Sharp R-231NW Service Manual

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Page 1

R-231NW

6 Pan

COCCIONRECALENTAR

1 Caserola 2 Sopa 3 Pizza 4 Bebida 5 Plato Principal

Derretir Suavizar Calentar

Function Rapida

Cronometro

Reloj

Nivel de Potencia

Comienzo

Detencion

Cancelacion

1 Papa Asada 2 Verdura Fresca 3 Verdura Congelada 4 Entradas Congeladas

Minuto Extra

DescongelacionPalomitas de Maiz

CONTENTS

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

BEFORE SERVICING

CHAPTER 1. WARNING TO SERVICE PERSONNEL

CHAPTER 2. MICROWAVE MEASUREMENT PROCEDURE

CHAPTER 3. FOREWORD AND WARNING

CHAPTER 4. PRODUCT DESCRIPTION

CHAPTER 5. GENERAL INFORMATION

CHAPTER 6. OPERATION

S3911R231NPAL

MICROWAVE OVEN

R-231NW

In the interests of user-safety the oven should be restored to its original condition and only parts identical to those speci? ed 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 se-

vere, possibly fatal, electrical shock. (High Voltage Capaci-

tor,

High Voltage Power Transformer, Magnetron, High

Voltage Rectifier Assembly, High Voltage Harness etc..)

SERVICE MANUAL

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

CHAPTER 7. TROUBLESHOOTING GUIDE

CHAPTER 8. TEST PROCEDURES

CHAPTER 9.

TOUCH CONTROL PANEL ASSEMBLY

CHAPTER 10. PRECAUTIONS FOR USING LEADFREE SOLDER

CHAPTER 11. COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

CHAPTER 12. CIRCUIT DIAGRAMS

Parts Guide

MODEL

Page 2

CONTENTS

PRECAUTIONS TO BE OBSERVED BEFORE

AND DURING SERVICING TO AVOID EXPOSURE

TO EXCESSIVE MICROWAVE ENERGY

BEFORE SERVICING

CHAPTER 1. WARNING TO SERVICE PERSONNEL

[1]

Before Servicing

[2] When the testing is completed ....................1-1

[3] After repairing ..............................................1-1

CHAPTER 2. MICROWAVE MEASUREMENT PROCEDURE

[1]

Requirements:

[2] Preparation for testing: ................................2-1

[3] Leakage test: ...............................................2-1

CHAPTER 3. FOREWORD AND WARNING

[1]

FOREWORD

[2] WARNING ...................................................3-1

[3] DANGER .....................................................3-1

CHAPTER 4. PRODUCT DESCRIPTION

[1] SPECIFICATIONS .......................................4-1

CHAPTER 5. GENERAL INFORMATION

[1] GROUNDING INSTRUCTIONS ..................5-1

[2] OVEN DIAGRAM .........................................5-1

CHAPTER 6. OPERATION

[1] DESCRIPTION OF OPERATING SE-

QUENCE .....................................................6-1

[2] OVEN SCHENATIC .....................................6-2

[3] DESCRIPTION AND FUNCTION OF

COMPONENTS ...........................................6-3

CHAPTER 7. TROUBLESHOOTING GUIDE

[1] TROUBLESHOOTING CHART ...................7-1

CHAPTER 8. TEST PROCEDURES

[1] A: MAGNETRON ASSEMBLY TEST... ........8-1

[2] B: POWER TRANSFORMER TEST ............8-1

[3] C: HIGH VOLTAGE RECTIFIER TEST .......8-1

[4] D: HIGH VOLTAGE CAPACITOR TEST ......8-2

[5] E: THERMAL CUT-OUT (OVEN ) TEST ......8-2

[6] E: TEMPERATURE FUSE (OVEN)

