Sharp R-1850 Service Manual

Over the range microwave oven

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BEFORE SERVICING ........................................................................................................................................... 1
MICROWAVE MEASUREMENT PROCEDURE ................................................................................................... 2
FOREWORD .......................................................................................................................................................... 3
PRODUCT SPECIFICATIONS .............................................................................................................................. 4
GENERAL INFORMATION ................................................................................................................................... 4
OPERATION .......................................................................................................................................................... 6
TROUBLESHOOTING GUIDE ............................................................................................................................ 14
TEST PROCEDURE ............................................................................................................................................ 16
TOUCH CONTROL PANEL ................................................................................................................................. 23
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................ 29
PICTORIAL DIAGRAM ........................................................................................................................................ 37
CONTROL PANEL CIRCUIT ............................................................................................................................... 38
PRINTED WIRING BOARD ................................................................................................................................. 39
PARTS LIST ........................................................................................................................................................ 40
PACKING AND ACCESSORIES ......................................................................................................................... 46
SHARP ELECTRONICS CORPORATION
Service Headquarters:
SERVICE MANUAL
MODELS
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.

TABLE OF CONTENTS

Sharp Plaza,
Mahwah,
OVER THE RANGE
MICROWAVE OVEN
R-1850
R-1851
New Jersey
07430-2135
R-1850
R-1851
S6804R1850X//
Page

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Summary of Contents for Sharp R-1850

  • Page 1: Table Of Contents

    COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ..............29 PICTORIAL DIAGRAM ............................37 CONTROL PANEL CIRCUIT ..........................38 PRINTED WIRING BOARD ..........................39 PARTS LIST ................................ 40 PACKING AND ACCESSORIES ......................... 46 SHARP ELECTRONICS CORPORATION Service Headquarters: Sharp Plaza, Mahwah, New Jersey 07430-2135...
  • Page 2: Precautions To Be Observed Before And During Service To Avoid Possible Exposure To Excessive Microwave Energy

    R-1850 R-1851 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. (b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other...
  • Page 3: Before Servicing

    Before servicing an operative unit, perform a microwave emission check as per the Microwave Measurement Procedure outlined in this service manual. If microwave emissions level is in excess of the specified limit, contact SHARP ELECTRONICS CORPORATION immediately @ 1-800-237-4277. If the unit operates with the door open, service person should 1) tell the user not to operate the oven and 2) contact SHARP ELECTRONICS CORPORATION and Food and Drug Administration's Center for Devices and Radiological Health immediately.
  • Page 4: Microwave Measurement Procedure

    R-1850 R-1851 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/cm at any point 5cm or more from the external surface of the oven, measured prior to acquisition...
  • Page 5: Foreword

    MICROWAVE OVEN GENERAL INFORMATION R-1850 / R-1851 FOREWORD OPERATION This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service Informa- tion for the SHARP OVER THE RANGE MICROWAVE OV- ENS, R-1850/ R-1851. TROUBLESHOOTING GUIDE AND...
  • Page 6: Product Specifications

    R-1850 R-1851 SPECIFICATION ITEM DESCRIPTION Power Requirements 120 Volts / 13.2 Amperes (Microwave), 13.2 Amperes (Convection) 60 Hertz Single phase, 3 wire grounded Power Output 850 watts (IEC-705 TEST PROCEDURE) Operating frequency of 2450MHz Convection Power Output 1400 watts Case Dimensions Width 29-15/16"...
  • Page 7: Oven Diagram

    R-1850 R-1851 Electrical Requirements The oven is equipped with a 3-prong grounding plug. DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE GROUNDING PIN FROM THE PLUG. The power supply cord and plug must be connected to a separate 120 Volt AC, 60 Hz, 15 Amp. or more branch circuit, using a grounded receptacle.
  • Page 8: Operation

