SHARP R-320HK, R-320HQ, R-320HW Service Manual

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SERVICE MANUAL

S4309R320HPW/

MICROWAVE OVEN

R-320HK R-320HQ R-320HW

MODELS

R-320HK R-320HQ R-320HW

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..)

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.................................................................................................................................20

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE................................................................25

PICTORIAL DIAGRAM ........................................................................................................................................31

CONTROL UNIT CIRCUIT ..................................................................................................................................32

PRINTED WIRING BOARD ................................................................................................................................. 33

PARTS LIST ........................................................................................................................................................34

PACKING AND ACCESSORIES .........................................................................................................................38

SHARP CORPORATION

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

R-320HK R-320HQ R-320HW

PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY

(a) Do not operate or allow the oven to be operated with the door open. (b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other

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

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

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

generation and transmission systems shall be repaired, replaced, or adjusted by procedures described in this manual before the oven is released to the owner.

(e) A microwave leakage check to verify compliance with the Federal Performance Standard should be

performed on each oven prior to release to the owner.

BEFORE SERVICING

Before servicing an operative unit, perform a microwave emission check as per the Microwave Measurement Procedure outlined in this service manual. If microwave emissions level is in excess of the specified limit, contact SHARP ELECTRONICS CORPORATION immediately @1-800-237-4277.

If the unit operates with the door open, service person should 1) tell the user not to operate the oven and 2) contact SHARP ELECTRONICS CORPORATION and Food and Drug Administration's Center for Devices and Radiological Health immediately.

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

WARNING TO SERVICE PERSONNEL

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

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

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

Read the Service Manual carefully and follow all instructions.

may result in a severe, possibly

Don't Touch ! Danger High Voltage

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Before Servicing

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

WARNING:RISK OF ELECTRIC SHOCK.

DISCHARGE THE HIGH-VOLTAGE CAPACITOR BEFORE SERVICING.

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

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

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the leads to the primary of the power transformer.

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

6. After that procedure, reconnect the power supply cord.

When the testing is completed,

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

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

5. Reinstall the outer case (cabinet).

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

7. Run the oven and check all functions.

After repairing

1. Reconnect all leads removed from components during testing.

2. Reinstall the outer case (cabinet).

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

4. Run the oven and check all functions.

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

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

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MICROWAVE MEASUREMENT PROCEDURE

A. Requirements:

1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven should not exceed 1mW/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external surface of the oven.

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

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

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

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

2) Place the oven tray in the oven cavity.

3) Place the load of 275±15 ml (9.8 oz) of tap water initially at 20±5˚C (68˚F) in the center of the oven cavity. The water container shall be a low form of 600 ml (20 oz) beaker with an inside diameter of approx. 8.5 cm (3-1/2 in.) and made of an electrically nonconductive material such as glass or plastic. The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any leakage is measured accurately.

4) Set the cooking control on Full Power Cooking Mode.

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

C. Leakage test:

Closed-door leakage test (microwave measurement)

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

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

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

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

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

SERVICE MANU AL

R-320HK R-320HQ R-320HW

MICROWAVE OVEN

R-320HK/ R-320HQ/ R-320HW

FOREWORD

This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service Information for the SHARP MICROWAVE OVENS,R-320HK,R-320HQ and R-320HW.

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.

PRODUCT DESCRIPTION

GENERAL INFORMATION

OPERATION

TROUBLESHOOTING GUIDE AND TEST PROCEDURE

TOUCH CONTROL PANEL

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

WIRING DIAGRAM

PARTS LIST

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

Removal of the outer wrap gives access to voltage above 250V. All the parts marked “∆” on parts list may cause undue microwave

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

SHARP ELECTRONICS CORPORATION

SHARP PLAZA, MAHWAH,

NEW JERSEY 07430-2135

R-320HK R-320HQ R-320HW

SPECIFICATION

ITEM DESCRIPTION

Power Requirements 120 Volts / 14.2 Amperes

60 Hertz Single phase, 3 wire grounded

Power Output 1200 watts (IEC TEST PROCEDURE)

Operating frequency of 2450MHz

Case Dimensions Width 20-1/2"

Height 12-1/4" Depth 17-1/4"

Cooking Cavity Dimensions Width 14-3/4"

Height 8-7/8"

1.2 Cubic Feet Depth 15-1/4" Control Complement Touch Control System

Clock ( 1:00 - 12:59 ) Timer (0 - 99 min. 99 seconds)

Microwave Power for Variable Cooking Repetition Rate;

HIGH................................................Full power throughout the cooking time

P-90 .................................................................... approx. 90% of Full Power

P-80 .................................................................... approx. 80% of Full Power

P-70 .................................................................... approx. 70% of Full Power

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

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

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

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

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

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

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

POPCORN pad, KEEP WARM PLUS pad, SENSOR REHEAT pad CUSTOM HELP pad, SENSOR COOK pad, HOT WATER pad INSTANT ACTION pads, DEFROSTpad, Number selection pads POWER LEVEL pad, TIMER/CLOCK pad STOP/CLEAR pad, START/MINUTE PLUS pad

Oven Cavity Light Yes Safety Standard UL Listed FCC Authorized

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

GENERAL INFORMATION

GROUNDING INSTRUCTIONS

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

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

Electrical Requirements The electrical requirements are a 120 volt 60 Hz, AC only, 15 or more protected 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

R-320HK R-320HQ R-320HW

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

11 3

1 Door opening button

Push to open door.

2 Oven door with see-through window 3 Safety door latches

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

4 Door hinges 5 Door seals and sealing surfaces 6 Turntable motor shaft 7 Removable turntable support

Carefully place the turntable support in the center of the oven floor.

8 Removable turntable

Place the turntable on the turntable support securely. The turntable will rotate clockwise or counterclockwise. Only remove for cleaning.

9 Ventilation openings (Rear) 10 Oven light

It will light when oven is operating door is open.

11 Waveguide cover: DO NOT REMOVE. 12 Auto-Touch control panel 13 Time display: 99 minutes, 99 seconds 14 Power supply cord

Grounded Receptacle Box

3-Pronged Plug

Grounding Pin

3-Pronged Receptacle

TOUCH CONTROL PANEL

NOTE: Some one-touch cooking features such as "MINUTE PLUS" 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.

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OPERATION

DESCRIPTION OF OPERATING SEQUENCE

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

OFF CONDITION

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

1. The display will show "ENJOY YOUR OVEN PRESS CLEAR AND PRESS CLOCK".

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

COOKING CONDITION

Program desired cooking time by touching the NUMBER pads. Program the power level by touching the POWER LEVEL pad. 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)

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

POWER LEVEL P-0 TO P-90 COOKING

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

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

2. 120 volts A.C. is supplied to the primary winding of the power transformer and is converted to about 3.3 volts A.C. output on the filament winding, and approximately 2360 volts A.C. on the high voltage winding.

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

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

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

6. When the door is opened during a cook cycle, the monitor switch, door sensing switch, secondary interlock switch, 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

VARI-MODE ON TIME OFF TIME HIGH (100% power) 32 sec. 0 sec. P-90 (approx. 90% power) 30 sec. 2 sec. P-80 (approx. 80% power) 26 sec. 6 sec. P-70 (approx. 70% power) 24 sec. 8 sec. P-60 (approx. 60% power) 22 sec. 10 sec. P-50 (approx. 50% power) 18 sec. 14 sec. P-40 (approx. 40% power) 16 sec. 16 sec. P-30 (approx. 30% power) 12 sec. 20 sec. P-20 (approx. 20% power) 8 sec. 24 sec. P-10 (approx. 10% power) 6 sec. 26 sec.