TEST ...........................................................8-2

[7] F: SECONDARY INTERLOCK SWITCH

TEST ...........................................................8-2

[8] F: PRIMARY INTERLOCK SYSTEM

TEST ...........................................................8-3

[9] G: MOTOR SWITCH TEST .........................8-3

[10] H: BLOWN MINITOR FUSE TEST ..............8-4

[11] I: NOISE FILTER TEST ...............................8-4

[12] J: TOUCH CONTROL PANEL ASSEMBLY

TEST ...........................................................8-4

...........................................1-1

..............................................2-1

................................................3-1

[13] K: KEY UNIT TEST ..................................... 8-5

[14] L: RELAY TEST .......................................... 8-6

[15] M: DEFROST TEST ................................... 8-6

[16] N: FOIL PATTERN ON THE PRINTED

WIRING BOARD TEST .............................. 8-6

CHAPTER 9. TOUCH CONTROL UNIT ASSEMBLY

[1]

OUTLINE OF TOUCH CONTROL UNIT

[2]

DESCRIPTION OF LSI [3] SERVICING FOR TOUCH CONTROL

PANEL ......................................................... 9-3

CHAPTER 10. PRECAUTIONS FOR USING LEADFREE SOLDER

[1]

Employing lead-free solder [2]

Using lead-free wire solder

[3] Soldering .....................................................10-1

CHAPTER 11. COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

[1] WARNING ...................................................11-1

[2] OUTER CASE REMOVAL ...........................11-2

[3] MAGNETRON REMOVAL ...........................11-2

[4] HIGH VOLTAGE COMPONENTS REMOVAL (HIGH VOLTAGE CAPACITOR AND HIGH

VOLTAGE RECTIFIER ASSEMBLY) ...........11-2

[5] POWER TRANSFORMER REMOVAL ........11-2

[6] POSITIVE LOCK CONNECTOR (NO-

CASE TYPE) REMOVAL .............................11-3

CONTROL PANEL ASSEMBLY REMOVAL

[7] [8] GRAPHIC SHEET AND MEMBRANE

SWITCH REPLACEMENT ..........................11-3

[9] POWER SUPPLY CORD REPLACEMENT ...11-4

[10] TURNTABLE MOTOR REMOVAL ...............11-4

[11] COOLING FAN MOTOR REMOVAL ...........11-4

[12] DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR

SWITCH REMOVAL ....................................11-5

[13] DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR

SWITCH ADJUSTMENT .............................11-5

[14] DOOR REPLACEMENT ..............................11-6

CHAPTER 12. CIRCUIT DIAGRAMS

[1] Pictorial Diagram (Figure S-1) .....................12-1

[2] Control Panel Circuit (Figure S-2) ...............12-2

[3] Printed Wiring Board (Figure S-3) ...............12-3

Parts Guide

................................ 9-1

...........................10-1

....... 9-1

..11-3

Page 3

R-231NW

R230KW

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

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.

BEFOR SERVICING

BEFORE SERVICING

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

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

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

Page 4

R-231NW

CHAPTER 1. WARNING TO SERVICE PERSONNEL

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

(Example)

High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectiﬁ er Assembly, High Voltage Harness etc.. Read the Service Manual carefully and follow all instructions.

Don't Touch ! Danger High Voltage

[1] 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

HIGHVOLTAGE 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 shortcircuit the connection of the high-voltage capacitor (that is the connecting lead of the high-voltage rectiﬁ er) 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.

[2] When the testing is completed,

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).

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

7. Run the oven and check all functions.

[3] 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 o 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 re-examine 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 microwave leakage test should be carried out.

1 - 1

Page 5

R-231NW

CHAPTER 2. MICROWAVE MEASUREMENT PROCEDURE

[1] 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/cm

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/

at any point 5cm or more from the external surface of the oven.

[2] Preparation for testing:

Before beginning the actual measurement of leakage, proceed as follows:

1. Make sure that the actual instrument is operating normally as speciﬁ ed 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±5 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 meas ured 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.

at any point 5cm or more from the external surface of the oven.

