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40 F 1.5
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INSTRUCTIONS
With the door closed,turn the timer to
the desired time. Oven will begin
operating immediately.
To shut oven off manually,return timer
to "0".
1000W/ R-21JCA
TIME GUIDE FOR ONE SERVING
15 - 30 sec. 30 - 60 sec.
Bagel, Roll Hot Dog
Muffin, Pastry Pizza Slice
Pie Slice Small Sandwich
1 - 2 min. 2 - 3 min.
Beverage, Soup Casserole, Stew
Large Sandwich Chili, Cho
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R-21JCA-F 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
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R-21JCA-F WARNING TO SERVICE PERSONNEL Microwave ovens contain circuitry capable of pro- ducing very high voltage and current, contact with following parts may result in a severe, possibly fatal, electrical shock. (Example) High Voltage Capacitor, High Voltage Power Trans- former, Magnetron, High Voltage Rectifier Assem- bly, High Voltage Harness etc.. Read the Service Manual carefully and follow all instructions. Don't Touch ! Danger High Voltage 1. Disconnect the power supply cord, and then
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R-21JCA-F MICROWAVE MEASUREMENT PROCEDURE A. Requirements: 1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should 2 not exceed 1mW/cm at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a 2 purchaser, and thereafter (through the useful life of the oven), 5 mW/cm at any point 5cm or more from the external surface of the oven. 2) Safety interlock switches Primary interlock relay and
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R-21JCA-F SERVICE MANUAL PRODUCT DESCRIPTION LIGHT DUTY COMMERCIAL MICROWAVE OVEN GENERAL INFORMATION R-21JCA-F FOREWORD This Manual has been prepared to provide Sharp Electronics Corp. OPERATION Service Personnel with Operation and Service Information for the SHARP MICROWAVE OVENS, R-21JCA-F. It is recommended that service personnel carefully study the entire text of TROUBLESHOOTING GUIDE AND this manual so that they will be qualified to render satisfactory customer TEST PROCEDURE service. Chec
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R-21JCA-F SPECIFICATION ITEM DESCRIPTION Power Requirements 120 Volts 14 Amperes 60 Hertz / Single phase, 3 wire grounded Power Output 1000 watts (IEC 705 Test Procedure) Operating frequency of 2450MHz Case Dimensions Width 20-1/2" (520mm) Height 12-1/8"(309mm) Depth 16" (406mm) NOTE: Internal capacity is calculated by measuring Cooking Cavity Dimensions Width 13-7/8" (353mm) maximum width, depth and height. (1.0 Cubic Feet ) Height 8-1/8" (207mm) Actual capacity for holding food is less. Dept
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R-21JCA-F OVEN DIAGRAM 1. Back splash cover 2. Side splash cover 3. Oven light 4. Ceramic shelf 12 9 1 3 2 14 5. Control panel 13 6. Cavity face plate 7. Door latch openings 8. Door latches 11 4 9. Door hinges 10.Door seals and sealing surfaces 15 11.Door handle 16 12.Oven door with see-through 5 8 10 6 7 window 13.Air ventilation cover and openings 14.Power supply cord 15.Air intake openings 16.Outer case cabinet CONTROL PANEL TIME GUIDE FOR ONE SERVING 15 - 30 sec. 30 - 60 sec. Bagel, Roll Hot
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R-21JCA-F OPERATION DESCRIPTION OF OPERATING SEQUENCE The following is a description of component functions during 5. Upon completion of the cooking time, the power transformer, oven operation. oven lamp, etc. are turned off, and the generation of microwave energy is stopped. The oven will revert to the OFF CONDITION OFF condition. Closing the door activates door sensing switch and secondary 6. When the door is opened during a cook cycle, monitor interlock switch. (In this condition, the monitor
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R-21JCA-F SCHEMATIC NOTE: Indicates components with potential above 250 V. NOTE: CONDITION OF OVEN 1. LIGHT UP DIAL OFF. 2. DOOR CLOSED. THERMAL THERMAL CUT-OUT CUT-OUT NOISE FILTER 125˚C (OVEN) 145˚C (MAG.) POWER TRANSFORMER A5 AC120V 60 Hz CAPACITOR 0.94 µF CONTROL UNIT 2400V A3 A1 OL FM AM DOOR SENSING SWITCH OVEN FAN ANTENNA LAMP MOTOR MOTOR SECONDARY INTERLOCK SWITCH Figure O-1 Oven Schematic-OFF Condition SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. LIGHT UP DIAL ON. THERMAL THER
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R-21JCA-F DESCRIPTION AND FUNCTION OF COMPONENTS DOOR OPEN MECHANISM and secondary interlock switch contacts fail to open, the The door is opened by grasping the door handle, refer to Figure monitor fuse blows simultaneously with closing of the D-1. monitor switch contacts. When the door handle is grasped, the handle lever is pulled. CAUTION: BEFORE REPLACING A BLOWN MONITOR And then the upper and lower latch heads are moved upward FUSE TEST THE DOOR SENSING SWITCH, by the handle lever, and they
