Sharp R-3A88 Service Manual
  1. Manuals
  2. Brands
  3. Sharp Manuals
  4. Microwave Oven
  5. R-3A88
  6. Service manual
Sharp R-3A88 Service Manual

Sharp R-3A88 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 ........................................................................................................................ 24
WIRING DIAGRAM ............................................................................................................................................. 25
PICTORIAL DIAGRAM ....................................................................................................................................... 26
CONTROL PANEL CIRCUIT ............................................................................................................................... 27
PRINTED WIRING BOARD ................................................................................................................................. 28
PARTS LIST ....................................................................................................................................................... 29
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-3A88
R-3A88
S3614R3A88PX/
Page

Advertisement

Table of Contents
loading

Related Manuals for Sharp R-3A88

Summary of Contents for Sharp R-3A88

  • Page 1: Table Of Contents

    R-3A88 SERVICE MANUAL S3614R3A88PX/ MICROWAVE OVEN R-3A88 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-3A88...

  • Page 3: Caution Microwave Radiation

    MICROWAVE OVEN R-3A88 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-3A88 PRODUCT SPECIFICATIONS ITEM DESCRIPTION Power Requirements 220 Volts 50 Hertz Single phase, 3 wire earthed Power Consumption 1.35 kW Power Output 850 watts nominal of RF microwave energy (IEC 705) Operating fequency 2450 MHz Case Dimensions Width 520 mm...

  • Page 5: Appearance View

    R-3A88 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.Wave guide cover 12.Power supply cord...

  • Page 6: Operation Sequence

    A3+A5 in the control unit. MONITOR SWITCH CIRCUIT Figure O-1 on page 25 The monitor switch is mechanically controlled by oven 1. The display shows SHARP , MICRO- , WAVE door, and monitors the operation of the 1st latch switch OVEN .

  • Page 7: Function Of Important Components

    R-3A88 FUNCTION OF IMPORTANT COMPONENTS DOOR OPEN MECHANISM FUSE M8A The door is opened by pushing the open button on the control panel, refer to the Figure D-1. 1. The fuse M8A blows when the contacts (COM-NO) of the When the open button is pushed, the open button pushes up 1st.

  • 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-3A88 CK = Check / RE = Replace TEST PROCEDURE A B C D E E E G F F H H I K L M N RECKCKRE CK CKCKCK CK POSSIBLE CAUSE DEFECTIVE PARTS PROBLEM CONDITION Home fuse blows when power supply cord is plugged into wall outlet.

  • Page 10: Test Procedure

    R-3A88 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 CHECK. Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal.
  • Page 11 R-3A88 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 (49 + 2) = 51 sec.
  • Page 12 R-3A88 TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER 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-3A88 TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER MONITOR RESISTOR TEST CARRY OUT 3D CHECKS. Disconnect the leads from the monitor resist. Using an ohmmeter and set on a low range. Check between the terminals of the monitor resistor. The resistance of monitor resistor is approx. 0.8 ohms.
  • Page 14 R-3A88 TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER 2-2 In connection with indicators a) At a certain digit, all or some segments do not light up. b) At a certain digit, brightness is low. c) Only one indicator does not light.
  • Page 15 R-3A88 TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS APPROX. 25.0V D.C. Oven lamp / Turntable motor / Cooling fan motor APPROX. 25.0V 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-3A88 TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL 7) Relay Circuit The touch control section consists of the following units To drive the magnetron, fan motor, turntable motor and as shown in the touch control panel circuit. light the oven lamp.
  • Page 17 R-3A88 DESCRIPTION OF LSI LSI(IZA683DR) The I/O signal of the LSI(IZA683DR) are detailed in the following table. Pin No. Signal Description Vdisp Anode (segment) of Fluorescent Display light-up voltage: -34V Vp voltage of power source circuit input. Signal coming from touch key.
  • Page 18 R-3A88 Pin No. Signal Description BUZZ Signal to sound buzzer. A: key touch sound (0.12 sec.). B: Completion sound (2.4 sec.). 26-27 D4-D5 Segment data signal. Refer to the touch control panel circuit for the relationship between signals and indicators.
  • Page 19 R-3A88 SERVICING 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. equivalent to the oven door being closed. As for the sensor-...