[3] Leakage test:

Closed-door leakage test (microwave measurement)

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

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

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

4. Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW/cm 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.

, and that

2 - 1

Page 6

R-231NW

CHAPTER 3. FOREWORD AND WARNING

[1] FOREWORD

This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service Information for the SHARP MICROWAVE OVENS, R-230KK and R-230KW.

It is recommended that service personnel carefully study the entire text of this manual so that they will be qualiﬁ ed to render satisfac- tory customer service.

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

[2] 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 not any other visible damage with the oven. Servicing and repair work must be carried out only by trained service personnel.

[3] 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 Rectiﬁ er Assembly, High Voltage Harness; If provided, Vent Hood, Fan assembly, Cooling Fan Motor. All the parts marked

on parts list are used at voltages more than 250V.

“S”

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.

3 - 1

Page 7

R-231NW

4 - 1

NOITPIRCSEDMETI

Power Requirements

120 Volts 60 Hertz Single phase, 3 wire grounded

Power Consumption 1170W / Approx. 10 Amperes

Power Output

800 W nominal of RF microwave energy (IEC Test procedure) Operating frequency 2450 MHz

Case Dimensions

Width 18-1/8” (460mm) Height 10-7/8” (275mm) Depth 14-1/8” (370mm)

Cooking Cavity Dimensions (0.8 Cubic feet)

Width 12-1/2” (319mm) Height 8” (215mm) Depth 13-1/4” (336mm)

NOTE: Internal capacity is calculated by measuring maximum

width, depth and height. Actual capacity for holding food is less.

Control Complement

Touch Control System Clock (1:00 - 12:59) Timer (0 - 99 minutes 99 seconds) Microwave Power for Variable Cooking

Repetition Rate;

P-HI -------------------- Full power throughout the cooking time P-90 -------------------- approx. 90% of FULL Power P-80 -------------------- approx. 80% of FULL Power P-70 -------------------- approx. 70% of FULL Power P-60 -------------------- approx. 60% of FULL Power P-50 -------------------- approx. 50% of FULL Power P-40 -------------------- approx. 30% of FULL Power P-30 -------------------- approx. 40% 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

“Palomitas de Maíz” pad “Descongelación” pad Number selection pads “Nivel de Potencia” pad “Cronómetro / Reloj” pad “Detencion / Cancelacion” pad “Comienzo / Minuto Extra” pad “Functión Rápida” pad “Derretir” pad “Suavizar” pad “Calentar” pad “RECALENTAR” pad “COCCIÓN” pad

Oven Cavity Light Yes

CHAPTER 4. PRODUCT DESCRIPTION

[1] SPECIFICATIONS

Page 8

R-231NW

CHAPTER 5. GENERAL INFORMATION

[1] 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 115 -120 volt 60 Hz, AC only, 15 or 20 amp. fused electrical supply. It is recommended that a separate circuit serving only this appliance be provided. When installing this appliance, observe all applicable codes and ordinances. A short powersupply cord is provided to reduce risks of becoming entangled in or tripping over a longer cord. Where a twopronged wall-receptacle is encountered, it is the personal responsibility and obligation of the customer to contact a qualiﬁ ed electrician and have it replaced with a properly grounded threepronged wall receptacle or have a grounding adapter properly grounded and polarized. If the extension cord must be used, it should be a 3-wire, 15 amp. or higher rated cord. Do not drape over a countertop or table where it can be pulled on by children or tripped over accidentally.

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

GROUNDING PRONG FROM THIS PLUG.

Grounded Receptacle Box

3-Pronged Plug

Grounding Pin

3-Pronged Receptacle

[2] OVEN DIAGRAM

1. OVEN

1. Door open 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 ﬂ oor.

8. Removable turntable

Place the turntable securely on the turntable support. 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.

