Sharp R-340D Service manual

SMART

& EASY

T O U C H S C R E E

N

1

12 : 30 PM

2

3

4

5 6

7

8 9

Minute

PLus +

0

Kitchen

Timer

T O U C H . S C R E E N

MINUTE

PLUS

STOP

CLEAR START

ONE TOUCH SENSOR

Reheat

Popcorn

Baked

Potatoes

6x6 NO GUESS COOKING

6 Categories + 36 Foods

Vegetables

Meat

Poultry

Fish/

Seafood

Frozen

Seafood

Pasta

Grains

More Frozen Your Microwave

6 x 6

Beverage

Senter

Defrost

Set Up

R - 340DK

R -340DW

SERVICE MANUAL

S2008R340DPW/

MICROWAVE OVEN

MODELS

R-340DK

R-340DW

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 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 ............................................................................................................................ 10

TEST PROCEDURE ............................................................................................................................................ 11

TOUCH CONTROL PANEL ................................................................................................................................. 21

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ................................................................ 27

PICTORIAL DIAGRAM ........................................................................................................................................ 33

POWER UNIT CIRCUIT ...................................................................................................................................... 34

CPU UNIT CIRCUIT ............................................................................................................................................ 35

PRINTED WIRING BOARD ................................................................................................................................. 36

PARTS LIST ........................................................................................................................................................ 37

PACKING AND ACCESSORIES ......................................................................................................................... 41

SHARP CORPORATION

This document has been published to be used for after sales service only.

The contents are subject to change without notice.

R -340DK

R-340DW

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.

(c) Before turning on microwave power for any service test or inspection within the microwave generating 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/cm

2

. The owner of the unit should be instructed not to use the unit until the oven has been brought into compliance.

R -340DK

R-340DW

WARNING TO SERVICE PERSONNEL

Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts may result in a severe, possibly fatal, electrical shock.

(Example)

High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..

Read the Service Manual carefully and follow all instructions.

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.



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,




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.




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.

1

R- 340DK

R-340DW

MICROWAVE MEASUREMENT PROCEDURE

A. Requirements:

1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm 2 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/cm 2 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/cm 2 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/cm 2 , 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.

2

R -340DK

R-340DW

SERVICE MANUAL

MICROWAVE OVEN

R-340DK/ R-340DW

FOREWORD

This Manual has been prepared to provide Sharp Electronics Corp.

Service Personnel with Operation and Service Information for the

SHARP MICROWAVE OVEN, R-340DK, R-340DW.

It is recommended that service personnel carefully study the entire text of this manual so that they will be qualified to render satisfactory customer service.

Check the interlock switches and the door seal carefully. Special attention should be given to avoid electrical shock and microwave radiation hazard.

WARNING

Never operate the oven until the following points are ensured.

(A) The door is tightly closed.

(B) The door brackets and hinges are not defective.

(C) The door packing is not damaged.

(D) The door is not deformed or warped.

(E) There is no other visible damage with the oven.

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

DANGER

Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing. Service personnel - Do not contact the following parts while the appliance is energized;

High Voltage Capacitor, Power Transformer, Magnetron, High

Voltage Rectifier Assembly, High Voltage Harness;

If provided, Vent Hood, Fan assembly, Cooling Fan Motor.

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

250V.

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

All the parts marked “

∆

” on parts list may cause undue microwave exposure, by themselves, or when they are damaged, loosened or removed.

PRODUCT DESCRIPTION

GENERAL INFORMATION

OPERATION

TROUBLESHOOTING GUIDE AND

TEST PROCEDURE

TOUCH CONTROL PANEL

COMPONENT REPLACEMENT

AND ADJUSTMENT PROCEDURE

WIRING DIAGRAM

PARTS LIST

SHARP ELECTRONICS CORPORATION

SHARP PLAZA, MAHWAH,

NEW JERSEY 07430-2135

3

R- 340DK

R-340DW

ITEM

Power Requirements

Power Output

Case Dimensions

Cooking Cavity Dimensions

1.2 Cubic Feet

Control Complement

Oven Cavity Light

Safety Standard

SPECIFICATION

DESCRIPTION

120 Volts / 14 Amperes

60 Hertz

Single phase, 3 wire grounded

1150 watts (IEC TEST PROCEDURE)

Operating frequency of 2450MHz

Width 20-1/2"

Height 11-7/8"

Depth 17-1/8"

Width 14-3/4"

Height 8-3/4"

Depth 15-3/4"

Touch Control System

Clock ( 1:00 - 12:59 )

Timer (0 - 99 min. 99 seconds)

Microwave Power for Variable Cooking

Repetition Rate;

POWER 100% ................................. Full power throughout the cooking time

POWER 90% .................................................... approx. 90% of Full Power









POWER 0% .................................. No power throughout the cooking time

TOUCH SCREEN, MINUTE PLUS pad, STOP/CLEAR pad

START pad, ONE TOUCH SENSOR pads

6 X 6 NO GUESS COOKING pads

More From Your Microwave pad

Beverage Center pad, Defrost pad, Set Up pad

Yes

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.

Electrical Requirements

The electrical requirements are a 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

4

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 RE-

MOVE THE ROUND GROUNDING PRONG FROM THIS

PLUG.

OVEN DIAGRAM

6

1. Door open handle.

Pull to open door.

2. Door latches.

The oven will not operate unless the door is securely closed.

3. Removable turntable support.

4. Removable turntable.

The turntable will rotate clockwise or counterclockwise.

5. Oven lamp.

It will light when oven is operating or door is opened.

6. Oven door with see-through window.

7. Ventilation openings. (Rear)

8. Auto-Touch control panel.

9. Touch screen.

10. Coupling.

11. Wave guide cover.

12. Power supply cord

1

2

10

5

11

NOTE:

The directed features are disabled after three minutes when the oven is not in use. These features are automatically enabled when the door is opened and closed or the

STOP/ CLEAR pad is pressed.

Grounded

Receptacle Box

3-Pronged

Plug

Grounding Pin

3-Pronged Receptacle

9

8

12

4

3

TOUCH CONTROL PANEL

7

See note

1

12 : 30 PM

2 3

4 5 6

7 8 9

Minute

Plus +

0

Kitchen

Timer

T O U C H . S C R E E N

MINUTE

PLUS

STOP

CLEAR

START

ONE TOUCH SENSOR

Reheat Popcorn

Baked

Potatoes

6x6 NO GUESS COOKING

6 Categories + 36 Foods

Vegetables Meat Poultry

Fish/

Seafood

Frozen

Food

Pasta

Grains

More From Your Microwave

6 x 6

Beverage

Center

Defrost

3 + 6

Set Up

5

R -340DK

R-340DW

R- 340DK

R-340DW

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 oven is plugged in, 120 volts A.C. is supplied to the control unit (Figure O-1).

1. "Set clock" key and "Video demo" key will be appeared on the touch screen.

2. Touch "Set clock" key and set the clock referring to the operation manual.

NOTE: If any keys are not touched for 30 seconds, the touch screen will go on to the Video Demo mode. To cancel the Video Demo mode, touch the STOP/

CLEAR pad. And then set the clock.

3. The touch screen will show the home page after setting the clock.

4. The following is the example of the Home page in the case the time of the day is set to 12:30 p.m..

1

4

7

Minute

Plus +

12 : 30 PM

2 3

5

8

6

0

9

Kitchen

Timer

NOTE: Even if the clock is not set, the display will show the

Home page by touching the STOP/CLEAR pad within 30 seconds after plugged in.

COOKING CONDITION

Program desired cooking time by touching the NUMBER keys on the touch screen. Program the power level by touching the POWER LEVEL key and then touch the desired percentage key on the touch screen.

When the START pad is touched, the following operations occur:

1. The contacts of relays are closed and components connected to the relays are turned on as follows.

(For details, refer to Figure O-2)

RELAY

RY-1

RY-2

CONNECTED COMPONENTS oven lamp/turntable motor/fan motor power transformer

2. 120 volts A.C. is supplied to the primary winding of the power transformer and is converted to about 3.1 volts

A.C. output on the filament winding, and approximately

2370 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 feed-

6 box, 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, relay (RY1) and primary interlock relay are activated with the following results. The circuits to the turntable motor, the cooling fan motor, and the high voltage components are de-energized, the oven lamp remains on, and the digital read-out displays the time still remaining in the cook cycle when the door was opened.

