R-21HC SERVICE MANUAL S7813R21HCP// LIGHT DUTY COMMERCIAL MICROWAVE OVEN MODEL 1000W/ R-21HC TIME GUIDE FOR ONE 15 - 30 sec. Bagel, Roll Muffin, Pastry Pie Slice 1 - 2 min. Beverage, Soup Large Sandwich 40 50 30 D E 20 C 1 F 1.5 G H I B 2 J A 0 K L M COMM ERCIA N L MICR O T WAVE O VEN R-21HC 2 - 3 min. Casserole, Stew Chili, Chowder Popcorn, 3.5 oz. Popcorn, 1.5 oz. 10 SERVING 30 - 60 sec. Hot Dog Pizza Slice Small Sandwich 6 O S R P Q 2.
R-21HC 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-21HC 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-21HC 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-21HC SERVICE MANUAL PRODUCT DESCRIPTION LIGHT DUTY COMMERCIAL MICROWAVE OVEN GENERAL INFORMATION R-21HC FOREWORD This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service Information for the SHARP MICROWAVE OVEN, R-21HC. 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-21HC SPECIFICATION ITEM Power Requirements Power Output Case Dimensions Cooking Cavity Dimensions (1.
R-21HC OVEN DIAGRAM 12 9 1 3 2 14 13 11 4 15 16 8 1. 2. 3. 4. 5. 6. 7. 8. 10 6 5 7 9. Door hinges 10.Door seals and sealing surfaces 11.Door handle 12.Oven door with see-through window 13.Air ventilation cover and openings 14.Power supply cord 15.Air intake openings 16.Outer case cabinet Back splash cover Side splash cover Oven light Ceramic shelf Control panel Cavity face plate Door latch openings Door latches TOUCH CONTROL PANEL TIME GUIDE FOR ONE SERVING 15 - 30 sec.
R-21HC OPERATION DESCRIPTION OF OPERATING SEQUENCE If the secondary interlock switch and primary interlock relay (RY1) fail with the contacts closed when the door is opened, the closing of the monitor switch contacts will form a short circuit through the monitor fuse, secondary interlock switch, and primary interlock relay(RY1), causing the monitor fuse to blow. The following is a description of component functions during oven operation.
R-21HC NOTE: SCHEMATIC NOTE: CONDITION OF OVEN 1. LIGHT UP DIAL OFF. 2. DOOR CLOSED. THERMAL THERMAL CUT-OUT CUT-OUT 125˚C (OVEN) 145˚C (MAG.) MONITOR SWITCH RY2 COOK RELAY RY1 PRIMARY INTERLOCK RELAY AC120V 60 Hz CONTROL UNIT A3 CAPACITOR 0.94 µF 2400V A1 OL DOOR SENSING SWITCH OVEN LAMP FM FAN MOTOR MAGNETRON POWER TRANSFORMER A5 RECTIFIER MONITOR FUSE 20A Indicates components with potential above 250 V.
R-21HC DESCRIPTION AND FUNCTION OF COMPONENTS (RY1) and secondary interlock switch contacts fail to open, the monitor fuse blows simultaneously with closing of the monitor switch contacts. CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE TEST THE DOOR SENSING SWITCH, PRIMARY INTERLOCK RELAY (RY1), 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.
R-21HC 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.
R-21HC 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-21HC TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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. 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.
R-21HC TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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. Open the door and block it open. Discharge high voltage capacitor.
R-21HC TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 5. 6. 7. 8. Reconnect all leads removed from components during testing. Reinstall the outer case (cabinet). Reconnect the power supply cord after the outer case is installed. Run the oven and check all functions. MONITOR SWITCH SCREW DRIVER WHT/ WHT OHMMETER H BLOWN MONITOR FUSE 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.
R-21HC TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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 defective control unit. a) Buzzer does not sound or continues to sound. b) Clock is not possible. c) Cooking time can not be set. When testing is completed, 1) Disconnect the power supply cord and then remove outer case.