11. Waveguide cover: DO NOT REMOVE.

12. Auto-Touch control panel

13. Time display: 99 minutes, 99 seconds

11 310

5 - 1

Page 9

2. TOUCH CONTROL PANEL

R-231NW

Palomitas de Maiz

Nivel de

Potencia

Detencion

Cancelacion

Derretir Suavizar Calentar

1 Caserola 2 Sopa 3 Pizza 4 Bebida 5 Plato Principal 6 Pan

Descongelacion

Cronometro

Reloj

Comienzo

Minuto Extra

Function Rapida

COCCIONRECALENTAR

1 Papa Asada 2 Verdura Fresca 3 Verdura Congelada 4 Entradas Congeladas

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.

5 - 2

Page 10

R-231NW

CHAPTER 6. OPERATION

[1] DESCRIPTION OF OPERATING SEQUENCE

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

1. OFF CONDITION

Closing the door activates 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. through the noise ﬁ lter (Figure O-1).

1) The display will show ﬂ ashing “88:88”.

To set any program or set the clock, touch the STOP/CLEAR pad.

The display will clear, and “ : “ will appear.

2. COOKING CONDITION

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

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

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

(For details, refer to Figure O-2)

3. POWER LEVEL COOKING

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

VARI-MODE ON TIME OFF TIME P-HI (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 (0% power) 0 sec. 32 sec.

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 3.35 volts A.C. output on the ﬁ lament winding, and approximately 2000 volts A.C. on the high voltage winding.

The ﬁ lament winding voltage heats the magnetron ﬁ lament and

the H.V. winding voltage is sent to a voltage doubler circuit.

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

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

6) When the door is opened during a cook cycle, monitor switch, door sensing switch, secondary interlock switch and primary interlock relay are activated with the following results. The circuits to the oven lamp, turntable motor, the cooling fan motor, and the high voltage components are de-energized, and the digital read-out displays the time still remaining in the cook cycle when the door was opened.

7) The monitor switch is electrically monitoring the operation of the secondary interlock switch and primary interlock relay (RY2) and is mechanically associated with the door so that it will function in the following sequence.

a) When the door opens from the closed position, the sec-

ondary interlock switch, door sensing switch and primary interlock relay (RY2) open their contacts. Then the moni- tor switch contacts close.

b) When the door is closed from the open position, the monitor switch contacts open ﬁ rst. Then the contacts

of the secondary interlock switch and door sensing switch close.

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

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 ﬁ lament.

4. POWER OUTPUT REDUCTION

If the oven is set for more than 20 minutes at 80, 90 or 100% power level, after the ﬁ rst 20 minutes the power level will auto- matically adjust itself to 70% power to avoid overcooking.

6 - 1

Page 11

[2] OVEN SCHENATIC

1. Off Condition

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED

2. CLOCK APPEARS ON DISPLAY

FUSE 15A

R E T LI F

ROT

120V AC 60 Hz

ESION

GRN

LIOCNOISSERPPUSESION

V052

CAPACSSORCEN

C A/Fµ

2.0

I L

R-231NW

THERMAL CUT-OUT (OVEN)

TEMPERATURE FUSE (OVEN)

V052CA/Fµ3300.0

ROTICAPAC S A PY

B E N

V052CA/Fµ3300.0

ROTICA S A P YBENI

PAC

CONTROL UNIT

OL FM

OVEN LAMP

SECONDARY INTERLOCK SWITCH

NOTE: " " indicates components with potentials above 250V

TTM

(RY-1)

TURNTABLE MOTOR

N.O.

(RY-2)

B2 B1

FAN MOTOR

PRIMARY INTERLOCK RELAY

DOOR SENSING SWITCH

COM.

MONITOR SWITCH

POWER TRANSFORMER

CAPACITOR

0.82µF AC2100V

AC1900V

RECTIFIER

MAGNETRON

Figure O-1. Oven Schematic-Off Condition

2. Cooking Condition

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. COOKING TIME PROGRAMMED.