7. The monitor switch electrically monitors the operation of the secondary interlock switch and primary interlock relay 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 primary interlock relay (RY2) and secondary interlock switch open their contacts. And contacts of the relay (RY1) remains closed. 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. And contacts of the relay (RY1) open.

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 monitor fuse, secondary interlock switch, relay (RY1) and primary interlock relay (RY2), causing the monitor fuse to blow.

POWER LEVEL 0% TO 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

POWER 100%

ON TIME

(100% power) 32 sec.

POWER 90% (approx. 90% power) 30 sec.










OFF TIME

0 sec.

2 sec.

6 sec.

8 sec.

10 sec.

14 sec.

16 sec.

20 sec.

24 sec.

26 sec.

32 sec.

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.

SENSOR COOKING CONDITION

Using the Sensor cooking function (See sensor cooking menus), the food is cooked without figuring time, power level or quantity. When the oven senses enough steam from the food, it relays the information to its microprocessor which will calculate the remaining cooking time and power level needed for best results. When the food is cooked, water vapor is developed. The sensor “senses” the vapor and its resistance increases gradually. When the resistance reaches the value set according to the menu, supplementary cooking is started. The time of supplementary cooking is determined by experiment with each food category and inputted into the LSI.

An example of how sensor works: (BAKED POTATOES)

1. Potatoes at room temperature. Vapor is emitted very slowly.

MICROWAVE

R -340DK

R-340DW

The 16 seconds is the cooling time required to remove any vapor from the oven cavity and sensor.

NOTE: During this first stage, do not open the door or touch

STOP/CLEAR pad.

4. When the sensor detects the vapor emitted from the food, the display switches over to the remaining cooking time and the timer counts down to zero.

At this time, the door may be opened to stir, turn, or season food.

5. When the timer reaches zero, an audible signal sounds.

The shut-off relay and cook relay are de-energized and the power transformer, oven lamp, etc. are turned off.

6. Opening the door or touching the STOP/CLEAR pad, the time of day will reappear on the display and the oven will revert to an OFF condition.

The followings are the sensor cooking menus.

Reheat

Popcorn

Baked potatoes

Vegetables

Ground beef of Meat

Boneless Chicken Breast, Bone-in Chicken Pieces and

Ground Poultry of Poultry

Fish / Seafood

Vegetables, Entrees, Main Dishes and Snacks of Frozen food

White Rice and Brown Rice of Pasta Grains

Frozen breakfast food, Meal in cup, Hot dogs in buns,

Soup, Frozen sandwich, Stuffed Acorn Squash,

Ratatouille of More from Your Microwave

2. Heated Potatoes. Moisture and humidity is emitted rapidly.

You can smell the aroma as it cooks.

MICROWAVE

AH SENSOR

3. Sensor detects moisture and humidity and calculates cooking time and variable power.

Cooking Sequence.

1. Touch one of the One Touch Sensor pads (in case of one touch sensor).

NOTE: The oven should not be operated on SENSOR immediately after plugging in the unit. Wait two minutes before cooking on SENSOR.

2. The coil of shut-off relay (RY-1) is energized, the turntable motor, oven lamp and cooling fan motor are turned on, but the power transformer is not turned on.

3. After about 16 seconds, the cook relay (RY-2) is energized. The power transformer is turned on, microwave energy is produced and first stage is started.

7

R- 340DK

R-340DW

SCHEMATIC

NOTE: CONDITION OF OVEN.

1. DOOR CLOSED.

2. CLOCK APPEARS ON DISPLAY.

NOTE: Indicates components with potential above 250 V.

MONITOR

FUSE 20A

THERMAL

CUT-OUT (OVEN)

THERMAL

CUT-OUT (MG.)

A2

N.O.

N.O.

POWER

TRANSFORMER

A1

(RY-1) (RY-2)

PRIMARY

INTERLOCK

RELAY

120V AC

60 Hz

GRN

CONTROL UNIT COM.

OL OVEN

LAMP

SECONDARY

INTERLOCK

SWITCH

TTM

TURN-

TABLE

MOTOR

FM

FAN

MOTOR

COM.

SH-B SH-A

DOOR

SENSING

SWITCH

MONITOR

SWITCH

RECTIFIER

MAGNETRON

Figure O-1. Oven Schematic-Off Condition

SCHEMATIC

NOTE: CONDITION OF OVEN.

1. DOOR CLOSED.

2. COOKING TIME PROGRAMMED.

3. VARIABLE COOKING POWER (100%) PROGRAMMED.

4. "START" PAD TOUCHED.

MONITOR

FUSE 20A

THERMAL

CUT-OUT (OVEN)

THERMAL

CUT-OUT (MG.)

A2

N.O.

(RY-1)

A1

(RY-2)

PRIMARY

INTERLOCK

RELAY

N.O.

120V AC

60 Hz

GRN

CONTROL UNIT COM.

OL OVEN

LAMP

SECONDARY

INTERLOCK

SWITCH

TTM

TURN-

TABLE

MOTOR

FM

FAN

MOTOR

COM.

SH-B SH-A

DOOR

SENSING

SWITCH

MONITOR

SWITCH

POWER

TRANSFORMER

RECTIFIER

MAGNETRON

Figure O-2. Oven Schematic-Cooking Condition

8

R -340DK

R-340DW

DESCRIPTION AND FUNCTION OF COMPONENTS

DOOR OPEN MECHANISM

The door is opened by pulling the door. Refer to the Figure

D-1.

Door

Latch Hook

Latch

Heads

Door Sensing

Switch

Monitor Switch

Secondary

Interlock Switch

Figure D-1. Door Open Mechanism

DOOR SENSING AND SECONDARY INTERLOCK

SWITCHES

The secondary interlock switch is mounted in the lower position of the latch hook and the door sensing 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 blowing the monitor 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 contact 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 their 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 the secondary interlock switch contacts close.

(On opening the door, each of these switches operate inversely.)

3. If the door is opened, and the primary interlock relay

(RY2) and secondary interlock switch contacts fail to open, the monitor fuse blows simultaneously with closing of the monitor switch contacts.

CAUTION: BEFORE REPLACING A BLOWN MONITOR

FUSE TEST THE DOOR SENSING SWITCH,

PRIMARY INTERLOCK RELAY (RY2), RELAY

(RY1), SECONDARY INTERLOCK SWITCH

AND MONITOR SWITCH FOR PROPER OP-

ERATION. (REFER TO CHAPTER "TEST PRO-

CEDURE").

NOTE: MONITOR 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 foods on the turntable cook evenly during cooking. 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 vapors given off from the heating foods. It is then exhausted through the exhausting air vents at the oven cavity.

MONITOR FUSE

1. The monitor 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 monitor fuse blows to prevent an electric shock or fire hazard.

OVEN THERMAL CUT-OUT

The thermal cut-out, 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 control unit, the thermal cut-out will open.

Under normal operation, the oven thermal cut-out remains closed. However, when abnormally high temperatures are reached within the oven cavity, the oven thermal cut-out will open at 257˚F(125˚C), causing the oven to shut down.

MAGNETRON THERMAL CUT-OUT

The thermal cut-out located near the magnetron 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

293˚F(145˚C) causing the oven to shut down.

9

R- 340DK

R-340DW

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 monitor fuse, check the monitor switch, relay (RY1) primary interlock relay (RY2), door sensing switch and secondary interlock switch before replacing the monitor fuse. If the monitor fuse is replaced, the monitor switch must also be replaced. Use part FFS-

BA021WRK0 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,





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








10

TEST PROCEDURE

R -340DK

R-340DW

CK = Check / RE = Replace

RE RE A B C D E F F G H RE RE CK I CK CK CK J K L M N

CONDITION

OFF

CONDITION

COOKING

CONDITION

SENSOR

COOKING

CONDITION

PROBLEM

Home fuse or circuit breaker blows when power cord is plugged into wall receptacle

Monitor 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.

