SHARP R203CW2, R-203CW Service Manual

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SER VICE MANU AL

S2902R203CPW/

MICROWAVE OVEN

R-203CW

DEF. LBS. QTY.

CHECK

1. Ground meat

2. Steaks/chops

3. Chicken pieces

COMPU DEFROST

To adjust quantity-touch pad again

SNACKS

POPCORN

BEVERAGE

COOKING

BAKED

FRESH

POTATO

VEGETABLES

REHEATING

DINNER

ROLL,

PLATE

MUFFIN

123 456 78

Power Level

Timer

Clock

Stop

START

Clear

Minute Plus



MODEL

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.



WARNING TO SERVICE PERSONNEL: Microwave ovens contain circuitry capable of producing very high voltage and

R-203CW

current, contact with following parts may result in a severe, possibly fatal, electrical shock. (High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..)

TABLE OF CONTENTS

Page PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO

AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY ...................INSIDE FRONT COVER

BEFORE SERVICING ......................................................................................................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

SHARP CORPORATION

This document has been published to be used for after sales service only. The contents are subject to change without notice.

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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

microwave source, and make repairs as necessary: (1) interlock operation, (2) proper door closing, (3) seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges and latches, (5) evidence of dropping or abuse.

compartments, check the magnetron, wave guide or transmission line, and cavity for proper alignment, integrity, and connections.

(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave

generation 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 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.

Service personnel should inform SHARP ELECTRONICS CORPORATION of any certified unit found with emissions in excess of 4mW/cm2. The owner of the unit should be instructed not to use the unit until the oven has been brought into compliance.

WARNING TO SERVICE PERSONNEL

Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts fatal, electrical shock.

(Example) High Voltage Capacitor, High Voltage Power Trans-

former, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..

Read the Service Manual carefully and follow all instructions.

may result in a severe, possibly

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Don't Touch ! Danger High Voltage

Before Servicing

1. Disconnect the power supply cord , and then remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

WARNING:RISK OF ELECTRIC SHOCK.

DISCHARGE THE HIGH-VOLTAGE CAPACITOR BEFORE SERVICING.

The high-voltage capacitor remains charged about 60 seconds after the oven has been switched off. Wait for 60 seconds and then short-circuit the connection of the highvoltage capacitor (that is the connecting lead of the highvoltage rectifier) against the chassis with the use of an insulated screwdriver.

Whenever troubleshooting is performed the power supply must be disconnected. It may in, some cases, be necessary to connect the power supply after the outer case has been removed, in this event,

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 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. Reconnect the leads to the primary of the power transformer.

5. Reinstall the outer case (cabinet).

6. Reconnect the power supply cord after the outer case is installed.

7. Run the oven and check all functions.

After repairing

1. Reconnect all leads removed from components during testing.

2. Reinstall the outer case (cabinet).

3. Reconnect the power supply cord after the outer case is installed.

4. Run the oven and check all functions.

Microwave ovens should not be run empty. To test for the presence of microwave energy within a cavity, place a cup of cold water on the oven turntable, close the door and set the power to HIGH and set the microwave timer for two (2) minutes. When the two minutes has elapsed (timer at zero) carefully check that the water is now hot. If the water remains cold carry out Before Servicing procedure and reexamine the connections to the component being tested.

When all service work is completed and the oven is fully assembled, the microwave power output should be checked and a microwave leakage test should be carried out.

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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/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external surface of the oven.

2) Safety interlock switches Primary interlock relay and door sensing switch shall prevent microwave radiation emission in excess of the requirement as above mentioned, secondary interlock switch shall prevent microwave radiation emission in excess of 5 mW/cm2 at any point 5cm or more from the external surface of the oven.

B. Preparation for testing: Before beginning the actual measurement of leakage, proceed as follows:

1) Make sure that the actual instrument is operating normally as specified in its instruction booklet.

Important: Survey instruments that comply with the requirement for instrumentation as prescribed by the performance standard for microwave ovens, 21 CFR 1030.10(c)(3)(i), must be used for testing.

2) Place the oven tray in the oven cavity.

3) Place the load of 275±15 ml (9.8 oz) of tap water initially at 20±5˚C (68˚F) in the center of the 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 Mode

5) Close the door and select a cook cycle of several minutes. If the water begins to boil before the survey is completed, replace it with 275 ml of cool water.

C. Leakage test:

Closed-door leakage test (microwave measurement)

1) Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven.

2) Move the probe slowly, not faster than 1 in./sec. (2.5 cm/sec.) along the gap, watching for the maximum indication on the meter.

3) Check for leakage at the door screen, sheet metal seams and other accessible positions where the continuity of the metal has been breached (eg., around the switches, indicator, and vents). While testing for leakage around the door pull the door away from the front of the oven as far as is permitted by the closed latch assembly.

4) Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW/cm2, and that the secondary interlock switch does turn the oven OFF before any door movement.

NOTE: After servicing, record data on service invoice and microwave leakage report.

SERVICE MANUAL

MICROWAVE OVEN

R-203CW

PRODUCT DESCRIPTION

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.

GENERAL INFORMATION

OPERATION

TROUBLESHOOTING GUIDE AND TEST PROCEDURE

TOUCH CONTROL PANEL

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

WIRING DIAGRAM

PARTS LIST

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.

SHARP ELECTRONICS CORPORATION

SHARP PLAZA, MAHWAH,

NEW JERSEY 07430-2135

R-203CW

PRODUCT DESCRIPTION

SPECIFICATIONS

ITEM DESCRIPTION

Power Requirements 120 Volts

60 Hertz

Single phase, 3 wire grounded Power Consumption 1100W / Approx. 9.5 Amperes Power Output 700 W nominal of RF microwave energy (IEC 705 Test procedure)

Operating frequency 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 .................................................... approx. 70% of FULL Power

P-60 .................................................... approx. 60% of FULL Power

P-50 .................................................... approx. 50% of FULL Power

P-40 .................................................... approx. 40% of FULL Power

P-30 .................................................... approx. 30% of FULL Power

P-20 .................................................... approx. 20% of FULL Power

P-10 .................................................... approx. 10% of FULL Power

P-0 ...................................... No power throughout the cooking time

COMPU DEFROST pad Instant Start pads Number selection pads Timer/Clock pad Power Level pad START/ Minute plus pad Stop/Clear pad

Oven Cavity Light Yes Safety Standard UL Listed.

FCC Authorized DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J

GENERAL INFORMATION

GROUNDING INSTRUCTIONS

This oven is equipped with a three prong grounding plug. It must be plugged into a wall receptacle that is properly installed and grounded in accordance with the National Electrical Code and local codes and ordinances. In the event of an electrical short circuit, grounding reduces the risk of electric shock by providing an escape wire for the electric current.

WARNING: Improper use of the grounding plug can result in a risk of electric shock.

R-203CW

1. Ground meat

2. Steaks/chops

3. Chicken pieces

To adjust quantity-touch pad again

COMPU DEFROST

POPCORN

BEVERAGE

BAKED

POTATO

DINNER

PLATE

Power

Level

Timer Clock

Stop

Clear

START



Minute Plus

ROLL,



MUFFIN

FRESH

VEGETABLES

SNACKS

COOKING

REHEATING

123 456

DEF. LBS. QTY.

CHECK

Time display Indicator

Electrical Requirements The electrical requirements are a 115 -120 volt 60 Hz, AC only, 15 or 20 amp. fused electrical supply. It is recommended that a separate circuit serving only this appliance be provided. When installing this appliance, observe all applicable codes and ordinances. A short power-supply cord is provided to reduce risks of becoming entangled in or tripping over a longer cord. Where a two-pronged wall-receptacle is encountered, it is the personal responsibility and obligation of the customer to contact a qualified electrician and have it replaced with a properly grounded three-pronged wall receptacle or have a grounding adapter properly grounded and polarized. If the extension cord must be used, it should be a 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.

CAUTION: DO NOT UNDER ANY CIRCUMSTANCES CUT OR REMOVE THE ROUND GROUNDING PRONG FROM

THIS PLUG.

3-Pronged Plug

Grounding Pin

3-Pronged Receptacle

Grounded Receptacle Box

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 turntable

8. Ventilation openings. (Rear)

9. Oven lamp.

10.Wave guide cover.

11.Power supply cord

TOUCH CONTROL PANEL

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OPERATION

DESCRIPTION OF OPERATING SEQUENCE

The following is a description of component functions during oven operation.

OFF CONDITION

Closing the door activates the door sensing switch and secondary interlock switch. (In this condition, the monitor switch contacts are opened.) When the oven is plugged in, 120 volts A.C. is supplied to the control unit. (Figure O-1).

1. The display will show flashing "88:88". To set any program or set the clock, you must first touch the STOP/CLEAR pad. The display will clear, and " : " will appear.

