hit counter script
Sharp R-7A55 Service Manual
  1. Manuals
  2. Brands
  3. Sharp Manuals
  4. Microwave Oven
  5. R-7A55
  6. Service manual
Sharp R-7A55 Service Manual

Sharp R-7A55 Service Manual

Grill and convection microwave oven
Hide thumbs
Table of Contents

Advertisement

Quick Links

R-7A55(W)
CAUTION, MICROWAVE RADIATION ................................................................................ INSIDE COVER
PRODUCT SPECIFICATIONS ................................................................................................................... 2
GENERAL IMPORTANT INFORMATION ...................................................................................................2
APPEARANCE VIEW ................................................................................................................................. 3
OPERATION SEQUENCE .......................................................................................................................... 4
FUNCTION OF IMPORTANT COMPONENTS .......................................................................................... 6
SERVICING ................................................................................................................................................ 9
TEST PROCEDURE ................................................................................................................................. 12
TOUCH CONTROL PANEL ....................................................................................................................... 20
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ..................................................... 25
MICROWAVE MEASUREMENT .............................................................................................................. 30
TEST DATA AT A GLANCE ..................................................................................................................... 31
WIRING DIAGRAM ................................................................................................................................... 32
PICTORIAL DIAGRAM ............................................................................................................................. 35
CONTROL PANEL CIRCUIT ..................................................................................................................... 36
PRINTED WIRING BOARD ....................................................................................................................... 38
PARTS LIST ............................................................................................................................................. 39
SERVICE MANUAL
MODELS
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
GRILL AND CONVECTION
MICROWAVE OVEN
R-7A55(W)
R-7A55(B)
R-7E45(W)
R-7E45(B)
R-7A55(W)/(B)
R-7E45(W)/(B)
SY308R7A55EHW
Page

Advertisement

Table of Contents
loading

Related Manuals for Sharp R-7A55

Summary of Contents for Sharp R-7A55

  • Page 1: Table Of Contents

    R-7A55(W)/(B) R-7E45(W)/(B) SERVICE MANUAL SY308R7A55EHW GRILL AND CONVECTION MICROWAVE OVEN R-7A55(W) MODELS R-7A55(B) R-7E45(W) R-7E45(B) R-7A55(W) 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 ................

  • Page 2: Caution Microwave Radiation

    R-7A55(W)/(B) R-7E45(W)/(B) CAUTION MICROWAVE RADIATION Personnel should not be exposed to the microwave energy which may radiate from the magnetron or other microwave generating devices if it is improperly used or connected. All input and output microwave connections, waveguides, flanges and gaskets must be secured.

  • Page 3: Product Specifications

    GENERAL INFORMATION R-7A55(W)/ R-7A55(B)/R-7E45(W)/R-7E45(B) GENERAL IMPORTANT INFORMATION APPEARANCE VIEW This Manual has been prepared to provide Sharp Corp. Service engineers with Operation and Service Information. It is recommended that service engineers carefully study the OPERATING SEQUENCE entire text of this manual, so they will be qualified to render satisfactory customer service.

  • Page 4: General Important Information

    MEDIUM ......approx. 50% of FULL Power MEDIUM LOW ....approx. 30% of FULL Power LOW ........approx. 10% of FULL Power POTATO keys (R-7A55 only) INSTANT ACTION keys (R-7A55 only) LESS( )/MORE( ) (R-7A55 only) DUAL COOK, GRILL, MICROWAVE, CONVECTION MINUTE TIMER/HOLD...

  • Page 5: Appearance View

    R-7A55(W)/(B) R-7E45(W)/(B) APPEARANCE VIEW OVEN Door Door hinges Grill heating elements Oven lamp Ventilation openings Wave guide cover Control panel Outer cabinet Coupling Rear cabinets Door lock openings Oven cavity Door seals and sealing surfaces Power supply cord Safety door latches...

  • Page 6: Operation Sequence

    R-7A55(W)/(B) R-7E45(W)/(B) OPERATION SEQUENCE OFF CONDITION COM-NO of the 2nd latch switch are made open. The relay Closing the oven door activates all door interlock switches RY2 and RY6 are made open when the door is opened. The (1st. latch switch, 2nd. latch switch and stop switch.
  • Page 7 R-7A55(W)/(B) R-7E45(W)/(B) 2. The coil of shut-off relay RY3 is energized by the control convection motor are energized. unit and the main supply voltage is added to the convection 3. Relay RY3 is energized (If the cavity temperature is lower heating element.