Touch screen does not operate properly when STOP/CLEAR key is touched. (Buzzer should sound and

Home page should appear in display.)

Oven lamp does not light when door is opened.

Oven lamp does not go out when door is closed.

Oven lamp lights but fan motor and turntable motor do not operate.

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 50% mode. (Operates properly on Cooking Power 100% mode.)

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

AH sensor does not end during Sensor cooking condition. (Oven does not shut off after a cup of water is boiling by sensor cooking.)

Oven stops at 16 sec. after starting.

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TEST PROCEDURES

PROCEDURE

LETTER

A

COMPONENT TEST

MAGNETRON ASSEMBLY TEST




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.





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:

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 100% 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 34.3

to 63.6˚F(19.1 to 35.4˚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




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 74.2 ohms; the resistance of the filament coil should be less than 1 ohm.




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TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST


(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




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.





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

D

E

HIGH VOLTAGE CAPACITOR TEST




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.





OVEN THERMAL CUT-OUT TEST




4. A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the temperature of the thermal cut-out reaches approximately 257˚F(125˚C).

An open thermal cut-out indicates overheating of the oven, exchange the oven thermal cut-out and check inside of oven cavity and for improper setting of cooking time or operation of control unit. Check for restricted air flow through the vent holes of the oven cavity, especially the cooling fan and air guide.





MAGNETRON THERMAL CUT-OUT TEST




4. A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the temperature of the magnetron reaches approximately 293˚F(145˚C). An open thermal cut-out

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TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST indicates overheating of the magnetron. Check for restricted air flow to the magnetron, especially the cooling fan air guide.





CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,

REPLACE THERMAL CUT-OUT.

F

G

SECONDARY INTERLOCK SWITCH TEST




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





PRIMARY INTERLOCK SYSTEM TEST

DOOR SENSING SWITCH




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





NOTE: If the door sensing switch contacts fail in the open position and the door is closed, the cooling fan, turntable and oven light will be activated by RY1.

PRIMARY INTERLOCK RELAY (RY2)




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.





MONITOR SWITCH TEST




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

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TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST 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.




8. Run the oven and check all

WHT functions.

RED

H

I

Screw Driver

Monitor Switch

Secondary

Interlock Switch

Ohmmeter

BLOWN MONITOR FUSE TEST




4. If the monitor 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 monitor fuse.

CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE PRIMARY INTERLOCK

RELAY, SECONDARY INTERLOCK SWITCH, DOOR SENSING SWITCH AND MONITOR

SWITCH FOR PROPER OPERATION.

If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must be replaced with "monitor fuse and monitor switch assembly" part number FFS-BA021WRK0, even if the monitor switch operates normally. The monitor fuse and monitor switch assembly is comprised of a 20 ampere fuse and switch.





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 also the Control Unit is divided into two units, CPU Unit and Power 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.

1. Key Unit.

NOTE ;

1) Check Key unit ribbon connection before replacement.

2) Reconnect all leads removed from components during testing.

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TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

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

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

5) 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.

c) When touching the pads, sometimes a pad produces no signal.

If the Key unit is defective.




4) Replace the Key unit.





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.

h) The following symptoms indicate a defective CPU unit.

• When touching the keys on the touch screen, a certain key produces no signal at all.

• When touching a number key on the touch screen, two figures or more are displayed.

• When touching the keys on the touch screen, sometimes a key produces no signal.

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,








J KEY UNIT TEST




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

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TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST unit and make sure the door sensing switch is closed (either close the door or short the door sensing switch connector). 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

G 1 G 2 G 3 G14 control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the control unit

G 5 Set Up

Defrost

3+6

More from

Your

Microwave 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.

G 6

G13

Pasta

Grains

Beverage

Center

Vegetables

STOP

CLEAR

Frozen

Food

START


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



G12

G11

Baked

Potatoes

Poultry

Reheat

Fish /

Seafood

Popcorn

Meat

MINUTE

PLUS

G15

K

L

RELAY TEST





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. 1 of the 2 pin connector (A) and the common terminal of the relay RY1 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

RY1

RY2

OPERATIONAL VOLTAGE

Approx. 24.8V D.C.

Approx. 23.9V D.C.

CONNECTED COMPONENTS

Oven lamp / Turntable motor / Cooling fan motor

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 function.

COMPU DEFROST TEST

WARNING : The oven should be fully assembled before following procedure.

(1) Place one cup of water in the center of the turntable tray in the oven cavity.

(2) Close the door, touch the Defrost pad and select compu Defrost. Then select Steaks/Chops/Fish.

(Now, weight 0.5lb is set.) And then touch the start pad.

(3) The oven is in Compu Defrost cooking condition.

(4) The oven will operate as follows

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PROCEDURE

LETTER

TEST PROCEDURES

COMPONENT TEST

WEIGHT 1ST STAGE

0.5lb

2ND STAGE

LEVEL TIME LEVEL TIME

70% 40sec.

40% 30sec.

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

M FOIL PATTERN ON THE PRINTED WIRING BOARD 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.




4) Follow the troubleshooting guide given below for repair.

CAUSE OR CORRECTION

*Insert jumper wire J1 and solder.

*Insert the coil RCILF2003YAZZ between "c" and "d".

STEPS

1

2

OCCURRENCE

Only pattern at "a" is broken.

Pattern at "a" and "b" are broken.

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 133

Ω ±

10%). If any abnormal condition is detected, replace the defective parts.

c a b

(J1)

VRS1 d





2. Follow the troubleshooting guide given below, if indicator does not light up after above check and repairs are finished.






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

7) Follow the troubleshooting guide given below for repair.

STEPS OCCURRENCE CAUSE OR CORRECTION

1

2

The rated AC voltage is not present between

Pin No. 1 of the 2-pin connector (A) and the common terminal of the relay RY1.

The rated AC voltage is present at primary side of low voltage transformer.

Check supply voltage and oven power cord.

Low voltage transformer or secondary circuit defective.

Check and repair.





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PROCEDURE

LETTER

N

TEST PROCEDURES

COMPONENT TEST




AH SENSOR TEST

Checking the initial sensor cooking condition


(1) The oven should be plugged in at least two minutes before sensor cooking.

(2) Room temperature should not exceed 95˚F (35˚C).

(3) The unit should not be installed in any area where heat and steam are generated. The unit should not be installed, for example, next to a conventional surface unit. Refer to the “INSTALLATION

INSTRUCTIONS” of the operation manual.

(4) Exhaust vents are provided on the back of the unit for proper cooling and air flow in the cavity. To permit adequate ventilation, be sure to install so as not to block these vents. There should be some space for air circulation.

(5) Be sure the exterior of the cooking container and the interior of the oven are dry. Wipe off any moisture with a dry cloth or paper towel.

(6) The Sensor works with food at normal storage temperature. For example, chicken pieces would be at refrigerator temperature and canned soup at room temperature.

(7) Avoid using aerosol sprays or cleaning solvents near the oven while using Sensor settings. The sensor will detect the vapor given of by the spray and turn off before food is properly cooked.

(8) If the sensor has not detected the vapor of the food, ERROR will appear and the oven will shut off.

Water load cooking test


Make sure the oven has been plugged in at least two minutes before checking sensor cook operation.

The cabinet should be installed and screws tightened.

(1) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.

(2) Place the container on the center of tray in the oven cavity.

(3) Close the door.

(4) Touch Reheat pad. Now, the oven is in the sensor cooking condition and "REHEAT" will appear in the display for approx. 7 sec. and then "SENSING" will appear.

(5) The oven will operate for the first 16 seconds, without generating microwave energy.

NOTE: ERROR will appear if the door is opened or STOP/CLEAR pad is touched during first stage of sensor cooking.

(6) After approximately 16 seconds, microwave energy is produced, and the display should start to count down the remaining cooking time and oven should turn off after water is boiling (bubbling).

If the oven does not turn off, replace the AH sensor or check the control unit, refer to explanation below.

TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNIT

To determine if the sensor is defective, the simplest method is to replace it with a new replacement sensor.