  • Page 20: Component Replacement And Adjustment Procedure

    R-3A88 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before operating the oven. 1. Disconnect oven from power supply. 1. Door does not close firmly. 2. Make sure that a definite” click” can be heard when the 2.
  • Page 21 R-3A88 plate right. 3. Rest transformer on the bottom plate right with its primary 4. Remove transformer from bottom plate right. terminals toward the oven face plate. 5. Remove the one (1) terminal insulator from filament lead 4. Secure transformer with four screws to bottom plate (longer one) of power transformer.

  • Page 22: Turntable Motor Removal

    4. Where the corners have been snipped off bend corner areas flat. No sharp edge must be evident after removal NOTE: The one (1) screw to fit the turntable motor cover of the turntable motor cover.

  • Page 23: Power Supply Cord Replacement

    R-3A88 OVEN LAMP AND LAMP SOCKET REMOVAL Oven lamp socket 1. CARRY OUT 3D CHECKS. 2. Pull the wire leads from the oven lamp socket by pushing Terminal the terminal hole of the oven lamp socket with the small Wire lead flat type screw driver.

  • Page 24: Door Replacement

    R-3A88 should be less than 0.5mm. The vertical position of the 3. Monitor switch contacts close when door is opened. latch hook should be adjusted so that the 1st. latch 4. Re-install outer case and check for microwave leakage switch 2nd. interlock relay control switch are activated around door with an approved microwave survey meter.
  • Page 25 R-3A88 SEALER FILM Note: After any service to the door; (A) Make sure that door sensing switch and secondary Installation interlock switch are operating properly. (Refer to 1. Put the adhesive tape on the backing film of the sealer chapter "Test Procedures".).

  • Page 26: Microwave Measurement

    R-3A88 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 27: Wiring Diagram

    R-3A88 SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED NOTE: " " indicates components with potentials above 250V. 2. CLOCK APPEARS ON DISPLAY COM. N.O. 2ND. INTERLOCK RELAY CONTROL SWITCH 1ST. LATCH THERMAL CUT-OUT SWITCH 95˚C (FAN) Figure O-1. Oven Schematic-OFF Condition...

  • Page 28: Pictorial Diagram

    R-3A88 RECTIFIER H.V.

  • Page 29: Control Panel Circuit

    R-3A88 UNIT 100K 100K IZA683DR 100K 4.7K 4.7K 4.7K 4.7K HZ4C3 4MHz /16V SP40 3.3K /50V /35V /25V 0.01 /50V /35V VRS1 (J1) (J2)

  • Page 30: Printed Wiring Board

    R-3A88 QKITPB014MRE0 FLR. DISPLAY TAPE (R81) (R80) R75 E (D56) (D55) (J4) (J3) (J6) (J5) R30 R31 (R7) (J7) DOOR CN - B POWER FM TTM OL (D3) (D5) (D4) CN - A (D6) (J1) VRS1 (J2) Figure S-3. Printed Wiring Board...

  • Page 31: Parts List

    R-3A88 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 QSW-MA110WRE0 1st. latch and 2nd. Iinterlock relay control switches...
  • Page 32 R-3A88 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 (J35) VRD-B12EF511J Resistor 510 ohm 1/4W RRLY-A080DRE0 Relay (OJ-SS-124LM) RRLY-A076DRE0...
  • Page 33 R-3A88 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 PACKING AND ACCESSORIES TOP PAD ASSEMBLY FPADBA311WRK0 DOOR PROTECTION SHEET...
  • Page 34 R-3A88 OVEN AND CABINET PARTS 1-13 1-12 4-13 4-12 4-11 6-10 6-15 4-19 6-14 1-17 4-10 4-14 4-18 1-14 4-15 6-11 1-10 1-16 4-17 1-11 1-15 4-16...
  • Page 35 R-3A88 3- 2 CONTROL PANEL PARTS 3- 1 3- 5 3-2-1 DOOR PARTS 3- 3 3- 4 MISCELLANEOUS Actual wire harness may be different from illustration. 6-12...
  • Page 36 R-3A88 '96SHARP CORP. (3U0.07E) Printed in Japan...

Table of Contents