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R-203CW

SHARP ELECTRONICS CORPORATION

SHARP PLAZA, MAHWAH,

NEW JERSEY 07430-2135

SERVICE MANUAL

MICROWAVE OVEN

R-203CW

FOREWORD

This Manual has been prepared to provide Sharp Electronics Corp.
Service Personnel with Operation and Service Information for the
SHARP MICROWAVE OVEN, R-203CW.

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. Special
attention should be given to avoid electrical shock and microwave
radiation hazard.

WARNING

Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is no other visible damage with the oven.

Servicing and repair work must be carried out only by trained service
personnel.

DANGER

Certain initial parts are intentionally not grounded and present
a risk of electrical shock only during servicing. Service
personnel - Do not contact the following parts while the
appliance is energized;
High Voltage Capacitor, Power Transformer, Magnetron, High
Voltage Rectifier Assembly,  High Voltage Harness;
If provided, Vent Hood, Fan assembly, Cooling Fan Motor.

All the parts marked “*” on parts list are used at voltages more than
250V.

Removal of the outer wrap gives access to voltage above 250V.

All the parts marked “

” on parts list may cause undue microwave

exposure, by themselves, or when they are damaged, loosened
or removed.

PRODUCT DESCRIPTION

GENERAL INFORMATION

OPERATION

TROUBLESHOOTING GUIDE AND
TEST PROCEDURE

TOUCH CONTROL PANEL

COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE

WIRING DIAGRAM

PARTS LIST

Summary of Contents for R-203CW

Page 1: ...INSIDE FRONT COVER WARNING TO SERVICE PERSONNEL 1 MICROWAVE MEASUREMENT PROCEDURE 2 FOREWORD AND WARNING 3 PRODUCT SPECIFICATIONS 4 GENERAL INFORMATION 4 OPERATION 6 TROUBLESHOOTING GUIDE 8 TEST PROCEDURE 10 TOUCH CONTROL PANEL 17 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE 21 PICTORIAL DIAGRAM 27 CONTROL PANEL CIRCUIT 28 PRINTED WIRING BOARD 29 PARTS LIST 30 PACKING AND ACCESSORIES 34 S2902R20...

Page 2: ... and transmission systems shall be repaired replaced or adjusted by procedures described in this manual before the oven is released to the owner e A microwave leakage check to verify compliance with the Federal Performance Standard should be performed on each oven prior to release to the owner BEFORE SERVICING Before servicing an operative unit perform a microwave emission check as per the Microwa...

Page 3: ...acitor 4 Disconnect the leads to the primary of the power transformer 5 Ensure that the leads remain isolated from other components and oven chassis by using insulation tape 6 After that procedure reconnect the power supply cord When the testing is completed 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 Reconnec...

Page 4: ...e oven cavity The water container shall be a low form of 600 ml 20 oz beaker with an inside diameter of approx 8 5 cm 3 1 2 in and made of an electrically nonconductive material such as glass or plastic The placing of this standard load in the oven is important not only to protect the oven but also to insure that any leakage is measured accurately 4 Set the cooking control on Full Power Cooking Mo...

Page 5: ...amaged D The door is not deformed or warped E There is no other visible damage with the oven Servicing and repair work must be carried out only by trained service personnel DANGER Certaininitialpartsareintentionallynotgroundedandpresent a risk of electrical shock only during servicing Service personnel Do not contact the following parts while the appliance is energized HighVoltageCapacitor PowerTr...

Page 6: ...uency 2450 MHz Case Dimensions Width 18 1 8 Height 11 3 8 Depth 14 5 8 Cooking Cavity Dimensions Width 12 3 8 0 7 Cubic feet Height 7 7 8 Depth 12 5 8 Control Complement Touch Control System Clock 1 00 12 59 Timer 0 99 minutes 99 seconds Microwave Power for Variable Cooking Repetition Rate P HI Full power throughout the cooking time P 90 approx 90 of FULL Power P 80 approx 80 of FULL Power P 70 ap...

Page 7: ...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 3 Pronged Plug Grounded Receptacle Box Grounding Pin 3 Pronged Receptacle OVEN DIAGRAM 1 Oven door with see through window 2 Safety door latches 3 Door hinges 4 Door seals and sealing surfaces 5 Turntable motor shaft 6 Removable turntable support 7 Removable...