(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) Remove the AH sensor.

(5) Install the new AH sensor.

(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) Reconnect the oven to the power supply and check the sensor cook operation as follows:

9-1. Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.

9-2. Place the container on the center of tray in the oven cavity.

9-3. Close the door.

9-4. Touch Reheat pad.

9-5. The control panel is in automatic Sensor operation.

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PROCEDURE

LETTER

TEST PROCEDURES

COMPONENT TEST

9-6. The display will start to count down the remaining cooking time, and the oven will turn off automatically after the water is boiling (bubbling).

If new sensor does not operate properly, the problem is with the control unit, and refer to explanation below.

CHECKING CONTROL UNIT




(4) Disconnect the sensor connector that is mounted to control panel.

(5) Then connect the dummy resistor circuit (see fig. below) to the sensor connector of control panel.

(6) Disconnect the leads to the primary of the power transformer.

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

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

(9) Check the sensor cook operation proceed as follows:

9-1. Touch Reheat pad.

9-2. The control panel is in the sensor cooking operation.

9-3. After approximately 50 seconds, push plunger of select switch for more than 3 seconds. This condition is same as judgement by AH sensor.

9-4. After approximately 3 seconds, the display shows “ X X . X X “ which is the remaining cooking time, and the display counts down.

If the above is not the case, the control unit is probably defective.

If the above is indicated, the AH sensor is probably defective.




(13) Disconnect the dummy resistor circuit from the sensor connector of control panel.

(14) Carry out necessary repair.

(15) Reconnect all leads removed from components during testing and repairing.

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

(17) Reconnect the power supply cord after the outer case is installed. Run the oven and check all functions.

(18) Carry out "Water load cooking test" again and ensure that the oven works properly.

F-1

F-2

F-3

To connector (F) on Control Unit.

1

2

3

CONNECTOR

R1, R2 : 82

Ω ±

1% 1/2W

R3 : 10k

Ω ±

5% 1/4W

R4 : 1M

Ω ±

5% 1/4W

R1

R2 R3 R4

Sensor Dummy Resistor Circuit

COM

NO

NC

Plunger

NC

NO

COM

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TOUCH CONTROL PANEL ASSEMBLY

(1) Key Unit

(2) Control Unit (The Control Unit consists of Power Unit and CPU Unit).

OUTLINE OF TOUCH CONTROL PANEL

The touch control section consists of the following units.

7) Indicator Circuit

This circuit consists of 100 x 160 dots using a Liquid

Crystal Display. The Liquid Crystal Display (LCD) is drived by IC5.

The principal functions of these units and the signals communicated among them 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 P93, P94, P95 and

P40. When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through

PB1, PB2, PB3, PB4, PB5 and AN1 to perform the function that was requested.

8) Power Source Circuit

This circuit generates voltages 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

VC

Voltage

+5V

Application

LSI(IC1)

9) Relay Circuit

A circuit to drive the magnetron, fan motor, turntable motor and light the oven lamp.

Control Unit

Control unit consists of LSI, IC, ACL circuit, indicator circuit, power source circuit, relay circuit, buzzer circuit, synchronizing signal circuit, key unit circuit, touch screen circuit, absolute humidity sensor circuit and back light circuit.

10) Buzzer Circuit

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

1) IC1 (LSI)

This is a microcomputer, responsible for controlling the entire control unit.

11) 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.

2) IC2

This is a read only memory IC, responsible for giving IC1 the all programs.

12) Door Sensing Switch

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

3) IC3

This is an amplifier IC. This IC controls the contrast of

LCD and amplify the sensor signal.

13) Back Light Circuit

A circuit to drive the back light (Light emitting diodes

LED1 and LED2).

4) IC4

This is a memory IC. This memorizes the contrast of

LCD.

14) Absolute Humidity Sensor Circuit

This circuit detects moisture of the cooking food to allow its automatic cooking.

5) IC5

This IC drives the LCD.

6) ACL

This circuit generates a signal which resets the LSI (IC1) to the initial state when power is supplied.

15) Touch Screen

The touch screen is composed of a matrix, signal generated in the LSI are sent to the key unit through

P41, P42, P43 and P44. When a key is touched, a signal is completed through the touch screen and passed back to the LSI through PB1, PB2, PB3, PB4 and PB5 to perform the function that was requested.

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LSI(IXA029DR)

The I/O signal of the LSI(IXA029DR) is detailed in the following table.

Pin No.

1

2

3

4

5

6

7

8

9

Signal

TIOCA2 OUT Terminal not used.

A20 OUT Terminal not used.

Vcc

I/O

TMO0

PB1

PB2

PB3

Description

IN

OUT Signal to sound buzzer.

A: key touch sound (short beep). B: Completion sound (melody or long beep).

IN Signal coming from touch key.

When either G11 line on key matrix is touched, a corresponding signal out of P93, P94,

P95, P40, P41, P42, P43 and P44 will be input into PB1. When no key is touched, the signal is held at "H" level.

IN

Power source voltage : +5.0V.

The power source voltage to drive LSI is input to Vcc terminal. Connected to Vcc.

IN

Signal similar to PB1.

When either G12 line on key matrix is touched, a corresponding signal will be input into PB2.



PB4

PB5

IN

IN





10-11 PB6-PB7 OUT Terminal not used.

12 RESO OUT Terminal not used.

13 Vss IN Power source voltage: GND(0V).

The power source voltage to drive LSI is input to Vss terminal.

14

15

16

17

TxD0

P91

RxD0

P93

OUT

OUT

OUT

Data signal is output to a memory IC (IC4).

Clock signal is output to a memory IC (IC4).

Terminal not used.

OUT Key strobe signal.

Signal applied to key unit section. A pulse signal is input to PB1-PB5 terminal while one of G1 line keys on key matrix is touched.

18 P94

19

20

21

22

23

24

P95

P40

P41

P42

P43

Vss






Signal applied to key unit section. A pulse signal is input to PB1-PB5 and AN1 terminal while one of G14 line keys on key matrix is touched.


Signal applied to touch screen section. A pulse signal is input to PB1-PB5 terminal while one of G7 line keys on key matrix is touched.





IN Power source voltage : GND(0V).

The power source voltage to drive LSI is input to VSS terminal.

22

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Pin No.

25

26

27

28

29-36

37

38-45

46

47-58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

Signal

P44

P45

I/O Description



OUT Oven lamp, fan motor and turntable motor driving signal

16.7 msec.

To turn on and off shut off relay (RY1). The square waveform voltage is delivered to the

RY1 driving circuit and RY2 control circuit.

During cooking

H : +5V

L : GND

P46

P47

OUT Magnetron high-voltage circuit driving signal.

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

100

PERCENT

70

PERCENT

OFF

ON

24 sec.

ON

H : +5V

L : GND

H : +5V

8 sec.

OFF

L : GND

(ON and OFF times for other power level.)

OUT Terminal not used.

D8-D15 OUT Data signal is output to IC2 and IC5.

Vcc

WATT

P61

IN Power source voltage : +5V.

The power source voltage to drive LSI is input to Vcc terminal. Connected to VCC.

OUT Address signal is output to IC2 and IC5.

A0-A7

Vss IN Power source voltage : GND (0V).


A8-A19 OUT Address signal is output to IC2 and IC5.

Vss IN Power source voltage : GND (0V).


Connected to VCC.

IN

OUT Envelope signal to sound buzzer.

A: key touch sound (short beep). B: Completion sound (melody or long beep).

P62

P67

STBY

RES

OUT Reset signal is output to IC5.


IN

IN

Connected to VCC.

Auto clear terminal.

Signal is input to reset the LSI to the initial state when power is applied. Temporarily set

"L" level the moment power is applied, at this time the LSI is reset. Thereafter set at "H" level.

NMI

Vss

IN

IN

Connected to GND.

Power source voltage : GND (0V).


EXTAL OUT Internal clock oscillation output.

Output to control oscillation input to EXTAL.

XTAL IN Internal clock oscillation frequency control input setting.

The internal clock frequency is set by inserting the ceramic filter oscillation circuit with respect to XTAL.

Vcc IN Power source voltage : +5V.

