R-820BK R-820BW SERVICE MANUAL S5812R820BPW/ DOUBLE GRILL CONVECTION MICROWAVE OVEN MODELS COOK HELP Iinteractive PIZZA BAKE CUSTOM HELP GRILL COMPU ROAST COOK DEFROST CONVEC GRILL POPCORN REHEAT ROAST R-820BK R-820BW MINUTE PLUS 1 2 3 4 5 6 7 8 9 O 100˚ F 150˚ F 350˚ F 375˚ F KITCHEN TIMER STOP CLEAR GRILL 275˚ F 300˚ F 325˚ F 400˚ F 425˚ F 450˚ F CLOCK POWER LEVEL START TOUCH ON In the interest of user-safety the oven should be restored to its original condition and only pa
R-820BK R-820BW 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.
R-820BK R-820BW WARNING TO SERVICE PERSONNEL Microwave ovens contain circuitry capable of producing 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 Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc.. Read the Service Manual carefully and follow all instructions. Don't Touch ! Danger High Voltage When the testing is completed, 1.
R-820BK R-820BW MICROWAVE MEASUREMENT PROCEDURE A. Requirements: 1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external surface of the oven.
R-820BK R-820BW SERVICE MANUAL PRODUCT DESCRIPTION DOUBLE GRILL CONVECTION MICROWAVE OVEN GENERAL INFORMATION R-820BK / R-820BW FOREWORD This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service Information for the SHARP MICROWAVE OVEN, R-820BK, R-820BW. OPERATION It is recommended that service personnel carefully study the entire text of this manual so that they will be qualified to render satisfactory customer service.
R-820BK R-820BW SPECIFICATION ITEM Power Requirements Power Output DESCRIPTION 120 Volts 12.5 Amperes (Microwave) / 13.0 Amperes (Grill/ Convection) 60 Hertz / Single phase, 3 wire grounded 900 watts (IEC 705 Test Procedure) Operating frequency of 2450MHz Top Heater Power Output Top & Bottom Heater Power Output 1000 Watts 1500 Watts Case Dimensions Cooking Cavity Dimensions (0.
R-820BK R-820BW A short power-supply cord is provided to reduce risks of becoming entangled in or tripping over a longer cord. Where a two-pronged wall-receptacle is encountered, it is the personal responsibility and obligation of the customer to contact a qualified electrician and have it replaced with a properly grounded three-pronged wall receptacle or have a grounding adapter properly grounded and polarized. If the extension cord must be used, it should be a 3-wire, 15 amp. or higher rated cord.
R-820BK R-820BW OPERATION DESCRIPTION OF OPERATING SEQUENCE the secondary interlock switch and primary interlock relay and is mechanically associated with the door so that it will function in the following sequence. (1) When the door opens from the closed position, the relay (RY5), primary interlock relay(RY2) and secondary interlock switch open their contacts. And contacts of the relay(RY6) remains closed. Then the monitor switch contacts close.
R-820BK R-820BW TOP AND BOTTOM HEATER MODE In this mode, the food is cooked by both the top heaters and bottom heater. Press the GRILL pad and number "1" pad and then enter the cooking time by pressing the number pads. When the START pad is pressed, the following operations occur (Figure O-3a): 1. The relays(RY3, RY4, RY5 and RY6) are energized. 2. The numbers of the digital read-out start the count down to zero. 3.
R-820BK R-820BW ROAST COOKING CONDITION FIRE SENSING FEATURE (MICROWAVE MODE) Touch the ROAST pad once. And then program desired cooking time by touching the number pads. The ROAST pad is preprogrammed for 325˚F with 30% microwave power. NOTE: The microwave power can not be changed. To change the temperature, touch the ROAST pad twice. When the display says "SELECT TEMP", touch desired temperature pad. When the START pad is pressed, the following operations occur: 1.
