R-204EWA SERVICE MANUAL S6115R204EPWA MICROWAVE OVEN MODEL ON DEF. EXPRESS DEFROST POWER LEVEL LBS. R-204EWA QTY. CHECK MINUTE PLUS In the interest of user-safety the oven should be restored to its original condition and only parts identical to those specified should be used.
R-204EWA 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-204EWA 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-204EWA 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-204EWA SERVICE MANUAL PRODUCT DESCRIPTION MICROWAVE OVEN R-204EWA GENERAL INFORMATION FOREWORD This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service Information for the SHARP MICROWAVE OVEN, R-204EWA. 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-204EWA PRODUCT DESCRIPTION SPECIFICATIONS ITEM DESCRIPTION Power Requirements 120 Volts 60 Hertz Single phase, 3 wire grounded Power Consumption 1250W / Approx. 10.6 Amperes Power Output 800 W nominal of RF microwave energy (IEC Test procedure) Operating frequency 2450 MHz Case Dimensions Width 18-1/8" Height 11-3/8" Depth 14-5/8" Cooking Cavity Dimensions (0.
R-204EWA 15 or 20 amp. fused electrical supply. It is recommended that a separate circuit serving only this appliance be provided. When installing this appliance, observe all applicable codes and ordinances. A short power-supply cord is provided to reduce risks of becoming entangled in or tripping over a longer cord.
R-204EWA OPERATION DESCRIPTION OF OPERATING SEQUENCE relay (RY2) 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 secondary interlock switch, door sensing switch and primary interlock relay (RY2) open their contacts. Then the monitor switch contacts close. (2) When the door is closed from the open position, the monitor switch contacts open first.
R-204EWA SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED 2. CLOCK APPEARS ON DISPLAY C/T FUSE NOTE: " " indicates components with potential above 250V. MAGNETRON THERMAL CUT-OUT COM. POWER TRANSFORMER N.O. (RY-2) (RY-1) A3 PRIMARY INTERLOCK RELAY CAPACITOR 0.86µF CONTROL UNIT A1 B1 B2 DOOR SENSING SWITCH TTM OL MONITOR SWITCH FM TURNTABLE MOTOR OVEN LAMP MAGNETRON GRN 120V AC 60 Hz RECTIFIER FAN MOTOR SECONDARY INTERLOCK SWITCH Figure O-1.
R-204EWA DESCRIPTION AND FUNCTION OF COMPONENTS DOOR OPEN MECHANISM ARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE"). NOTE: C/T FUSE AND MONITOR SWITCH ARE REPLACED AS AN ASSEMBLY The door is opened by pulling the door, refer to the Figure D-1. Latch Heads Latch Hook TURNTABLE MOTOR The turntable motor rotates the turntable located on the bottom of the oven cavity, so that the food on the turntable is cooked evenly.
R-204EWA 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-204EWA CK = Check / RE = Replace FOIL PATTERN ON PWB. EXPRESS DEFROST/ COMPU DEFROST KEY UNIT DIRTY OVEN CAVITY LOW VOLTAGE WRONG OPERATION CONTROL UNIT OR RELAY TURNTABLE MOTOR COOLING FAN MOTOR OVEN LAMP OR SOCKET C/T FUSE MONITOR SWITCH F G H RE RE CK I/K CK CK CK J M L SECONDARY INTERLOCK SWITCH PRIMARY INTERLOCK SYSTEM MAGNETRON THERMAL CUT-OUT HIGH VOLTAGE CAPACITOR POWER TRANSFORMER C D E F H.V.
R-204EWA TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads and chassis ground. This test should indicate an infinite resistance. If there is little or no resistance the magnetron is grounded and must be replaced. 6. Reconnect all leads removed from components during testing. 7. Reinstall the outer case (cabinet). 8. Reconnect the power supply cord after the outer case is installed. 9.
R-204EWA TEST PROCEDURES PROCEDURE LETTER C COMPONENT TEST 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-204EWA 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. PRIMARY INTERLOCK SYSTEM TEST DOOR SENSING SWITCH 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.
R-204EWA TEST PROCEDURES PROCEDURE LETTER H COMPONENT TEST BLOWN C/T 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. If the C/T 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 C/T fuse.
R-204EWA TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 2) Open the door and block it open. 3) Discharge high voltage capacitor. 4) Replace the key unit. 5) Reconnect all leads removed from components during testing. 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. 2. Control Unit. The following symptoms indicate a defective control unit.
R-204EWA TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST G6 G5 G4 G3 G2 G7 BEVERAGE 6 2 DINNER PLATE MINUTE PLUS G8 FRESH VEGETABLES 3 5 4 EXPRESS DEFROST POWER LEVEL G9 ROLLS & MUFFINS TIMER CLOCK 0 1 BAKED POTATOES STOP CLEAR 9 8 7 POPCORN START G10 K G1 RELAY TEST 1. 2. 3. 4. 5. 6. 7. Disconnect the power supply cord and then remove outer case. Open the door and blocked it open. Discharge high voltage capacitor.
R-204EWA TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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. 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".
R-204EWA TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL 3) Power Source Circuit This circuit generates voltage necessary in the control unit from the AC line voltage. In addition, the synchronizing signal is available in order to compose a basic standard time in the clock circuit. The touch control section consists of the following units as shown in the touch control panel circuit.
R-204EWA DESCRIPTION OF LSI The I/O signal of the LSI are detailed in the following table. Pin No. Signal I/O 1 RESET IN 2 3 TEST VSS IN IN 4 OCS3 IN 5 OCS4 OUT 6 7 VD1 VDD IN IN 8 AVDD IN 9 AVREF IN 10 AVSS IN P40-P42 IN 14 P43 IN 15 BZ OUT 11-13 Description Auto clear terminal. Signal is input to reset the LSI to the initial state when power is supplied. Temporarily set to “L” level the moment power is supplied, at this time the LSI is reset.