The power source voltage to drive LSI is input to Vcc terminal. Connected to VCC.

AS

RD

HWR


OUT Read strobe signal is output to RD terminal of IC5.

OUT Write strobe signal is output to WR terminal of IC5.

23

R- 340DK

R-340DW

Pin No.

Signal I/O Description

74 LWR OUT Terminal not used.

75-76 MD0-MD1 IN Connected to VCC.

77

78

MD2

Avcc

IN

IN

Connected to GND.

A/D converter power source voltage : +5V.

The power source voltage to drive the A/D converter. Connected to VCC.

79 Vref IN

80

81

82

83

84

AN0

AN1

AN2

AN3

AN4

IN

IN

IN

IN

IN

A/D converter power source voltage : +5V.

The power source voltage to drive the A/D converter. Connected to VCC.

Terminal to judge whether the model has the sensor cooking function or not.

By using the A/D converter contained in the LSI, DC voltage in accordance with the Model in operation is applied to judge whether the model has the sensor cooking function or not.

Input terminal to judge the model.

The signal out of P40 will be input into AN1 through G15 line on key matrix. The LSI will judge the model by this signal.

Terminal to change cooking input 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 cooking constant.

Connected to VCC.

To input signal which communicates the door open/close information to LSI.

Door close "H" level signal (+5V). Door open "L" level signal (GND).

85

86

87

88

89

AN5

AN6

DA1

Avss

IRQ0

IN

IN

Used for initial balancing of the bridge circuit (absolute humidity sensor). This input is an analog input terminal from the AH sensor circuit, and connected to the A/D converter built into the LSI.

AH sensor input.

This input is an analog input terminal from the AH sensor circuit, and connected to the

A/D converter built into the LSI.

OUT The signal for the power source to drive the LCD is output to IC3.

IN A/D converter power source voltage : GND(0V).

The power source voltage to drive the A/D converter. Connected to GND.

IN Signal synchronized with commercial power source frequency.

This is the basic timing for time processing of LSI.

H : +5V

L : GND

16.7 msec.

90-91 P81-P82 OUT Terminal not used.

92

93

94

CS1

CS0

Vss

OUT

OUT

IN

Chip select signal is output to CS terminal of IC5.

Chip select signal is output to CE terminal of IC2.

Power source voltage : GND (0V).

The power source voltage to drive the LSI is input to Vss terminal.

95-99 PA0-PA4 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor).

100 PA5 OUT Clock signal is output to IC5.

24

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ABSOLUTE HUMIDITY SENSOR CIRCUIT

(1) Structure of Absolute Humidity Sensor

The absolute humidity sensor includes two thermistors as shown in the illustration. One thermistor is housed in the closed vessel filled with dry air while another in the open vessel. Each sensor is provided with the protective cover made of metal mesh to be protected from the external airflow.

Thermistors ventilation opening for sensing

Sensing part

(Open vessel)

Sensing part

(Closed vessel)

(2) Operational Principle of Absolute Humidity Sensor

The figure below shows the basic structure of an absolute humidity sensor. A bridge circuit is formed by two thermistors and two resistors (R1 and R2).

The output of the bridge circuit is to be amplified by the operational amplifier.

Each thermistor is supplied with a current to keep it heated at about 150˚C (302˚F), the resultant heat is dissipated in the air and if the two thermistors are placed in different humidity conditions they show different degrees of heat conductivity leading to a potential difference between them causing an output voltage from the bridge circuit, the intensity of which is increased as the absolute humidity of the air increases. Since the output is varied every minute, it is amplified by the operational amplifier.

R3

Absolute humidity vs, output voltage characteristic

S R1

Operational amplifier

+

Output voltage

C R2

S : Thermistor

open vessel

C : Thermistor

closed vessel resistance balance of the bridge circuit is deviated to increase the voltage available at AN6 terminal of the LSI.

Then the LSI observes that voltage at AN6 terminal and compares it with its initial value, and when the comparison rate reaches the preset value (fixed for each menu to be cooked), the LSI causes the unit to stop sensor cooking; thereafter, the unit goes in the next operation automatically.

When the LSI starts to detect the initial voltage at AN6 terminal 16 seconds after the unit has been put in the

Sensor Cooking mode, if it is not possible to balance the bridge circuit due to disconnection of the absolute humidity sensor, ERROR will appear on the display and the cooking is stopped.

1) Absolute humidity sensor circuit

VA : +15V VC : +5V

D40

F2

S

F3

C

F1

R41 3.32K

R42 3.57K

C. Thermistor in

closed vessel

S. Thermistor in

open vessel

R43 1.8K

3

2

+

-

8

IC3

4

1

C41 0.015

µ

F

R45 10K

R44 360K

86

R46 47K

C42 0.01

µ

F

86

AN6

LSI

(IC1)

R47 47K

R48 620K

R49 300K

R50 150K

R51 75K

R52 37.4K

C43 0.01

µ

F

85

AN5

95

PA0

SW1

96

PA1

SW2

SW3

97

PA2

98

PA3

SW4

SW5

99

PA4

(3) Detector Circuit of Absolute Humidity Sensor Circuit

This detector circuit is used to detect the output voltage of the absolute humidity circuit to allow the LSI to control sensor cooking of the unit. When the unit is set in the sensor cooking mode, 16 seconds clearing cycle occurs than the detector circuit starts to function and the LSI observes the initial voltage available at its AN6 terminal.

With this voltage given, the switches SW1 to SW5 in the

LSI are turned on in such a way as to change the resistance values in parallel with R47 ~ R52. Changing the resistance values results in that there is the same potential at both F-3 terminal of the absolute humidity sensor and AN5 terminal of the LSI. The voltage of AN6 terminal will indicate about +2.5V. This initial balancing is set up about 16 seconds after the unit is put in the

Sensor Cooking mode. As the sensor cooking proceeds, the food is heated to generate moisture by which the

25

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TOUCH CONTROL PANEL 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 all 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.

approx. 1M ohm

2. Shapes of Electronic Components

Transistor

B

2SD1859

C

E

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,






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

After checking the performance of the touch control panel,

1) Disconnect the power supply cord.


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


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


A. 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, 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 activates 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 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 activates 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 sensor-related 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 connectors 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.

26

R -340DK

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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.

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.

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 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.

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.

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:

OUTER CASE REMOVAL

To remove the outer case, proceed as follows.


2. Open the oven door and block it open.

3. Remove the two (2) screws from the lower portion of the rear cabinet using a T20H Torx type or GTXH20-100 screw driver.

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

(1) screw along the right side of outer case.

5. Slide the entire outer case back out about 1 inch (3 cm) to free it from retaining clips on the cavity face plate.

6. Lift entire outer case from the unit.

Special screw

Screw Driver

(Type: TORX T20 H or

GTXH20-100)

27

R- 340DK

R-340DW

CAUTION: 1. DISCONNECT OVEN FROM POWER SUP

PLY BEFORE REMOVING OUTER CASE.

2. DISCHARGE THE HIGH VOLTAGE CA-

PACITOR BEFORE TOUCHING ANY OVEN

COMPONENTS OR WIRING.

NOTE: When replacing the outer case, the 2 special

Torx screws must be reinstalled in the same locations.

POWER TRANSFORMER REMOVAL

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

2. Open the oven door and block it open.


4. Disconnect wire leads (primary and high voltage) from power transformer and the filament leads from the magnetron and capacitor terminals.

5. Remove four (4) screws holding transformer to bottom plate.

6. Remove transformer from bottom plate.

Re-installation

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

2. Secure transformer with four screws to bottom plate.

3. Re-connect wire leads (primary and high voltage) to power transformer and filament leads of transformer to magnetron and high voltage capacitor. Refer to

"PICTORIAL DIAGRAM" on page 33.