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

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

the percentage of microwave power, because approx. 3 seconds are needed for heating of the magnetron filament.

SENSOR COOKING CONDITION

Using the SENSOR function, 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: (POTATOES)

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

MICROWAVE

2. Heat Potates. Moisture and humidity is emitted rapidly. You can smell the aroma as it cooks.

AH SENSOR

MICROWAVE

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

Cooking Sequence.

1. Operate the oven in sensor cooking mode by referring to the operation manual.

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. 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.

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NOTE: CONDITION OF OVEN

SCHEMATIC

1. DOOR CLOSED

2. CLOCK APPEARS ON DISPLAY NOTE: " " indicates components with potential above 250V.

AH SENSOR

120V AC 60 Hz

C/T FUSE TEMPERATURE

GRN

OVEN LAMP RELAY

N.O.

(RY1)

FUSE 150˚C (OVEN)

OVEN LAMP

SECONDARY INTERLOCK SWITCH

COM.

CONTROL UNIT

TTM

TURNTABLE MOTOR

FAN MOTOR

N.O.

COM.

PRIMARY INTERLOCK RELAY

DOOR SENSING SWITCH

(RY2)

MONITOR

SWITCH

POWER TRANSFORMER

CAPACITOR 1µF AC 2300V

RECTIFIER

Figure O-1. Oven Schematic-Off Condition

NOTE: CONDITION OF OVEN

1. DOOR CLOSED

2. COOKING TIME PROGRAMMED

3. VARIABLE COOKING CONTROL "HIGH" (100%)

4. "START" PAD TOUCHED

SCHEMATIC

C/T FUSE TEMPERATURE

FUSE 150˚C (OVEN)

N.O.

AH SENSOR

POWER TRANSFORMER

MAGNETRON

120V AC 60 Hz

GRN

N.O.

OVEN LAMP RELAY

(RY1)

COM.

PRIMARY INTERLOCK RELAY

CONTROL UNIT

OVEN LAMP

SECONDARY INTERLOCK SWITCH

TTM

TURNTABLE MOTOR

FAN MOTOR

COM.

(RY2)

DOOR SENSING SWITCH

Figure O-2. Oven Schematic-Cooking Condition

MONITOR

SWITCH

CAPACITOR 1µF AC 2300V

RECTIFIER

MAGNETRON

DESCRIPTION AND FUNCTION OF COMPONENTS

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DOOR OPEN MECHANISM

The door is opened by pushing the open button on the control panel, refer to the Figure D-1. When the open button is pushed, the open button pushes up the switch lever, and then the switch lever pushes up the latch head. The latch heads are moved upward and released from latch hook. Now the door will open.

Door

Latch Heads

Switch Lever

Latch Hook

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

Functions:

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

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

3. If the door is opened, and the primary interlock relay (RY2) and the secondary interlock switch contact fail to

open, the C/T fuse blows simultaneously with closing of the monitor switch contacts.

CAUTION: BEFORE REPLACING A BLOWN C/T FUSE,

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

NOTE: C/T FUSE AND MONITOR SWITCH ARE

REPLACED AS AN ASSEMBLY.

TURNTABLE MOTOR

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

COOLING FAN MOTOR

The cooling fan motor drives a blade which draws external cool air. This cool air is directed through the air vents surrounding the magnetron and cools the magnetron. This air is channelled through the oven cavity to remove steam and vapours given off from the heating foods. It is then exhausted through the exhausting air vents at the oven cavity.

TEMPERATURE FUSE (OVEN)

The temperature fuse, located on the top of the oven cavity, is designed to prevent damage to the oven by fire. If the food load is overcooked, by either error in cook time or defect in the control unit, the temperature fuse will open. Under normal operation, the temperature fuse remains closed. However, when abnormally high temperatures are reached within the oven cavity, the temperature fuse will open at 302˚F(150˚C), causing the oven to shut down.

C/T FUSE

1. The C/T fuse blows when the contacts (COM-NO) of the primary interlock relay (RY2) and secondary interlock switch remain closed with the oven door open and when the monitor switch closes.

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

3. The C/T fuse, located near the magnetron, is designed to prevent damage to the magnetron. If an over heated condition develops in the magnetron due to cooling fan failure, obstructed air guide, dirty or blocked air intake, etc., the C/T fuse will open.

Under normal operation, the C/T fuse remains closed. However, when abnormally high temperatures are reached within the oven cavity, the C/T fuse will open at 302˚F (150˚C), causing the oven to shut down or when the electric currents beyond 20A flow, the C/T fuse will open.

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TROUBLESHOOTING GUIDE

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

When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which will be found in the "Test Procedure "section.

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

interlock relay (RY2), door sensing switch and secondary interlock switch before replacing the C/T fuse. If C/T fuse is replaced, the monitor switch must also be replaced. Use part FFS-BA034WRKZ as an assembly.

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

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

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the leads to the primary of the power transformer.

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

6. After that procedure, reconnect the power supply cord.

When the testing is completed,

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

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

5. Reinstall the outer case (cabinet).

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

7. Run the oven and check all functions.

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CK = Check / RE = Replace

CONDITION

OFF CONDITION

COOKING CONDITION

SENSOR COOKING CONDITION

TEST PROCEDURE

AND

POSSIBLE CAUSE

DEFECTIVE PARTS

PROBLEM

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

C/T fuse blows when power cord is plugged into wall receptacle.

All letters and indicators do not appear in display when power cord is first plugged into wall outlet.

Display does not operate properly when STOP/CLEAR key is touched. (Buzzer should sound and ":" or time of day 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 P50 mode. (Operates properly on Cooking Power P-HI (HIGH) mode.)

Oven goes into DEFROST CENTER 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.

RE RE

ABCDEFFGH

SHORT IN POWER CORD

SHORT OR OPENED WIRING

MAGNETRON

POWER TRANSFORMER

H.V. RECTIFIER ASSEMBLY

RERE

HIGH VOLTAGE CAPACITOR

TEMPERATURE FUSE (OVEN)

PRIMARY INTERLOCK SYSTEM

SECONDARY INTERLOCK SWITCH

MONITOR SWITCH

C/T FUSE

OVEN LAMP

CKICK CKCK

COOLING FAN MOTOR

TURNTABLE MOTOR

TOUCH CONTROL PANEL

WRONG OPERATION

LOW VOLTAGE

DIRTY OVEN CAVITY

JKLMN

KEY UNIT (MEMBRANE SWITCH)

RELAY (RY1)

DEFROST CENTER

FOIL PATTERN ON PWB.

AH SENSOR

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TEST PROCEDURES

PROCEDURE

LETTER

A MAGNETRON ASSEMBLY TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron filament leads should indicate less than 1 ohm.