    R-1850 R-1851 OPERATION DESCRIPTION OF OPERATING SEQUENCE The following is a description of component functions during (1) When the door opens from a closed position, the primary interlock relay and secondary interlock switch oven operation. open their contacts, and then the monitor switch contacts close.
  • Page 9 R-1850 R-1851 2. The shut-off relays (RY1, RY4, RY5 and RY7) are energized, the oven lamp, turntable motor, cooling fan energized, turning on the oven lamp, turntable motor, motor and convection motor are turned on. cooling fan motor and convection motor.
  • Page 10 R-1850 R-1851 BROIL, COMPU ROAST or COMPU BAKE pad, and number pad. Enter the weight by touching the Number pads. When the START pad is touched, the following operations occur: 1. The COOK indicator will light and the CONV or MIX indicator will light.
  • Page 11 R-1850 R-1851 3. Once the fire sensor feature has shut the unit down, the 3. RE-CIRCULATION (INSIDE VENTING) programmed cooking cycle may be resumed by pressing The air handing is same as VERTICAL VENTING except the "START" pad or the unit may be reset by pressing the that the final air discharge is directed horizontally through "CLEAR"...
  • Page 12 R-1850 R-1851 SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. CLOCK APPEARS ON DISPLAY. MAGNETRON TEMPERATURE FUSE COM. N.O. CONTROL UNIT FUSE AH SENSOR POWER TRANSFORMER HOOD FAN THERMAL CUT OUT RY10 HOOD 120 V AC. CAPACITOR 60 Hz COM.
  • Page 13 R-1850 R-1851 SCHEMATIC NOTE: CONDITION OF OVEN 1. DOOR CLOSED. 2. CONVECTION PAD TOUCHED. 3. DESIRED TEMP. TOUCHED. 4. START PAD TOUCHED. MAGNETRON TEMPERATURE FUSE COM. N.O. CONTROL UNIT FUSE AH SENSOR POWER TRANSFORMER HOOD FAN THERMAL CUT OUT RY10 HOOD 120 V AC.
  • Page 14 R-1850 R-1851 DESCRIPTION AND FUNCTION OF COMPONENTS (On opening the door, each of these switches operate DOOR OPEN MECHANISM inversely.) The door is opened by pushing the open button on the 3. If the door is opened, and the primary interlock relay and control panel, refer to the Figure D-1.
  • Page 15 R-1850 R-1851 STIRRER MOTOR Damper Operation 1. When power supply cord is plugged in: The stirrer motor drives the stirrer fan to stir the microwave 1-1. When power supply cord is plugged in, a signal is radiation from the waveguide.
  • Page 16: Troubleshooting Guide

    R-1850 R-1851 TROUBLESHOOTING GUIDE 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"...
  • Page 17 R-1850 R-1851 IMPORTANT: If the oven becomes inoperative because of a blown monitor fuse, check the monitor switch, primary interlock relay, door sensing switch and secondary interlock switch before replacing the monitor fuse. If monitor fuse is replaced, the monitor switch must also be replaced. Use part FFS-BA016/KIT as an assembly.
  • Page 18: Test Procedure

    R-1850 R-1851 TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER MAGNETRON ASSEMBLY TEST HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD BE OBSERVED. DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING. 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.
  • Page 19 R-1850 R-1851 TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER HIGH VOLTAGE CAPACITOR TEST DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING. If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads and check for short or open between the terminals using an ohmmeter.
  • Page 20 R-1850 R-1851 TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER BLOWN MONITOR FUSE If the monitor fuse in the secondary-monitor switch and primary interlock relay circuit is blown when the door is opened, check the primary interlock relay, door sensing switch, secondary interlock switch and monitor switch according to the "TEST PROCEDURE"...
  • Page 21 R-1850 R-1851 TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER DAMPER MOTOR TEST When the power cord is plugged into the wall receptacle and 120 volts A.C. is supplied to the damper motor, the motor operates until the damper is opened and the damper switch closes. Then the damper motor stops operation.
  • Page 22 R-1850 R-1851 TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER Note: When defective components, the Control Unit or Key Unit are replaced, the defective part or parts must be properly packed for return in the shipping carton, with its cushion material, in which the new replacement part was shipped to you.
  • Page 23 R-1850 R-1851 TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER 4. Touch " START " pad. 5. The oven will operate as follows. MENU WEIGHT 1ST STAGE 2ND STAGE 3RD STAGE (LBS) LEVEL TIME LEVEL TIME LEVEL TIME 28sec. 5sec. 1min.28sec. CHICKEN PIECES 6.
  • Page 24 R-1850 R-1851 TEST PROCEDURES PROCEDURE COMPONENT TEST LETTER sensor will detect the vapor given of by the spray and turn off before food is properly cooked. (8) If the sensor has not detected the vapor of the food, ERROR will appear and the oven will shut off.
  • Page 25: Touch Control Panel