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

TERMINAL INSULATOR REPLACEMENT




4. Open covers of the terminal insulator by using small flat type screw driver.

5. Remove the receptacle from the terminal insulator.

6. Now, the terminal insulator is free.

Installation

1. Insert the receptacle into terminal insulator.

2. Close covers of the terminal insulator, as shown below.





Covers

Terminal insulator

Flat type screw driver

Receptacle

HIGH VOLTAGE RECTIFIER AND HIGH VOLTAGE CAPACITOR REMOVAL




4. Disconnect the high voltage wire B from the power transformer.

5. Disconnect the high voltage wire of high voltage rectifier assembly from the magnetron.

6. Disconnect the filament lead (short one) of the power transformer from the high voltage capacitor.

7. Remove one (1) screw holding capacitor holder to oven cavity rear plate.

8. Remove one (1) screw holding high voltage rectifier assembly to capacitor holder.

9. Disconnect rectifier terminal from capacitor.

High voltage rectifier assembly is now free.

10.Disconnect the high voltage wire B from the high voltage capacitor.

11.Remove capacitor holder. Capacitor is now free.

CAUTION: WHEN REPLACING HIGH VOLTAGE RECTI-

FIER AND HIGH VOLTAGE CAPACITOR,

GROUND SIDE TERMINAL OF THE HIGH

VOLTAGE RECTIFIER MUST BE SECURED

FIRMLY WITH A GROUNDING SCREW.

MAGNETRON REMOVAL

Removal




4. Disconnect all wire leads from magnetron.

5. Disconnect the wire leads from thermal cut-out (MG).

6. Remove the four (4) screws holding chassis support to magnetron, oven cavity back plate, oven cavity front flange and fan duct.

7. Remove the chassis support from oven.

8. Carefully remove the four (4) screws holding magnetron

28

to waveguide flange.

9. Lift up magnetron with care so that magnetron antenna is not hit by any metal object around antenna.

10.Remove the two (2) screws holding the magnetron duct to magnetron.

11.Remove the magnetron duct with thermal cut-out (MG) from magnetron.

12.Now, the magnetron is free.

Re-install

1. Re-install the magnetron duct with thermal cut-out (MG) to magnetron with the two (2) screws.

2. Re-install the magnetron to waveguide flange with the four (4) screws.

R -340DK

R-340DW

3. Insert the two (2) tabs of the chassis support to the oven cavity front plate and the back plate.

4. Hold the chassis support to the oven cavity back plate, oven cavity front flang, magnetron and the fan duct with the four (4) screws.

5. Reconnect the wire leads to the magnetron and thermal cut-out (MG). Refer to "PICTORIAL DIAGRAM" on page

33.

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

CAUTION: WHEN REPLACING MAGNETRON, BE SURE

THE R.F. GASKET IS IN PLACE AND MOUNT-

ING SCREWS ARE TIGHTENED SECURELY

OVEN LAMP AND LAMP SOCKET REMOVAL

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



4. Remove the oven lamp from the oven lamp socket.

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

6. Bend the tab of the partition angle holding the lamp socket.

7. Lift up the oven lamp socket.

8. Now, the oven lamp socket is free.

Oven lamp socket

Terminal

Wire lead

Flat type small screw driver

Terminal hole

Figure C-1. Oven lamp socket

POSITIVE LOCK

®

CONNECTOR (NO-CASE TYPE) REMOVAL




4. Push the lever of positive lock ® connector.

5. Pull down on the positive lock ® connector.

CAUTION: WHEN CONNECTING THE POSITIVE LOCK ®

CONNECTORS TO THE TERMINALS, CON-

NECT THE POSITIVE LOCK ® SO THAT THE

LEVER FACES YOU

Positive lock® connector

Lever

Terminal

1

Push

2

Pull down

Figure C-2. Positive lock ® connector

CONTROL PANEL ASSEMBLY REMOVAL




4. Disconnect wire leads from the door sensing switch and the oven cavity front flange.

5. Disconnect the wire leads from panel components.

6. Make one (1) tab of the oven cavity front plate straight holding the control panel assembly to the oven flange.

7. Slide the control panel assembly upward and remove it.

8. Now, individual components can be removed.

NOTE: 1. Before attaching a new key unit, wipe off remaining adhesive on the control panel frame surfaces completely with a soft cloth soaked in 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.

29

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R-340DW

TURNTABLE MOTOR REMOVAL


2. Remove turntable and turntable support from oven cavity.

3. Lay the oven on it's backside. Remove the turntable motor cover by snipping off the material in four corners.

4. Where the corners have been snipped off bend corner areas flat. No sharp edges must be evident after removal of the turntable motor cover.

5. Disconnect wire leads from turntable motor.

(See "Positive lock connector removal")

6. Remove two (2) screws holding turntable motor to oven cavity.

7. Now the turntable motor is free.

8. After replacement use the one (1) screw to fit the turntable motor cover.

COOLING FAN MOTOR REMOVAL

REMOVAL




4. Disconnect the wire leads from the fan motor.

5. Remove the magnetron and chassis support from the waveguide flange, referring to "MAGNETRON

REMOVAL".

6. Release the snap of the main wire harness from the fan duct.

7. Remove one (1) screw holding the fan duct assembly to oven cavity.

8. Release the main wire harness from the hole of the fan duct.

9. Release the fan duct from the waveguide flange.

10.Release the fan duct 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 that 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 damaged.

* Do not disfigure the bracket by pinching with the pliers.

13.Remove the fan blade 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 reuse 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 strongly when installed because the bracket may be disfigured.

* Make sure that the fan blade rotates smooth after installation.

* Make sure that the axis of the shaft is not slanted.

6. Catch three holes of fan duct on three tabs of the waveguide flange.

7. Install the fan duct assembly to the oven cavity with the one (1) screw.

8. Insert the snap of the main wire harness to the hole of the fan duct and insert the main wire harness into the hole of the fan duct.

9. Install the magnetron and the chassis support to the oven cavity, referring to "Re-install of MAGNETRON

REMOVAL".

10.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

30

Center of bracket

R -340DK

R-340DW

DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL

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



4. Disconnect wire leads from the switches.

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

6. Remove latch hook assembly from oven flange.

7. Push outward on the two (2) retaining tabs holding switch in place.

8. Switch is now free.

Re-install

1. Re-install each switch in its place. The secondary interlock/monitor switches are in the lower position and the door sensing switch is in the upper position.

2. Re-connect wire leads to each switch.

Refer to pictorial diagram.

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

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

DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT




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 latch hook to the oven cavity front flange.

5. With 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 vertical position of the latch hook should be adjusted so that the door sensing switch and secondary interlock switch are activated with the door closed. The horizontal position of the latch hook should be adjusted so that the plunger of the monitor switch is pressed with the door closed.

6. Secure the screws with washers 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, check the following.

1. In and out play of 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 the door toward the oven face. Both results (play in the door) should be less than 0.5mm.

2. The contacts of door sensing switch and secondary interlock switch open within 0.9mm gap between right side of cavity face plate and door when door is open.

3. Monitor switch contacts close when door is opened.

4. Re-install outer case and check for microwave leakage around door with an approved microwave survey meter.

(Refer to Microwave Measurement Procedure.)

Door

Latch

Heads

Latch Hook

Door Sensing

Switch

Monitor Switch

Secondary

Interlock Switch

Figure C-3. Latch Switch Adjustments

DOOR REPLACEMENT

REMOVAL


2. Open the door slightly.

3. Insert a putty knife (thickness of about 0.5mm) into the gap between the choke cover and door frame as shown in Figure C-4 to free engaging parts.

4. Pry the choke cover by inserting a putty knife as shown

Figure C-4.

5. Release choke cover from door panel.

6. Now choke cover is free.

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 with door frame is free from oven cavity.

Door Frame

Putty Knife

Choke Cover

Figure C-4. Door Disassembly

9. Remove the four (4) screws holding the door panel to the door frame.

10.Release door panel from eight (8) tabs of door frame.

31

R- 340DK

R-340DW

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

12.Tear sealer film from door panel.

13.Now, door panel is free.

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

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

16.Remove door screen from door frame.

17.Now, door screen is free.

RE-INSTALL

1. Re-install door screen to door frame.

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

3. Re-install door panel to door frame by fitting eight (8) tabs of door frame to eight (8) holes of door panel.

4. Hold the door panel to the door frame with the four (4) screws.

5. Put sealer film on door panel. Refer to “Sealer Film” about how to handle new one.

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

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

Note: After any service to the door;

(A) Make sure that door sensing switch and secondary interlock 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.

