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;...
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. MODEL 721. 63682 721. 63683 721. 63684 721. 63689 TABLE OF CONTENTS (Page) SAFETY PRECAUTIONS ......................
SPECIFICATIONS Rated Power Consumption 1400W maximum (Microwave oven+Cook top lamps+Ventilation fan) Microwave Output 1200W (IEC 60705) Frequency 2,450 MHz ± 50 MHz Power Supply 120 VAC, 60 Hz Rated Current 12 Amp. (Microwave oven+Cook top lamps+Ventilation fan) Magnetron Cooling Forced Air Cooling Rectification Rectification Voltage Double Half-Wave Door Sealing...
CAUTIONS Unlike other appliances, the microwave oven is MICROWAVE RADIATION high-voltage and high-current equipment. Personnel should not be exposed to the Though it is free from danger in ordinary use, microwave energy which may radiate from the extreme care should be taken during repair. magnetron or other microwave generating device if it is improperly used or connection.
INSTALLATIONS BEFORE YOU BEGIN, READ THE FOLLOWING INSTRUCTIONS COMPLETELY AND CAREFULLY. PRECAUTIONS ON INSTALLATION A. Plug the power supply cord into a 120V AC, 60Hz, single-phase power source with a capacity of at least 20 amperes. B. Avoid placing the unit in a location where there is direct heat or splashing water.
CONTROL PANEL INSTRUCTIONS 1. Display. The display includes a clock and indicators to 15. Start. Touch this pad to start a function. If you open the tell you time of day, cooking time settings, cook powers, door after the oven begins to cook, retouch Start. quantities, weights, and cooking functions selected.
GENERAL INFORMATION FOR SERVICE FEATURES AND SPECIFICATIONS GENERAL PRECAUTIONS IN USE FEATURES A. Never operate the unit when it is empty. Operating the oven with no load may shorten the A. The safety systems incorporated in this model are: life of the magnetron. Whenever cooking dry foods (1) Primary interlock switch (dried fish, bread, etc.) or a small amount of food, (2) Secondary interlock switch...
SERVICE INFORMATION PRECAUTIONS AND REPAIR SERVICE TIPS PRELIMINARY (3) Do not operate the unit until it is completely A. SINCE NEARLY 4000 VOLTS EXISTS IN SOME repaired, if any of the following conditions exist. CIRCUITS OF THIS UNIT REPAIRS SHOULD BE The unit must not be operated.
MICROWAVE LEAKAGE TEST EQUIPMENT CAUTIONS • TESTER (VOLTS-DC, AC, Ohmmeter) • Be sure to check microwave leakage prior to servicing the oven if the oven is operative prior to • Microwave survey meter servicing. - Holaday HI-1500 • The service personnel should inform the HI-1501 manufacture importer, or assembler of any certified - Narda...
MEASUREMENT WITH THE OUTER CASE NOTE WHEN MEASURING REMOVED (1) Do not exceed meter full scale deflection. (2) The test probe must be removed no faster than (1) When you replace the magnetron, measure for 1 inch/sec (2.5cm/sec) along the shaded area, microwave energy leakage before the outer case otherwise a false reading may result.
DISASSEMBLY INSTRUCTIONS IMPORTANT NOTES: (4) Remove 3 screws securing the circuit board. UNIT MUST BE DISCONNECTED FROM ELEC- TRICAL OUTLET WHEN MAKING REPAIRS, RE- PLACEMENTS, ADJUSTMENTS AND CONTIN- Circuit Board UITY CHECKS. WHEN RECONNECTING THE WIRE LEADS TO ANY PART, MAKE SURE THE WIRING CONNE- CTIONS AND LEAD COLORS ARE CORRECTLY MATCHED ACCORDING TO THE OVERALL CIR- CUIT DIAGRAM.
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HOW TO INSERT THE F.P.C. CONNECTOR HOW TO REMOVE THE F.P.C. CONNECTOR Follow the steps below as illustrated in Figures 6 Follow the steps below as illustrated in Figures 4 and 7 to insert the F.P.C. connector. and 5 to remove the F.P.C. connector. (1) Insert the F.P.C.
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B. REMOVING THE OUT CASE(Figure 8) (1) Remove the vent grille by removing two screws securing it to the out case. (2) Remove two screws securing it to the air duct. (3) Remove the mounting plate by turning the screws (1 or 2 screws) securing it to the out case.
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C REMOVING THE DOOR INTERLOCK SWITCHES (Figures 9,10) (1) Disconnect the wire leads from the interlock switches. (2) Remove two screws securing the Latch Board. (3) Make necessary replacements and check microwave energy leakage according to Latch Board “ADJUSTMENT PROCEDURES” on page 7-12. Primary Interlock Switch Latch Board...
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D. REMOVING MAGNETRON E. REMOVING THE INVERTER MODULE (Figures 11 Through 12) (Figures 13 Through 15) (1) Remove the vent grille by loosening two screws. (1) Remove the vent grille by loosening two screws. (Figure 11) (Figure 11) (2) Remove the outcase. See page 7-6. (2) Remove the outcase.