  • Page 8: Function Of Important Components

    R-7A55(W)/(B) R-7E45(W)/(B) FUNCTION OF IMPORTANT COMPONENTS MONITOR RESISTOR R1 DOOR OPEN MECHANISM The monitor resistor prevents the fuse F2 F6.3A 250V The door can be opened by pushing the open button on the bursting when the fuse F2 F6.3A 250V blows due to the control panel.
  • Page 9 R-7A55(W)/(B) R-7E45(W)/(B) ASYMMETRIC RECTIFIER CONVECTION COOKING SYSTEM The asymmetric rectifier is solid state device that prevents This oven is designed with a hot air heating system where current flow is both directions. And it prevents the tempera- food is not directly heated up by the convection heating...
  • Page 10 R-7A55(W)/(B) R-7E45(W)/(B) DAMPER OPEN-CLOSE MECHANISM SENSING FIRE OPERATION Usually, the damper is in the open position except during The oven will stop its operation when there is a fire in the convection cooking, grill cooking and dual cooking. oven cavity in microwave cooking condition.

  • Page 11: Servicing

    3D checks and re-examine the insulated screwdriver. 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 12 R-7A55(W)/(B) R-7E45(W)/(B) TEST PROCEDURE A B C D E E E E F E G G G H POSSIBLE CAUSE DEFECTIVE PARTS PROBLEM Fuse F2 F6.3A browns when the door is opened. Home fuse blows when power cord is plugged into wall outlet.
  • Page 13 R-7A55(W)/(B) R-7E45(W)/(B) H H H L I K J M M N...
  • Page 14 R-7A55(W)/(B) R-7E45(W)/(B) 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 15: Test Procedure

    R-7A55(W)/(B) R-7E45(W)/(B) TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER 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 (42 + 2) = 44 sec.
  • Page 16 R-7A55(W)/(B) R-7E45(W)/(B) TEST PROCEDURES (CONT'D) PROCEDURE LETTER COMPONENT TEST Isolate the high voltage rectifier assembly from the HV circuit. The asymmetric can be tested using an ohmmeter set to its highest range across the terminals A+B of the asymmetric rectifier and note the reading obtained.
  • Page 17 R-7A55(W)/(B) R-7E45(W)/(B) TEST PROCEDURES (CONT'D) PROCEDURE LETTER COMPONENT TEST THERMAL CUT-OUT TEST CARRY OUT 3D CHECKS Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make a continuity test across the two terminals as described in the below.
  • Page 18 R-7A55(W)/(B) R-7E45(W)/(B) TEST PROCEDURES (CONT'D) PROCEDURE LETTER COMPONENT TEST FUSE F1 15A CARRY OUT 3D CHECKS If the fuse F1 15A is blown, there is a shorts or grounds in electrical parts or wire harness. Check them and replace the defective parts or repair the wire harness.
  • Page 19 R-7A55(W)/(B) R-7E45(W)/(B) TEST PROCEDURES (CONT'D) PROCEDURE LETTER COMPONENT TEST THERMOSTAT TEST CARRY OUT 3D CHECKS. Disconnect connector B from CPU unit. Measure the resistance of thermistor with an ohmmeter. Connect the ohmmeter leads to Pin No's B5 and B6 of the thermistor harness.
  • Page 20 R-7A55(W)/(B) R-7E45(W)/(B) TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER STOP G-10 G-11 G-12 KEY UNIT R-7A55(B)/(W) STOP G-10 G-11 G-12 KEY UNIT R-7E45(B)/(W) CARRY OUT 4R CHECKS RELAY TEST CARRY OUT 3D CHECKS Remove the outer case and check voltage between Pin Nos. 1 and 3 of the 9 pin connector (A) on the control unit with an A.C.
  • Page 21 R-7A55(W)/(B) R-7E45(W)/(B) TEST PROCEDURES (CONT'D) PROCEDURE COMPONENT TEST LETTER PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRIN ING BOAD(PWB) IS OPEN 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.