Page 8: ...th the following results The circuits to the oven lamp turntable motor the cooling fan motor and the high voltage components are de energized and the digital read out displays the time still remaining in the cook cycle when the door was opened 7 Themonitorswitchiselectricallymonitoringtheoperation of the secondary interlock switch and primary interlock relay RY2 and is mechanically associated with...

Page 9: ...T OUT A1 DESCRIPTION AND FUNCTION OF COMPONENTS DOOR OPEN MECHANISM The door is opened by pulling the door refer to the Figure D 1 Latch Heads Latch Hook Door Door Sensing Switch Monitor Switch Secondary Interlock Switch Figure D 1 Door Open Mechanism DOOR SENSING AND SECONDARY INTERLOCK SWITCHES The secondary interlock switch is mounted in the lower position of the latch hook and the door sensing...

Page 10: ...e etc Undernormaloperation thethermalcut outremainsclosed However when abnormally high temperatures are reached within the magnetron the thermal cut out will open at 257 F 125 C causing the oven to shut down C T FUSE 1 The C T fuse blows when the contacts COM NO of the primary interlock relay RY2 and secondary interlock switch remain closed with the oven door open and when the monitor switch close...

Page 11: ...PATTERN ON PWB Home fuse blows when power cord is plugged into wall receptacle C T fuse blows when power cord is plugged into wall receptacle All letters and indicators do not ap pear 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 time of day should appear in display C T fuse blows when the door ...

Page 12: ...Power output of the magnetron can be measured by performing a water temperature rise test This test shouldonlybeusedifabovetestsdonotindicateafaultymagnetronandthereisnodefectinthefollowing componentsorwiring siliconrectifier highvoltagecapacitorandpowertransformer Thistestwillrequire a 16 ounce 453cc measuring cup and an accurate mercury thermometer or thermocouple type temperature tester For acc...

Page 13: ...ns An open thermal cut out indicates overheating of the magnetron Check for restricted air flow to the magnetron especially the cooling fan air guide 5 Reconnect all leads removed from components during testing 6 Reinstall the outer case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 Run the oven and check all functions CAUTION IFTHETHERMALCUT OUTINDICATESANOPENCIRCU...

Page 14: ... removed from components during testing 6 Reinstall the outer case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 Run the oven and check all functions PRIMARY INTERLOCK SYSTEM TEST DOOR SENSING SWITCH 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 Isolatetheswitchandconnecttheohmmet...

Page 15: ...ERATURE REPLACE THE C T FUSE 5 Reconnect all leads removed from components during testing 6 Reinstall the outer case cabinet 7 Reconnect the power supply cord after the outer case is installed 8 Run the oven and check all functions The touch control panel consists of circuits including semiconductors such as LSI ICs etc Therefore unlike conventional microwave ovens proper maintenance cannot be per...

Page 16: ... Discharge high voltage capacitor 4 Reconnect all leads removed from components during testing 5 Re install the outer case cabinet 6 Reconnect the power supply cord after the outer case is installed 7 Run the oven and check all functions TEST PROCEDURES PROCEDURE LETTER COMPONENT TEST J KEY UNIT TEST 1 Disconnect the power supply cord and then remove outer case 2 Open the door and block it open 3 ...

Page 17: ...and the common terminal of the relay RY2 on the control unit with an A C voltmeter The meter should indicate 120 volts if not check oven circuit RY1 and RY2 Relay Test These relays are operated by D C voltage Check voltage at the relay coil with a D C voltmeter during the microwave cooking operation DC voltage indicated Defective relay DC voltage not indicated Check diode which is connected to the...

Page 18: ...oubleshooting guide given below if indicator does not light up after above check and repairs are finished 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 Disconnect the leads to the primary of the power transformer 5 Ensure that these leads remain isolated from other components and oven chassis by using insulation...

Page 19: ...en power is supplied 2 Indicator Circuit This circuit consists of 4 digits 12 segments and 3 common electrodes using a Liquid Crystal Display TOUCH CONTROL PANEL ASSEMBLY OUTLINE OF TOUCH CONTROL PANEL 3 Power Source Circuit This circuit generates voltage necessary in the control unitfromtheAClinevoltage Inaddition thesynchronizing signal is available in order to compose a basic standard time in t...