    R-1850 R-1851 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...
  • Page 26: Description Of Lsi

    R-1850 R-1851 DESCRIPTION OF LSI LSI(IZA719DR) The I/O signals of the LSI(IZA719DR) are detailed in the following table. Pin No. Signal Description Connected to GND. Anode (segment) of Fluorescent Display illumination voltage: -31V. Vp voltage of power source circuit input.
  • Page 27 R-1850 R-1851 Pin No. Signal Description Convection motor driving signal. During To turn on and off shut-off relay(RY7). "L" level during cooking (Convection) CONVECTION; "H" level otherwise. Hood lamp driving signal. H : GND To turn on and off relay(RY8). "L" level: During Hood lamp ON.
  • Page 28 R-1850 R-1851 Pin No. Signal Description XOUT Internal clock oscillation frequency control output. Output to control oscillation input of XIN. Power source voltage:-5V. VC voltage of power source circuit input. Signal coming from touch key. When any one of G12 line keys on key matrix is touched, a corresponding signal will be input into P27.
  • Page 29 R-1850 R-1851 Pin No. Signal Description Key strobe signal. Signal applied to touch-key section. A pulse signal is input to AN1 and P27 - P24 terminal while one of G2 line keys on key matrix is touched. Segment data signal.
  • Page 30 R-1850 R-1851 SERVICING B. On some models, the power supply cord between the 1. Precautions for Handling Electronic Components touch control panel and the oven proper is long enough This unit uses CMOS LSI in the integral part of the that they may be separated from each other.
  • Page 31: Component Replacement And Adjustment Procedure

    R-1850 R-1851 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE CAUTION: DISCONNECT OVEN FROM POWER SUPPLY BEFORE REMOVING OUTER CASE. DISCHARGE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING AFTER REMOVING OUTER CASE. THE FOLLOWING ADJUSTMENTS OR COMPONENT REPLACEMENT CAN BE PERFORMED WITHOUT REMOVING THE OVEN FROM THE WALL 1.
  • Page 32: Pictorial Diagram

    R-1850 R-1851 3. Re-connect wire leads (primary and high voltage) to the transformer. transformer and filament leads of transformer to 5. Disconnect wire leads from transformer. magnetron and high voltage capacitor. Refer to 6. Remove two (2) screws holding the transformer to base "PICTORIAL DIAGRAM".
  • Page 33 R-1850 R-1851 8. Disconnect the high voltage rectifier assembly from the CAUTION: WHEN REPLACING THE HIGH VOLTAGE high voltage capacitor. RECTIFIER ASSEMBLY, THE GROUND SIDE 9. Now, the high voltage rectifier assembly is free. TERMINAL MUST BE SECURED FIRMLY 10.Remove capacitor from the holder.
  • Page 34 R-1850 R-1851 3. Install the fan duct assembly to the oven cavity with the And reverse their procedure. one (1) screw. And install the hood intake duct R, hood exhaust duct 4. Install the magnetron duct to the fan duct and oven and outer case.
  • Page 35 R-1850 R-1851 2. To remove the middle section push both sides of the 6. Release the control panel from the oven cavity front face middle section towards d until c breaks as shown in plate by lifting it up. step 2.
  • Page 36 R-1850 R-1851 CONVECTION DUCT ASSEMBLY REMOVAL 1. Unplug the oven from power outlet, remove the oven using by long nose pliers as shown following from wall and remove outer case. (Refer to procedure of illustration. "Removal of Oven from Wall" and Outer case Removal") Long nose plier 2.
  • Page 37: Door Replacement

    R-1850 R-1851 4. Make sure that the monitor switch is operating properly diagram. and check continuity of the monitor circuit. Refer to 3. Secure the latch hook (with two (2) mounting screws) to chapter "Test Procedure" and "Adjustment procedure". oven cavity front flange.
  • Page 38: Door Disassembly

