R-305EW SERVICE MANUAL S2104R305EPW/ MICROWAVE OVEN NO. LBS. CUPS. OZ.
R-305EW 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-305EW 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-305EW 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-305EW SERVICE MANUAL PRODUCT DESCRIPTION MICROWAVE OVEN R-305EW 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-305EW. 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. Check the interlock switches and the door seal carefully.
R-305EW SPECIFICATION ITEM DESCRIPTION Power Requirements 120 Volts / 13 Amperes 60 Hertz Single phase, 3 wire grounded Power Output 1100 watts (IEC TEST PROCEDURE) Operating frequency of 2450MHz Case Dimensions Width 20-1/2" Height 11-7/8" Depth 17-1/8" Cooking Cavity Dimensions Width 14-3/4" Height 8-3/4" Depth 15-3/4" 1.2 Cubic Feet Control Complement Touch Control System Clock ( 1:00 - 12:59 ) Timer (0 - 99 min. 99 seconds) Microwave Power for Variable Cooking Repetition Rate; P-HI .........
R-305EW 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. Do not drape over a countertop or table where it can be pulled on by children or tripped over accidentally. CAUTION: DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRONG FROM THIS PLUG.
R-305EW OPERATION DESCRIPTION OF OPERATING SEQUENCE The following is a description of component functions during oven operation. 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 primary interlock relay (RY2) and secondary interlock switch open their contacts. And contacts of the relay (RY1) remains closed. Then the monitor switch contacts close.
R-305EW SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED 2. CLOCK APPEARS ON DISPLAY NOTE: MONITOR FUSE 20A THERMAL CUT-OUT (OVEN) Indicates components with potential above 250 V. THERMAL CUT-OUT (MG.) N.O. N.O. A2 (RY-2) (RY-1) A1 POWER TRANSFORMER CONTROL UNIT COM. COM. SH-B GRN 120V AC 60 Hz SH-A DOOR SENSING SWITCH TTM OL OVEN LAMP CAPACITOR 0.
R-305EW DESCRIPTION AND FUNCTION OF COMPONENTS DOOR OPEN MECHANISM CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE TEST THE DOOR SENSING SWITCH, PRIMARY INTERLOCK RELAY (RY2), 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. The door is opened by pulling the door. Refer to the Figure D-1.
R-305EW 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-305EW CK = Check / RE = Replace Home fuse or circuit breaker blows when power cord is plugged into wall receptacle Monitor fuse blows when power cord is plugged into wall receptacle. OFF CONDITION All letters and indicators do not appear in display when power cord is first plugged into wall outlet. Display does not operate properly when STOP/CLEAR key is touched. (Buzzer should sound and ":" or time of day should appear in display.) Oven lamp does not light when door is opened.
R-305EW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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 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.
R-305EW 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-305EW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 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. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch.
R-305EW 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 WHT functions. RED Screw Driver Monitor Switch Secondary Interlock Switch H Ohmmeter 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.
R-305EW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST c) When touching the pads, sometimes a pad produces no signal. If the Key unit is defective. 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) 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.
R-305EW TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 8. Run the oven and check all functions. G8 G7 G6 G5 G4 G3 G9 5 4 3 2 1 MINUTE PLUS G10 0 9 8 7 6 FRESH VEGETABLES G2 G1 ROLLS / MUFFINS G11 TIMER COMPU DINNER FROZEN POWER ENTREES LEVEL CASSEROLE POPCORN START CLOCK DEFROST PLATE G12 STOP BEVERAGE CLEAR BAKED POTATOES GROUND MEAT G13 G14 K RELAY TEST 1. 2. 3. 4. 5. Disconnect the power supply cord, and then remove outer case. Open the door and block it open.
R-305EW TEST PROCEDURES PROCEDURE LETTER M COMPONENT TEST 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.
R-305EW TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL The touch control section consists of the following units. 3) Power Source Circuit This circuit generates voltages 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. (1) Key Unit (2) Control Unit (The Control Unit consists of Power Unit and CPU Unit).