THERMAL CUT-OUT (MAG.) 9 RY3 RY4 COM. COM. SECONDARY INTERLOCK SWITCH Figure O-2 Oven Schematic-Microwave cooking Condition H.V. RECTIFIER CAPACITOR 0.94µF AC2200V N.O. N.O. N.O. COM. MAGNETRON POWER TRANSFORMER MONITOR SWITCH GRILL HEATER (TOP) BOTTOM HEATER CONTROL UNIT RY2: RPIMARY INTERLOCK RELAY RY6 THERMAL CUT-OUT (OVEN) TURNTABLE MOTOR A3 RY5 COM. COM. COM. N.O. A3 A5 RY4 RY3 H.V. RECTIFIER CAPACITOR 0.94µF AC2200V N.O. MAGNETRON POWER TRANSFORMER MONITOR SWITCH N.
R-820BK R-820BW MAGNETRON H.V. RECTIFIER CAPACITOR 0.94µF AC2200V MONITOR SWITCH GRILL HEATER (TOP) BOTTOM HEATER COM. COM. TURNTABLE MOTOR COM. TTM N.O. OL OVEN LAMP POWER TRANSFORMER N.O. N.O. RY4 RY3 RY6 RY5 A3 A5 FAN MOTOR FM RY1 CM CONVECTION MOTOR THERMISTOR D3 D1 B2 B1 DOOR SENSING SWITCH THERMAL CUT-OUT (MAG.) N.O. COM. RY2: RPIMARY INTERLOCK RELAY CONTROL UNIT A1 FUSE 20A Indicates components with potential above 250 V.
R-820BK R-820BW MAGNETRON H.V. RECTIFIER CAPACITOR 0.94µF AC2200V MONITOR SWITCH GRILL HEATER (TOP) BOTTOM HEATER COM. COM. TURNTABLE MOTOR COM. TTM N.O. OL OVEN LAMP POWER TRANSFORMER N.O. N.O. RY4 RY3 RY6 A3 RY5 A5 FAN MOTOR FM RY1 CM CONVECTION MOTOR THERMISTOR D3 D1 B2 DOOR SENSING SWITCH B1 EARTH THERMAL CUT-OUT (MAG.) N.O. COM.
R-820BK R-820BW DESCRIPTION AND FUNCTION OF COMPONENTS DOOR OPEN MECHANISM of the monitor switch contacts. CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE TEST THE DOOR SENSING SWITCH, PRIMARY INTERLOCK RELAY (RY2), RELAY (RY6), SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE"). NOTE: MONITOR FUSE AND MONITOR SWITCH ARE REPLACED AS AN ASSEMBLY. The door is opened by pushing the open button on the control panel, refer to Figure D-1.
R-820BK R-820BW BOTTOM HEATER Most of this hot air is reheated by the top heaters and the bottom heater and passes through the convection passage and enters the inside of the oven cavity again, in a continuing cycle. In this way, the hot air circulates inside the oven cavity to raise its temperature and, at the same time, comes into contact with the food being cooked. When the temperature inside the oven cavity reaches the selected temperature, the top heaters and the bottom heater are de-energized.
R-820BK R-820BW CK = Check / RE = Replace POSSIBLE CASE AND DEFECTIVE PARTS CONDITION PROBLEM A B C D E E F F G H I Monitor fuse blows when power cord is plugged into wall outlet. Monitor fuse blows when the door is opened. Oven lamp does not light when door is opened. (Display operates.) OFF CONDITION Home fuse blows when power cord is plugged into wall outlet. "SHARP SIMPLY ..... PRESS CLOCK" does not appear in display when power cord is plugged into wall outlet.
R-820BK R-820BW TEST PROCEDURES PROCEDURE LETTER A COMPONENT TEST MAGNETRON ASSEMBLY TEST 1. 2. 3. 4. 5. 6. 7. 8. 9. Disconnect the power supply cord, and then remove outer case. Open the door and block it open. Discharge high voltage capacitor. 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.
R-820BK R-820BW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST (HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE.) C HIGH VOLTAGE RECTIFIER TEST 1. 2. 3. 4. Disconnect the power supply cord, and then remove outer case. Open the door and block it open. Discharge high voltage capacitor. Isolate the rectifier from the circuit.
R-820BK R-820BW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 5. Reconnect all leads removed from components during testing. 6. Reinstall the outer case (cabinet). 7. Reconnect the power supply cord after the outer case is installed. 8. Run the oven and check all functions. CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE, REPLACE THERMAL CUT-OUT. F SECONDARY INTERLOCK SWITCH TEST 1. 2. 3. 4. 5. 6. 7. 8. Disconnect the power supply cord, and then remove outer case.