COOKING CONDITION

Program desired cooking time by touching the NUMBER pads. And program the power level by touching the POWER LEVEL pad and then a Number pad. When the START pad is touched, the following operations occur:

1. The contacts of the relays are closed and components connected to the relays are turned on as follows. (For details, refer to Figure O-2)

RELAY CONNECTED COMPONENTS RY-1 oven lamp/turntable motor/fan motor RY-2 power transformer

2. 120 volts A.C. is supplied to the primary winding of the power transformer and is converted to about 3.5 volts A.C. output on the filament winding, and approximately 2000 volts A.C. on the high voltage winding.

3. The filament winding voltage heats the magnetron filament and the H.V. winding voltage is sent to a voltage doubler circuit.

4. The microwave energy produced by the magnetron is channelled through the waveguide into the cavity feedbox, and then into the cavity where the food is placed to be cooked.

5. Upon completion of the cooking time, the power transformer, oven lamp, etc. are turned off, and the generation of microwave energy is stopped. The oven will revert to the OFF condition.

6. When the door is opened during a cook cycle, the monitor switch, door sensing switch, secondary interlock switch and primary interlock relay are activated with 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. The monitor switch is electrically monitoring the operation of the secondary interlock switch and primary interlock

relay (RY2) and is mechanically associated with the door so that it will function in the following sequence.

(1) When the door opens from the closed position, the

secondary interlock switch, door sensing switch and primary interlock relay (RY2) open their contacts. Then the monitor switch contacts close.

(2) When the door is closed from the open position, the

monitor switch contacts open first. Then the contacts of the secondary interlock switch and door sensing

switch close. If the secondary interlock switch and primary interlock relay (RY2) fail with the contacts closed when the door is opened, the closing of the monitor switch contacts will form a short circuit through the C/T fuse and primary interlock relay (RY2), causing the C/T fuse to blow.

POWER LEVEL P-0 TO P-90 COOKING

When Variable Cooking Power is programmed, the 120 volts A.C. is supplied to the power transformer intermittently through the contacts of relay (RY-2) which is operated by the control unit within a 32 second time base. Microwave power operation is as follows:

VARI-MODE ON TIME OFF TIME Power 10(P-HI) 32 sec. 0 sec.

(100% power) Power 9(P-90) 30 sec. 2 sec.

(approx. 90% power) Power 8(P-80) 26 sec. 6 sec.

(approx. 80% power) Power 7(P-70) 24 sec. 8 sec.

(approx. 70% power) Power 6(P-60) 22 sec. 10 sec.

(approx. 60% power) Power 5(P-50) 18 sec. 14 sec.

(approx. 50% power) Power 4(P-40) 16 sec. 16 sec.

(approx. 40% power) Power 3(P-30) 12 sec. 20 sec.

(approx. 30% power) Power 2(P-20) 8 sec. 24 sec.

(approx. 20% power) Power 1(P-10) 6 sec. 26 sec.

(approx. 10% power) Power 0(P-0) 0 sec. 32 sec.

(0% power)

Note: The ON/OFF time ratio does not correspond with

the percentage of microwave power, because approx. 2 seconds are needed for heating of the magnetron filament.

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SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED

2. CLOCK APPEARS ON DISPLAY

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED

2. COOKING TIME PROGRAMMED

3. VARIABLE COOKING CONTROL "HIGH"

4. "START" PAD TOUCHED

120V AC 60 Hz

C/T FUSE

CONTROL UNIT

GRN

OL FM

OVEN LAMP

SECONDARY INTERLOCK SWITCH

Figure O-1. Oven Schematic-Off Condition

C/T FUSE

MAGNETRON  THERMAL CUT-OUT

(RY-1)

TTM

TURN- TABLE MOTOR

MAGNETRON  THERMAL CUT-OUT

(RY-1)

COM.

(RY-2)

B1 B2

FAN  MOTOR

COM.

(RY-2)

PRIMARY INTERLOCK RELAY

DOOR SENSING SWITCH

PRIMARY INTERLOCK RELAY

N.O.

MONITOR  SWITCH

POWER  TRANSFORMER

CAPACITOR

0.86µF

RECTIFIER

MAGNETRON

CONTROL UNIT

120V AC 60 Hz

GRN

OL FM

OVEN LAMP

SECONDARY INTERLOCK SWITCH

Figure O-2. Oven Schematic-Cooking Condition

DESCRIPTION AND FUNCTION OF COMPONENTS

DOOR OPEN MECHANISM

The door is opened by pulling the door, refer to the Figure D-1.

Latch Heads 

Door

Secondary Interlock Switch

Figure D-1. Door Open Mechanism

Latch Hook

Door Sensing Switch

Monitor Switch

CAPACITOR

0.86µF

RECTIFIER

MAGNETRON

TTM

TURN- TABLE MOTOR

B1 B2

FAN  MOTOR

DOOR SENSING SWITCH

MONITOR  SWITCH

DOOR SENSING AND SECONDARY INTERLOCK SWITCHES

The secondary interlock switch is mounted in the lower position of the latch hook and the door sensing switch in the primary interlock system is mounted in the upper position of the latch hook. They are activated by the latch heads on the door. When the door is opened, the switches interrupt the power to all high voltage components. A cook cycle cannot take place until the door is firmly closed thereby activating both interlock switches. The primary interlock system consists of the door sensing switch and primary interlock relay located on the control circuit board.

MONITOR SWITCH

The monitor switch is activated (the contacts opened) by the latch head on the door while the door is closed. The switch is intended to render the oven inoperative, by means of

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blowing the C/T fuse, when the contacts of the primary interlock relay (RY2) and secondary interlock switch fail to open when the door is opened.

Functions:

1. When the door is opened, the monitor switch contacts close (to the ON condition) due to their being normally closed. At this time the primary interlock relay (RY2) and secondary interlock switch are in the OFF condition (contacts open) due to its being normally open contact switches.

2. As the door goes to a closed position, the monitor switch contacts are first opened and then the door sensing switch and secondary interlock switch contacts close.

3. If the door is opened, and the primary interlock relay (RY2) and the secondary interlock switch contact fail to open, the C/T fuse blows simultaneously with closing of the monitor switch contacts.

CAUTION: BEFORE REPLACING A BLOWN C/T FUSE,

TEST THE DOOR SENSING SWITCH, PRIMARY INTERLOCK RELAY (RY2), SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER "TEST PROCEDURE").

NOTE: C/T FUSE AND MONITOR SWITCH ARE

REPLACED AS AN ASSEMBLY

TURNTABLE MOTOR

The turntable motor rotates the turntable located on the bottom of the oven cavity, so that the food on the turntable is cooked evenly. The turntable may turn in either direction.

COOLING FAN MOTOR

The cooling fan motor drives a blade which draws external

cool air. This cool air is directed through the air vanes surrounding the magnetron and cools the magnetron. This air is channelled through the oven cavity to remove steam and vapours given off from the heating foods. It is then exhausted through the exhausting air vents at the oven cavity.

MAGNETRON THERMAL CUT-OUT

The thermal cut-out located on the top of the oven cavity is designed to prevent damage to the magnetron if an over heated condition develops in the tube due to cooling fan failure, obstructed air guide, dirty or blocked air intake, etc. Under normal operation, the thermal cut-out remains closed. 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 closes.

2. If the wire harness or electrical components are shortcircuited, this C/T fuse blows to prevent an electric shock or fire hazard.

3. The C/T fuse, located on the top of the oven cavity, is designed to prevent damage to the oven by fire. If the food load is overcooked, by either error in cook time or defect in the timer, the C/T fuse will open.

Under normal operation, the C/T fuse remains closed. However, when abnormally high temperatures are reached within the oven cavity, the C/T fuse will open at 248˚F (120˚C), causing the oven to shut down or when the electric currents beyond 13A flow, the C/T fuse will open.

TROUBLESHOOTING GUIDE

Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.

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 "section.

IMPORTANT: If the oven becomes inoperative because of a blown C/T fuse, check the monitor switch, primary

interlock relay (RY2), door sensing switch and secondary interlock switch before replacing the C/T fuse. If the C/T fuse is replaced, the monitor switch must also be replaced. Use part FFS-BA020WRK0 as an assembly.

IMPORTANT: Whenever troubleshooting is performed with the power supply cord disconnected. It may in, some cases,

be necessary to connect the power supply cord after the outer case has been removed, in this event,

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. sge 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. Reconnect the leads to the primary of the power transformer.

5. Reinstall the outer case (cabinet).

6. Reconnect the power supply cord after the outer case is installed.

7. Run the oven and check all functions.

CK = Check / RE = Replace

TEST PROCEDURE

RE CK AB C

EFFGHRE RE CK

I/K

CK CKCK J L M

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CONDITION

OFF CONDITION

COOKING CONDITION

POSSIBLE CAUSE

AND

DEFECTIVE PARTS

PROBLEM

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 appear 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 is opened.