3. VARIABLE COOKING CONTROL "P-HI".

4. START PAD TOUCHED.

THERMAL

120V AC 60 Hz

GRN

CUT-OUT (OVEN)

TEMPERATURE

FUSE 15A

V0 5

SAPY

/Fµ33

APA

R E T L

IFESION

R OTIC

LIO V 0

C 2C

PACS

SER

F µ

ORCEN

22.

PUSE

I L

E NIL

0 0

V 0 5

SSAPYBENIL

C A

Fµ

3 0

0. 0

FUSE (OVEN)

CONTROL UNIT

OL FM

OVEN LAMP

SECONDARY INTERLOCK SWITCH

NOTE: " " indicates components with potentials above 250V

(RY-1)

TTM

TURNTABLE MOTOR

N.O.

(RY-2)

B2 B1

FAN MOTOR

PRIMARY INTERLOCK RELAY

DOOR SENSING SWITCH

COM.

MONITOR SWITCH

POWER TRANSFORMER

CAPACITOR

0.82µF AC2100V

AC1900V

RECTIFIER

MAGNETRON

Figure O-2. Oven Schematic-Cooking Condition

6 - 2

Page 12

R-231NW

[3] DESCRIPTION AND FUNCTION OF COMPONENTS

1. 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

Figure D-1. Door Open Mechanism.

Latch Hook

Door Sensing Switch

Monitor Switch

Secondary Interlock Switch

2. 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 ﬁ rmly 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.

3. MONITOR SWITCH

The monitor switch is activated (the contacts opened) by the latch head on the door while the door is closed. The switch is intended to render the oven inoperative, by means of blowing the monitor fuse, when the contacts of the primary interlock relay (RY2) and secondary interlock switch fail to open when the door is opened.

Functions:

1) When the door is opened, the monitor switch 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 ﬁ rst 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 monitor fuse blows simultaneously with closing of the monitor switch contacts. CAUTION: BEFORE REPLACING A BLOWN MONITOR FUSE, TEST THE DOOR SENSING SWITCH, PRIMARY INTERLOCK RELAY (RY2), SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER “TEST PROCEDURE”).

NOTE: MONITOR FUSE AND MONITOR SWITCH ARE

REPLACED AS AN ASSEMBLY.

4. 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.

5. 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.

6. TEMPERATURE FUSE (OVEN)

The temperature fuse, located on the top of the oven cavity, is designed to prevent damage to the oven by ﬁ re. 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.

7. THERMAL CUT-OUT (OVEN)

The thermal cut-out, located on the top of the oven cavity, is designed to prevent damage to the oven by ﬁ re. If the food load is overcooked, by either error in cook time or defect in the control unit, the thermal cutout will open.

Under normal operation, the oven thermal cut-out remains closed. However, when abnormally high temperatures are reached within the oven cavity, the oven thermal cut-out will open at 293°F(145°C), causing the oven to shut down.

8. MONITOR FUSE

1) The monitor fuse blows when the contacts (COM-NO) of the primary interlock relay (RY2) and the 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 short- circuited, this monitor fuse blows to prevent an electric shock or ﬁ re hazard.

9. NOISE FILER

The noise ﬁ lter prevents the radio frequency interference that might ﬂ ow back in the power circuit.

6 - 3

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CHAPTER 7. 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 speciﬁ c test be performed. These tests are given a procedure letter which will be found in the “Test Procedure “section.

IMPORTANT:

If the oven becomes inoperative because of a blown monitor fuse, check the monitor switch, primary interlock relay (RY2), door sensing switch and secondary interlock switch before replacing the monitor fuse. If monitor fuse is replaced, the monitor switch must also be replaced. Use part FFSBA026WRKZ 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.

[1] TROUBLESHOOTING CHART

TTEST PROCEDURE

POSSIBLE CASE

AND DEFECTIVE PARTS

CONDITION PROBLEM

OFF

CONDITION

COOKING

CONDITION

Home fuse blows when power cord is plugged into wall receptacle.