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

6. Reconnect all leads removed from components during testing.

7. Reinstall the outer case (cabinet).

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

9. Run the oven and check all functions.

MICROWAVE OUTPUT POWER

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

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

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

COMPONENT TEST

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

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

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

4. Subtract the cold water temperature from the hot water temperature. The normal result should be 35 to 65˚F(19.4 to 36.1˚C) rise in temperature. If the water temperatures are accurately measured and tested for the required time period the test results will indicate if the magnetron tube has low power output (low rise in water temperature) which would extend cooking time or high power output (high rise in water temperature) which would reduce cooking time. Because cooking time can be adjusted to compensate for power output, the magnetron tube assembly should be replaced only if the water temperature rise test indicates a power output well beyond the normal limits. The test is only accurate if the power supply line voltage is 120 volts and the oven cavity is clean.

B POWER TRANSFORMER TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the primary input terminals and measure the resistance of the transformer with an ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil should be less than 1 ohm and the resistance of the high voltage coil should be approximately 89 ohms; the resistance of the filament coil should be less than 1 ohm.

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

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

TEST PROCEDURES

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PROCEDURE

LETTER

C HIGH VOLTAGE RECTIFIER TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

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

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

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

D HIGH VOLTAGE CAPACITOR TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads and check for short or open between the terminals using an ohmmeter. Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate continuity for a short time and should indicate an open circuit once the capacitor is charged. If the above is not the case, check the capacitor with an ohmmeter to see if it is shorted between either of the terminals and case. If it is shorted, replace the capacitor.

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

COMPONENT TEST

E TEMPERATURE FUSE TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. A continuity check across the temperature fuse terminals should indicate a closed circuit unless the temperature of the temperature fuse reaches approximately 302˚F(150˚C). An open temperature fuse indicates overheating of the oven, exchange the temperature fuse 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.

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

F SECONDARY INTERLOCK SWITCH TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate an open circuit with the door open and a closed circuit with the door closed. If improper operation is indicated, replace the secondary interlock switch.

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

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TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

PRIMARY INTERLOCK SYSTEM TEST

DOOR SENSING SWITCH

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

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)

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

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

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

G MONITOR SWITCH TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

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

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

H BLOWN C/T FUSE TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

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

Screw Driver

Monitor Switch

GRY WHT

BLK

Secondary Interlock Switch

Ohmmeter

TEST PROCEDURES

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PROCEDURE

LETTER

I TOUCH CONTROL PANEL ASSEMBLY TEST

COMPONENT TEST

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

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

If the C/T fuse is blown by improper switch operation, the C/T fuse and monitor switch must be replaced with "C/T fuse and monitor switch assembly" part number FFS-BA034WRKZ, even if the monitor switch operates normally. The C/T fuse and monitor switch assembly is comprised of a 20 ampere fuse and switch.

A continuity check across the C/T fuse terminals should indicate a closed circuit unless the temperature of the C/T fuse reaches approximately 302˚F(150˚C). An open C/T fuse indicates overheating of the magnetron. Check for restricted air flow to the magnetron, especially the cooling fa air guide.

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

THE C/T FUSE.

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be 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, LSI 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) Re-install the outer case (cabinet).

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

3) 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.

2. Control Unit The following symptoms indicate a defective control unit.

2-1 In connection with pads.

a) When touching the pads, a certain group of pads do not produce a signal. b) When touching the pads, no pads produce a signal.

2-2 In connection with indicators

a) At a certain digit, all or some segments do not light up. b) At a certain digit, brightness is low. c) Only one indicator does not light. d) The corresponding segments of all digits do not light up; or they continue to light up. e) Wrong figure appears. f) A certain group of indicators do not light up. g) The figure of all digits flicker.

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

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

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TEST PROCEDURES

PROCEDURE

LETTER

3. If the Key unit or the Control unit is defective.

4. When testing is completed,

J KEY UNIT TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Using an ohmmeter and referring to the key unit matrix indicated on the control unit circuit, check the circuit

5. Reconnect all leads removed from components during testing.

6. Re-install the outer case

7. Reconnect the power supply

8. Run the oven and check all

COMPONENT TEST

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Replace the Control unit assembly.

5) Reconnect all leads removed from components during testing.

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

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

8) Run the oven and check all functions.

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Reconnect all leads removed from components during testing.

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

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

7) Run the oven and check all functions.

between the pins of the key unit that correspond to the STOP/CLEAR pad. When the pad is pressed, the ohmmeter should indicate short circuit. When the pad is released, the ohmmeter should indicate open circuit. If incorrect readings are obtained, the key unit is faulty and must be replaced. About the other pads, the above method may be used.

(cabinet). cord after the outer case is

installed. functions.

Pin NO. G1

Pin NO. G13

G8 G7 G5 G4 G3 G2 G1G6

BEVERAGE

POPCORN

G13 G12 G11 G10 G9

ROLLS/

MUFFINS GROUND

MEAT

BONELESS

POULTRY SENSOR

COOK

STEAKS/

CHOPS

HOT

WATER

BONE-IN POULTRY

2 1 438 7

KEEP

WARM START

MINUTE PLUS

TIMER

CLOCK

STOP

CLEAR

POWER

LEVEL

CUSTOM

HELP

SENSOR

REHAET

K RELAY TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the leads to the primary of the power transformer.

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

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

7. Remove the outer case and check voltage between the normal open terminal of the relay RY1 and the normal open terminal of the relay RY2 on the control unit with an A.C. voltmeter. The meter should indicate 120 volts, if not check oven circuit.

Key unit ribbon cable

Key unit (Membrane Switch) front view

TEST PROCEDURES

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PROCEDURE

LETTER

RY1 and RY2 Relay Test

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

9. Open the door and block it open.

10. Discharge high voltage capacitor.

11. Reconnect all leads removed from components during testing.

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

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

14. Run the oven and check all functions.

L 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.

3. Touch the " STEAKS / CHOPS " pad once.

4. The oven is in Defrost cooking condition.

5. The oven will operate as follows

COMPONENT TEST

These relays are operated by D.C. voltage Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.

DC. voltage indicated..................Defective relay.

DC. voltage not indicated............Check diode which is connected to the relay coil. If diode is good,

control unit is defective.

RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS

RY1 Approx. 24.0V D.C. Oven lamp / Turntable motor / Cooling fan motor RY2 Approx. 24.0V D.C. Power transformer

MENU 1ST STAGE 2ND STAGE 3RD STAGE

STEAKS/CHOPS LEVEL TIME LEVEL TIME LEVEL TIME

0.5lb 70% 15sec. 60% 25sec. 30% 37sec.

6. 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.

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Follow the troubleshooting guide given below for repair.

STEPS OCCURRENCE CAUSE OR CORRECTION

1 Only pattern at "a" is broken. *Insert jumper wire J1 and solder. 2Pattern at "a" and "b" are broken.

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

5) Make a visual inspection of the varistor. Check for burned damage and examine the transformer with a tester for the presence of layer short-circuit (check the primary coil resistance which is approximately 212Ω ± 10%). If any abnormal condition is detected, replace the control unit assembly.

6) Reconnect all leads removed from components during testing.

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

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

9) Run the oven and check all functions.

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

RY2

VRS1

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TEST PROCEDURES

PROCEDURE

LETTER

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Disconnect the leads to the primary of the power transformer.

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

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

7) Follow the troubleshooting guide given below for repair. STEPS OCCURRENCE CAUSE OR CORRECTION

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

9) Open the door and block it open.

10) Discharge high voltage capacitor.

11) Reconnect all leads removed from components during testing.

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

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

14) Run the oven and check all functions.

N AH SENSOR TEST

COMPONENT TEST

The rated AC voltage is not present between

1 the normal open terminal of the relay RY1 and Check supply voltage and oven power cord.