Fan motor does not operate. (All other electric components function.)

Oven lamp does not light at all. (All other electric components function.)

Turntable motor does not operate. (All other electric components function.)

Oven does not go into cook cycle when START pad is touched

Oven seems to be operating but little or no heat is produced in oven load. (Food incompletely cooked or not cooked at all at end of cook cycle.)

Oven goes into a cook cycle but extremely uneven heating is produced in oven load (food).

Oven does not cook properly when programmed for Cooking Power 5 mode. (Operates properly on Cooking Power 10 (HIGH) mode.)

Oven lamp, turntable motor and fan motor do not operate.

Oven goes into EXPRESS DEFROST but food is not defrosted well.

SHORT IN POWER CORD

SHORT OR OPEN WIRING

MAGNETRON

POWER TRANSFORMER

H.V. RECTIFIER ASSEMBLY

HIGH VOLTAGE CAPACITOR

MAGNETRON THERMAL CUT-OUT

PRIMARY INTERLOCK SYSTEM

SECONDARY INTERLOCK SWITCH

MONITOR SWITCH

C/T FUSE

OVEN LAMP OR SOCKET

COOLING FAN MOTOR

TURNTABLE MOTOR

CONTROL UNIT OR RELAY

WRONG OPERATION

LOW VOLTAGE

DIRTY OVEN CAVITY

KEY UNIT

EXPRESS DEFROST

FOIL PATTERN ON PWB.

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TEST PROCEDURES

PROCEDURE

LETTER

A MAGNETRON ASSEMBLY TEST

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. 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.

5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament leads and chassis ground. This test should indicate an infinite resistance. If there is little or no resistance the magnetron is grounded and must be replaced.

6. Reconnect all leads removed from components during testing.

7. Reinstall the outer case (cabinet).

8. Reconnect the power supply cord after the outer case is installed.

9. Run the oven and check all functions.

MICROWAVE OUTPUT POWER

The following test procedure should be carried out with the microwave oven in a fully assembled condition (outer case fitted).

HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD BE OBSERVED.

Power output of the magnetron can be measured by performing a water temperature rise test. This test should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following components or wiring: silicon rectifier, high voltage capacitor and power transformer. This test will require a 16 ounce (453cc) measuring cup and an accurate mercury thermometer or thermocouple type temperature tester. For accurate results, the following procedure must be followed carefully:

COMPONENT TEST

1. Fill the measuring cup with 16 oz. (453cc) of tap water and measure the temperature of the water with a thermometer or thermocouple temperature tester. Stir the thermometer or thermocouple through the water until the temperature stabilizes. Record the temperature of the water.

2. Place the cup of water in the oven. Operate oven at POWER 10(HIGH) selecting more than 60 seconds cook time. Allow the water to heat for 60 seconds, measuring with a stop watch, second hand of a watch or the digital read-out countdown.

3. Remove the cup from the oven and again measure the temperature, making sure to stir the thermometer or thermocouple through the water until the maximum temperature is recorded.

4. Subtract the cold water temperature from the hot water temperature. The normal result should be 18 to 33˚F(10 to 18.3˚C) rise in temperature. If the water temperatures are accurately measured and tested for the required time period the test results will indicate if the magnetron tube has low power output (low rise in water temperature) which would extend cooking time or high power output (high rise in water temperature) which would reduce cooking time. Because cooking time can be adjusted to compensate for power output, the magnetron tube assembly should be replaced only if the water temperature rise test indicates a power output well beyond the normal limits. The test is only accurate if the power supply line voltage is 120 volts and the oven cavity is clean.

B POWER TRANSFORMER TEST

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 primary input terminals and measure the resistance of the transformer with an ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil should be less than 1 ohm and the resistance of the high voltage coil should be approximately 124 ohms; the resistance of the filament coil should be less than 1 ohm.

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.

TEST PROCEDURES

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PROCEDURE

LETTER

(HIGH VOLTAGES ARE PRESENT AT THE HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE.)

C HIGH VOLTAGE RECTIFIER TEST

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. Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance across the terminals and observe, reverse the leads to the rectifier terminals and observe meter reading. If a short is indicated in both directions, or if an infinite resistance is read in both directions, the rectifier is probably defective and should be replaced.

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.

NOTE: Be sure to use an ohmmeter that will supply a forward bias voltage of more than 6.3 volts.

D HIGH VOLTAGE CAPACITOR TEST

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. 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. Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate continuity for a short time and should indicate an open circuit once the capacitor is charged. If the above is not the case, check the capacitor with an ohmmeter to see if it is shorted between either of the terminals and case. If it is shorted, replace the capacitor.

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.

COMPONENT TEST

E MAGNETRON THERMAL CUT-OUT TEST

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. A continuity check across the thermal cut-out terminals should indicate a closed circuit. If the temperature of the magnetron reaches approximately 257˚F(125˚C), the thermal cut-out opens. 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: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,

REPLACE THERMAL CUT-OUT.

F SECONDARY INTERLOCK SWITCH TEST

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. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate an open circuit with the door open and a closed circuit with

R-203CW

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

the door closed. If improper operation is indicated, replace the secondary interlock switch.

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.

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.

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.

PRIMARY INTERLOCK RELAY (RY2)

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 two (2) wire leads from the male tab terminals of the Primary Interlock Relay. Check the state of the relay contacts using a ohmmeter. The relay contacts should be open. If the relay contacts are closed, replace the circuit board entirely or the relay itself.

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.

G MONITOR SWITCH TEST

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. Before performing this test, make sure that the secondary interlock switch and the primary interlock relay are operating properly, according to the above Switch Test Procedure. Disconnect the wire lead from the monitor switch (COM) terminal. Check the monitor switch operation by using the ohmmeter as follows. When the door is open, the meter should indicate a closed circuit. When the monitor switch actuator is pushed by a screw driver through the lower latch hole on the front plate of the oven cavity with the door opened (in this condition the plunger of the monitor switch is pushed in), the meter should indicate an open circuit. If improper operation is indicated, the switch may be defective. After testing the monitor switch, reconnect the wire lead to the monitor switch (COM) terminal and check the continuity of the monitor circuit.

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.

SCREW  DRIVER

MONITOR  SWITCH

OHMMETER

TEST PROCEDURES

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PROCEDURE

LETTER

H BLOWN C/T FUSE TEST

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. If the C/T fuse is blown when the door is opened, check the primary interlock relay, secondary interlock switch and monitor switch according to the "TEST PROCEDURE" for those switches before replacing the blown C/T fuse.

CAUTION: BEFORE REPLACING A BLOWN C/T FUSE, TEST THE PRIMARY INTERLOCK RELAY,

If the C/T fuse is blown by improper switch operation, the C/T fuse and monitor switch must be replaced with "C/T fuse and monitor switch assembly" part number FFS-BA020WRK0, even if the monitor switch operates normally. The C/T fuse and monitor switch assembly is comprised of a 13 ampere fuse and switch.

A continuity check across the C/T fuse terminals should indicate a closed circuit unless the temperature of the C/T fuse reaches approximately 248˚F(120˚C). An open C/T fuse indicates the oven overheated, Replace the oven C/T fuse and check the inside of the oven cavity, the proper setting of cooking time and the proper operation of control unit. Also check for proper air flow through the ovens venting system. Especially check the cooling fan for proper operation and the air guide for restriction.

CAUTION: IF THE C/T FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE, REPLACE

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.

COMPONENT TEST

SECONDARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONITOR SWITCH FOR PROPER OPERATION.

THE C/T FUSE.

I TOUCH CONTROL PANEL ASSEMBLY TEST

The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter. In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key Unit, and troubleshooting by unit replacement is described according to the symptoms indicated.

Before testing,

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 tape.

6) After that procedure, re-connect the power supply cord.

1. Key Unit. NOTE ;

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) Check key unit ribbon connection before replacement.

5) Reconnect all leads removed from components during testing.

6) Re-install 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 following symptoms indicate a defective key unit. a) When touching the pads, a certain pad produces no signal at all. b) When touching a number pad, two figures or more are displayed.

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TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

c) When touching the pads, sometimes a pad produces no signal. If the key unit is defective.

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) Replace the key unit.

5) Reconnect all leads removed from components during testing.

6) Re-install the outer case (cabinet).

7) Reconnect the power supply cord after the outer case is installed.

8) Run the oven and check all functions.

2. Control Unit. The following symptoms indicate a defective control unit. Before replacing the control unit, perform the Key unit test (Procedure J) 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. b) When touching the pads, no pads produce a signal.

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. d) The corresponding segments of all digits do not light up; or they continue to light up. e) Wrong figure appears.

f) A certain group of indicators do not light up.

g) The figure of all digits flicker.

2-3 Other possible problems caused by defective control unit.

a) Buzzer does not sound or continues to sound. b) Clock does not operate properly. c) Cooking is not possible.