Monitor fuse blows when power cord is plugged into wall receptacle.

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

Display does not operate properly when STOP/CLEAR key is touched. (Buzzer should sound and time of day should appear in display.)

Monitor fuse blows when the door is opened.

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

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

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

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

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

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

Oven does not cook properly when programmed for Cooking 50% mode. (Operates properly on Cooking Power 100% mode.)

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

Oven goes into DEFROST but food is not defrosted well.

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7 - 1

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R-231NW

CHAPTER 8. TEST PROCEDURES

[1] Procedure 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 ﬁ lament, isolate the magnetron from the high voltage circuit. A continuity check across the magnetron ﬁ lament leads should indicate less than 1 ohm.

5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron ﬁ lament leads and chassis ground. This test should indicate an inﬁ nite 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.

1. MICROWAVE OUTPUT POWER

The following test procedure should be carried out with the microwave oven in a fully assembled condition (outer case ﬁ tted). 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 rectiﬁ er, high voltage ca- pacitor and power transformer. This test will require a 16 ounce (453cc) measuring cup and an accurate mercury thermometer or thermocouple type temperature tester. For accurate results, the following procedure must be followed carefully:

1. Fill the measuring cup with 16 oz. (453cc) of tap water and measure the temperature of the water with a thermometer or thermo couple 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 P-HI (100% Power) 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 20 to 38°F(11.1 to 21.1°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.

[2] Procedure 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 202 ohms (RTRN-A727WRZZ) or 190 ohms (RTRN-A728WRZZ); the resistance of the ﬁ lament 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.)

[3] Procedure 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 rectiﬁ er from the circuit. Using the highest ohm scale of the meter, read the resistance across the terminals and observe, reverse the leads to the rectiﬁ er terminals and observe meter reading. If a short is indicated in both directions, or if an inﬁ nite resist- ance is read in both directions, the rectiﬁ er 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.

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[4] Procedure 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.

[5] Procedure E : THERMAL CUT-OUT (OVEN ) TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

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

An open thermal cut-out indicates overheating of the oven, exchange the oven thermal cut-out and check inside of oven cavity and

for improper setting of cooking time or operation of control unit. Check for restricted air ﬂ ow through the vent holes of the oven cav- ity, 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.

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

[6] Procedure E : TEMPERATURE FUSE (OVEN) 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 ﬂ ow through the vent holes of the oven cav- ity, 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.

CAUTION: IF THE TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE, REPLACE IT

[7] Procedure 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.

8 - 2

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[8] Procedure F : PRIMARY INTERLOCK SYSTEM 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.

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.

2. 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.

[9] Procedure G : MONITOR SWITCH TEST

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

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

5. Reconnect all leads removed from components during testing.

6. Reinstall the outer case (cabinet).

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

8. Run the oven and check all functions.

SCREW DR IVE R

BLK

GRY

MONITO R SWITCH

OHMME TE R

8 - 3

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[10] Procedure H : BLOWN MINITOR 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 monitor fuse is blown when the door is opened, check the primary interlock relay, secondary interlock switch and monitor switch according to the “TEST PROCEDURE” for those switches before replacing the blown monitor fuse.

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

LOCK SWITCH, DOOR SENSING SWITCH AND MONITOR SWITCH FOR PROPER OPERATION.

If the monitor fuse is blown by improper switch operation, the monitor fuse and monitor switch must be replaced with “monitor fuse

and monitor switch assembly” part number FFS-BA026WRKZ, even if the monitor switch operates normally. The monitor fuse and monitor switch assembly is comprised of a 15 ampere fuse and 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.

[11] Procedure I : NOISE FILTER 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 lead wires from the terminal the noise ﬁ lter. Using an ohmmeter, check

NOISE FILTER

LINE CROSS CAPACITOR

0.22µF / AC 250V

NOISE SUPPRESSION COIL

FUSE 15A

between the terminals as described in the following table. If incorrect reading are obtained, replace the noise ﬁ lter.