R-820BK R-820BW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 5. 6. 7. 8. with the door opened (in this condition the plunger of the monitor switch is pushed in), the meter should indicate an open circuit. If improper operation is indicated, the switch may be defective. After testing the monitor switch, reconnect the wire lead to the monitor switch (COM) terminal and check the continuity of the monitor circuit. Reconnect all leads removed from components RED during testing.
R-820BK R-820BW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 10.Reconnect the power supply cord after the outer case is installed. 11.Run the oven and check all functions. J K THERMISTOR TEST 1. 2. 3. 4. Disconnect the power supply cord, and then remove outer case. Open the door and block it open. Discharge high voltage capacitor. Disconnect connector-D from the control unit. Measure the resistance of the thermistor with an ohmmeter. Connect the ohmmeter leads to Pin No’s D1 and D3.
R-820BK R-820BW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 6) Re-install the outer case (cabinet). 7) Reconnect the power supply cord after the outer case is installed. 8) Run the oven and check all functions. The following symptoms indicate a defective key unit. a) When touching the pads, a certain pad produces no signal at all. b) When touching a number pad, two figures or more are displayed. c) When touching the pads, sometimes a pad produces no signal. If the key unit is defective.
R-820BK R-820BW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the control unit does not respond, it is faulty and must be replaced. If a specific pad does not respond, the above method may be used (after clearing the control unit) to determine if the control unit or key pad is at fault. 5. Reconnect all leads removed from components during testing. 6. Re-install the outer case (cabinet). 7.
R-820BK R-820BW TEST PROCEDURES PROCEDURE LETTER O COMPONENT TEST COMPU DEFROST TEST WARNING : The oven should be fully assembled before following procedure. (1) Place one cup of water in the center of the turntable tray in the oven cavity. (2) Close the door, touch the " Compu Defrost " pad once and touch the Number pad "1", and touch the Number pad 5. And then touch the "START" pad. (3) The oven is in Compu Defrost cooking condition. (4) The oven will operate as follows WEIGHT 0.
R-820BK R-820BW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST STEPS 8) 9) 10) 11) 12) 13) 14) OCCURRENCE CAUSE OR CORRECTION 1 The rated AC voltage is not present between Pin No. 1 of the 3-pin connector (A) and the common terminal of the relay RY6. Check supply voltage and oven power cord. 2 The rated AC voltage is present at primary side of low voltage transformer. Low voltage transformer or secondary circuit defective. Check and repair.
R-820BK R-820BW TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL The touch control section consists of the following units as shown in the touch control panel circuit. 4) ACL A circuit to generate a signal which resets the LSI to the initial state when power is supplied. (1) Key Unit (2) Control Unit (The Control unit consists of Power unit and CPU unit.) 5) Buzzer Circuit The buzzer is responsive to signals from the LSI to emit audible sounds (key touch sound and completion sound).
R-820BK R-820BW DESCRIPTION OF LSI LSI(IZA888DR) The I/O signal of the LSI(IZA888DR) are detailed in the following table. Pin No. 1 2 Signal C1 VL1 I/O IN IN AN7-AN5 IN 6 7 AN4 AN3 IN IN Terminal not used. Temperature measurement input: OVEN THERMISTOR. By inputting DC voltage corresponding to the temperature detected by the thermistor, this input is converted into temperature by the A/D converter built into the LSI.
R-820BK R-820BW Pin No. Signal I/O Description 26 P40 OUT Key strobe signal. Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G7 line key on matrix is touched. 27 P77 OUT Key strobe signal. Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G6 line key on matrix is touched. 28 P76 OUT Key strobe signal. Signal applied to touch-key section.
R-820BK R-820BW Pin No. Signal I/O 39 XOUT OUT 40 VSS IN Power source voltage: -5V. VC voltage of power source circuit input. 41 P27 OUT Bottom heater driving signal. To turn on and off the bottom relay (RY4). "L" level during grill (TOP AND BOTTOM) cooking, Convection cooking or Roast cooking, "H" level otherwise. The heater relay turns on and off within a 48 second time base in accordance with the special program in LSI. 42 P26 OUT Convection motor driving signal.