R-204EWA Pin No. 23 Signal P23 I/O IN 24 K00 IN 25 K01 IN 26 K02 IN 27 K03 IN Description Signal similar to K02. When either G7 line on key matrix is touched, a corresponding signal will be input into P23. Signal similar to K02. When either G8 line on key matrix is touched, a corresponding signal will be input into K00. Signal similar to K02. When either G9 line on key matrix is touched, a corresponding signal will be input into K01. Signal coming from touch key.
R-204EWA 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-204EWA 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-204EWA CAUTION: 1. DISCONNECT OVEN FROM POWER SUPPLY 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. MAGNETRON REMOVAL 1. 2. 3. 4. 5. 6. Remove the magnetron from waveguide. 7. Now, the magnetron is free. CAUTION: WHEN REPLACING THE MAGNETRON, BE SURE THE R.F.
R-204EWA CONTROL PANEL ASSEMBLY REMOVAL 1. 2. 3. 4. 5. Disconnect the power supply cord and remove outer case. Open the door and block it open. Discharge high voltage capacitor. Disconnect the leads from the control unit. Remove the one (1) screw holding the chassis support to the front plate of the oven cavity. 6. Remove the chassis support from the oven. 7. Lift up the control panel and release it from the oven cavity. 8. Now, the control panel assembly is free. NOTE: 1.
R-204EWA CAUTION: • Make sure that no metal pieces enter the gap between the rotor and the stator of the fan motor. Because the rotor is easily damaged by pliers and metal pieces may be produced. • Do not touch the pliers to the coil of the fan motor because the coil may be cut or damaged. • Do not disfigure the bracket by pinching with the pliers. 14.Remove the fan blade assembly from the shaft of the fan motor by pulling and rotating the fan blade with your hand. 15.Now, the fan blade will be free. 5.
R-204EWA 3. Secure latch hook (with two (2) mounting screws) to oven flange. 4. Re-install the control panel assembly to the oven cavity front flange. 5. Re-connect wire leads to the control unit. Refer to chapter "Pictorial Diagram". 6. Make sure that monitor switch is operating properly and check continuity of the monitor circuit. Refer to chapter "Test Procedure", and Adjustment Procedure below.
R-204EWA upper and lower oven hinges by lifting up. 8. Now, door panel is free from oven cavity. 9. Release door panel from ten (10) tabs of door frame and remove door frame by sliding the door panel downward. 10.Now, door panel with sealer film is free. 11.Tear sealer film from door panel. 12.Now, door panel is free. 13.Slide latch head upward and remove it from door frame with releasing latch spring from door frame and latch head. 14.Now, latch head and latch spring are free. 15.
H 1 2 1 3 28 3 ORG ORG RED CN-A 1 ORG 2 3 WHT 4 GRY WHT WHT WHT SECONDARY INTERLOCK SWITCH COM N.O. COM GRY GRY GRY 5 WHT GRY ORG ORG N H.V. RECTIFIER POWER TRANSFORMER HIGH VOLTAGE WIRE B MAGNETRON HIGH VOLTAGE CAPACITOR HIGH VOLTAGE COMPONENTS BLK MAGNETRON THERMAL CUT-OUT NOTE: The neutral (WHT) wire must be connected to the terminal with "N" mark on the power supply cord. POWER SUPPLY CORD 120V 60Hz 4 5 Figure S-1.
3 29 4 DOOR SENSING SWITCH B1 B2 COM NO A1 c d RY2 RY1 C1 0.1µ/50v C2 470µ/25v 3.3k 1/4w R30 SP1 PKM22EPT Q20 DTA143EKA 5 R5 1k ZD1 HZ4C3 R73 15k R72 15k R71 15k R70 15k (J12) 7.5k (J10) (J14) (J13) 10k (J15) 4.7k C7 0.1µ (J11) 4.
R-204EWA 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-204EWA * REF. NO. 6- 5 6- 6 6- 7 6- 8 6- 9 6-10 PART NO.
R-204EWA 2 1 4 3 6 5 7-8 OVEN AND CABINET PARTS 7-10 A A 7-8 2-1 7-9 7-12 7-10 1-9 B B 7-8 4-3 7-11 4-2 C 1-8 4-17 C 7-9 6-8 6-7 6-9 7-4 4-5 4-14 1-2 1-3 4-14 D 7-5 D 7-5 4-6 4-7 7-5 A 4-11 A 1-7 E 1-5 6-2 7-3 7-1 7-6 1-11 E 1-6 4-9 4-4 4-16 7-7 1-10 F 6-1 1-1 4-10 7-2 1-2 7-1 F 4-1 7-8 1-1 4-15 4-3 4-8 1-4 G G 2-2 7-8 2-3 4-13 7-8 7-8 7-8 2-3 H 7-8 H 4-12 7-8 1 2 4 3 32 5 6
R-204EWA 2 1 Befor attaching Control unit to Control panel, foil side of Control unit must be cleaned by ethylalcohol. A 4 3 6 5 CONTROL PANEL PARTS 3-1 A 3-4 3-2 B 3-2-2 3-3 B 6-10 C C DOOR PARTS 5-6 5-8 3-2-1 D D 5-7 E E 5-1 5-8 5-2 5-3 F F 5-4 5-5 MISCELLANEOUS G G 6-4 6-5 6-6 H H Actual wire harness may be different than illustration.
R-204EWA COPYRIGHT © 2001 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. 2001 SHARP CORP. (6S1.700E) Printed in U.S.