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.)

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.

Pin

Upper

Oven Hinge

Upper Oven

Hinge

Lower Oven

Hinge

Pin

Lower

Oven Hinge

Choke Cover

Figure C-5. Door Replacement

SEALER FILM

Installation

1. Put the adhesive tape on the backing film of the sealer film as shown in Fig. C-6.

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

Figure C-6. Sealer film

32

D

E

F

G

H

1

B

C

A

1

2

2

CN-G

3

3

33

4

4

5

5

RECTIFIER

H.V.

6

R -340DK

R-340DW

A

B

C

D

E

6

H

F

G

R- 340DK

R-340DW

1

A

2 3

4 5 6

A

B

C

D

AC

CN-A

A 2

A 1

AC120V

60Hz

E

OVEN LAMP

FAN MOTOR

TURNTABLE

MOTOR

NO

AC COM

NO

MICRO

COM a b d

T1

GND

D1

D1

S1NB10 c

RY1

RY2

F

G

(GREEN)

SH-A

DOOR

SENSING

SWITCH

SH-B

NOTE

: IF NOT SPECIFIED, 0.1

µ

F / 50V

+

–

R2 91 1w R3 91 1w

Q1 2SD1859

C 3

C 5

INT

VR

C 6 VA

SP30

B

C

C 4 GND

C11 BZ/EN

C10

C 9

BUZZR

OVEN LAMP

FAN MOTOR

TURNTABLE

MOTOR

D

E

C 7 MICRO

F

C 8 N.C

C 2 N.C

C 1

DOOR

SENSING

SWITCH

CN-C

11P LEAD WIRE HARNESS

G

H H

1 2

Figure S-2. Power Unit Circuit

3

4

34

5 6

1 2 3

4 5

100 x 160 Dots

LIQUID CRYSTAL DISPLAY

A

IC5 IXA031DR

R90 43kF

R91 18kF

5G2M40B333J

TH1 R92 20kF

B

/25v

µ

C19 0.1

C

D

E

F

G

D14

D7

D15/A-1

A14

A13

A16

A15

BYTE

GND

22

23

21

19

20

25

26

27

24

3.3k

R82

1/4w

D80 D81

1SS355

D80-81

R81 27 0 ohm

(J80)

/25v

µ

/25v

µ

/25v

/25v

µ

µ

µ

/16v

VCC

NC

Cd

V0

NC

NC

NC

GND

IC6

C13 47

M51953AFP

C14 0.01

C16 0.01

C15 0.1

C130 0.01

UDZ5.6B

ZD10

/50v

µ

µ

/35v

C11 0.1

C10 10

R40 330 1w

/50v

µ

1.2k

R11

1/4w

C12 0.1

/50v

µ

C17 0.1

R42

3.57kD

/50v

/50v µ

µ 0.1

0.1

C45

C44

R43 1.8kF

+

-

/25v

µ

/25v

µ

C43 0.01

R44 360kF

C42 0.01

R45 10k

D40 MA152WK

P62

P67

P61

STBY

WAIT

A15

A16

A14

A12

A13

A18

A19

Vss

A17

NMI

Vss

RES

EXTAL

AS

RD

HWR

Vcc

LWR

XTAL

MD0

MD1

MD2

Vref

AN0

Avcc

71

72

70

74

75

73

77

78

76

79

80

63

64

65

66

68

69

67

52

53

51

55

56

54

58

59

57

61

62

60

/35v

µ

C30 10

D0

0E

D8

GND

A2

A3

A0

A1

CE

2

1

4

3

45

44

43

42

41

R30 3.3k

D9

D8

P47

P46

P45

P44

Vss

P43

P42

P41

P40

P95

P94

P93

RxD0

P91

TxD0

Vss

RES0

PB7

PB6

PB5

PB4

PB2

PB1

PB3

TM00

Vcc

A20

TI0CA2

11

10

5

4

6

2

1

3

8

7

9

12

13

15

14

16

18

17

19

21

20

22

24

23

25

27

26

28

30

29

µ

C22

10

/35v

/25v

µ

0.1

C21

R21 4.7k

H

0.01

C98

/25v

µ

R100 4.7k

4.7k

R111

4.7k

R110

47k

R112

R65 15k

R66 15k

R64 15k

R67 15k

R61 15k

R62 15k

R60 15k

R63 15k

C63 330pF/50v

C64 330pF/50v

C62 330pF/50v

C65 330pF/50v

C60 330pF/50v

C61 330pF/50v

R78 270k

R79 270k

R74 270k

R75 270k

R76 270k

R77 270k

1/2w

150

R113

1 2 5 3

35

4 6

6

R -340DK

R-340DW

A

B

C

D

E

F

G

H

D

E

F

B

C

R- 340DK

R-340DW

1

A

G

H

1

2 3

4 5 6

A

B

D20

O M

D U

O M

D U

11

R3

CN - C

Q1

B

E

R1

R2

1

ZD1

C2

C1

RY3

E

(J1)

XA

VRS1

1 2

2 1

CN - A

VH

QKITPB031MREO

2

Figure S-5. Printed Wiring Board of Power Unit

3 4

36

5 6

H

F

G

C

D

R - 340DK

R -340DW

∆

*

*

*

1- 1

1- 2

1- 3

1- 4

1- 5

1- 5

1- 6

1- 7

1- 8

1- 9

1- 9

1-10

1-11

1-11

1-12

1-12

1-12

1-13

1-14

1-15

∆

∆

4- 1

4- 2

4- 3

4- 4

4- 5

4- 6

4- 7

4- 8

4- 9

4-10

4-11

4-12

4-13

Q1

R1

R2-3

RY1

RY2

SP1

T1

VRS1

3- 1

3- 1A

3- 1B

3- 1C

3- 1D

C1

C2

D1

ZD1

3- 2

3- 3

3- 3

3- 3-1

3- 3-1

3- 4

Note: The parts marked “

PARTS LIST

∆

” may cause undue microwave exposure.

The parts marked “*” are used in voltage more than 250V.

REF. NO.

2- 1

2- 1

2- 2

2- 3

2- 4

PART NO.

DESCRIPTION

ELECTRIC PARTS

QSW-MA147WRZZ 2nd interlock switch / door sensing switch

QFSHDA009WRE0 Fuse holder

FFS-BA021WRK0 Monitor fuse 20A and monitor switch (V-16G-2C25) assembly

RTHM-A078WRE0 Thermal cut-out 125 deg.

FACCDA083WREZ Power supply cord

FACCDA085WRE0 Power supply cord (Interchangeable)

FH-DZA094WRKZ High voltage rectifier assembly

RC-QZA234WRE0 High voltage capacitor

RV-MZA288WRE0 Magnetron

RMOTEA383WRE0 Fan motor

RMOTEA355WRE0 Fan motor (Interchangeable)

QSOCLA021WRE0 Oven lamp socket

RLMPTA068WRE0 Oven lamp

RLMPTA030WRE0 Oven lamp (Interchangeable)

RMOTDA161WRE0 Turntable motor

RMOTDA229WRE0 Turntable motor (Interchangeable)

RMOTDA211WRE0 Turntable motor (Interchangeable)

RTHM-A080WRE0 Thermal cut-out 145 deg.