  • Page 22: Touch Control Panel

    R-7A55(W)/(B) R-7E45(W)/(B) TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOIUCH CONTROL PANEL The touch control section consists of the following clock circuit. It accompanies a very small error units because it works on commercial frequency. as shown in the touch control panel circuit.
  • Page 23 R-7A55(W)/(B) R-7E45(W)/(B) DESCRIPTION OF LSI LSI(IZA516DR) The I/O signal of the LSI(IZA516DR) is detailed in the following table. Pin No. Signal Description Convection motor driving signal. During cooking To turn on and off shut-off relay (RY4). "L" level (Convection) during CONVECTION; "H" level otherwise.
  • Page 24 R-7A55(W)/(B) R-7E45(W)/(B) Pin No. Signal Description Temperature measurement input: OVEN THERMISTOR. By inputting DC voltage corresponding to the temperature detected by the themistor, this input is converted into temperature by the A/D converter built into the LSI. 21-27 AN1-AN7 Terminal not used.
  • Page 25 R-7A55(W)/(B) R-7E45(W)/(B) Pin No. Signal Description 48-49 R80-R81 Segment data signal. Signal similar to D12. Segment data signal. Signal similar to D12. Key strobe signal. Signal applied to touch-key section. A pulse signal is input to R20-R23 terminal while one of G-3 line keys on key matrix is touched.
  • Page 26 R-7A55(W)/(B) R-7E45(W)/(B) SERVICING 1. Precautions for Handling Electronic the touch control panel and the oven itself is so Components short that the two can’t be separated. For those This unit uses CMOS LSI in the integral part of the models, check and repair all the controls (sensor- circuits.

  • Page 27: Component Replacement And Adjustment Procedure

    R-7A55(W)/(B) R-7E45(W)/(B) COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before operating the oven. 1. CARRY OUT 3D CHECKS. 1. Door does not close firmly. 2. Make sure that a definite” click” can be heard when the 2.
  • Page 28 R-7A55(W)/(B) R-7E45(W)/(B) MAGNETRON REMOVAL 1. CARRY OUT 3D CHECKS. magnetron to prevent it from falling. 2. Remove the air separate duct B from the chassis support 8. Remove the magnetron from the waveguide with care so and the air intake duct.
  • Page 29 R-7A55(W)/(B) R-7E45(W)/(B) OVEN LAMP SOCKET REMOVAL Oven lamp socket 1. CARRY OUT 3D CHECKS Terminal 2. Pull the wire leads from the oven lamp socket by Wire lead pushing the terminal hole of the oven lamp socket with Flat type small the flat type small screw driver.
  • Page 30 R-7A55(W)/(B) R-7E45(W)/(B) GRILL HEATING ELEMENT ASSEMBLY REMOVAL 4. Push the two tabs holding the grill heating element 1. CARRY OUT 3D CHECKS assembly to the oven cavity. 2. Disconnect the wire leads to the grill heating element. 5. Release the grill heating element assembly from the 3.
  • Page 31 R-7A55(W)/(B) R-7E45(W)/(B) DOOR REPLACEMENT AND ADJUSTMENT REPLACEMENT 1. Adjust door latch heads at a position where they smoothly 1. CARRY OUT 3D CHECKS catch the latch hook through the latch holes. Refer to 2. Remove three (3) screws holding the lower oven hinge to latch switch adjustments.

  • Page 32: Microwave Measurement

    R-7A55(W)/(B) R-7E45(W)/(B) MICROWAVE MEASUREMENT After adjustment of door latch switches, monitor switch Recommended instruments are: 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 33: Test Data At A Glance

    R-7A55(W)/(B) R-7E45(W)/(B) TEST DATA AT A GLANCE Parts Symbol Value / Data Fuse 15A 250V Fuse F6.3A 250V Fuse F10A 250V Monitor resistor 4.3Ω 20W Thermal cut-out 170˚C Thermal cut-out 125˚C Thermal cut-out 190˚C (Off point) 170˚C (On point) Thermistor Approx.
  • Page 34 R-7A55(W)/(B) R-7E45(W)/(B) Note: SCHEMATIC AC CORD CONNECTION NOTE: CONDITION OF OVEN BRN : BROWN BLU : BLUE 1.DOOR CLOSED. G-Y : GREEN AND 2.CLOCK APPEARS ON DISPLAY. YELLOW STRIPE : SECTIONAL AREA OF 1.5mm MIN. SW4: MONITOR SWITCH SW1: 1ST LATCH SWITCH...
  • Page 35 R-7A55(W)/(B) R-7E45(W)/(B) SCHEMATIC Note: NOTE: CONDITION OF OVEN AC CORD CONNECTION BRN : BROWN 1. DOOR CLOSED. BLU : BLUE 2. COOKING TIME PROGRAMMED. G-Y : GREEN AND 3. CONVECTION KEY TOUCHED YELLOW STRIPE /15 : SECTIONAL AREA ONCE. OF 1.5mm MIN.
  • Page 36 R-7A55(W)/(B) R-7E45(W)/(B) SCHEMATIC Note: NOTE: CONDITION OF OVEN AC CORD CONNECTION BRN : BROWN 1. DOOR CLOSED. BLU : BLUE 2. COOKING TIME PROGRAMMED. G-Y : GREEN AND 3. DUAL COOK KEY TOUCHED ONCE. YELLOW STRIPE : SECTIONAL AREA 4. START KEY TOUCHED.
  • Page 37 R-7A55(W)/(B) R-7E45(W)/(B)
  • Page 38 R-7A55(W)/(B) R-7E45(W)/(B)
  • Page 39 R-7A55(W)/(B) R-7E45(W)/(B)
  • Page 40 R-7A55(W)/(B) R-7E45(W)/(B) (C92) (R91) (R90) F ⁄ ( c 70) ( c 71) (J8) (J7) (J6) (R100) (J4) CN |H (R94) VRS1 (R97) (R96) (R95)(J9) (ZD3) (Q2) (R93) (J2) Figure S-5 Printed Wiring Board...