When 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) 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.

J KEY UNIT TEST

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. If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is making good contact, verify that the door sensing switch (stop switch) operates properly; that is the contacts are closed when the door is closed and open when the door is open. If the door sensing switch (stop switch) is good, disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the door sensing switch is closed (either close the door or short the door sensing switch connecter). Use the Key unit matrix indicated on the control panel schematic and place a jumper wire between the pins that correspond to the STOP/CLEAR pad making momentary contact. If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the control unit does not respond, it is faulty and must be replaced. If a specific pad does not respond, the above method may be used (after clearing the control unit) to determine if the control unit or key pad is at fault.

5. Reconnect all leads removed from components during testing.

6. Re-install the outer case (cabinet).

7. Reconnect the power supply cord after the outer case is installed.

8. Run the oven and check all functions.

TEST PROCEDURES

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PROCEDURE

LETTER

K RELAY TEST

COMPONENT TEST

G 6 G 5 G 4 G 3 G 2 G 1

1 7

COMPU

DEFROST

BAKED

POTATO

POPCORN

Power

Level

Stop

Clear

START

Minute Plus



G 7

G 8

G 9

G10

BEVERAGE

FRESH

VEGETABLES

ROLL,

MUFFIN

6 3

Timer Clock

DINNER

PLATE

45 0 89

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 tape.

6. After that procedure, re-connect the power supply cord.

7. Remove the outer case and check voltage between Pin No. 3 of the 2 pin connector (A) 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 relay coil. If diode is

good, control unit is defective.

RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS

RY1 Approx. 15.0V D.C. Oven lamp / Turntable motor / Cooling fan motor RY2 Approx. 14.0V D.C. Power transformer

8.Disconnect the power supply cord and then remove outer case.

9.Open the door and block it open.

10.Discharge high voltage capacitor.

11.Reconnect all leads removed from components during testing.

12.Re-install the outer case (cabinet).

13.Reconnect the power supply cord after the outer case is installed.

14. Run the oven and check all functions.

L COMPU DEFROST TEST

(1)Place one cup of water in the center of the turntable tray in the oven cavity. (2)Close the door, touch the "COMPU DEFROST" pad once and touch the Number pad "5". And then

touch the "START" pad.

(3)The oven is in Compu Defrost cooking condition. (4)The oven will operate as follows.

WEIGHT 1ST STAGE 2ND STAGE 3RD STAGE

LEVEL TIME LEVEL TIME LEVEL TIME

0.5lb

50% 1min.25sec. 30% 1min.40sec. 10% 1min.2sec.

(5)If improper operation is indicated, the control unit is probably defective and should be checked.

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TEST PROCEDURES

PROCEDURE

LETTER

M FOIL PATTERN ON THE PRINTED WIRING BOARD TEST

COMPONENT TEST

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.

1. Foil pattern check and repairs.

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) Follow the troubleshooting guide given below for repair.

STEPS OCCURRENCE CAUSE OR CORRECTION

1 Only pattern at "a" is broken. *Insert jumper wire J1 and solder. 2 Pattern at "a" and "b" are broken. *Insert the coil RCILF2003YAZZ between "c" and "d".

5) Make a visual inspection of the varistor. Check for burned damage and examine the transformer with a tester for the presence of layer short-circuit (check the primary coil resistance which is approximately 563Ω ± 10%). If any abnormal condition is detected, replace the defective parts.

(J1)

RY2

VRS1

AC (N) FM TTM OL

RY1

6) Reconnect all leads removed from components during testing.

7) Re-install the outer case (cabinet).

8) Reconnect the power supply cord after the outer case is installed.

9) Run the oven and check all functions.

2. Follow the troubleshooting 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 tape.

6) After that procedure, re-connect the power supply cord.

7) Follow the troubleshooting guide given below for repair.

STEPS OCCURRENCE CAUSE OR CORRECTION

The rated AC voltage is not present between

1 Pin No. 3 of the 2-pin connector (A) and the Check supply voltage and oven power cord.

common terminal of the relay RY2. The rated AC voltage is present at primary Low voltage transformer or secondary circuit defective.

side of low voltage transformer. Check and repair.

8) Disconnect the power supply cord and then remove outer case.

9) Open the door and block it open.

10) Discharge high voltage capacitor.

11) Reconnect all leads removed from components during testing.

12) Re-install the outer case (cabinet).

13) Reconnect the power supply cord after the outer case is installed.

14) Run the oven and check all functions.

TOUCH CONTROL PANEL ASSEMBLY

OUTLINE OF TOUCH CONTROL PANEL

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The touch control section consists of the following units as shown in the touch control panel circuit.

(1) Key Unit (2) Control Unit

The principal functions of these units and their related signals are explained below.

Key Unit

The key unit is composed of a matrix, signals generated in the LSI are sent to the key unit through R81, R82, R83, R90, R91 and R92. When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through R60, R61, R62, R63 to perform the function that was requested.

Control Unit

Control unit consists of LSI, ACL circuit, indicator circuit, power source circuit, relay circuit, buzzer circuit and synchronizing signal circuit.

1) ACL

This circuit generates a signal which resets the LSI to the initial state when power is supplied.

3) Power Source Circuit

This circuit generates voltage necessary in the control unit from the AC line voltage. In addition, the synchronizing signal is available in order to compose a basic standard time in the clock circuit.

Symbol Voltage Application

VC -5V LSI(IC1)

4) Relay Circuit

To drive the magnetron, fan motor, turntable motor and light the oven lamp.

5) Buzzer Circuit

The buzzer is responsive to signals from the LSI to emit audible sounds (key touch sound and completion sound).

6) Synchronizing Signal Circuit

The power source synchronizing signal is available in order to compose a basic standard time in the clock circuit. It accompanies a very small error because it works on commercial frequency.

7) Door Sensing Switch

A switch to "tell" the LSI if the door is open or closed.

2) Indicator Circuit

This circuit consists of 4-digits, 12-segments and 3common electrodes using a Liquid Crystal Display.

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DESCRIPTION OF LSI

LSI(IZA868DR)

The I/O signal of the LSI(IZA868DR) are detailed in the following table.

Pin No. Signal I/O Description

1-12 SEG0-SEG11 OUT Segment data signal.

Connected to LCD. The relation between signals are as follows:

LSI signal (Pin No.) LCD (Pin No.) LSI signal (Pin No.) LCD (Pin No.)

SEG 0 (1).............................. S12 SEG 6 (7)................................. S6

SEG 1 (2).............................. S11 SEG 7 (8)................................. S5

SEG 2 (3).............................. S10 SEG 8 (9)................................. S4

SEG 3 (4)................................ S9 SEG 9 (10)............................... S3

SEG 4 (5)................................ S8 SEG 10 (11)............................. S2

SEG 5 (6)................................ S7 SEG 11 (12)............................. S1

13 R60 IN Signal coming from touch key.

When either G10 line on key matrix is touched, a corresponding signal out of R81 R83 and R90 - R92 will be input into R60. When no key is touched, the signal is held at "H" level.

14 R61 IN Signal similar to R60.

When either G9 line on key matrix is touched, a corresponding signal will be input into R60.

15 R62 IN Signal similar to R60.

When either G8 line on key matrix is touched, 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 converter contained in the LSI, DC voltage in accordance with the Model in operation is applied to set up its function.

21 VSS IN Power source voltage: -5V.

VSS voltage of power source circuit input.

22 R70 OUT Magnetron high-voltage circuit driving signal.

To turn on and off the cook relay (RY2). The signals holds "L" level during microwave cooking and "H" level while not cooking. In other cooking modes (variable cooking) the signal turns to "H" level and "L" level in repetition according to the power level.

P-HI

P-70

OFF

24 sec.

OFF

8 sec.

H : GND

L : -5V H : GND

L : -5V

23 PULSE OUT Signal to sound buzzer (2.0 kHz).

A: key touch sound. B: Completion sound.

0.1 sec.

2 sec.

24 R72 OUT Oven lamp, fan motor and turntable motor driving signal.

To turn on and off shut off relay (RY1). The

16.7 msec.

square waveform voltage is delivered to the RY1 driving circuit and RY2 control circuit.

25 R73 OUT Terminal not used.

During cooking

H : GND L : -5V

H : GND

L : -5V

H : GND

L : -5V

Pin No. Signal I/O Description

26 INT2 IN Signal synchronized with commercial power source frequency.

This is the basic timing for time processing of LSI.

H : GND

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16.7 msec

L : -5V

27 R81 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while one of G6 line keys on key matrix is touched.

28 R82 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while one of G5 line keys on key matrix is touched.

29 R83 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while one of G4 line keys on key matrix is touched.

30 R90 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal while one of G3 line keys on key matrix is touched.

31 R91 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to R60 - R63 terminal 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.