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

of low voltage transformer. Check and replace control unit assembly.

Checking the initial sensor cooking condition WARNING : The oven should be fully assembled before following procedure.

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

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 the TIMER/CLOCK pad once, the POWER LEVEL pad twice and the START pad once. And touch

the number pads 1 once and the number pad 4 once. Now, the oven is in the sensor cooking condition,

and "AH20", "SENSOR" and "COOK" will appear in the display. (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. If ERROR is displayed or the oven does not turn off, replace the AH sensor or check the control unit, refer to explanation below. If the oven stops after 5 minutes and ERROR is displayed, the AH sensor is normal. Check other parts except the AH sensor.

TEST PROCEDURES

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PROCEDURE

LETTER

COMPONENT TEST

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 the TIMER/CLOCK pad once, the POWER LEVEL pad twice and the START pad once. And

touch the number pads 1 once and the number pad 4 once. 9-5. The control panel is in automatic Sensor operation. 9-6. The oven turns off automatically, and the time for detecting moisture will be displayed.

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

CHECKING CONTROL UNIT

(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 sensor connector that is mounted to control panel. (5) Then connect the dummy resistor circuit (see fig.) 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. Close the door. Touch the TIMER/CLOCK pad once, the POWER LEVEL pad twice and the START

pad once. And touch the number pads 1 once and the number pad 4 once. 9-2. The control panel is in the sensor cooking operation. 9-3. After approximately 25 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 time for detecting moisture.

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

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

(10) Disconnect the power supply cord, and then remove outer case. (11) Open the door and block it open. (12) Discharge high voltage capacitor. (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.

Plunger

R1, R2 : 22Ω ± 1% 1/2W

R3 : 4.3kΩ ± 5% 1/4W R4 : 1MΩ ± 5% 1/4W

F-1 F-2

F-3

To connector (F) on Control Unit.

CONNECTOR

1 2 3

R3 R4

COM

NC NO

COM

Sensor Dummy Resistor Circuit

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TOUCH CONTROL PANEL ASSEMBLY

OUTLINE OF TOUCH CONTROL PANEL

The touch control section consists of the following units. (1) Key Unit

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

LSI Unit).

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 P20-P27. When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through P70, P71, P41, P45, P47 and AN3 to perform the function that was requested.

Control Unit

Control unit consists of LSI, reset circuit, indicator circuit, power source circuit, relay circuit, buzzer circuit, synchronizing signal circuit, absolute humidity sensor circuit and back light circuit.

1) Reset Circuit

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

3) 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 Voltage Application

VC -5V LSI(IC1)

4) Relay Circuit

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

5) Buzzer Circuit

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

6) Synchronizing Signal Circuit

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

7) Door Sensing Switch

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

2) Indicator Circuit

This circuit consists of 25 segments and 4 common electrodes using a Liquid Crystal Display.

8) Back Light Circuit

A circuit to drive the back light (Light emitting diodes LD1- LD4).

9) Absolute Humidity Sensor Circuit

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

DESCRIPTION OF LSI

LSI

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

Pin No. Signal I/O Description

1-2

3-6 AN7-AN4 IN

7 AN3 IN

8 AN2 IN

VL2-VL1

IN Power source voltage input terminal.

Standard voltage for LCD.

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.

Signal coming from touch key.

When either G13 line on key matrix is touched, a corresponding signal out of P20 - P27 will be input into AN3. When no key is touched, the signal is held at “H” level.

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

Door close "H" level signal (0V). Door Open "L" level (-5V).

Pin No. Signal I/O Description

9 AN1 IN 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.

10 AN0 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.

11-13 P57-P55 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor).

14 CNTR0 OUT

Signal to sound buzzer (2.0 kHz).

A: key touch sound. B: Completion sound.

0.1 sec.

2.0 sec.

H : GND

L : -5V H : GND

L : -5V

15 P53 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor). 16 P52 OUT

Oven lamp, fan motor and turntable motor driving signal

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

16.7 msec.

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

During cooking

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H : GND

L : -5V

17 P51 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor). 18 P50 OUT

19 P47 IN

Magnetron high-voltage circuit driving signal.

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

Signal similar to AN3.

Maximum output

70% of maximum output

OFF

OFF OFF

24 sec.

When either G13 line on key matrix is touched, a corresponding signal will be input into P46. 20 P46 OUT Terminal not used. 21 P45 IN

Signal similar to AN3.

When either G12 line on key matrix is touched, a corresponding signal will be input into P45.

22-23 P44-P43 OUT Terminal not used.

24 INT0 IN

Signal synchronized with commercial power source frequency.

This is the basic timing for time processing of LSI.

16.7 msec.

25 P41 IN Signal similar to AN3.

When either G11 line on key matrix is touched, a corresponding signal will be input into P41. 26 P40 IN Connected to GND through the pull-down resistor. 27 RESET IN

Auto clear terminal.

Signal is input to reset the LSI to the initial state when power is applied. 28 P71 IN

Signal similar to AN3.

When either G10 line on key matrix is touched, a corresponding signal will be input into P71. 29 P70 IN

Signal similar to ANI3.

When either G9 line on key matrix is touched, a corresponding signal will be input into P70. 30 XIN IN

Internal clock oscillation frequency control input setting.

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

to XOUT terminal. 31 XOUT OUT

Internal clock oscillation output.

Output to control oscillation input to XIN. 32 VSS IN

Power source voltage : -5.0V.

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

8 sec.

H : GND

L : -5V H : GND

L : -5V

H : GND

L : -5V

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Pin No. Signal I/O Description

33 P27 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P70, P71, P41, P45, P47 and AN3 terminal while one of G8 line keys on key matrix is touched.

34 P26 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P70, P71, P41, P45, P47 and AN3 terminal while one of G7 line keys on key matrix is touched.

35 P25 OUT

Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P70, P71, P41, P45, P47 and AN3 terminal while one of G6 line keys on key matrix is touched.

36 P24 OUT

Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P70, P71, P41, P45, P47 and AN3 terminal while one of G5 line keys on key matrix is touched.

37 P23 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P70, P71, P41, P45, P47 and AN3 terminal while one of G4 line keys on key matrix is touched.

38 P22 OUT

Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P70, P71, P41, P45, P47 and AN3 terminal while one of G3 line keys on key matrix is touched.

39 P21 OUT

Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P70, P71, P41, P45, P47 and AN3 terminal while one of G2 line keys on key matrix is touched.

40 P20 OUT

Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P70, P71, P41, P45, P47 and AN3 terminal while one of G1 line keys on key matrix is touched.

41 P17 OUT Back light signal. (Light emitting diodes) driving signal

42-46 P16-P12 OUT Terminal not used.

47 SEG25 OUT Terminal not used.

48-72

SEG24-SEG0

OUT Segment data signal.

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

LSI signal (Pin No.) LCD (Pin No.) LSI signal (Pin No.) LCD (Pin No.) SEG0 (72)

SEG1 (71) SEG2 (70) SEG3 (69) SEG4 (68) SEG5 (67) SEG6 (66) SEG7 (65) SEG8 (64) SEG9 (63) SEG10 (62) SEG11 (61) SEG12 (60)

.................................

................................