Page 20: ... a corresponding signal will be input into R60 16 R63 IN Signal similar to R60 When either G7 line on key matrix is touched a corresponding signal will be input into R60 17 AIN0 IN To input signal which communicates the door open close information to LSI Door close H level signal 0V Door open L level 5V 18 20 AIN1 AIN3 IN Terminal to change functions according to the Model By using the A D convert...

Page 21: ...minal while one of G2 line keys on key matrix is touched 32 R92 OUT Key strobe signal Signal applied to touch key section A pulse signal is input to R60 R63 terminal while one of G1 line keys on key matrix is touched 33 XIN IN Internal clock oscillation frequency setting input The internal clock frequency is set by inserting the capacitor resistor oscillation circuit with respect to XOUT terminal ...

Page 22: ...ntrol unit being sure that the lead wires are not twisted 3 After aluminium foil is removed be careful that abnormal voltage due to static electricity etc is not applied to the input or output terminals 4 Attach connectors electrolytic capacitors etc to PWB making sure that all connections are tight 5 Be sure to use specified components where high precision is required 1 Precautions for Handling E...

Page 23: ...and High voltage rectifier assembly 2 Hot parts Oven lamp Magnetron High voltage transformer and Oven cavity WARNING FOR WIRING 1 Disconnect the power supply cord 2 Visuallycheckthedoorandcavityfaceplatefordamage dents cracks signs of arcing etc Carry out any remedial work that is necessary before operating the oven Do not operate the oven if any of the following conditions exist 1 Door does not c...

Page 24: ...ER WHEN REPLACING IT RE PLACE HIGH VOLTAGE RECTIFIER ASSEM BLY HIGH VOLTAGE COMPONENTS REMOVAL HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY POWER TRANSFORMER REMOVAL 1 Disconnect the power supply cord and remove outer case 2 Open the oven door and block it open 3 Discharge high voltage capacitor 4 Disconnect the wire leads main wire harness and H V wire from power transformer 5 Disco...

Page 25: ...ng the turntable motor cover to the bottom plate with the cutting pliers as shown in Figure C 3 CAUTION DO NOT DROP THE TURNTABLE MOTOR COVER INTO THE OVEN AFTER CUTTING THE BRIDGES BECAUSE IT WILL DAMAGE THE WIRE LEADS OF THE MOTOR AND IT IS DIFFICULT TO REMOVE IT OUT OF THE OVEN 5 Remove the turntable motor cover from the bottom plate 6 Disconnect the wire leads from the turntable motor 7 Remove...

Page 26: ...lock tight into the hole for shaft of the fan blade 5 Install the fan blade to the shaft of fan motor by pushing the fan blade with a small light weight ball peen hammer or rubber mallet CAUTION Do not hit the fan blade hard when installing because the bracket may become disfigured Make sure that the fan blade rotates smoothly after installation Make sure that the axis of the shaft is not slanted ...

Page 27: ... sensing switch and secondary interlock switch open within 1 6mm gap between right side of cavity face plate and door when door is open 5 Re install outer case and check for microwave leakage around the door with an approved microwave survey meter Refer to Microwave Measurement Procedure 8 2 Thenpullouttheswitchwhilepushingtheplungerofthe switch again 8 3 Now the secondary interlock switch is free...

Page 28: ... Refer to chapter Test Procedures B An approved microwave survey meter should be used to assure compliance with proper microwave radiation emission limitation standards After any service make sure of the following 1 Door latch heads smoothly catch latch hook through latch holes and that latch head goes through center of latch hole 2 Deviation of door alignment from horizontal line of cavity face p...

Page 29: ...rounding conductor of the power supply cord has been grounded by power supply cord fixing screw The screw must allways be kept tight NOTE The neutral WHT wire must be connected to the terminal with N mark on the power supply cord RED WHT DOOR SENSING SWITCH GRY RED POWER TRANSFORMER HIGH VOLTAGE WIRE B BLK Blue Mark NOTE Hot RED wire must be connected to the terminal with blue mark on the oven lig...

Page 30: ...k R60 15k R64 220k R63 220k R62 220k R61 220k C64 C63 C62 C61 C61 C64 330pF 50v x 4 G10 G 9 G 8 G 7 G 6 G 5 G 4 G 3 G 2 G 1 R55 15k R54 15k R53 15k R52 15k R51 15k R50 15k R80 15k 0 9 7 8 5 6 1 2 4 3 START Minute Plus COMPU DEFROST Power Level Stop Clear Timer Clock POPCORN BEVERAGE BAKED POTATO DINNER PLATE FRESH VEGETABLES ROLL MUFFIN IC1 IZA868DR 1 42 40 22 25 30 35 10 5 15 21 SEG 0 SEG 1 SEG 2...