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F. REMOVING STIRRER FAN G. REMOVING DOOR (Figure 18) (Figures 16 and 17) (1) Remove the vent grille by two screws securing it to (1) Remove one rivet ASS'Y securing it to the oven the outcase loosening. upper plate by using knife blade. (2) Lift up and draw the door.
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I. ASSEMBLING DOOR (3) Carefully pull the ventilation motor ASS'Y out of (1) When mounting the door assembly to the oven the microwave oven. (See Figure 21-b) 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.
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K. REMOVING THE TURNTABLE MOTOR (1) Remove the glass tray and rotating ring. (2) Remove the turntable shaft VERY CAREFULLY with a hand. (Figure 22) (3) Remove the base plate by removing 8 screws securing it to the oven cavity. (Figure 23) (4) Disconnect the leadwire from the turntable motor terminals.
INTERLOCK SYSTEM 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. CHECK THE DOOR LATCH AND SWITCH ADJUSTMENT PROCEDURES CLOSING.
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TEST THE LATCH AND SWITCH SEQUENCE (5) Open the oven door slowly. Watch the door latch, (7) When you achieve the proper sequence of the Secondary Switch. Release Rod and Lever switches in Steps 5 and 6, tighten the latch board on the switches to make sure they are zero to the screws at that point.
INTERLOCK CONTINUITY TEST A. PRIMARY INTERLOCK SWITCH TEST B. SECONDARY INTERLOCK SWITCH TEST Disconnect the wire lead from the secondary When the door is opened slowly, an audible click switch. should be heard at the same time or successively Connect the ohmmeter leads to the common at intervals and the latches should activate the (COM) and normally open (NO) terminals of the switches with an audible click.
TEST AND CHECKOUT PRECEDURES 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 LEAD WIRES FROM THE INVERTER MODULE. 2.
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COMPONENTS TEST PROCEDURE RESULTS Antenna Gasket Chassis Filament 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. SENSOR Normal: Approximately 1. Disconnect sensor connector from micom BK-RD: 5.6 Kohms computer board.
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COMPONENTS TEST PROCEDURE RESULTS Measure the resistance. FAN MOTOR Normal: Approx. 50 ~ 150 ohms (Wire leads removed) (Ohm-meter scale: R x 100) Abnormal: Infinite or several B(BK) ohms. A(RD) C(WH) A-B: 76 ohms B-C: 22 ohms A-C: 96 ohms Measure the resistance.
KEY MATRIX COMPONENTS TEST PROCEDURES RESULTS Measure the resistance between terminal When When not pins of connector KEY CONNECTOR. Resistance touched touched NOTE: value Less than More than When reconnecting the FPC connector, 400 ohms 1 mega ohm make sure that the holes on the FPC connector are properly engaged with hooks on the plastic fastener.
NOTES: • A MICROWAVE ENERGY TEST MUST ALWAYS BE PERFORMED WHEN THE UNIT IS SERVICED FOR ANY REASON. • MAKE SURE THE WIRE LEADS ARE IN THE CORRECT POSITION. • WHEN REMOVING THE WIRE LEADS FROM THE PARTS, BE SURE TO GRASP THE CONNECTOR, NOT THE WIRES.
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(2) CHECKOUT PROCEDURES FOR RELAY. - PROBLEM (A) - - PROBLEM (A) - FAN motor turns on without touching START key Oven lamp turns on without touching START key when the door is closed. when the door is closed. Remove the mate connector of I/O Remove the mate connector of I/O GOOD GOOD...
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(3) CHECKOUT PROCEDURES FOR CIRCUIT BOARD The following symptoms indicate a defective circuit 5) Some segments of one or more digits do not light board. up, or they continue to light up, or segments light 1) Check the input current. If the input current is more when they should not.
C. 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 1.
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(TROUBLE 1) The following visual conditions indicate a probable defective control circuit. 1. Incomplete segments. • Segment missing. • Partial segment missing. • Digit flickering (NOTE: Slight flickering is normal.) 2. Colon does not turn on or blink. 3. A distinct change in the brightness of one or more numbers in display. 4.
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(TROUBLE 2) Oven does not operate at all, Display window does not display any figures, and no input is accepted. CONDITION CHECK RESULT CAUSE REMEDY Malfunction of the Check continuity 1. Fuse blows. Continuity. Replace fuse, monitor switch. of monitor primary, monitor switch (with switches, and...
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(TROUBLE 3) Display shows all figures set, but oven does not start cooking while desired program times are set and START pad is touched. CONDITION CHECK RESULT CAUSE REMEDY Defective Replace Check continuity 1. Setting time No continuity. secondary switch. secondary switch.
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CONDITION CHECK RESULT CAUSE REMEDY Connect them Check the Abnormal Loose connection. 4. The display tightly. connection between shows F-4. sensor wire and control PCB. Normal Check the sensor. Abnormal Defective sensor. Replace sensor. Defective Control Replace PCB Normal PCB assembly. assembly.
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