    R-1850 R-1851 around door with an approved microwave survey meter. Hood Exhaust Louver (Refer to Microwave Measurement Procedure.) Upper Door Hinge Pin Upper Note: The door on a microwave oven is designed to Oven Hinge act as an electronic seal preventing the leakage...
  • Page 39 R-1850 R-1851...
  • Page 40: Control Panel Circuit

    R-1850 R-1851 3.3k 3.3k 3.3k 3.3k 3.3k 3.3k 100k 100k 3.3k 100k R100 3.3k 3.3k 3.3k 3.3k 3.3k IZA719DR 100k 4.7k (J7) (J5) 4.7k 220F 3.6kF HZ4A2 (J3) (J6) /35v (J4) /50v /50v (J2) HZ5C2 3.3k /35v /50v /50v HZ16-1 SP40 1.5k...
  • Page 41: Printed Wiring Board

    R-1850 R-1851 TAPE R100 ,BFB (D65) (R65) (C65) CN - E (JA) OVEN LAMP RY10 VRS1 CN - B CN - A CONV DAMP FAN.M T T M AC (N) MOTOR CAPACITOR Figure S-3. Printed Wiring Board...
  • Page 42: Parts List

    Base plate left 2- 5 GCABUB065MRP0 Outer case cabinet 2- 6 TMAPCB050MRR0 Schematic diagram 2- 7 FANGKB009MRY0 Hood lamp glass assembly [R-1850] 2- 7 FANGKB010MRY0 Hood lamp glass assembly [R-1851] 2-7-1 LANGQB016MRP0 Hood lamp glass angle [R-1850] 2-7-1 LANGQB020MRP0 Hood lamp glass angle [R-1851]...
  • Page 43 Zener diode (HZ6A-3) VHEHZ161///-1 Zener diode (HZ16-1) VHEHZ5C2///-1 Zener diode (HZ5C-2) VHEHZ4A2///-1 Zener diode (HZ4A-2) 3- 2 FPNLCB153MRK0 Control panel sub. assembly [R-1850] 3- 2 FPNLCB154MRK0 Control panel sub. assembly [R-1851] 3- 2-1 FUNTKB108MRE0 Key unit [R-1850] 3- 2-1 FUNTKB109MRE0...
  • Page 44 Cushion 4-48 PCUSUB021MRP0 Cushion 4-49 PCUSUB024MRP0 Cushion 4-50 PCUSGB031MRP0 Cushion DOOR PARTS CDORFB166MRK0 Door assembly, complete [R-1850] CDORFB167MRK0 Door assembly, complete [R-1851] 5- 1 DDORFB069MRY0 Door panel assembly 5- 2 GWAKPB058MRF0 Door frame [R-1850] 5- 2 GWAKPB059MRF0 Door frame [R-1851]...
  • Page 45 To have your order filled promptly and correctly, please furnish the following information. 1. MODEL NUMBER 2. REF. NO. 3. PART NO. 4. DESCRIPTION Order Parts from the authrized SHARP parts Distributor for your area. Defective parts required return should be returned as indicated in the Service Policy.
  • Page 46 R-1850 R-1851 OVEN AND CABINET PARTS 1-17 7-25 7-24 4-16 7-24 2-10 4-39 4-46 7-11 4-36 4-25 7-24 7-24 4-37 1-21 4-24 7-11 4-40 4-45 7-17 1-13 4-38 7-11 4-22 7-20 4-44 4-20 7-21 1-16 7-14 7-15 1-18 1-20 7-23...
  • Page 47 R-1850 R-1851 CONTROL PANEL PARTS 3-2-2 3-2-6 DOOR PARTS 3-2-1 4-35 3-2-5 3-2-4 3-2-3 MISCELLANEOUS 6-1-1 6-1-4 6-1-5 6-1-2 6-1-6 6-1-7 6-1-3 6-10 6-11...
  • Page 48: Packing And Accessories

    LOW RACK 6-10 HIGH RACK BOTTOM PAD SPADBB018MRE0 MILLER MAT 4-3 TURNTABLE TRAY PACKING CASE TAPE SPAKCB211MRR1 (R-1850) SPAKCB211MRR2 (R-1851) 4-2 TURNTABLE Non-replaceable items SUPPORT ASSEMBLY TRAY HOLDER 4-1 DAMPER ASSEMBLY DAMPER HOLDER '96 SHARP CORP. (8K5.550E) Printed in U.S.A...

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