34 XOUT OUT Internal clock oscillation frequency control output.

Output to control oscillation input of XIN.

35 RESET IN Auto clear terminal.

Signal is input to reset the LSI to the initial state when power is supplied. Temporarily set "L" level the moment power is supplied, at this time the LSI is reset. Thereafter set

at "H" level. 36 HOLD IN/OUT Connected to GND. 37 VLC IN Signal synchronized with commercial power source frequency.

Signal similar to VSS. 38 COM1 OUT Common data signal: COM1.

Connected to LCD (Pin No. C1) 39 COM2 OUT Common data signal: COM2.

Connected to LCD (Pin No. C2) 40 COM3 OUT Common data signal: COM1.

Connected to LCD (Pin No. C3) 41 COM4 OUT Terminal not used. 42 VDD IN Power source voltage input terminal.

Connected to GND.

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SERVICING

1. Precautions for Handling Electronic Components

This unit uses CMOS LSI in the integral part of the circuits. When handling these parts, the following precautions should be strictly followed. CMOS LSI have extremely high impedance at its input and output terminals. For this reason, it is easily influenced by the surrounding high voltage power source, static electricity charge in clothes, etc., and sometimes it is not fully protected by the built-in protection circuit. In order to protect CMOS LSI.

1) When storing and transporting, thoroughly wrap them in aluminium foil. Also wrap PW boards containing them in aluminium foil.

2) When soldering, ground the technician as shown in the figure and use grounded soldering iron and work table.

2. Shapes of Electronic Components

3. Servicing of Touch Control Panel

We describe the procedures to permit servicing of the touch control panel of the microwave oven and the precautions you must take when doing so. To perform the servicing, power to the touch control panel is available either from the power line of the oven itself or from an external power source.

(1)Servicing the touch control panel with power supply

of the oven : CAUTION:

THE HIGH VOLTAGE TRANSFORMER OF THE MICROWAVE OVEN IS STILL LIVE DURING SERVICING AND PRESENTS A HAZARD .

Therefore, before checking the performance of the touch control panel,

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.

Ensure that these leads remain isolated from other components and oven chassis by using insulation tape.

After that procedure, re-connect the power supply cord.

After checking the performance of the touch control panel,

1) Disconnect the power supply cord.

2) Open the door and block it open.

3) Re-connect the leads to the primary of the power transformer.

4) Re-install the outer case (cabinet).

approx. 1M ohm

Transistor 2SA933S DTA143ES KRA101M KRC243M

5) Re-connect the power supply cord after the outer case is installed.

6) Run the oven and check all function.

On some models, the power supply cord between the touch control panel and the oven itself is so short that the two can't be separated. For those models, check and repair all the controls (sensor-related ones included) of the touch control panel while keeping it connected to the oven.

B. On some models, the power supply cord between the

touch control panel and the oven proper is long enough that they may be separated from each other. For those models, therefore, it is possible to check and repair the controls of the touch control panel while keeping it apart from the oven proper; in this case you must short both ends of the door sensing switch (on PWB) of the touch control panel with a jumper, which brings about an operational state that is equivalent to the oven door being closed. As for the sensor-related controls of the touch control panel, checking them is possible if the dummy resistor(s) with resistance equal to that of the controls are used.

(2)Servicing the touch control panel with power supply

from an external power source:

Disconnect the touch control panel completely from the oven proper, and short both ends of the door sensing switch (on PWB) of the touch control panel, which brings about an operational state that is equivalent to the oven door being closed. Connect an external power source to the power input terminal of the touch control panel, then it is possible to check and repair the controls of the touch control panel; it is also possible to check the sensorrelated controls of the touch control panel by using the dummy resistor(s).

4. Servicing Tools

Tools required to service the touch control panel assembly.

1) Soldering iron: 30W (It is recommended to use a soldering iron with a grounding terminal.)

2) Oscilloscope: Single beam, frequency range: DC 10MHz type or more advanced model.

3) Others: Hand tools

5. Other Precautions

1) Before turning on the power source of the control unit, remove the aluminium foil applied for preventing static electricity.

2) Connect the connector of the key unit to the control 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.

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Special Screw

Screw Driver Type: TORX T20 H or GTXH20-100

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

WARNING AGAINST HIGH VOLTAGE:

Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result in severe, possibly fatal, electric shock. (Example) High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..

WARNING:

Avoid possible exposure to microwave energy. Please follow the instructions below before operating the oven.

1. Disconnect the power supply cord.

2. Visually check the door and cavity face plate for damage (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 close firmly.

2. Door hinge, support or latch hook is damaged.

3. The door gasket or seal is damaged.

WARNING FOR WIRING

To prevent an electric shock, take the following precautions.

1. Before wiring,

1) Disconnect the power supply cord.

2) Open the door and block it open.

3) Discharge the high voltage capacitor and wait for 60 seconds.

2. Don’t let the wire leads touch to the following parts;

1) High voltage parts: Magnetron, High voltage transformer, High voltage capacitor and High voltage rectifier assembly.

2) Hot parts: Oven lamp, Magnetron, High voltage transformer and Oven cavity.

4. The door is bent or warped.

5. There are defective parts in the door interlock system.

6. There are defective parts in the microwave generating and transmission assembly.

7. There is visible damage to the oven.

Do not operate the oven:

1. Without the RF gasket (Magnetron).

2. If the wave guide or oven cavity are not intact.

3. If the door is not closed.

4. If the outer case (cabinet) is not fitted.

3) Sharp edge:

Bottom plate, Oven cavity, Waveguide flange, Chassis support and other metallic plate.

4) Movable parts (to prevent a fault)

Fan blade, Fan motor, Switch, Switch lever, Open button.

3. Do not catch the wire leads in the outer case cabinet.

4. Insert the positive lock connector until its pin is locked and make sure that the wire leads do not come off even if the wire leads are pulled.

5. To prevent an error function, connect the wire leads correctly, referring to the Pictorial Diagram.

Please refer to ‘OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS’, when carrying out any of the following removal procedures:

To remove the outer case, procedure as follows.

1. Disconnect the power supply cord.

2. Open the oven door and block it open.

3. Remove the two (2) screws from the lower portion of the

4. Remove the remaining two (2) screws from rear and four

5. Slide the entire outer case back out about 1 inch (3 cm)

6. Lift entire outer case from the unit.

OUTER CASE REMOVAL

rear cabinet using a T20H Torx type or GTXH20-100 screw driver.

(4) screws along the right and left side of outer case. to free it from retaining clips on the cavity face plate.

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Oven lamp socket

Terminal

Wire lead

Terminal hole

Flate type small screw driver

CAUTION: 1. DISCONNECT OVEN FROM POWER SUP-

PLY BEFORE REMOVING OUTER CASE.

2. DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPONENTS OR WIRING.

MAGNETRON REMOVAL

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 from magnetron.

5. Remove the three (3) screws holding the magnetron to the waveguide.

HIGH VOLTAGE COMPONENTS REMOVAL

(HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY)

To remove the components, proceed as follows.

Disconnect the power supply cord and remove outer case.

2. Open the oven door and block it open.

3. Discharge high voltage capacitor.

4. Remove one (1) screw holding capacitor holder to rear cabinet.

5. Disconnect the H.V. wire of the H.V. rectifier assembly from the magnetron.

6. Disconnect the filament lead of the power transformer from the H.V. capacitor.

7. Remove one (1) screw holding ground side terminal of high voltage rectifier assembly, and remove capacitor holder.

NOTE: When replacing the outer case, the 2 special

Torx screws must be reinstalled in the same locations.

6. Remove the magnetron from waveguide.

7. Now, the magnetron is free. CAUTION: WHEN REPLACING THE MAGNETRON, BE

SURE THE R.F. GASKET IS IN PLACE AND THE MAGNETRON MOUNTING SCREWS ARE TIGHTENED SECURELY.

8. Disconnect all the leads and terminals of high voltage rectifier assembly from high voltage capacitor.

9. Now the H.V. rectifier assembly and H.V. capacitor should be free.

CAUTION: WHEN REPLACING HIGH VOLTAGE RECTI-

FIER ASSEMBLY, ENSURE THAT THE CATHODE (GROUND) CONNECTION IS SECURELY FIXED TO THE CAPACITOR HOLDER WITH A GROUNDING SCREW.

CAUTION: DO NOT REPLACE ONLY HIGH VOLTAGE

RECTIFIER. WHEN REPLACING IT, REPLACE 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. Disconnect the lead from magnetron filament.

6. Disconnect the lead of the power transformer from high voltage capacitor.

7. Remove the two (2) screws holding the transformer to bottom plate.

8. Remove the transformer.

OVEN LAMP AND LAMP SOCKET REMOVAL

Disconnect the power supply cord and remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Pull the wire leads from the oven lamp socket by pushing the terminal hole of the oven lamp socket with the flat type small screw driver.