R-820BK R-820BW Pin No. Signal I/O 81 SEG9 OUT Segment data signal. Connected to LCD. No connection in LCD. SEG8-SEG0 OUT Segment data signal. Connected to LCD. Signal is similar to SEG39. 91 VCC IN Connected to GND. 92 VREF IN Connected to GND. 93 AVSS IN Connected to VC. 94 COM3 OUT Common data signal: COM4. Connected to LCD (Pin No. 36). 95 COM2 OUT Common data signal: COM3. Connected to LCD (Pin No. 35). 96 COM1 OUT Common data signal: COM2. Connected to LCD (Pin No.
R-820BK R-820BW SERVICING 1. Precautions for Handling Electronic Components 5) Re-connect the power supply cord after the outer case is installed. 6) Run the oven and check all functions. This unit uses CMOS LSI in the integral part of the circuits. When handling these parts, the following precautions should be strictly followed. CMOS LSI have extremely high impedance at its input and output terminals.
R-820BK R-820BW COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE WARNING AGAINST HIGH VOLTAGE: Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result in severe, possibly fatal, electric shock. (Example) High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc.. WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before operating the oven. 1.
R-820BK R-820BW 8. Lift the entire case from the oven. 9. Discharge the H.V. capacitor before carrying out any further work. 10.Do not operate the oven with the outer case removed. CAUTION: 1. DISCONNECT OVEN FROM POWER SUP PLY BEFORE REMOVING OUTER CASE. 2. DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING. NOTE: When replacing the outer case, the 2 special Torx screws must be reinstalled in the same locations.
R-820BK R-820BW 4. Disconnect the main wire harness, thermistor harness and the switch harness from the power unit. 5. Straighten the tab of the oven cavity front flange holding the tab of the control panel frame. 6. Lift up the control panel assembly. 7. Now, the control panel assembly is free. CONTROL UNIT 8. Disconnect the flat ribbon cable from the connector CN-G. 9. Remove the two (2) screws holding the CPU unit to the control panel frame. 10.
R-820BK R-820BW COOLING FAN MOTOR REMOVAL REMOVAL 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. Disconnect the wire leads from the fan motor. 5. Remove the one (1) screw holding the capacitor holder to the oven cavity rear plate. 6. Remove the one (1) screw holding the fan duct to the oven cavity rear plate. 7. Release the tabs of the capacitor holder from fan duct. 8. Remove the fan duct from the oven. 9.
R-820BK R-820BW THERMISTOR REMOVAL 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. Now, the back plate with the sub back plate should be removed. 5. Disconnect the connector CN-D from the control unit. 6. Remove the one (1) screw holding the air duct to the oven cavity rear plate. 7. Remove the air duct with the air guide cover and the partition plate from the oven cavity rear plate. 8.
R-820BK R-820BW 4. Remove the control panel assembly referring to "CONTROL PANEL ASSEMBLY REMOVAL". 5. Disconnect the leads from all switches. 6. Remove the two (2) screws holding the latch hook to the oven cavity. 7. Remove the latch hook. 8. Push the retaining tab slightly and remove the switch. Latch Hook Door Sensing Switch Tab Monitor Switch Tab Secondary Interlock Switch Tab Figure C-4. Switches DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT 1.
R-820BK R-820BW 7. Release two (2) pins of door panel from two (2) holes of upper and lower oven hinges by lifting up. 8. Now, door sub assembly is free from oven cavity. 9. Remove the four (4) screws holding the door panel to the door frame. 10.Release door panel from seven (7) tabs of door frame by sliding door panel downward. 11.Now, door panel is free. 12.Slide latch head upward and remove it from door frame with releasing latch spring from door frame and latch head. 13.