SEG 0 SEG13 (59) SEG 1 SEG14 (58) SEG 2 SEG15 (57) SEG 3 SEG16 (56) SEG 4 SEG17 (55) SEG 5 SEG18 (54) SEG 6 SEG19 (53) SEG 7 SEG20 (52) SEG 8 SEG21 (51)

SEG 9 SEG22 (50) SEG 10 SEG23 (49) SEG 11 SEG24 (48) SEG 12

...............................

SEG 13 SEG 14 SEG 15 SEG 16 SEG 17 SEG 18 SEG 19 SEG 20 SEG 21 SEG 22 SEG 23 SEG 24

73 VCC IN Power source voltage : GND(0V). 74 VREF IN

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

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

75 AVSS IN

A/D converter power source voltage : -5.0V.

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

76 COM3 OUT

Common data signal.

Connected to LCD signal COM0.

77 COM2 OUT

Common data signal.

Connected to LCD signal COM3.

78 COM1 OUT

Common data signal.

Connected to LCD signal COM2.

Pin No. Signal I/O Description

SW1 SW2

SW3 SW4

SW5

P57 P56 P55 P51 P53

LSI (IC1)

AN0

AN1

620k

300k 150k

75k

37.4k

47k

10k

1234

8765

0.01uF

0.015uF

0.01uF

VA : -15V

R90

C90

C91

C93

C92

F-2

1.8k

IC2

F-1

F-3

3.57k

3.32k

VC : -5V

0.1

C. Thermistor in closed vessel S. Thermistor in open vessel

R98 R99

R96

R91

360k

R93

R92

R94

R95

D90

R100 R101

R102

R97

79 COM0 OUT Common data signal.

Connected to LCD signal COM1.

80 VL3 IN

Power source voltage input terminal.

Standard voltage for LCD. Connected to GND.

ABSOLUTE HUMIDITY SENSOR CIRCUIT

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(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.

ventilation opening for sensing

Sensing part (Open vessel)

Thermistors

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 very minute, it is amplified by the operational amplifier.

observes the initial voltage available at its AN1 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 R98 ~ R102. Changing the resistance values results in that there is the same potential at both F-3 terminal of the absolute humidity sensor and AN0 terminal of the LSI. The voltage of AN1 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 resistance balance of the bridge circuit is deviated to increase the voltage available at AN1 terminal of the LSI. Then the LSI observes that voltage at AN1 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 AN1 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

Absolute humidity vs, output voltage characteristic

Absolute humidity (g/m )

Operational amplifier

S : Thermistor open vessel

C : Thermistor closed vessel

Output voltage

(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

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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. Servicing of Touch Control Panel

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

(1)Servicing the touch control panel with power supply

of the oven: CAUTION: THE HIGH VOLTAGE TRANSFORMER OF THE MICROWAVE OVEN IS STILL LIVE DURING SERVICING AND PRESENTS A HAZARD.

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

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Disconnect the leads to the primary of the power transformer.

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.

After checking the performance of the touch control panel,

1) Disconnect the power supply cord.

2) Open the door and block it open.

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

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

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

6) Run the oven and check all functions.

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).

3. 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

4. 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.

R-320HK R-320HQ R-320HW

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:

1. Disconnect the power supply cord.

2. Make sure that a definite” click” can be heard when the microwave oven door is unlatched. (Hold the door in a closed position with one hand, then push the door open button with the other, this causes the latch leads to rise, it is then possible to hear a “click’ as the door switches operate.)

3. 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;

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

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, Power transformer and Oven cavity.

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.

3) Sharp edge:

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

4) Movable parts (to prevent a fault)

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

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

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

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

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

OUTER CASE REMOVAL

To remove the outer case, proceed as follows.

1. Disconnect the power supply cord.

2. Open the oven door and block it open.

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

4. Remove the remaining three (3) 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.

R-320HK R-320HQ R-320HW

6. Lift entire outer case from the unit. CAUTION: 1. DISCONNECT OVEN FROM POWER SUP

PLY BEFORE REMOVING OUTER CASE.

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

NOTE: When replacing the outer case, the 2 special

Torx screws must be reinstalled in the same locations.

POWER TRANSFORMER REMOVAL

Special screw

Screw Driver (Type: TORX T20 H or GTXH20-100)

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

2. Open the oven door and block it open.

3. Discharge high voltage capacitor.

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

5. Remove four (4) screws (two (2) screws from the upper side and two (2) screws from bottom side) holding transformer to bottom plate.

6. Remove transformer from bottom plate.

HIGH VOLTAGE RECTIFIER AND HIGH VOLTAGE CAPACITOR REMOVAL

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 high voltage wire of the power transformer from the high voltage capacitor.

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 the one (1) screw holding capacitor holder to

Reinstallation

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

Secure transformer with four (4) screws

(two (2) screws from the upper side and two (2) screws from bottom side) to bottom plate.

3. Reconnect wire leads (primary) to power transformer and filament leads and high voltage wire of transformer to magnetron and high voltage capacitor. Refer to "PICTORIAL DIAGRAM" on page 28.

4. Reinstall outer case and check that oven is operating properly.

bottom 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.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

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 all wire leads from magnetron.

5. Remove the one (1) screw holding the chassis support to the magnetron.

6. Release the chassis support from the hole of the oven cavity front flange.

7. Remove the two (2) screws holding air duct to magnetron and oven cavity top plate.

8. Remove the air duct from oven.

9. Carefully remove the four (4) screws holding magnetron to waveguide flange.

10.Remove magnetron with care so that magnetron antenna is not hit by any metal object around antenna.

11.Now, the magnetron is free.

Reinstallation

1. Reinstall the magnetron to waveguide flange with the four (4) screws.

2. Reinstall the air duct to the oven cavity top plate and the magnetron with two (2) screws.

3. Insert the end of the chassis support into the hole of the oven cavity front flange.

4. Hold the other end of the chassis support to the magnetron with the one (1) screw.

5. Reconnect the wire leads to the magnetron. Refer to "PICTORIAL DIAGRAM" on page 28.

6. Reinstall outer case and check that the oven is operating properly.

CAUTION: WHEN REPLACING MAGNETRON, BE SURE

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

POSITIVE LOCK® CONNECTOR (NO-CASE TYPE) REMOVAL

R-320HK R-320HQ R-320HW

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. 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, CONNECT THE POSITIVE LOCK® SO THAT THE LEVER FACES YOU

CONTROL PANEL ASSEMBLY REMOVAL

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 wire leads from control unit.

Terminal

Positive lock® connector

Push

Lever

Pull down

Figure C-1. Positive lock® connector

5. Remove the one (1) screw holding the control panel assembly to the oven flange.

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

7. Now, individual components can be removed.

CONTROL UNIT ASSEMBLY REPLACEMENT

Removal

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 control panel assembly, referring to chapter of CONTROL PANEL ASSEMBLY REMOVAL.

5. Tear away the graphic sheet from the control panel frame and control unit assembly

6. Remove the two (2) screws holding the control unit assembly to the control panel frame.

7. Release the ontrol unit assembly from the six (6) tabs of the control panel frame.

8. Now, the ontrol unit assembly is free.

Installation

1. Remove remaining adhesive on the control panel frame surfaces with a soft cloth soaked in alcohol.

2. Make sure that the LED sheet and liquid crystal display are installed in position.

3. Reinstall the control unit assembly to the control panel frame with the two (2) screws.

4. Tear the backing paper from the graphic sheet.

5. Adjust the upper edge and left edge of the graphic sheet to the large depression on the surface of the control panel frame.