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R-21JCA-F TROUBLESHOOTING GUIDE Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected. When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which will be found in the "Test Procedure "section. IMPORTANT: If the oven becomes inoperative because of a blo
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R-21JCA-F TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER A MAGNETRON ASSEMBLY TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. Discharge high voltage capacitor. 4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron filament leads should indicate less than 1 ohm. 5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads and
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R-21JCA-F TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER C HIGH VOLTAGE RECTIFIER TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. Discharge high voltage capacitor. 4. Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance across the terminals and observe, reverse the leads to the rectifier terminals and observe meter reading. If a short is indicated in both directions, or if an infinite r
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R-21JCA-F TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER F SECONDARY INTERLOCK SWITCH TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. Discharge high voltage capacitor. 4. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate an open circuit with the door open and a closed circuit with the door closed. If improper operation is indicated, replace the sec
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NOISE FILTER R-21JCA-F TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER H BLOWN MONITOR FUSE TEST 1. Disconnect the power supply cord, and then remove outer case. 2. Open the door and block it open. 3. Discharge high voltage capacitor. 4. If the monitor fuse is blown when the door is opened, check the primary interlock relay, secondary interlock switch and monitor switch according to the "TEST PROCEDURE" for those switches before replacing the blown monitor fuse. CAUTION: BEFORE REPLACING A BLOWN
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R-21JCA-F TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER 6) After that procedure, re-connect the power supply cord. 1. Control Panel The following symptoms indicate a defective control unit. 1-1 In connection with LEDs a) At a certain LED, all or some LEDs do not light up. b) At a certain LED, brightness is low. c) Only one LED does not light up. d) All or some LEDs continue to light up. e) A certain group of LEDs do not light up. f) The LEDs flicker. 1-2 Other possible troubles caused by defec
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RY2 RY1 R-21JCA-F TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER L FOIL PATTERN ON THE PRINTED WIRING BOARD TEST To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary on the PWB, this foil pattern acts as a fuse. 1. Foil pattern check and repairs. 1) Disconnect the power supply cord and then remove outer case. 2) Open the door and block it open. 3) Discharge high voltage capacitor. 4) Follow the troubleshooting guide given below for repair. S
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R-21JCA-F TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL Control Unit 4) Reset Circuit Control unit consists of LSI, power source circuit, synchroniz- A circuit to generate a signals which resets the LSI to the ing signal circuit, reset circuit, buzzer circuit, encoder circuit initial state when power is supplied. and indicator circuit. 5) Buzzer Circuit 1) LSI The buzzer is responsive to signals from the LSI to emit This LSI controls the encoder signal, relay driving signal for aud
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R-21JCA-F Pin No. Signal I/O Description 9 IN Auto clear terminal. RESET Signal is input to reset the LSI to the initial state when power is applied. Temporarily set to "L" level the moment power is applied, at this time the LSI is reset. Thereafter set at "H" level. 10 CNVSS IN Power source voltage. The power source voltage to drive the LSI is input to CNVSS terminal. 11 XOUT OUT Internal clock oscillation frequency control output. Output to control oscillation input of XIN. 12 XIN IN Internal
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R-21JCA-F TOUCH CONTROL PANEL SERVICING 1. Precautions for Handling Electronic Components panel while keeping it connected to the oven. This unit uses CMOS LSI in the integral part of the circuits. B. On some models, the power supply cord between the touch When handling these parts, the following precautions should control panel and the oven proper is so long enough that be strictly followed. CMOS LSI have extremely high they may be separated from each other. For those models, impedance at its i