R-21HC TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 2) Open the door and block it open. 3) Discharge high voltage capacitor. 4) Follow the troubleshooting guide given below for repair. STEPS OCCURRENCE CAUSE OR CORRECTION 1 Only pattern at "a" is broken. *Insert jumper wire J1 and solder. 2 Pattern at "a" and "b" are broken. *Insert the coil RCILF2003YAZZ between "c" and "d". ORG BRK RY1 RY2 5) Make a visual inspection of the varistor. Check for burned damage.
R-21HC CONTROL PANEL ASSEMBLY OUTLINE OF CONTROL PANEL 4) ACL A circuit to generate a signals which resets the LSI to the initial state when power is supplied. Control Unit Control unit consists of LSI, power source circuit, synchronizing signal circuit, ACL circuit, buzzer circuit, encoder circuit and indicator circuit. 5) Buzzer Circuit The buzzer is responsive to signals from the LSI to emit audible sounds (completion sound).
R-21HC 9 S0 OUT 10 S1 OUT 11 S2 OUT Digit selection signal. Signal is input to the anodes of the light-emitting diodes (LD11 - LD15). 12 S3 OUT Digit selection signal. Signal is input to the anodes of the light-emitting diodes (LD16 - LD20). 13-14 NC 15 D0 OUT 16 D1 OUT 17 CNVS IN 18 VSS IN Power source voltage: -0V. The power source voltage to drive the LSI is input to VSS terminal. Connected to GND. 19 D2 OUT Segment data signal.
R-21HC SERVICING 1. Precautions for Handling Electronic Components 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. For this reason, it is easily influenced by the surrounding high voltage power source, static electricity charge in clothes, etc., and sometimes it is not fully protected by the built-in protection circuit.
R-21HC 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-21HC POWER TRANSFORMER REMOVAL 1. Disconnect the power supply cord and then remove outer case. 2. Open the oven door and block it open. 3. Discharge high voltage capacitor. 4. Disconnect the filament leads of power transformer from high voltage capacitor and the magnetron. 5. Disconnect the H.V. wire from the power transformer. 6. Disconnect the main wire harness from the power transformer. 7. Remove the two (2) screws holding the transformer to base plate. 8. Remove the transformer. 9.
R-21HC OVEN LAMP AND LAMP SOCKET REMOVAL Oven lamp socket 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. Lift up the oven lamp socket from air intake duct. 5. Pull the wire leads from the oven lamp socket by pushing the terminal hole of the oven lamp socket with the small flat type screw driver. 6. Now, the oven lamp socket is free. Terminal Wire lead Terminal hole Flate type small screw driver Figure C-1.
R-21HC 4. Install the fan blade to the shaft of fan motor by pushing the fan blade with a small, light weight, ball peen hammer or rubber mallet. CAUTION: * Do not hit the fan blade hard when installing because the bracket may be disfigured. * Make sure that the fan blade rotates smooth after installation. * Make sure that the axis of the shaft is not slanted. 5. Install the fan duct to the oven cavity rear plate with the one (1) screw. 6. Insert the tabs of the capacitor holder to the fan duct. 7.
R-21HC oven cavity. 7. Remove the latch hook. 8. Push the retaining tab outward slightly and remove the switch. Re-install 1. Re-install each switch in its place. The door sensing switch and monitor switch are in the lower position and the secondary interlock switch is in the upper position. 2. Re-connect wire leads to each switch. Refer to pictorial diagram. 3. Secure latch hook (with two (2) mounting screws) to oven flange. 4.
R-21HC RE-INSTALL OF THE DOOR 1. Re-install all door parts except the choke cover. 2. Catch two (2) pins of door panel on two (2) holes of upper and lower oven hinges. 3. Re-install choke cover to door panel by pushing. Choke Cover NOTE: After any service to the door; (A) Make sure that door sensing switch and secondary interlock switch are operating properly. (Refer to chapter "Test Procedures".).
R-21HC INSTALLATION OF CERAMIC SHELF 1. Disconnect the power supply cord. 2. Open the door and block it open. 3. Make sure that the smooth surface of the ceramic shelf face up. 4. Make sure that the rubber packing without a fin of the ceramic shelf faces the front of the oven. NOTE: The three (3) rubber packings with the fins and the one (1) rubber packing without a fin are attached to the four (4) edges of the ceramic shelf. The one (1) rubber packing without a fin is the front edge of the ceramic shelf.