R-305EW Pin No. Signal I/O Description 11 P57 OUT Back light circuit (Light emitting diodes) driving signal. 12-13 P56-P55 OUT Terminal not used. 14 CNTR0 OUT Signal to sound buzzer (2.0 kHz). A: key touch sound. B: Completion sound. 0.1 sec. H : GND A L : -5V 2.0 sec. H : GND B L : -5V 15 P53 OUT Oven lamp, fan motor and turntable motor driving signal 16.7 msec. To turn on and off shut off relay (RY1).
R-305EW Pin No. Signal I/O Description 33 P27 OUT Key strobe signal. Signal applied to touch-key section. A pulse signal is input to P41, P43, P44 and P45 terminal while one of G8 line keys on key matrix is touched. 34 P26 OUT Key strobe signal. Signal applied to touch-key section. A pulse signal is input to P41, P43, P44 and P45 terminal while one of G7 line keys on key matrix is touched. 35 P25 OUT Key strobe signal. Signal applied to touch-key section.
R-305EW TOUCH CONTROL PANEL SERVICING A. On some models, the power supply cord between the touch control panel and the oven itself is so short that the two can’t be separated. For those models, check and repair all the controls (sensor-related ones included) of the touch control panel while keeping it connected to the oven. B. On some models, the power supply cord between the touch control panel and the oven proper is long enough that they may be separated from each other.
R-305EW 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-305EW 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. POWER TRANSFORMER REMOVAL Reinstallation 1. Rest transformer on the bottom plate with its primary terminals toward the oven face plate. 2. Secure transformer with four screws to bottom plate. 3.
R-305EW 9. Now, the magnetron is free. Reinstallation 1. Re-install the magnetron to waveguide flange with the four (4) screws. 2. Insert the two (2) tabs of the chassis support to the oven cavity front plate and the back plate. 3. Hold the chassis support to the oven cavity back plate, oven cavity front flang, magnetron and the fan duct with the five (5) screws. 4. Reconnect the wire leads to the magnetron and thermal cut-out (MG). Refer to "PICTORIAL DIAGRAM" on page 28. 5.
R-305EW TURNTABLE MOTOR REMOVAL 1. Disconnect the power supply cord. 2. Remove turntable and turntable support from oven cavity. 3. Lay the oven on it's backside. Remove the turntable motor cover by snipping off the material in four corners. 4. Where the corners have been snipped off bend corner areas flat. No sharp edges must be evident after removal of the turntable motor cover. 5. Disconnect wire leads from turntable motor. (See "Positive lock connector removal") 6.
R-305EW DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL Reinstallation 1. Re-install each switch in its place. The secondary interlock/monitor switches are in the lower position and the door sensing 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. Make sure that the monitor switch is operating properly and check continuity of the monitor circuit.
R-305EW 11.Now, door panel with sealer film is free. 12.Tear sealer film from door panel. 13.Now, door panel is free. 14.Slide latch head upward and remove it from door frame with releasing latch spring from door frame and latch head. 15.Now, latch head and latch spring are free. 16.Remove door screen from door frame. 17.Now, door screen is free. REINSTALLATION 1. Re-install door screen to door frame . 2. Re-install the latch spring to the latch head. Re-install the latch spring to the door frame.
1 2 H 3 28 BLK YLW YLW 2 4 (POWER UNIT) YLW BLK RED RED CN-A 1 WHT N.C. 5 COM. WHT TURNTABLE MOTOR BLK WHT D Figure S-1. Pictorial Diagram WHT BLK MONITOR FUSE & HOLDER BLK FAN MOTOR WHT GRY BLK BLK RED GRY GRY BLK POWER TRANSFORMER HIGH VOLTAGE WIRE B MAGNETRON HIGH VOLTAGE CAPACITOR HIGH VOLTAGE COMPONENTS BLK THERMAL CUT-OUT (MG) NOTE: The neutral (WHT) wire must be connected to the neutral (WHT) wire of the power supply cord.
R-305EW 2 1 4 3 6 5 A A B B C9 T1 C A2 d a CN-C 9PIN LEAD WIRE HARNESS GND 4 10G471K A1 VRS1 AC 3 1 + D1 S1NB10 – C3 GND C5 VR C SP1 (J1) b 7 C1 1000µ/25v CN-A INT D D c OVEN LAMP TURNTABLE MOTOR FAN MOTOR AC E RY1 COM C4 BUZZER NO C6 OVEN LAMP TURNTABLE MOTOR FAN MOTOR NO C8 MICRO COM C7 SH-A C2 NC C1 DOOR SENSING SWITCH E RY2 MICRO F F DOOR SENSING SWITCH SH-B G G H H Figure S-2.
4 DOOR SENSING SWITCH MICRO OVEN LAMP TURNTABLE MOTOR FAN MOTOR NC BUZZER INT VR R4 560 1/2w – + Q22 DTA123JKA Q21 DTD143EKA : IF NOT SPECIFIED 1/10W ± 5% D40 MA152WA D20 MA152WA NOTE C-1 C-8 C-7 C-6 C-2 C-4 C-9 C-5 C21 R41 15k Q20 DTA143EKA C20 0.1µ/50v Q30 DTA143EKA Q10 DTA143EKA – 5 R73 15k R72 15k R71 15k R70 15k (J17) 4.7k CF1 CST4.00MGW (J15) 4.7k (J16) 47k (J13) 4.7k (J11) 4.7k C60-65 330pF/50v 80 25 Figure S-3.
R-305EW 2 1 4 3 6 5 A A 1 1 CN - C 9 SH - B B 2 SH - A B DIP CN - B VH C C D1 C1 SP1 (D2) D D (D3) RY2 OM DU OM RY1 DU E E 7 (J1) 1 F F S P XA 3 VRS1 4 T1 VH G 2 G 1 CN - A H H Figure S-4.
R-305EW 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-305EW REF. NO. PART NO.
R-305EW 2 1 4 3 2-1 OVEN AND CABINET PARTS 6 5 7-5 7-8 A A 7-5 4-18 7-10 1-10 B 7-8 1-11 B 4-17 4-20 1-4 C 1-8 6-7 7-6 7-7 6-6 4-13 C 4-11 7-6 4-7 4-19 4-10 4-16 7-3 D D 1-5 7-6 7-4 7-3 4-23 4-18 7-1 4-12 1-7 4-16 1-6 4-15 E 7-9 4-4 4-2 1-12 1-2 4-5 4-3 1-14 7-1 4-8 7-6 1-3 4-9 6-1 E 1-13 4-14 6-2 F 7-6 7-2 1-1 7-6 7-3 1-1 F 7-5 7-1 4-1 4-22 2-2 4-21 4-6 2-4 G 1-9 G 7-6 2-3 H H 7-6 7-6 7-6 7-6 2-3 1 2 4 3 34 5 6
R-305EW 2 1 4 3 6 5 3-2 CONTROL PANEL PARTS A A 3-6 3-5 3-3 3-4 3-6 B B 3-1 DOOR PARTS 3-3-1 C C 5-11 5-7 5-2 5-7 D D 5-1 5-9 5-10 5-7 E E 5-7 5-3 5-7 5-10 5-9 F F 5-5 5-4 5-6 5-8 G G 6-3 MISCELLANEOUS (CAPACITOR) 6-4 H H 6-5 Actual wire harness may be different from illustration.
R-305EW 2 1 4 3 6 5 TOP PAD ASSEMBLY A A FPADBA416WRKZ PACKING AND ACCESSORIES DOOR PROTECTION SHEET SPADPA204WRE0 PLASTIC BAG B B SSAKHA034WRE0 6- 8 INSTRUCTION BOOK & PRINTING MATTER 6- 2 TURNTABLE TRAY BOTTOM PAD ASSEMBLY C C FPADBA417WRKZ 6- 1 TURNTABLE SUPPORT TRAY PACK INTO THE OVEN CAVITY SPADFA451WRE0 D D Not replaceable items.
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R-305EW 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. (2S2.530E) Printed in U.S.