5. Tear the cushion from the light mount plate.

6. Bend the tab of the light mount plate holding the oven.

7. Lift up the oven lamp socket.

8. Now, the oven lamp socket is free.

9. Now the power transformer is free.

Re-install

1. Rest transformer on the bottom plate with its primary terminals toward the oven face plate.

2. Secure transformer with two (2) screws to the bottom plate.

3. Re-connect wire leads (primary and high voltage) and filament leads to the power transformer, magnetron and high voltage capacitor, referring to "Pictorial Diagram".

4. Re-install outer case and check that the oven is operating properly.

Figure C-1. Oven lamp socket

POSITIVE LOCK® CONNECTOR (NO-CASE TYPE) REMOVAL

Terminal

Push

Pull down

Lever

Positive lock® connector

Washer

O-ring

Base of turntable motor shaft

Turntable motor

O-ring

Washer

Apply grease here

Disconnect the power supply cord, and remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Push the lever of positive lock® connector.

5. Pull down on the positive lock® connector.

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CAUTION: WHEN CONNECTING THE POSITIVE LOCK

CONNECTORS TO THE TERMINALS, CONNECT THE POSITIVE LOCK® SO THAT THE LEVER FACES YOU

CONTROL PANEL ASSEMBLY REMOVAL

Disconnect the power supply cord and remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the leads from the control unit.

5. Remove the one (1) screw holding the chassis support to the front plate of the oven cavity.

6. Remove the chassis support from the oven.

7. Lift up the control panel and release it from the oven cavity.

8. Now, the control panel assembly is free.

TURNTABLE MOTOR REMOVAL

Removal

1. Disconnect the power supply cord.

2. Remove the turntable and turntable support from the oven cavity.

3. Turn the oven over.

4. Cut the four (4) bridges holding 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 the single (1) screw holding the turntable motor to the oven cavity.

Screw; XHTSD40P08RV0 or XFPSD40P08K00

Cutting Pliers

Bridges

Figure C-3. Turntable Motor Cover

Turnrable Motor Cover

Bottom Plate

Tab

Hole

Figure C-2. Positive lock® connector

NOTE: 1. Before attaching a new key unit, remove remaining

adhesive on the control panel frame surfaces completely with alcohol.

2. When attaching the key unit to the control panel frame, adjust the upper edge and right edge of the key unit to the correct position of control panel frame.

3. Stick the key unit firmly to the control panel frame by rubbing with soft cloth not to scratch.

8. Remove the turntable motor from the oven cavity.

9. Remove the O-ring and washer from the turntable motor.

10.Now, the turntable motor is free.

Re-install

1. Remove any sharp edges on the turntable motor cover and the bottom plate with the cutting pliers.

2. Re-install the O-ring.

3. Apply the grease (Shinetsu silicone grease G-420 of Sinetsu Chemical Co. Ltd. or Toray Silicone grease SH14 of Toray Silicone Co., Ltd.) to the O-ring and the base of the turntable motor shaft as shown in Figure C-4.

4. Re-install the turntable motor with the O-ring and washer to the oven cavity with the single (1) screw.

5. Re-connect the wire leads to the turntable motor.

6. Insert the tab of the turntable motor cover into the hole of the bottom plate as shown in Figure C-3.

7. Re-install the turntable motor cover to the bottom plate with one (1) screw XHTSD40P08RV0 or XFPSD40P08K00 as shown in Figure C-3.

Figure C-4. Washer and O-ring Installation and

Grease Applying.

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COOLING FAN MOTOR REMOVAL

REMOVAL

Disconnect the power supply cord and remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the wire leads from the fan motor.

5. Remove the one (1) screw holding the chassis support to the oven cavity front plate.

6. Remove the chassis support .

7. Release the filament lead of the power transformer and the H.V. wire from the fan duct.

8. Remove the one (1) screw holding the light mounting plate to the oven cavity.

9. Release the wire leads (to the oven lamp) from the hole of the fan duct.

10.Release the fan motor assembly from the oven cavity.

11.Remove the fan blade from the fan motor shaft according to the following procedure.

12 Hold the edge of the rotor of the fan motor by using a pair

of groove joint pliers.

CAUTION:

• Make sure no metal pieces enter the gap between the rotor and the stator of the fan motor. Because the rotor is easily shaven by pliers and metal pieces may be produced.

• Do not touch the pliers to the coil of the fan motor because the coil may be cut or injured.

• Do not disfigure the bracket by touching with the pliers.

13 Remove the fan blade assembly from the shaft of the fan

motor by pulling and rotating the fan blade with your hand.

14 Now, the fan blade will be free.

CAUTION:

• Do not re-use the removed fan blade because the hole (for shaft) may be larger than normal.

Coil

Groove joint pliers

15. Remove the two (2) screws holding the fan motor to the fan duct.

16. Now, the fan motor is free.

INSTALLATION

1. Install the fan motor to the fan duct with the two (2) screws.

2. Install the fan blade to the fan motor shaft according to the following procedure.

3. Hold the center of the bracket which supports the shaft of the fan motor on the flat table.

4. Apply the screw 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.

6. Install the fan motor assembly to the oven cavity by fitting the tabs of the fan duct into the holes of the oven cavity and the waveguide flange.

7. Re-install the light mounting plate to the oven cavity with the one (1) screw.

8. Insert the end of the chassis support into the slit of the oven cavity rear cabinet.

9. Re-install the chassis support to the oven cavity front plate with the one (1) screw.

10. Install the filament lead and the H.V. wire into the hole of the fan duct .

11. Re-install the wire leads (to the oven lamp) to the hole of the fan duct.

12. Connect the wire leads to the fan motor, referring to the pictorial diagram.

Shaft

Stator

Gap

Bracket

Rotor

Rear View

Shaft

Axis

Stator

Rotor

Side View

These are the positions that should be pinched with pliers

Table

Center of bracket

DOOR SENSING SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL

Disconnect the power supply cord and remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect wire leads from the switches and control panel.

5. Remove the control panel assembly from the oven cavity front flange. Refer to chapter "CONTROL PANEL ASSEMBLY REMOVAL"

6. Remove two (2) screws holding latch hook to oven flange.

7. Remove latch hook assembly from oven flange.

8. To remove the secondary interlock switch.

8-1. Pull out the secondary interlock switch from the latch

hook, by pushing outward on the tab that is holding the switch. But the switch will be caught by the bar of the latch hook.

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8-2. Then pull out the switch while pushing the plunger of the

switch again.

8-3. Now the secondary interlock switch is free.

9. To remove the monitor switch or door sensing switch. 9-1. Push outward on the tab that is holding the switch, and

turn the switch so that the pole is on the axis.

5. Re-connect wire leads to the control unit. Refer to chapter "Pictorial Diagram".

6. Make sure that monitor switch is operating properly and check continuity of the monitor circuit. Refer to chapter "Test Procedure", and Adjustment Procedure below.

Latch Hook

9-2. Pull out the switch from the latch hook. Do not break the

pole or tab of the latch hook.

9-3. Now the switch is free.

Re-install

1. Re-install each switch in its place. The secondary interlock switch is in the lower position and the monitor switch is

Pole

Door Sensing Switch

in the middle position. The door sensing switch is in the upper position.

2. Re-connect wire leads to each switch. Refer to chapter "Pictorial Diagram".

3. Secure latch hook (with two (2) mounting screws) to oven flange.

4. Re-install the control panel assembly to the oven cavity front flange.

Figure C-5. Latch Switch Removal

Pole

Monitor Switch

Secondary Interlock Switch

Tab

Outward

Tab

Bar

Outward

DOOR SENSING SWITCH, SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT

Disconnect the power supply cord and remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

If the door sensing switch, secondary interlock switch and monitor switch do not operate properly due to a misadjustment, the following adjustment should be made.

4. Loosen the two (2) screws holding the latch hook to the flange of the oven front face.

5. With the door closed, adjust latch hook by moving it back and forth and up and down. In and out play of the door allowed by the upper and lower position of the latch hook should be less than 0.5mm. The horizontal position of the latch hook should be adjusted so that the monitor switch is activated with the door closed. The vertical position of the latch hook should be adjusted so that the door sensing switch and the secondary interlock switch are activated with the door closed.

6. Secure the screws firmly.

7. Check the operation of all switches. If each switch has not activated with the door closed, loosen screw and adjust the latch hook position.

After adjustment, make sure of the following.

1. In and out play of the door remains less than 0.5mm when in the latched position. First check upper position of latch hook, pushing and pulling upper portion of door toward the oven face. Then check lower portion of the latch hook, pushing and pulling lower portion of door

toward the oven face. Both results (play in the door) should be less than 0.5mm.

