5 and 6 TEST THE LATCH AND SWITCH SEQUENCE 5 Open the oven door slowly Watch the door latch the Primary Switch Release Rod and Lever on the switches to make sure they are zero to the body of the switches in the following sequence Primary Interlock Switch Secondary Interlock Switch Interlock Monitor Switch Adjust the latch board until the switches operate in this sequence See Steps 3 and 4 6 Close the oven door slowly and be sure it is tightl
34. re rise is normal condition 29 TROUBLE 5 No microwave oscillation even though oven lamp and fan motor run Display operates properly CONDITION CHECK RESULT CAUSE REMEDY No microwave Disconnect the gt No continuity Defective PCB Replace PCB oscillation wire leads from assembly assembly relay 2 and check continuity L Continuity of relay 2 Operate the unit Check high vol Abnormal Defective high Replace high tage transformer voltage voltage transformer transformer 1 Normal Check high vol gt Abnormal Defective high Replace high tage capacitor voltage capacitor voltage capacitor Normal Check high vol Defective high Replace high tage diode voltage diode voltage diode Normal Check Abnomal Defective Replace magnetron magnetron magnetron NOTE Make sure the wire leads 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 position and in good condition Output is full power 4 Disconnect the Abnormal Meer Defective PCB Replace
35. removed FILAMENT INDING PRIMARY TERMINAL SECONDARY WINDING 1 Measure the resistance Select the ohm scale on the meter Primary winding Secondary winding Filament winding 2 Measure the resistance Select the ohm scale on the meter Primary winding to ground Filament winding to ground Approx 0 7 0 9 ohm Approx 90 120 ohm Less than 1 ohm Normal Infinite Normal Infinite MAGNETRON Wire leads removed Measure the resistance Select the ohm scale on the meter Filament terminal 2 Measure the resistance Select the ohm scale on the meter Filament to chassis Normal Less than 1 ohm Normal Infinite 19 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 Y 1 Check DC 9V battery before performing tests 2 Select the DCV scale on the meter 3 Using the meter battery and jump wire connect the items as illustrated in figures Terminal to terminal Normal Approximately 9V 1 Check DC 9V battery before performing tests 2 Select the DCV scale on the meter 3 Using the meter battery and jump wire connect the items as illustrated in figures Terminal to case Normal Approximately OV or a value displayed
36. the weight of your food in decimal increments from 0 1 to 6 0 pounds 4 Touch START 5 At beeping turn food over by following the instructions in the manual 6 After turning food over touch START to resume defrosting 6 TIMED COOKING 1 Touch STOP CLEAR 2 Touch COOK TIME 3 Touch number for cooking time 4 Touch POWER 5 Touch number for cooking power level 6 Touch START 11 7 MULTI STAGE COOKING Touch STOP CLEAR Touch COOK TIME Touch number for cooking time Touch POWER Touch number for cooking power level Repeat steps 2 5 to set 2nd cooking stage Touch START gt TOASTER 1 TOAST 1 Touch STOP CLEAR 2 Touch TOAST 3 Touch Darkness Control 1 9 step 4 Touch START 2 BAGEL 1 Touch STOP CLEAR 2 Touch BAGEL 3 Touch Darkness Control 1 9 step 4 Touch START 3 DARKNESS SETTINGS Degree of darkness Select darkness level Light 1 3 Medium 4 6 Dark 7 9 8 PROCEDURE FOR MEASURING MICROWAVE ENERGY LEAKAGE A CAUTIONS 1 Be sure to check a microwave emission prior to servicing the oven if the oven is operative prior to servicing 2 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 5mW cm sq and should repair any unit found to have excessive emission levels at no cost to the owner and should
37. wn 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 programming when touching other pads Display is fixed at some figure and can not accept any input 27 CONDITION CHECK RESULT CAUSE REMEDY 1 No input can be Check the conn Continuit Defective PCB Replace PCB programmed ection between y assembly assembly membrane key assembly and gt Loose Connect them PCB assembly Ao continuity connection tightly 2 Some inputs Replace key Everything works Defective key Replace key cannot be membrane as specified membrane membrane programmed assembly and assembly assembly check operation 3 Display shows a Still have trouble Defective PCB Replace PCB number or figure assembly assembly different from touched 4 Random TROUBLE 2 Microwave oven does not operate at all Display window does not display any figures and no input is accepted Replace fuse CONDITION CHECK RESULT CAUSE REMEDY 1 Fuse blows Check continuity Continuity Malfunction of the Replace fuse of monitor monitor switch primary monitor switch with switches and door closed L No continuity RELAY RY2
38. y closed Watch the three switches to make sure they are zero 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 proper sequence of switches in Steps 5 and 6 tighten the latch board screws at that point TEST THE MICROWAVE ENERGY LEAKAGE 8 Using a survey meter make sure the microwave energy is below 5 mW cm sq Latch Board Interlock Switch Interlock Switch Primary Figure 1 a Figure 1 b LATCH x o 0 1 64 LATCH BOARD 2 PRECAUTIONS ON INSTALLATION Figure 2 Plug the power supply cord into a 120 V AC 60 Hz single phase power source with a capacity of at least 20 amperes B Since the unit weights about 34 lbs be sure to place it on a sturdy and flat surface Avoid placing the unit in a location where there 15 direct heat or splashing water D Place the unit as far away as possible from TV radio etc to prevent interference And do not place on or near a hot gas or electric burner or in a heated oven A CAUTION This unit is equipped with a 3 prong plug for your safety If the wall outlet is

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