RTRN-A603WRZZ Power transformer

FDTCTA197WRK0 AH sensor assebly

CABINET PARTS

GCABUA744WRPZ Outer case cabinet [R-340DK]

GCABUA690WRP0 Outer case cabinet [R-340DW]

GDAI-A316WRW0 Bottom plate

GLEGPA074WRE0 Foot

GLEGPA077WRF0 Leg

CONTROL PANEL PARTS

DPWBFC042WRKZ Power unit

QCNCMA446DRE0 2-pin connector (CN-A)

FW-VZA260DREZ 11pin lead wire (CN-C)

FW-VZA195DRE0 Switch harness A (SH-A)

FW-VZA256DREZ Switch harness B (SH-B)

RC-KZA087DRE0 Capacitor 0.1 uF 50V

VCEAB31VW108M Capacitor 1000 uF 35V

RSRCDA013DRE0 Diode bridge (S1NB10)

VS2SD1859//-3 Transistor (2SD1859R)

VRD-B12EF242J Resistor 2.4k ohm 1/4W

VRS-B13AA910J Resistor 91 ohm 1W

RRLY-A076DRE0 Relay (OMIF-S-124LM)

RRLY-A113DRE0 Relay (DU24D1-1P(M)-R)

RALM-A014DRE0 Buzzer (PKM22EPT)

RTRNPA113DRE0 Transformer

RH-VZA032DRE0 Varistor (10G471K)

VHEHZ161///-1 Zener diode (HZ16-1)

DPWBFC041WRKZ CPU unit

FPNLCB492WRKZ Control panel frame with key unit [R-340DK]

FPNLCB495WRKZ Control panel frame with key unit [R-340DW]

DUNTKA716WRKZ Key unit [R-340DK]

DUNTKA717WRKZ Key unit [R-340DW]

XEPSD30P08XS0 Screw; 3mm x 8mm

OVEN PARTS

PDUC-A724WRF0 Air separater

PPACGA084WRF0 TTM packing

PHOK-A116WRFZ Latch hook

LBNDKA099WRW0 Capacitor holder

NFANJA029WRE0 Fan blade

PDUC-A728WRW0 Fan duct

************* Oven cavity (Not a replaceable part)

LANGFA196WRWZ Chassis support

LANG-A067WRPZ Magnetron duct

LANG-A063WRPZ Air guide

LANG-A064WRPZ Barrier

NCPL-A053WRFZ Coupling

PCUSUA511WRP0 Cushion

37

Q'TY CODE

1

1

1

1

1

1

1

1

1

1

1

1

1

2

1

1

1

1

BC

AZ

AX

AC

AH

1

1

1

1

1

1

1

1

2

1

1

1

1

1

1

1

1

1

1

1

AG

AH

AK

AE

AC

AU

AF

AH

AD

AL

AT

--

AX

AQ

AU

AV

BK

AV

AU

AH

AG

AG

AH

AL

AL

AQ

AE

AS

AQ

AS

AP

BM

BC

1

1

1

1

1

1

2

1

1

1

1

1

1

1

1

1

1

1

6

1

1

1

1

AC

AA

AA

AK

AM

AG

AT

AE

BC

AC

AH

AD

AF

AA

AF

AG

AA

BE

BL

BL

BG

BG

AA

R -3 40DK

R-340DW

∆

∆

∆

∆

*

6- 1

6- 2

6- 3

6- 4

6- 5

6- 6

6- 7

6- 8

6- 9

5- 1

5- 2

5- 3

5- 3

5- 4

5- 4

5- 5

5- 6

5- 7

5- 8

5- 9

7- 1

7- 2

7- 3

7- 4

7- 5

7- 6

7- 7

7- 7

7- 8

7- 9

REF. NO.

4-14

4-15

4-16

4-17

4-18

4-19

4-20

4-21

4-22

4-23

4-24

4-25

PART NO.

PCOVPA349WRE0 Waveguide cover

PCUSGA339WRP0 Cushion









LANG-A065WRWZ Sensor guide

LANGTA365WRPZ Sensor mounting angle

DESCRIPTION

DOOR PARTS

FDORFA332WRT0 Door panel

PSHEPA382WRE0 Sealer film

GWAKPA727WRRZ Door frame [R-340DK]

GWAKPA728WRRZ Door frame [R-340DW]

HPNL-A740WRRZ Door screen [R-340DK]

HPNL-A742WRRZ Door screen [R-340DW]

LSTPPA193WRFZ Latch head

MSPRTA187WRE0 Latch spring

XCPSD40P08000 Screw : 4mm x 8mm


GCOVHA417WRFZ Choke cover

MISCELLANEOUS

FROLPA079WRK0 Turntable support

NTNT-A079WRE0 Turntable tray

FW-VZB771WREZ Main wire harness

QW-QZA150WRE0 High voltage wire B

PZET-A012WRE0 Terminal insulator

TCAUAA166WRR0 DHHS caution label

TCAUAA254WRR0 Monitor caution label

TINSEA836WRRZ Instruction book

TCAUAA255WRR0 Screw caution

SCREWS,NUTS AND WASHERS

XHPSD40P08K00 Screw : 4mm x 8mm

XHPSD30P06000 Screw : 3mm x 6mm

XHTSD40P08RV0 Screw : 4mm x 8mm

XHTSD40P12RV0 Screw : 4mm x 12mm

XOTSD40P12RV0 Screw : 4mm x 12mm

XOTSD40P12000 Screw : 4mm x 12mm

XOTSF40P08000 Screw : 4mm x 8mm [R-340DK]

XOTSE40P08000 Screw : 4mm x 8mm [R-340DW]

LX-CZA070WRE0 Special screw (Torx tamper proof screw)

LX-CZ0052WRE0 Special screw

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.

1

1

4

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

17

1

1

2

2

9

3

6

1

3

Q'TY CODE

1

1

2

1

1

2

1

1

2

2

1

1

AE

AG

AD

AB

AC

AE

AC

AB

AC

AF

AH

AH

AE

AC

AA

AB

AG

BD

AH

AX

AX

AS

AS

AQ

AR

AU

AF

AB

AC

AC

AK

AC

AA

AA

AA

AC

AA

AA

AA

AA

AA

AA

38

R - 340DK

R -340DW

1 2

OVEN AND CABINET PARTS

A

B

1-15

4-25

4-22

4-23

7-6

7-2

4-17

7-6

1-10

1-11

1-4

4-20

4-24

4-11

C

7-3

4-7

D

E

6-2

4-14

F

6-1

G

4-12

4-1

4-2

1-12

7-1

4-23

3 4

2-1

7-1

5

7-5

7-8

6

7-5

A

2-2

1-13

7-2

7-8

B

1-8

7-3

6-7

4-13

7-3

6-6

7-7

4-9

C

4-19

7-6

4-10

7-9

4-18

4-15

4-21

1-6

1-1

7-1

7-3

7-3

1-5

4-20

1-7

6-9

7-4

1-14

4-3

1-1

4-16

1-2

7-5

4-4

1-3

7-6

4-5

7-1

4-22

7-6

4-8

7-3

D

7-6

E

F

4-15

4-6

2-4 1-9

G

7-6

2-3

H 7-6 H

1 2

7-6

2-3

3

7-6

39

7-6

4 5 6

R -3 40DK

R-340DW

A

1 2

CONTROL PANEL PARTS

3-3

3

3-2

4

3-4

3-4

5 6

A

B B

C

3-3-1

3-1

5-9

5-7

5-2 5-7

3-4

C

D

DOOR PARTS

5-1

D

E

5-3

5-7

5-7

E

F

5-4

G

MISCELLANEOUS

6-3

H

1 2

6-4

Actual wire harness may be different from illustration.

6-5

3 4

40

5-6

5-8

5

5-5

(CAPACITOR)

6

F

G

H

F

G

H

1

1 2 3

PACKING AND ACCESSORIES

4

A

B

C

DOOR PROTECTION SHEET

SPADPA204WRE0

INTO THE

OVEN CAVITY

6- 8 INSTRUCTION BOOK

& PRINTING MATTER

6- 2 TURNTABLE TRAY

6- 1 TURNTABLE SUPPORT

TRAY PACK

SPADFA451WRE0

D

Not replaceable items.

E

2 5

5 6

R - 340DK

R -340DW

A

TOP PAD ASSEMBLY

FPADBA416WRKZ

B

PLASTIC BAG

SSAKHA034WRE0

BOTTOM PAD ASSEMBLY

FPADBA417WRKZ

C

D

PACKING CASE

SPAKCD371WREZ [R-340DK]

SPAKCD372WREZ [R-340DW]

E

F

G

6

H

3

41

4

R -3 40DK

R-340DW

COPYRIGHT © 2000 BY SHARP CORPORATION

ALL RIGHTS RESERVED.

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.

42

2000 SHARP CORP. (1S2.530E) Printed in U.S.A

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