2. The door sensing switch and secondary interlock switch interrupt the circuit before the door can be opened.

3. The monitor switch contacts close when the door is opened.

4. The contacts of door 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.)

Latch Heads

Door



Secondary Interlock Switch

Latch Hook

Door Sensing Switch

Monitor Switch

Figure C-6. Latch Switch Adjustments

DOOR REPLACEMENT

REMOVAL

Disconnect the power supply cord.

2. Open the door slightly.

3. Insert a putty knife (thickness of about 0.5mm) into the

gap between the choke cover and corner portion of door panel as shown in Figure C-7 to free engaging parts.

4. Pry the choke cover by inserting a putty knife in order shown in figure C-7.

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5. Release choke cover from door panel.

6. Now choke cover is free.

Choke Cover

Putty Knife

Door Frame

Figure C-7. Door Disassembly

7. Release two (2) pins of door panel from two (2) holes of upper and lower oven hinges by lifting up.

8. Now, door panel is free from oven cavity.

9. Release door panel from ten (10) tabs of door frame and remove door frame by sliding the door panel downward.

10.Now, door panel with sealer film is free.

11.Tear sealer film from door panel.

12.Now, door panel is free.

13.Slide latch head upward and remove it from door frame with releasing latch spring from door frame and latch head.

14.Now, latch head and latch spring are free.

15.Remove door screen from door frame.

16.Now, door screen is free.

RE-INSTALL

1. Re-install door screen to door frame.

2. Re-install latch spring to the head. Re-install latch spring to the door frame. Re-install latch head to the door frame.

3. Re-install door panel to door frame by fitting ten (10) tabs of door frame to ten (10) holes of door panel.

4. Put sealer film on door panel. Refer to "Sealer Film" and figure C-9, on how to handle the new film.

5. Catch two (2) pins of door panel on two (2) hole of upper and lower oven hinges.

6. Re-install choke cover to door panel by pushing.

Note: After any service to the door; (A) Make sure that door sensing switch, secondary

interlock switch and monitor switch are operating properly. (Refer to chapter "Test Procedures".).

(B) An approved microwave survey meter should be

used to assure compliance with proper microwave radiation emission limitation standards.

Note: The door on a microwave oven is designed to act as

an electronic seal preventing the leakage of microwave energy from oven cavity during cook cycle. This function does not require that door be airtight, moisture (condensation)-tight or light-tight. Therefore, occasional appearance of moisture, light or sensing of gentle warm air movement around oven door is not abnormal and do not of themselves, indicate a leakage of microwave energy from oven cavity.

Upper Oven

Hinge

Upper Oven Hinge

Door Panel

Lower Oven Hinge

Choke Cover

Lower

Oven Hinge

Figure C-8. Door Replacement

SEALER FILM

Installation

1. Put the adhesive tape on the backing film of the sealer film as shown in Fig. C-9.

2. Tear the backing film by pulling the adhesive tape.

3. Put the pasted side of the sealer film on the door panel

Sealer film

Backing film

Adhesive tape

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 plate is to be less than 1.0mm.

3. Door is positioned with its face pressed toward cavity face plate.

4. Check for microwave leakage around door with an approved microwave survey meter. (Refer to Microwave Measurement Procedure.)

Figure C-9. Sealer film

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NOTE:

The grounding conductor of

the power supply cord has

been grounded by power

supply cord fixing screw.

The screw must allways be

WHT

kept tight.

GRD

POWER SUPPLY CORD

120V 60Hz

NOTE:

The neutral (WHT) wire must be

RED

OVEN LAMP

& SOCKET

connected to the terminal with "N"

mark on the power supply cord.

BLK

ORG

RED

MAGNETRON

THERMAL CUT-OUT

GRY

WHT

HIGH 

VOLTAGE

CAPACITOR

H.V.

RECTIFIER

HIGH VOLTAGE

WIRE B

POWER 

MAGNETRON

TRANSFORMER

HIGH VOLTAGE COMPONENTS

GRY

WHT

ORG

NOTE: Hot (RED) wire must

be connected to the terminal

C/T FUSE

with blue mark on the oven

light socket.

BLK

RED

Blue Mark

DOOR

SENSING SWITCH

GRN

WHT

GRY

N.O.

COM

GRN

CN-B

GRY

GRN

FAN MOTOR

ORG

RED

GRY

N.C.

COM

MONITOR 

SWITCH

ORG

CN-A

GRY

ORG

TURNTABLE

MOTOR

Figure S-1. Pictorial Diagram

N.O.

COM

SECONDARY

INTERLOCK SWITCH

GRY

WHT

SP30

IC-1

CONTROL PANEL

RY2



PRIMARY

INTERLOCK

RELAY

CN-A

CN-B

RY1

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LIQUID CRYSTAL DISPLAY

CONTROL UNIT

D1~D4:11ES1

2SA933 Q1

R2 1k

ON DEF. LBS. QTY. CHECK

0.1µ/50v C5

–

VRS1

C 1 C 2 C 3 S 1 S 2 S 3 S 4 S 5 S 6 S 7 S 8 S 9

S10 S11 S12

R3 15k

HZ4C3 ZD1

C4 47µ/16v

C3 0.01µ/16v

15k R5

3.3k R30

C2 470µ/25v

R1 910 1/2w

C1 0.1µ/50v

SP30

(J1)

START

Minute Plus

POPCORN

G10

KEY UNIT

10kF R70

COM 4

SEG 1

SEG 2

COM 3

COM 2

COM 1

SEG 3

SEG 4

VLC

SEG 5

HOLD

SEG 6

33p C71

RESET 35

SEG 7

R92

R91

X IN

X OUT

10515

SEG 8

SEG 9

SEG10

SEG11

R90

R83

R60

R61

0.01µ/16v C70

VDD 42

SEG 0

R80 15k

R82

R81

R73

R72

R70

INT2

PULSE

IC1 IZA868DR

R62

R63

VSS

AIN0

AIN1

AIN2

AIN3

15k R50 

15k R51

15k R52

15k R53

15k R54

15k R55

Power

COMPU

DEFROST

PLATE

DINNER

BEVERAGE

C61

G 7

C62

FRESH

VEGETABLES

G 8

G 6 G 5 G 4 G 3 G 2 G 1

C63

Level

Stop

Clear

BAKED

POTATO



Clock

Timer

ROLL,

MUFFIN

G 9

C64

C61~C64

330pF/50v x 4

R61 220k R62 220k

(J7) 4.7k (J6) 3.3k

(J4) (J2)

C6 0.01µ/16v

Q30

R20 15k

– +

C20 0.1µ/50v

KRA101M

(J5) (J3)

4.7k R41

0.01µ/16v C40

R40 15k

R63 220k R64 220k

R57 15k

R58 15k

R59 15k

R60 15k

Figure S-2. Control Panel Circuit

R4 15k

Q20

KRA101M

–

C21

10µ/35v

Q22

DTA143ES

Q21

KRC243M

D21D22

IF NOT SPECIFIED, 1/4w ± 5%

D40

RY1

D20

RY2

IF NOT SPECIFIED, 1SS270A

NOTE :

AC120V

60Hz

OVEN LAMP

TURNTABLE

MOTOR

FAN MOTOR

MICRO

COM

DOOR

SWITCH

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DIP

R61 C61 R62

C62

R63

C63

R64

C64

R60 R59 R58 R57 R40 C40

R41

(J6) (J4) (J2) 8

R80

R55

R54

R53

R52

R51

1 IC1

R50

C70

(J7) (J5) (J3)

Q1 C5

(CF1)

R70

R30

ZD1

C71

SP30

Q30

E 6

Q22

D22

Q21

DOOR SW

C21

D20 D40

VRS1

CN - B

AC (N) FM TTM OL

Figure S-3. Printed Wiring Board

C20

R20

Q20

RY2

D21

(J1)

RY1

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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

ELECTRIC PARTS

1- 1 QSW-MA131WRE0 Secondary interlock switch & door sensing switch 2 AG 1- 2 FFS-BA020WRK0 C/T fuse & monitor switch assembly 1 AP 1- 3 FACCDA079WRE0 Power supply cord 1 AF 1- 4 QSOCLA021WRE0 Oven lamp socket 1 AH 1- 5 FH-DZA081WRK0 High voltage rectifier 1 AQ

1- 6 RC-QZA200WRE0 High voltage capacitor 1 AV

1- 6 RC-QZA201WRE0 High voltage capacitor (Interchangeable) 1 AW

1- 7 RMOTEA338WRE0 Fan motor 1 AV 1- 7 RMOTEA355WRE0 Fan motor (Interchangeable) 1 AU 1- 8 RV-MZA226WRE0 Magnetron 1 BE

∆

1- 8 RV-MZA282WRE0 Magnetron (Interchangeable) 1 BP

∆

1- 9 RLMPTA030WRE0 Oven lamp 1 AF 1-10 RMOTDA211WRE0 Turntable motor 1 AS 1-10 RMOTDA186WRE0 Turntable motor (Interchangeable) 1 AW 1-11 RTHM-A078WRE0 Thermal cut-out 125˚C 1 AK 1-12 RTRN-A561WRE0 Power transformer 1 BM