R-820BK R-820BW 2 4 3 Q2 2SB1238 R4 27 A D1-4 11ES1 (J1) B + D2 + D4 b – a LED C2 GND A R5 4.7k C3 0.1µ/50v 6 d 1 C10 D1 D3 – 4 D6 D5 C1 0.1µ/50v VRS1 10G471K 8 A1 C2 470µ/50v T1 AC120V 60Hz 6 5 C4 10µ/35v 1 B C3 VC C1 VA C9 VR C4 INT R3 510 1/2w R2 510 1/2w c SP1 C C D12 RY5 FAN MOTOR C5 BUZZER C15 FAN MOTOR C16 CONVECTION MOTOR C6 OVEN LAMP TURNTABLE MOTOR C14 BOTTOM HEATER R6 3.
C15 C16 FAN MOTOR CONVECTION MOTOR 5 OVEN THERMISTOR C17 C13 C12 D30 D23 Q20 DTA123JKA C7 MICRO DOOR SWITCH Q21 DTA123JKA C14 C21 0.1µ/50v Q22 DTA123JKA Q23 DTA143EKA Q24 DTA143EKA Q25 DTA143EKA LD10 LD9 LD8 LD7 LD6 BOTTOM HEATER C11 C11 0.1µ/50v LD1 LD2 LD3 LD4 LD5 C8 D22 + – Q40 DTA143EKA C10 47µ/16v TOP HEATER OVEN LAMP TURNTABLE C 6 MOTOR C9 C10 LED VR C1 C5 BUZZER VA C3 VC C13 0.1µ/50v R30 4.7k C30 Q11 DTA143EKA R81 C14 C2 R31 15k R10 1k C80 (J15) 4.
R-820BK R-820BW 2 1 4 3 6 5 DIP A A R3 CN - C 18 B 1 1 2 D6 CN - D 3 Q1 B 3 R4 E Q2 B C3 C4 R6 D9 D10 D8 B R5 D5 1 CN - B 4 D11 RY6 1 R1 E R2 C2 AC 2 ZD1 C5 E Q3 SP1 C B C D3 D1 C1 RY3 T-H D D 1 D2 8 RY4 B-H D4 E 6 RY2 MICRO E S P 4 VRS1 F F T1 5 (J1) FAN 1 5 CON AC G RY1 G 6 LOT NO. D12 D7 CN - A RY5 F H H Figure S-4.
R-820BK R-820BW PARTS LIST Note: The parts marked “ ∆” may cause undue microwave exposure. The parts marked “*” are used in voltage more than 250V. REF. NO. PART NO.
R-820BK R-820BW REF. NO. 3- 4 3- 5 3- 6 3- 7 PART NO.
R-820BK R-820BW REF. NO. 6-10 6-11 6-12 6-13 PART NO.
R-820BK R-820BW 2 1 4 3 OVEN AND CABINET PARTS 6 5 7-9 2-2 7-19 7-9 A A 6-11 7-11 7-9 2-1 7-19 4-33 6-2 4-4 7-10 B B 4-25 7-11 7-12 4-29 7-5 4-36 7-10 4-23 4-3 1-11 4-26 4-41 1-12 7-10 C 7-17 4-27 7-4 7-10 1-16 4-30 4-39 1-9 4-42 1-14 4-18 7-10 1-15 1-8 4-35 4-40 4-43 7-13 6-12 4-1 D C 4-38 7-1 6-13 7-10 7-13 7-10 4-31 4-19 4-32 7-15 1-10 4-15 7-6 4-34 x3 A 7-8 D 4-37 7-16 7-6 7-18 7-14 7-8 7-10 7-6 6-5 6-7 7-6 4-24 7-7 7-9 1-13 1-17 E 7-1
R-820BK R-820BW 2 1 4 3 6 5 3-7 CONTROL PANEL PARTS 3-4 A A 3-5 3-2 3-3 3-7 B B 3-3-3 3-6 3-1 C C DOOR PARTS 3-3-1 D D 5-8 3-3-2 5-9 5-1 E E 5-6 5-2 5-7 F F 5-3 5-4 5-5 MISCELLANEOUS G G 6-8 6-1 6-7 Actual wire harness may be different from illustration.
R-820BK R-820BW COPYRIGHT © 1998 BY SHARP CORPORATION ALL RIGHTS RESERVED. No part of this publication may be reproduced, stored in retrieval systems, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher. '98 SHARP CORP. (5S2.530E) Printed in U.S.