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.

LINE BYPASS

CAPACITOR

0.0033µF / AC 250V

LINE BYPASS

CAPACITOR

0.0033µF / AC 250V

REDWHITE

MEASURING POINT INDICATION OF OHMMETER

Between N and L Open circuit.

Between terminal N and WHITE Short circuit.

Between terminal L and RED Short circuit.

[12] Procedure J : TOUCH CONTROL PANEL ASSEMBLY TEST

The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter.

In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key Unit, and troubleshooting by unit replacement is described according to the symptoms indicated.

Before testing,

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

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

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

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

1. Key Unit

NOTE:

1) Check key unit ribbon connection before replacement.

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

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

4) 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 ﬁ gures or more are displayed. c) When touching the pads, sometimes a pad produces no signal.

8 - 4

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If the key unit is defective.

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Replace the key unit.

5) Reconnect all leads removed from components during testing.

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

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

8) Run the oven and check all functions.

2. Control Unit.

The following symptoms indicate a defective control unit. Before replacing the control unit, perform the Key unit test (Procedure K) to determine if control unit is faulty.

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) 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 ﬁ gure appears. f) A certain group of indicators do not light up. g) The ﬁ gure of all digits ﬂ icker.

3) Other possible problems caused by defective control unit. a) Buzzer does not sound or continues to sound. b) Clock does not operate properly. c) Cooking is not possible. When testing is completed,

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Reconnect all leads removed from components during testing.

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

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

7) Run the oven and check all functions.

[13] Procedure K : 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 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.

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.

START

G10

MELT 7 8 9

MINUTE PLUS

STOP

CLEAR

POWER

POPCORN

LEVEL

REHEAT WARMDEFORST

G6 G5 G4 G3 G2 G1

SOFTEN

TIMER

CLOCK

COOK

Pin NO. G1 Pin NO. G10

8 - 5

Key unit ribbon cable

Key unit (Membrane Switch) front view

Page 19

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[14] Procedure L : 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 Pin No. 1 of the 3 pin connector (A) 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.

RY1 and RY2 Relay Test

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

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

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

RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS

RY1 Approx. 12.5V D.C. Oven lamp / Turntable motor / Cooling fan motor

RY2 Approx. 11.2V D.C. Power transformer

8. If any abnormal condition is defected, replace the control unit.

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

10.Open the door and block it open.

11.Discharge high voltage capacitor.

12.Reconnect all leads removed from components during testing.

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

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

15.Run the oven and check all functions.

[15] Procedure M : DEFROST TEST

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

2. Close the door, touch the “DEFROST ” pad once.

3. The oven is in Defrost cooking condition.

4. The oven will operate as follows.

MENU 1ST STAGE 2ND STAGE 3RD STAGE 4TH STAGE

Steaks/

Chops

0.5lb

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

LEVEL TIME LEVEL TIME LEVEL TIME LEVEL TIME

70% 1min 2sec. 0% 50sec. 50% 37sec. 30% 40sec.

[16] Procedure N : FOIL PATTERN ON THE PRINTED WIRING BOARD TEST

To protect the electronic circuits, this model is provided with a ﬁ ne foil pattern added to the primary on the PWB, this foil pattern acts as a fuse.

1. Foil pattern check and repairs.

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Follow the troubleshooting guide given below for repair.

STEPS OCCURRENCE CAUSE OR CORRECTION

1 Only pattern at “a” is broken. *Insert jumper wire J1 and solder.

2 Pattern at “a” and “b” are broken. *Insert the coil RCILF2003YAZZ between “c” and “d”.

8 - 6

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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 915Ω±10%). If any abnormal condition is detected, replace the control unit.

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 ﬁ nished.

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

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

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

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

7) Follow the troubleshooting guide given below for repair.