CABINET PARTS

2- 1 GCABUA696WRP0 Outer case cabinet 1 AF 2- 2 FDAI-A203WRY0 Bottom plate 1 BB 2- 3 GLEGPA074WRE0 Foot 2 AC

CONTROL PANEL PARTS

3- 1 CPWBFA773WRK0 Control unit 1 BL 3- 1A QCNCMA431DRE0 2-pin connector (A) 1 AC 3- 1B QCNCMA275DRE0 2-pin connector (B) 1 AB C1 RC-KZA087DRE0 Capacitor 0.1 uF 50V 1 AA C2 VCEAB31EW477M Capacitor 470 uF 25V 1 AC C3 VCKYD11CY103N Capacitor 0.01 uF 16V 1 AA C4 VCEAB31CW476M Capacitor 47 uF 16V 1 AA C5 RC-KZA087DRE0 Capacitor 0.1 uF 50V 1 AA C6 VCKYD11CY103N 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) 3 AA D40 VHD1SS270A/-1 Diode (1SS270A) 1 AA IC1 RH-IZA868DRE0 LSI 1 AN Q1 VS2SA933S//-3 Transistor (2SA933) 1 AB Q20 VSKRA101M//-3 Transistor (KRA101M) 1 AB Q21 VSKRC243M//-3 Transistor (KRC243M) 1 AB Q22 VSDTA143ES/1B Transistor (DTA143ES) 1 AA Q30 VSKRA101M//-3 Transistor (KRA101M) 1 AB R1 VRD-B12HF911J Resistor 910 ohm 1/2W 1 AA R2 VRD-B12EF102J Resistor 1.0k ohm 1/4W 1 AA R3-5 VRD-B12EF153J Resistor 15k ohm 1/4W 3 AA R20 VRD-B12EF153J Resistor 15k ohm 1/4W 1 AA R30 VRD-B12EF332J Resistor 3.3k ohm 1/4W 1 AA R40 VRD-B12EF153J Resistor 15k ohm 1/4W 1 AA R41 VRD-B12EF472J Resistor 4.7k ohm 1/4W 1 AA R50-55 VRD-B12EF153J Resistor 15k ohm 1/4W 6 AA R57-60 VRD-B12EF153J Resistor 15k ohm 1/4W 4 AA R61-64 VRD-B12EF224J Resistor 220k ohm 1/4W 4 AA R70 VRN-B12EK103F Resistor 10k ohm 1/4W 1 AA R80 VRD-B12EF153J Resistor 15k ohm 1/4W 1 AA (J6) VRD-B12EF332J Resistor 3.3k ohm 1/4W 1 AA (J7) VRD-B12EF472J Resistor 4.7k ohm 1/4W 1 AA RY1 RRLY-A111DRE0 Relay (JV12S-KT) 1 AL RY2 RRLY-A094DRE0 Relay (OMIF-S-112LM) 1 AN SP30 RALM-A014DRE0 Buzzer (PKM22EPT-CA) 1 AG T1 RTRNPA110DRE0 Transformer 1 AP VRS1 RH-VZA032DRE0 Varistor (10G471K) 1 AE ZD1 VHEHZ4C3///-1 Zener diode (HZ4C-3) 1 AA 3- 2 FPNLCB426WRK0 Control panel frame with key unit and LCD 1 BE

REF. NO. PART NO. DESCRIPTION Q'TY CODE

3- 2-1 FUNTKA928WRE0 Key unit 1 AY 3- 2-2 RLCDSA045DRE0 Liquid crystal display 1 AM 3- 3 QCNC-A012WRE0 Rubber connector 1 AF 3- 4 XEPSD30P08XS0 Screw; Control unit mtg. 4 AA

OVEN PARTS

4- 1 PHOK-A105WRF0 Latch hook 1 AL

∆

4- 2 LANGQA477WRW0 Light mount plate 1 AY 4- 3 PCUSUA502WRP0 Waterproof cushion 1 AD 4- 4 LBNDKA038WRP0 Capacitor holder 1 AF 4- 5 NFANJA029WRE0 Fan blade 1 AL 4- 6 PDUC-A694WRF0 Fan duct 1 AG 4- 7 ************* Oven cavity (Not replaceable part) 1--

∆

4- 8 GLEGPA073WRF0 Leg 1 AD 4- 9 LANGTA318WRP0 Chassis support 1 AE 4-10 PCUSGA389WRP0 Cushion 1 AG 4-11 PCOVPA276WRE0 Waveguide cover 1 AM 4-12 PCOVPA342WRF0 B-cover Right 1 AH 4-13 PCOVPA343WRF0 B-cover Left 1 AH 4-14 PCUSUA443WRP0 Cushion 1 AE 4-15 PDUC-A700WRF0 Air separator 1 AN 4-16 PPACGA097WRE0 O-ring 1 AG 4-17 PCUSUA270WRP0 Cushion 1 AG

DOOR PARTS

5- 1 FDORFA321WRT0 Door panel 1 AT

∆

5- 2 GWAKPA628WRF0 Door frame 1 AY 5- 3 HPNL-A686WRR0 Door screen 1 AY 5- 4 LSTPPA175WRF0 Latch head 1 AE

∆

5- 5 MSPRTA084WRE0 Latch spring 1 AB 5- 6 PSHEPA622WRE0 Sealer film 1 AG 5- 7 GCOVHA390WRF0 Choke cover 1 AK 5- 8 XCPSD40P08000 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 6-10 TCAUAA145WRR0 Earth caution 2 AG 6-11 TCAUAA240WRR0 Screw caution 1 AC

SCREWS AND WASHERS

7- 1 XHPSD40P08K00 Screw : 4mm x 8mm 5 AA 7- 2 LX-EZA042WRE0 Special screw 2 AB 7- 3 LX-WZA028WRE0 Special washer 1 AB 7- 4 LX-BZA125WRE0 Special screw 2 AA 7- 5 XHTSD40P08RV0 Screw : 4mm x 8mm 5 AA 7- 6 XHPSD30P08000 Screw : 3mm x 8mm 1 AA 7- 7 LX-CZ0052WRE0 Special screw 2 AA 7- 8 XOTSD40P12000 Screw : 4mm x 12mm 6 AA 7- 9 XOTSE40P08000 Screw : 4mm x 8mm 4 AA 7-10 LX-CZA071WRE0 Special screw (Torx tamper proof screw) 2 AC 7-11 LX-CZA073WRE0 Special screw 2 AC 7-12 LX-CZA076WRE0 Special screw 1 AC

R-203CW

HOW TO ORDER REPLACEMENT PARTS

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 authorized SHARP parts Distributor for your area. Defective parts requiring return should be returned as indicated in the Service Policy.

R-203CW

OVEN AND CABINET PARTS

1-4

4-3

4-2

4-17

4-14

4-7

4-11

1-9

7-8

6-9

1-2

2-1

7-9

7-1

6-10

7-11

7-10

7-11

7-10

1-8

7-9

6-7

7-12

4-5

1-3

4-6

7-5

6-11

1-7

6-2

4-13

6-1

2-2

7-8

4-16

4-15

2-3

7-3

7-8

7-1

1-10

7-2

7-7

1-11

1-12

2-3

4-10

4-12

7-6

7-4

4-1

4-8

1-5

1-1 1-2

1-1

7-4

4-4

7-1

1-6

7-8

4-9

7-8

R-203CW

6-8

Befor attaching Control unit to Control panel, foil side of Control unit must be cleaned by ethylalcohol.

3-2

3-2-2

CONTROL PANEL PARTS

3-1

3-3

3-4

DOOR PARTS

3-2-1

MISCELLANEOUS

5-6

5-8

5-7

5-1

5-8

5-2

5-3

5-4

5-5

6-4

Actual wire harness may be different than illustration.

6-5

6-6

R-203CW

PACKING AND ACCESSORIES

TOP PAD ASSEMBLY FPADBA387WRK0

INTO THE  OVEN CAVITY

TRAY PAD ASSY

(CPADBA244WRK0)

DOOR PROTECTION SHEET SPADPA580WRE0

6-3 INSTRUCTION BOOK

6-2 TURNTABLE TRAY

6-1 TURNRABLE SUPPORT

MICROWAVE OVEN

Not replaceable items.

POLYETHYLENG BAG SSAKHA014WRE0

BOTTOM PAD ASSEMBLY FPADBA388WRK0

PACKING CASE SPAKCD209WRE0

No part of this publication may be reproduced, stored in retrieval systems, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of the publisher.

'99 SHARP CORP. (1S2.530E) Printed in U.S.A

SHARP R203CW2, R-203CW Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual