Sharp R-4A68 Service Manual
  1. Manuals
  2. Brands
  3. Sharp Manuals
  4. Microwave Oven
  5. R-4A68
  6. Service manual
Sharp R-4A68 Service Manual

Sharp R-4A68 Service Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

CAUTION, MICROWAVE RADIATION ................................................................................................................. 1
WARNING .............................................................................................................................................................. 1
PRODUCT SPECIFICATIONS ............................................................................................................................. 2
GENERAL INFORMATION .................................................................................................................................... 2
APPEARANCE VIEW ........................................................................................................................................... 3
OPERATION SEQUENCE .................................................................................................................................... 4
FUNCTION OF IMPORTANT COMPONENTS .................................................................................................... 5
SERVICING .......................................................................................................................................................... 6
TEST PROCEDURE ............................................................................................................................................. 8
TOUCH CONTROL PANEL ................................................................................................................................. 14
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ............................................................... 18
MICROWAVE MEASUREMENT ........................................................................................................................ 23
WIRING DIAGRAM ............................................................................................................................................. 24
PICTORIAL DIAGRAM ....................................................................................................................................... 25
CONTROL PANEL CIRCUIT ............................................................................................................................... 26
PRINTED WIRING BOARD ................................................................................................................................. 27
PARTS LIST ....................................................................................................................................................... 28
SERVICE MANUAL
MODEL
In interests of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.

TABLE OF CONTENTS

SHARP CORPORATION
MICROWAVE OVEN
R-4A68
R-4A68
S3613R4A68PX/
Page

Advertisement

Table of Contents
loading

Related Manuals for Sharp R-4A68

Summary of Contents for Sharp R-4A68

  • Page 1: Table Of Contents

    R-4A68 SERVICE MANUAL S3613R4A68PX/ MICROWAVE OVEN R-4A68 MODEL In interests of user-safety the oven should be restored to its original condition and only parts identical to those specified should be used. TABLE OF CONTENTS Page CAUTION, MICROWAVE RADIATION ......................... 1 WARNING ................................
  • Page 2 R-4A68...

  • Page 3: Caution Microwave Radiation

    MICROWAVE OVEN R-4A68 GENERAL IMPORTANT INFORMATION APPEARANCE VIEW This Manual has been prepared to provide Sharp Corp. Service engineers with Operation and Service Information. OPERATING SEQUENCE It is recommended that service engineers carefully study the entire text of this manual, so they will be qualified to render satisfactory customer service.

  • Page 4: Product Specifications

    R-4A68 PRODUCT SPECIFICATIONS ITEM DESCRIPTION Power Requirements 220 Volts 50 Hertz Single phase, 3 wire earthed Power Consumption 1.45 kW Power Output 900 watts nominal of RF microwave energy (IEC 705) Operating fequency 2450 MHz Case Dimensions Width 550 mm Height 314.5 mm...

  • Page 5: Appearance View

    R-4A68 APPEARANCE VIEW 1. Ventilation openings 2. Oven lamp 3. Door hinges 4. Door safety latches 5. See through door 6. Door seals and sealing surfaces 7. Coupling 8. Door open button 9. Touch control panel 10.Digital readout 11.Waveguide cover 12.Power supply cord...

  • Page 6: Operation Sequence

    R-4A68 OPERATION SEQUENCE OFF CONDITION The circuits to the power transformer, fan motor and turntable motor are cut off when the 1st. latch switch and Closing the door activates all door interlock switches 2nd. interlock relay control switch are made open. The (1st.

  • Page 7: Function Of Important Components

    R-4A68 FUNCTION OF IMPORTANT COMPONENTS DOOR OPEN MECHANISM oven catch fire due to over heating produced by improper setting of cook time or failure of control unit. Under normal The door can be opened by pushing the door open button on operation, the oven thermal cut-out remains closed.

  • Page 8: Servicing

    3D checks and re-examine the connections to the component being tested. Sharp recommend that wherever possible fault-finding is carried out with the supply disconnected. It may in, some cases, be necessary to connect the supply after...
  • Page 9 R-4A68 CK = Check / RE = Replace A B C D E E E F G G H H I J L M TEST PROCEDURE RE RE CKCK CK CK CK CK CK CK CK POSSIBLE CAUSE DEFECTIVE PARTS...

  • Page 10: Test Procedure

    R-4A68 TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST MAGNETRON TEST NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL WHILE THE OVEN IS IN OPERATION. CARRY OUT 3D CHECKS. Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal.
  • Page 11 R-4A68 TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST 6. Measure the final water temperature. (Example: The final temperature T2 = 21°C) 7. Calculate the microwave power output P in watts from above formula. Initial temperature ....................T1 = 11°C Temperature after (47 + 2) = 49sec............... T2 = 21°C Temperature difference Cold-Warm..............
  • Page 12 R-4A68 TEST PROCEDURES (CONT'D) PROCEDURE LETTER COMPONENT TEST CARRY OUT 4R CHECKS. HIGH VOLTAGE RECTIFIER NOTE: FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER, THE BATTERIES OF THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE AT LEAST 6 VOLTS, BECAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE SHOWN IN BOTH DIRECTIONS.
  • Page 13 R-4A68 TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER .Table: Thermal cut-out Test Temperature of "ON" condition Temperature of "OFF" condition Indication ofohmmeter Parts Name (closed circuit) (˚C) (open circuit) (˚C) (When room temperature is approx. 20˚C) Thermal cut-out 145˚C This is not resetable type.
  • Page 14 R-4A68 TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER perform the Key unit test (Procedure L) to determine if control unit is faulty. 2-1 In connection with pads. a) When touching the pads, a certain group of pads do not produce a signal.
  • Page 15 R-4A68 TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER unit is defective. RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS APPROX. 13.5V D.C. Oven lamp / Turntable motor / Cooling fan motor APPROX. 13.0V D.C. Power transformer CARRY OUT 4R CHECKS. PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD...

  • Page 16: Touch Control Panel

    R-4A68 TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL The touch control section consists of the following units 3) Synchronizing Signal Circuit as shown in the touch control panel circuit. The power source synchronizing signal is available in order to compose a basic standard time in the clock circuit.
  • Page 17 R-4A68 DESCRIPTION OF LSI LSI(IZA690DR) The I/O signal of the LSI(IZA690DR) are detailed in the following table. Pin No. Signal Description XOUT Internal clock oscillation frequency control output. Output to control oscillation input of XOUT. Internal clock oscillation frequency input setting.
  • Page 18 R-4A68 Pin No. Signal Description Segment data signal. Signal similar to R70. Key strobe signal. Signal applied to touch-key section. A pulse signal is input to R81, R82, R83 and R90 terminal while one of G7 line keys on key matrix is touched.
  • Page 19 R-4A68 SERVICING sensing switch (on PWB) of the touch control panel with a 1. Precautions for Handling Electronic Components jumper, which brings about an operational state that is This unit uses CMOS LSI in the integral part of the circuits.

  • Page 20: Component Replacement And Adjustment Procedure

    R-4A68 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before operating the oven. 1. Disconnect the oven from the power supply. 1. Door does not close firmly. 2. Make sure that a definite” click” can be heard when the 2.
  • Page 21 4. Where the portions have been snipped off bend portions plate left near by the turntable motor cover. This screw flat. No sharp edge must be evident after removal of the will be used at the following step 3. turntable motor cover.

  • Page 22: Control Panel Assembly Removal

    R-4A68 CONTROL PANEL ASSEMBLY REMOVAL adhesive on the control panel frame surfaces 1. CARRY OUT 3D CHECKS. completely with a soft cloth soaked in alcohol. 2. Disconnect wire leads from panel components. 2. When attaching the key unit to the control panel 3.
  • Page 23 R-4A68 4. Strip the blue wire lead of the power supply cord for Blue wire lead of power supply cord 15mm lengh from its end. 15 mm 5. Wind the conductor of the blue wire lead of the power supply cord and the conductor of the wire lead of the...
  • Page 24 R-4A68 DOOR REPLACEMENT REMOVAL Note: The door on a microwave oven is designed to act as 1. Disconnect oven from power supply. an electronic seal preventing the leakage of 2. Push the open button and open the door slightly. microwave energy from oven cavity during cook 3.

  • Page 25: Microwave Measurement

    R-4A68 MICROWAVE MEASUREMENT Recommended instruments are: After adjustment of door latch switches, monitor switch NARDA 8100 and door are completed individually or collectively, the NARDA 8200 following leakage test must be performed with a survey instrument and it must be confirmed that the result meets...

  • Page 26: Wiring Diagram

    R-4A68 SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. CLOCK APPEARS ON DISPLAY. NOTE: " " indicates components with potentials above 250V. N.O. COM. 2ND. INTERLOCK RELAY CONTROL SWITCH Figure O-1. Oven Schematic-OFF Condition SCHEMATIC NOTE: CONDITION OF OVEN 1.

  • Page 27: Pictorial Diagram

    R-4A68...

  • Page 28: Control Panel Circuit

    R-4A68...

  • Page 29: Printed Wiring Board

    R-4A68 Figure S-3. Printed Wiring Board...

  • Page 30: Parts List

    R-4A68 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. DESCRIPTION Q'TY CODE ELECTRICAL PARTS 1- 1 QFS-TA014WRE0 Temp. fuse 150˚C (MG)
  • Page 31 R-4A68 ∆ Note: The parts marked " " may cause undue microwave exposure. The parts marked "*" are used in voltage more than 250V. REF. NO. PART NO. DESCRIPTION Q'TY CODE SP40 RALM-A014DRE0 Buzzer (PKM22EPT-THAI) RTRNPA101DRE0 Transformer VRS1 RH-VZA034DRE0 Varistor (10G471K)
  • Page 32 R-4A68 HOW TO ORDER REPLACEMENT PARTS To have your order filled prompty and correctly, please furnish the following information. 1. MODEL NUMBER 2. REF. NO. 3. PART NO. 4. DESCRIPTION...
  • Page 33 R-4A68 OVEN AND CABINET PARTS 6-15 4-14 4-11 6-16 1-17 1-10 7-12 6-10 1-15 4-15 4-13 1-13 1-11 7-13 7-11 1-12 1-14 4-16 1-16 4-17 4-12 4-10...
  • Page 34 R-4A68 3- 1 3- 2 CONTROL PANEL PARTS 3- 3 3-2-1 DOOR PARTS 3-2-2 3-2-3 7-10 7-10 7-10 MISCELLANEOUS Actual wire harness may be different from illustration.

  • Page 35: Packing And Accessories

    R-4A68 PACKING AND ACCESSORIES TOP PAD ASSEMBLY FPADBA317WRK0 DOOR PROTECTION SHEET SPADPA403WRE0 PLASTIC BAG SSAKHA032WRE0 MENU LABEL WARRANTY CARD INSTRUCTION BOOKS (THAI/ENGLISH) BOTTOM PAD ASSEMBLY FPADBA318WRK0 TURNTABLE TRAY TURNTABLE SUPPORT INTO THE OVEN CAVITY TRAY PACK SPADFA389WRE0 PACKING CASE SPAKCC761WRE0...
  • Page 36 R-4A68 '96SHARP CORP. (03U0.07E) Printed in Japan...

Table of Contents