6. Attach the graphic sheet to the control panel frame by rubbing with a soft cloth not to scratch.

NOTE: Do not contact the contact surface of the ribbon cable (edge) and the rubber connector directly with your fingers. This is to avoid oxidized. If display digits are missing or scrambled, remove control unit and clean

contact surface with alcohol. After cleaning, do not attach the rubber connector until alcohol dries up. Do not use alcohol or solution to clean the rubber connector. Make sure that there is no trash or foreign substance on contact surface of the rubber connector.

Control panel frame

LED sheet

Liquid crystal display

Graphic sheet

Control panel frame (Rear side)

Contact surface

Ribbon cable of membrane switch

(Rear View)

Rubber connector

Figure C-2. Graphic Sheet Attachment

R-320HK R-320HQ R-320HW

TURNTABLE MOTOR REMOVAL

1. Disconnect the power supply cord.

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.

COOLING FAN MOTOR REMOVAL

REMOVAL

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 wire leads from the fan motor.

5. Remove the two (2) screws holding the fan motor to the oven cavity back plate.

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

7. 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 injured.

* Do not disfigure the bracket by touching with the

pliers.

8. Remove the fan blade from the shaft of the fan motor by pulling and rotating the fan blade with your hand.

9. Now, the fan blade will be free.

Coil

Groove joint pliers

5. Disconnect wire leads from turntable motor. (See "Positive lock connector removal")

6. Remove one (1) screw 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.

CAUTION: * Do not reuse the removed fan blade because the hole

(for shaft) may be larger than normal.

10.Now, the fan motor is free.

INSTALLATION

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

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

3. Apply the screw lock tight into the hole (for shaft) of the fan blade.

4. 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.

5. Install the fan motor to the oven cavity back plate with the two (2) screws.

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

Shaft

Stator

Gap

Bracket

Rotor

Rear View

Shaft

Axis

Stator

Rotor

Table

These are the positions that should be pinched with pliers.

Center of bracket

Side View

DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL

Disconnect the power supply cord and remove outer case.

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect wire leads from the switches.

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. At this time switch lever will be free, do not lose it.

Reinstallation

1. Reinstall 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.

R-320HK

Latch Heads

Door

Switch Lever

Latch Hook

Door Sensing Switch

Monitor Switch

Secondary Interlock Switch

R-320HQ R-320HW

2. Reconnect wire leads to each switch. Refer to pictorial diagram.

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

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.

oven flange.

DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

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

4. Loosen the two (2) screws holding 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.

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 door sensing switch and secondary interlock switch interrupt the circuit before the door can be open.

3. Monitor switch contacts close when door is opened.

4. Reinstall outer case and check for microwave leakage around door with an approved microwave survey meter. (Refer to Microwave Measurement Procedure.)

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

DOOR REPLACEMENT

REMOVAL

1. Disconnect the power supply cord.

2. Open the door slightly.

3. Insert a putty knife (thickness of about 0.5mm) into the gap between the choke cover and 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.

NOTE: When carrying out any repair to the door, do not

bend or warp the slit choke (tabs on the door panel assembly) to prevent microwave leakage.

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 zdoor frame is free from oven cavity.

Figure C-3. Latch Switch Adjustments

Choke Cover

Door Frame

Putty Knife

Figure C-4. Door Disassembly

9. Release door panel from ten (10) tabs of door frame.

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

11.Tear sealer film from door panel.

12.Now, door panel is free.

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

R-320HK R-320HQ R-320HW

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

15.Remove door screen from door frame.

16.Now, door screen is free.

REINSTALLATION

1. Reinstall door screen to door frame .

2. Reinstall the latch spring to the latch head. Reinstall the latch spring to the door frame. Reinstall latch head to door frame.

3. Reinstall door panel to door frame by fitting ten (10) tabs of door frame to ten (10) holes of door panel.

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

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

6. Reinstall 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.

Upper Oven Hinge

Lower Oven

Upper Oven Hinge

Slit choke of door panel

Lower Oven Hinge

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

Figure C-6. Sealer film

Backing film

Adhesive tape

R-320HK

HIGH VOLTAGE

CAPACITOR

H.V. RECTIFIER

POWER SUPPLY

CORD 120V 60Hz

HIGH VOLTAGE COMPONENTS

MAGNETRON

COM.

MONITOR

SWITCH

COM.

N.O.

N.C.

DOOR

SENSING

SWITCH

SECONDARY

INTERLOCK

SWITCH

TURNTABLE

MOTOR

POWER

TRANSFORMER

COM.

NOTE:

The neutral (WHT) wire must be

connected to the terminal with "N"

mark on the power supply cord.

GRY

RED

BLK

RED

PNK

WHT

GRY

RED

GRY

GRN

GRY

GRN

BLK

GRY

WHT

GRY

RED

BLK

PNK

GRY

C/T FUSE

FAN MOTOR

TEMPERATURE

FUSE (OVEN)

BLK

WHT

RED

RY1

PRIMARY

INTERLOCK

RELAY

CN-B

SP1

CN-F

CN-B

N.O.

COM.

RY2

N.O.

COM.

CONTROL UNIT

NOTE:

The grounding conductor of

the power supply cord has

been grounded by power

supply cord fixing screw.

The screw must allways be

kept tight.

GRY

OVEN LAMP

PNK

RED

PNK

BLK

AH SENSOR

RED

WHT

CN-F

R-320HQ R-320HW

Figure S-1. Pictorial Diagram

R-320HK

LSI UNIT

OVEN LAMP

TURNTABLE

MOTOR

FAN MOTOR

POWER

TRANSFOMER

IF NOT SPECIFIED 1/10W

±5%

G13

G12

G11

G10

F-1

F-2

B-1

COM

B-2

10uF/ 35V

2SB1238

ZD1

2.4K

HZ16- 1

3.3K

1/4W

10u/ 35V

D5 D6

a b

1/4W

510

1/ 2W

1SS270A x2

8 6 7

(J1)

-5V

GND

INT

1000uF

35V

1/ 4W

SP1

POWER UNIT

P26

PP27

IC1

NOTE:

D31 1SS270A

D30 1SS270A

DTA123JS

DOOR

SENSING

SWITCH

AC(H)

AC(N)

AH SENSOR

CN-F

LD4 LD3 LD2 LD1

WH-1

RY1

RY2

VRS1

10G471K

D1-- D4

1N4002x4

PA111DR

0.1uF

50V

C10

47uF/16V

680 1/2W

4.7K 1/4W

2SB1238

R90

330 1W

R91

3.32KD

KRC243M

1SS270A1SS270A

DOOR

COM

R40

4.7K

C40

R41

15K

0.01uF 25V

0.1uF

50V

C20

R68

15K

P70

R69

15K

P71

R70

15K

P41

R71

15K

R72

15K

P45

(G)

R74--R78:270Kx5

C60--C64:330pF/50Vx5

R78

R77

R76

R75

R74

C64

C63

C62

C61

C60

R67

15K

R66

15K

P25

R65

15K

P24

R64

15K

P23

R63

15K

P22

R62

15K

P21

R61

15K

P20

R60

15K

R110

15K

R80

P41

P40

RESET

P71

P70

XIN

XOUT

VSS

P27

P26

P25

P24

P23

P22

P21

P20

VL3

COM0

COM1

COM2

COM3

AVSS

VREF

VCC

SEG0

SEG1

SEG2

SEG3

SEG4

SEG5

SEG6

SEG7

SEG8

SEG9

SEG10

SEG11

SEG12

SEG13

SEG14

SEG15

SEG16

SEG17

SEG18

SEG19

SEG20

SEG21

SEG22

SEG23

SEG24

SEG25

CF1

CST4.00MGW

4124

(F)