Page 31: ...1 3 2 2 4 S P B Q1 Q22 D22 Q30 R59 R60 R58 R57 R40 R4 C40 D3 D20 D40 CN B AC N FM TTM OL RY1 DOOR SW C4 C6 C71 D5 C3 ZD1 R1 R30 SP30 C5 R70 C70 CF1 R41 R51 R50 R52 R54 R53 R55 DIP 22 B B Q20 Q21 VRS1 C21 D1 D4 D2 C2 C1 T1 C20 R20 R5 RY2 D21 10 E E 6 42 1 IC1 4 21 9 3 1 R61 R62 R63 R64 C61 C63 C64 C62 2 F 11 J7 J5 J3 J6 J4 J2 J1 8 R ...

Page 32: ...103N Capacitor 0 01 uF 16V 1 AA C20 VCEAB31HW104M Capacitor 0 1 uF 50V 1 AM C21 VCEAB31VW106M Capacitor 10 uF 35V 1 AA C40 VCKYD11CY103N Capacitor 0 01 uF 16V 1 AA C61 64 VCKYD11HB331K Capacitor 330 pF 50V 4 AA C70 VCKYD11CY103N Capacitor 0 01 uF 16V 1 AA C71 VCCCF61HH330J Capacitor 33 pF 50V 1 AB D1 4 VHD11ES1 1 Diode 11ES1 4 AB D5 VHD1SS270A 1 Diode 1SS270A 1 AA D20 22 VHD1SS270A 1 Diode 1SS270A...

Page 33: ...8000 Screw 4mm x 8mm 4 AA MISCELLANEOUS 6 1 FROLPA089WRK0 Turntable support 1 AP 6 2 NTNT A094WRE0 Turntable 1 AN 6 3 TINSEA794WRR0 Instruction book 1 AD 6 4 FW VZB657WRE0 Switch harness 1 AH 6 5 FW VZB658WRE0 Main wire harness 1 AV 6 6 QW QZA150WRE0 High voltage wire B 1 AF 6 7 TCAUAA166WRR0 DHHS caution label 1 AC 6 8 TCAUAA156WRR0 User caution label 1 AF 6 9 TCAUAA239WRR0 Monitor caution 1 AC 6...

Page 34: ...TS 7 11 2 1 7 11 7 10 7 10 7 9 7 5 4 6 4 4 4 9 7 1 7 8 7 7 4 10 7 1 1 12 7 4 7 8 7 4 4 1 2 2 2 3 7 8 7 8 4 13 2 3 7 2 4 16 7 3 1 10 6 11 1 11 7 5 7 12 1 3 1 7 7 6 1 1 1 1 1 2 1 6 1 5 7 9 7 1 1 8 6 10 6 10 4 7 4 11 6 2 6 1 4 15 4 8 6 7 4 5 4 12 6 9 7 8 1 9 1 4 4 3 4 2 4 14 1 2 4 17 7 5 A A ...

Page 35: ...S CONTROL PANEL PARTS DOOR PARTS 5 3 6 5 6 4 5 5 5 2 5 4 5 8 5 8 5 6 5 7 5 1 Actual wire harness may be different than illustration 6 6 3 2 6 8 3 2 2 3 2 1 3 3 3 1 3 4 3 4 3 4 Befor attaching Control unit to Control panel foil side of Control unit must be cleaned by ethyl alcohol ...

Page 36: ...ronic mechanical photocopying recording orotherwise withoutprior written permission of the publisher PACKING AND ACCESSORIES 6 2 TURNTABLE TRAY 6 3 INSTRUCTION BOOK 6 1 TURNRABLE SUPPORT INTO THE OVEN CAVITY Not replaceable items TRAY PAD ASSY CPADBA244WRK0 PACKING CASE MICROWAVE OVEN TOP PAD ASSEMBLY FPADBA387WRK0 POLYETHYLENG BAG SSAKHA014WRE0 DOOR PROTECTION SHEET SPADPA580WRE0 SPAKCD209WRE0 BO...

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