1 2 RY2 RY1 5 GRY 4 3 YLW 2 1 PNK CN-A ORG RED RED F 3 26 4 COM. YLW PNK N.O. DOOR SENSING SWITCH RED WHT 5 RED ORG EARTH BLK RED WHT WHT GRY WHT BLK WHT ORG ORG RED BRN BLK FUSE & HOLDER THERMAL CUT-OUT 145°C(MAG.) POWER TRANSFORMER MAGNETRON H.V. CAPACITOR HIGH VOLTAGE COMPONENTS FAN MOTOR NEUTRAL GRN POWER SUPPLY CORD 4 5 E Figure S-1.
AC120V 60Hz 10G471K1 R11 100 2w (A) c a b C (J1) 3 4 27 B SW1 d D2 R10 100k 1/2w C2 2.2µ/160VAC A R60 100k R62 4.7k R63 4.7k D4 – + Q1 2SC1740 5 LD1 20 LD6 2.30 LD11 D70 D74 D78 D82 VREF K0 K1 4 5 6 LD3 LD2 LD8 1 D71 40 LD7 3.
R-21HC 1 2 4 3 5 6 A A LD6 LD5 LD4 D73 LD7 LD8 D72 D71 LD10 D77 D76 LD2 B LD9 D75 D74 LD3 D70 LD1 B LD11 D78 D79 LD12 SW1 A B D80 C LD13 D81 C D82 D83 D84 LD15 D85 R74 LD17 LD18 LD16 R73 R72 R71 R70 LD20 LD19 C LD14 D D B Q1 ZD6 ZD1 F ICP1 C1 5 2 ZD3 1 (JA) ORG RED RED (J1) 5 C2 D30 RY2 RY1 ORG BRK D4 D3 DIP R10 ZD2 D1 D2 C4 C21 G H R2 + C3 25 SP1 D21 D20 R11 ZD5 (JC) R4 + 20 24 E C5 E Q2 R42 + R1 R3 B R5 R30 C7 (JD) 2
R-21HC 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-21HC REF. NO. R71 R72 R73 R74 RY1 RY2 SP1 SW1 VRS1 ZD1-3 ZD4-5 ZD6 3- 2 3- 2-1 3- 2-2 3- 3 3- 4 3- 5 PART NO.
R-21HC REF. NO. 5-13 5-14 5-15 5-16 5-17 5-18 5-19 5-20 PART NO.
R-21HC 2 1 4 3 7-3 6 5 OVEN AND CABINET PARTS 7-3 2-1 A A 7-3 1-10 1-9 4-28 7-13 7-3 6-6 4-9 B B 4-10 7-13 6-7 4-25 7-6 7-12 4-32 1-4 6-5 1-13 4-26 4-34 7-13 7-1 4-26 6-3 C 4-24 6-4 4-27 4-14 1-4 C 4-15 7-7 7-7 4-15 4-36 4-2 1-1 4-16 7-9 7-10 1-8 7-11 D 4-23 4-21 4-22 4-18 4-24 4-20 4-21 D 1-12 4-20 7-8 7-7 4-21 4-20 1-7 E 4-33 4-19 7-2 4-13 7-4 E 7-1 7-4 4-29 1-11 7-1 4-31 1-15 7-7 4-6 7-1 1-6 4-3 4-8 4-30 1-3 F 4-12 F 1-1 2-2 4-7
R-21HC 2 1 4 3 6 5 3-1 CONTROL PANEL PARTS 3-5 A A 3-2 3-2-1 3-5 3-2-2 B B 3-3 C C 3-4 DOOR PARTS 5-15 5-17 5-16 D D 5-13 5-2 5-16 5-20 E 5-4-2 5-16 5-13 5-16 E x4 5-4 5-1 5-4-1 5-4-3 5-16 x2 5-16 5-12 5-14 F F 5-8 5-7 5-19 5-9 5-18 5-12 5-11 5-3 G 5-8 G 5-19 MISCELLANEOUS 5-6 5-5 6-2 6-8 5-10 H H Actual wire harness may be different from illustration.
R-21HC 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. (7S2.530E) Printed in U.S.