(G)

VL2

VL1

AN7

AN6

AN5

AN4

AN3

AN2

AN1

AN0

P57

P56

P55

CNTR0

P53

P52

P51

P50

P47

P46

P45

P44

P12

P13

P14

P15

P16

P17

P43

INT0

R13

10K

R14

10K

R15

10K

LIQUID CRYSTAL DISPLAY

COOK SENSOR LBS KG DEF HELP

COM3

COM0

COM1

COM2

COM3

SEG0

SEG1

SEG2

SEG3

SEG4

SEG5

SEG6

SEG7

SEG8

SEG9

SEG10

SEG11

SEG12

SEG13

SEG14

SEG15

SEG16

SEG17

SEG18

SEG19

SEG20

SEG21

SEG22

SEG23

SEG24

COM0

COM1

COM2

GND

AN7

AN6AN5AN4

(J16)

(J17)

(J14)

(J12)

(J10)

3.6K

4.7K

(J15)

4.7K

(J13)

4.7K

(J11)

4.7K

0.01uF

25V

C14

15K

R11

Q10

2SA1037AK

UDZ4.3B

D90

MA152WA

ZD10

R10

Q11

DTA143EKA

0.01uF

25V

C13

C92

0.01uF

25V

C93

0.01uF/25V

R95

47K

R94

10K

R97

47K

R93

360KF

37.4KF

R102

R98 620K

R99 300K

R100 150KF

R101 75KF

P57

P56

P55

P51

P53

IC2

BA4558

2 3 4

C91

0.1uF50V

R92

1.8KF

0.1uF 50V

Q30

DTA143EKA

Q20

DTA143EKA

C90

R96

3.57KD

(F)

0.1uF/50V

C11

C12

0.1uF

50V

R12

15K

438

BEVERAGE

ROLLS/

MUFFINS

GROUND

MEAT

SENSOR

COOK

STEAKS/

CHOPS

HOT

WATER

BONELESS

POULTRY

BONE-IN

POULTRY

KEEP

WARM

TIMER

CLOCK

STOP

CLEAR

POWER

LEVEL

CUSTOM

HELP

SENSOR

REHAET

START

MINUTE PLUS

POPCORN

R-320HQ R-320HW

Figure S-2. Control Unit Circuit

R-320HK R-320HQ R-320HW

DIP

CHIP SIDE

CN-F

1 2 3

R90

D31

CN-B

E C B

D30

E C B

C10

WH-2

DZ1

E C B

LED

WH-2

112

SP1

Q3 Q4

RY2

D1C1D2

VRS1

RY1

Figure S-3. Printed Wiring Board of Power Unit

R-320HK R-320HQ R-320HW

PARTS LIST

Note: The parts marked “∆” may cause undue microwave exposure.

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

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

ELECTRIC PARTS

1-1 QSW-MA147WRZZ Secondary interlock switch / door sensing switch 2 AG 1-2 FFS-BA034WRKZ 1-3 FACCDA083WRE0 Power supply cord 1 AQ 1-3 FACCDA085WREZ Power supply cord (Interchangeable) 1 AQ 1-4 FH-DZA075WRK0 High voltage rectifier assembly 1 AR

1-4 FH-DZA083WRK0 High voltage rectifier assembly (Interchangeable) 1 AQ

1-4 FH-DZA109WRKZ High voltage rectifier assembly (Interchangeable) 1 AR

1-5 RC-QZA303WRZZ High voltage capacitor 1 AV

1-5 RC-QZA288WRZZ High voltage capacitor (Interchangeable) 1 AV

1-5 RC-QZA235WRE0 High voltage capacitor (Interchangeable) 1 AV

1-6 RMOTEA346WRE0 Fan motor 1 AV 1-6 RMOTEA356WRE0 Fan motor (Interchangeable) for production use 1 — 1-7 QFS-TA014WRE0 Temperature fuse 150deg.C(oven) 1 AG 1-8 RLMPTA082WRZZ Oven lamp 1 AL 1-8 RLMPTA085WRZZ Oven lamp (Interchangeable) for production use 1 — 1-9 RMOTDA211WRE0 Turntable motor 1 AS 1-9 RMOTDA186WRE0 Turntable motor (Interchangeable) 1 AW 1-10 RTRN-A700WRZZ Power transformer 1 BK

1-11 RV-MZA295WRE0 Magnetron 1 BF

∆

1-11 RV-MZA320WRZZ Magnetron (Interchangeable) 1 BH

1-12 FDTCTA230WRKZ AH sensor assembly 1 AX

2-1 GCABUA883WRPZ Outer case cabinet [R-320HW] 1 BF 2-1 GCABUA889WRPZ Outer case cabinet [R-320HK] 1 BF 2-1 GCABUA894WRPZ Outer case cabinet [R-320HQ] 1 BF 2-2 FDAI-A265WRYZ Bottom plate 1 AW 2-3 GLEGPA074WRE0 Foot 4 AC

3-1 CPWBFA862WRKZ Control unit assembly 1 BH 3-2 HPNLCB787WRRZ Control panel frame [R-320HW] 1 AT 3-2 HPNLCB791WRRZ Control panel frame [R-320HK] 1 AT 3-2 HPNLCB812WRRZ Control panel frame [R-320HQ] 1 AT 3-3 PSHEPA931WRZZ Graphic sheet [R-320HW] 1 AW 3-3 PSHEPA932WRZZ Graphic sheet [R-320HK] 1 AW 3-3 PSHEPA933WRZZ Graphic sheet [R-320HQ] 1 AW 3-4 XOTSD40P08000 Screw : 4mm x 8mm 2 AA 3-5 JBTN-B236WRFZ Open button [R-320HW] 1 AH 3-5 JBTN-B240WRFZ Open button [R-320HK] 1 AH 3-5 JBTN-B245WRFZ Open button [R-320HQ] 1 AH 3-6 MSPRCA050WRE0 Button spring 1 AB

∆

4-1 PHOK-A131WRFZ Latch hook 1 AL 4-2 LBNDKA163WRPZ Capacitor holder 1 AK 4-3 NFANJA020WRE0 Fan blade 1 AG

∆

4-4 ************* Oven cavity (Not a replacement part) 1 — 4-5 MLEVPA233WRF0 Switch lever 1 AG 4-6 PCLICA032WRE0 Hand clip 4 1 AD 4-7 PCOVPA394WREZ Waveguide cover 1 AK 4-8 PDUC-A833WRPZ Air duct 1 AM 4-9 PDUC-A832WRWZ Fan duct 1 AP 4-10 PPACGA176WREZ TTM packing 1 AC 4-11 PCUSGA399WRE0 Cushion 1 AF 4-12 PCUSUA278WRP0 Cushion 4 AB 4-13 PDUC-A842WRPZ Sensor duct 1 AP 4-14 PCUSGA620WRPZ Cushion 1 AF 4-15 PCUSGA615WRPZ Cushion 1 AE 4-16 MROD-A019WREZ Chassis support 1 AN 4-17 PCUSGA616WRPZ Cushion 1 AK