  • Page 41: Parts List

    R-7A55(W)/(B) R-7E45(W)/(B) PARTS LIST ∆ Note: The parts marked " " may cause undue microwave exposure. / The parts marked "*" are used in voltage more than 250V. / "§" Mark: Spare parts delivery section REF. NO. PART NO. §...
  • Page 42 Varistor (15G471K-T) VHEHZ6A3///-1 Zener diode (HZ6A3) VHEHZ4C3///-1 Zener diode (HZ4C-3) VHEHZ202///-1 Zener diode (HZ20-2) 3- 2 DUNTKA579WRK0 Key unit assembly [R-7A55(B)] 3- 2 DUNTKA580WRK0 Key unit assembly [R-7A55(W)] 3- 2 DUNTKA577WRK0 Key unit assembly [R-7E45(B)] 3- 2 DUNTKA578WRK0 Key unit assembly [R-7E45(W)]...
  • Page 43 Operation manual for R-7E45(B)/(W) 6-12 TSPCNB921WRR0 Rating label 6-13 TCADCA500WRR0 Cook book 6-14 TLABMA372WRR0 Menu label for R-7A55(W) only 6-14 TLABMA370WRR0 Menu label for R-7A55(B) only SCREWS,NUTS AND WASHERS 7- 1 XHPSD40P08K00 Screw : 4mm x 8mm 7- 2 XFPSD30P08000...
  • Page 44 R-7A55(W)/(B) R-7E45(W)/(B) ∆ Note: The parts marked " " may cause undue microwave exposure. / The parts marked "*" are used in voltage more than 250V. / "§" Mark: Spare parts delivery section REF. NO. PART NO. § DESCRIPTION Q'TY CODE...
  • Page 45 R-7A55(W)/(B) R-7E45(W)/(B) OVEN PARTS 7-20 4-38 7-20 4-33 7-16 7-20 7-22 4-30 4-40 4-13 4-11 7-20 7-20 4-36 7-20 7-11 7-10 7-13 7-12 7-18 7-22 7-24 7-16 4-10 7-23 7-10 7-17 4-12 7-16 7-17 4-19 7-16 4-21 7-17 7-16 4-18...
  • Page 46 R-7A55(W)/(B) R-7E45(W)/(B) CONTROL PANEL PARTS DOOR PARTS...
  • Page 47 HIGH RACK *(SSAKHA044WRE0) LOW RACK DOOR PROTECTION SHEET *(SPADPA468WRE0) COOK BOOK COVER *(SSAKHA045WRE0) COOK BOOK & INSTRUCTION BOOK ROLLER STAY BOTTOM PAD ASSEMBLY TRAY PAD *(FPADBA273WRK0) *(SPADPA474WRE0) PACKING CASE *(SPAKCC251WRR0); R-7A55(B) *(SPAKCC255WRR0); R-7A55(W) *(SPAKCC250WRR0); R-7E45(B) *Not Replaceable Items. *(SPAKCC254WRR0); R-7E45(W)
  • Page 48 R-7A55(W)/(B) R-7E45(W)/(B) '93 SHARP CORP. (12S1.31E) Printed in Germany...

This manual is also suitable for:

R-7e45R-7a55wR-7a55bR-7e45wR-7e45b

Table of Contents