∆

5-1 FDORFA364WRTZ Door panel 1 AS 5-2 PSHEPA382WRE0 Sealer film 1 AH

∆

5-3 GWAKPA887WRFZ Door frame [R-320HW] 1 AX

∆

5-3 GWAKPA893WRFZ Door frame [R-320HK] 1 AX

C.T.fuse(150deg.C/20A) and monitor switch (D3V-1G-2C25) assembly

CABINET PARTS

CONTROL PANEL PARTS

OVEN PARTS

DOOR PARTS

1AS

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

5-3 GWAKPA908WRFZ Door frame [R-320HQ] 1 AX

∆

5-4 HPNL-A790WRRZ Door screen [R-320HW] [R-320HQ] 1 AU 5-4 HPNL-A797WRRZ Door screen [R-320HK] 1 AU 5-5 LSTPPA188WRF0 Latch head 1 AG

∆

5-6 MSPRTA187WRE0 Spring 1 AC 5-7 GCOVHA450WRFZ Choke cover 1 AG

∆

MISCELLANEOUS

6-1 FROLPA101WRKZ Turntable support 1 AR 6-2 NTNT-A117WREZ Turntable 1 AS 6-3 FW-VZB978WREZ Main wire harness 1 AT 6-4 TCAUAA268WRRZ DHHS caution label 1 AF 6-5 TCAUAA280WRRZ Monitor caution 1 AF 6-6 TINSEA976WRRZ Instruction book 1 AP

SCREWS,NUTS AND WASHERS

7-1 XHPSD40P08K00 Screw : 4mm x 8mm 2 AA 7-2 LX-CZA070WRE0 Special screw 2 AC 7-3 LX-CZA073WRE0 Special screw 2 AC 7-4 LX-CZ0052WRE0 Special screw 2 AA 7-5 LX-EZA042WRE0 Special screw 2 AB 7-6 XHPSD30P06000 Screw : 3mm x 6mm 3 AA 7-7 XHPSD40P08000 Screw : 4mm x 8mm 5 AA 7-8 XHTSD40P08RV0 Screw : 4mm x 8mm 5 AA 7-9 XHTSD40P12RV0 Screw : 4mm x 12mm 1 AA 7-10 XOTSD40P08000 Screw : 4mm x 8mm 14 AA 7-11 XOTSE40P08000 Screw : 4mm x 8mm [R-320HW) (R-320HQ] 1 AA 7-11 XOTSF40P08000 Screw : 4mm x 8mm [R-320HK] 1 AA 7-12 XHTSD40P08000 Screw : 4mm x 8mm 1 AA 7-13 XHPSD30P08XS0 Screw : 3mm x 8mm 1 AB

R-320HK R-320HQ R-320HW

HOW TO ORDER REPLACEMENT PARTS

To have your order filled promptly and correctly, please furnish the following information.

1. MODEL NUMBER 2. REF. NO. 3. PART NO. 4. DESCRIPTION

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

R-320HK R-320HQ R-320HW

OVEN AND CABINET PARTS

7-10

7-2

7-10

4-9

4-15

7-2

7-11

2-1

7-3

7-12

1-1

6-4

7-7

7-10

1-8

7-7

4-8

7-6

4-13

1-12

1-7

4-3

7-8

7-3

7-6

1-2

1-6

7-8

4-16

7-9

1-3

6-5

7-10

4-6

4-4

7-10

7-8

4-7

6-2

7-4

4-10

1-9

1-10

4-12

7-5

4-14

1-11

4-17

4-1 4-5

6-1

7-1

4-11

7-8

2-2

4-12

7-1

4-2

1-5

1-4

1-2

1-1

2-3

7-10

2-3

7-10

2-3

7-10

2-3

4-12

R-320HK R-320HQ R-320HW

3-2

3-4

CONTROL PANEL PARTS

3-1

3-4

3-6

3-5

5-7

DOOR PARTS

3-3

5-2

5-1

5-3

5-4

5-6

5-5

MISCELLANEOUS

6-3

Actual wire harness may be different from illustration.

R-320HK R-320HQ R-320HW

TOP PAD ASSEMBLY FPADBA506WRKZ

DOOR PROTECTION SHEET SPADPA204WRE0

FOAM SHEET SPAKHA012WREZ

(only for R-320HK)

INTO THE OVEN CAVITY

6-6 INSTRUCTION BOOK

6-2 TURNTABLE TRAY

6-1 TURNRTABLE SUPPORT

PLASTIC SHEET (for R-320HK) SPADPA616WREZ

PLASTIC BAG SSAKHA034WRE0

CABINET COVER SPAKHA011WRE0

(only for R-320HK)

BOTTOM PAD ASSEMBLY FPADBA508WRKZ

PACKING AND ACCESSORIES

PACKING CASE

FPAK-A479WRKZ [R-320HK] FPAK-A480WRKZ [R-320HQ]

Not replaceable items.

TRAY PAD ASSY

(CPADBA317WRKZ)

FPAK-A478WRKZ [R-320HW]

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.

2003 SHARP CORP. (4S1.700E) Printed in U.S.A

SHARP R-320HK, R-320HQ, R-320HW Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

TABLE OF CONTENTS

BEFORE SERVICING

WARNING TO SERVICE PERSONNEL

MICROWAVE MEASUREMENT PROCEDURE

SPECIFICATION

GENERAL INFORMATION

OPERATION

DESCRIPTION OF OPERATING SEQUENCE

DESCRIPTION AND FUNCTION OF COMPONENTS

TROUBLESHOOTING GUIDE

TEST PROCEDURES

A MAGNETRON ASSEMBLY TEST

B POWER TRANSFORMER TEST

C HIGH VOLTAGE RECTIFIER TEST

D HIGH VOLTAGE CAPACITOR TEST

E TEMPERATURE FUSE TEST

F SECONDARY INTERLOCK SWITCH TEST

PRIMARY INTERLOCK SYSTEM TEST

G MONITOR SWITCH TEST

H BLOWN C/T FUSE TEST

I TOUCH CONTROL PANEL ASSEMBLY TEST

J KEY UNIT TEST

K RELAY TEST

L DEFROST TEST

M FOIL PATTERN ON THE PRINTED WIRING BOARD TEST

N AH SENSOR TEST

TOUCH CONTROL PANEL ASSEMBLY

OUTLINE OF TOUCH CONTROL PANEL

DESCRIPTION OF LSI

TOUCH CONTROL PANEL SERVICING

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

WARNING AGAINST HIGH VOLTAGE:

WARNING FOR WIRING

OUTER CASE REMOVAL

POWER TRANSFORMER REMOVAL

HIGH VOLTAGE RECTIFIER AND HIGH VOLTAGE CAPACITOR REMOVAL

MAGNETRON REMOVAL

POSITIVE LOCK® CONNECTOR (NO-CASE TYPE) REMOVAL

CONTROL PANEL ASSEMBLY REMOVAL

CONTROL UNIT ASSEMBLY REPLACEMENT

TURNTABLE MOTOR REMOVAL

COOLING FAN MOTOR REMOVAL

DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL

DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT

DOOR REPLACEMENT

SEALER FILM

PARTS LIST

HOW TO ORDER REPLACEMENT PARTS

OVEN AND CABINET PARTS

PACKING AND ACCESSORIES