STEPS OCCURRENCE CAUSE OR CORRECTION

The rated AC voltage is not present between Pin No. 1 of the

3-pin connector (A) and the normal open terminal of the relay RY2

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

transformer.

Check supply voltage and oven power cord.

Low voltage transformer or secondary circuit defective. Check and replace control unit.

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.

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9 - 1

CHAPTER 9. TOUCH CONTROL PANEL ASSEMBLY

[1] OUTLINE OF TOUCH CONTROL PANEL

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

(1) Key Unit (2) Control Unit The principal functions of these units and their related signals

are explained below.

1. Key Unit

The key unit is composed of a matrix, signals generated in the LSI are sent to the key unit through P52, P53, P54, P55, P56 and P57. When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through AN2, AN3, AN4 and AN5 to perform the function that was requested.

2. Control Unit

Control unit consists of LSI, reset circuit, indicator circuit, power source circuit, relay circuit, buzzer circuit and synchronizing sig-

nal circuit.

1) Reset Circuit This circuit generates a signal which resets the LSI to the ini-

tial state when power is supplied.

2) Indicator Circuit This circuit consists of 4-digits, 12-segments and 3-common

electrodes using a Liquid Crystal Display.

3) Power Source Circuit This circuit generates voltage necessary in the control unit

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

Symbol Voltage Application

VSS -5V LSI(IC1)

4) Relay Circuit To drive the magnetron, fan motor, turntable motor and light

the oven lamp.

5) Buzzer Circuit The buzzer is responsive to signals from the LSI to emit audi-

ble 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.

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[3] SERVICING FOR TOUCH CONTROL PANEL

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 in? uenced by the surrounding high voltage power source, static electricity charge in clothes, etc., and sometimes it is not fully protected by the built-in protection circuit.

In order to protect CMOS LSI.

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

2) When soldering, ground the technician as shown in the ? gure 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.

Servicing the touch control panel with power supply of the oven:

CAUTION: THE HIGH VOLTAGE TRANSFORMER OF THE

MI C ROWAVE OVEN IS STILL LIV E D U RIN G SERVICING AND PRESENTS A HAZARD.

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

Disconnect the power supply cord and then remove outer case.

2) Open the door and block it open.

3) Discharge high voltage capacitor.

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

Ensure that these leads remain isolated from other components

and oven chassis by using insulation tape.

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 so long enough that they may be separated from each other. For those models, therefore, it is possible to check

and repair the controls of the touch control panel while

keeping it apart from the oven proper; in this case you must short both ends of the door sensing switch (on PWB) of the touch control panel with a jumper, which brings about an operational state that is equivalent to the oven door being closed. As for the sensor related controls of the touch control panel, checking them is possible if the dummy resistor(s) with resistance equal to that of the controls are used.

2. Servicing the touch control panel with power supply from an external power source:

Disconnect the touch control panel completely from the

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

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

2) Connect the connector of the key unit to the control unit being sure that the lead wires are not twisted.

3) After aluminium foil is removed, be careful that abnormal voltage due to static electricity etc. is not applied to the input or output terminals.

4) Attach connectors, electrolytic capacitors, etc. to PWB, making sure that all connections are tight.

5) Be sure to use speci? ed components where high precision is required.

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CHAPTER 10. PRECAUTIONS FOR USING LEAD-FREE SOLDER

[1] Employing lead-free solder

The “Main PWB” of this model employs lead-free solder. This is indicated by the “LF” symbol printed on the PWB and in the service manual. The sufﬁ x letter indicates the alloy type of the solder.

Example:

Indicates lead-free solder of tin, silver and copper

[2] Using lead-free wire solder

When repairing a PWB with the “LF” symbol, only lead-free solder should be used. (Using normal tin/lead alloy solder may result in cold soldered joints and damage to printed patterns.)

As the melting point of lead-free solder is approximately 40°C higher than tin/lead alloy solder, it is recommend that a dedicated bit is used, and that the iron temperature is adjusted accordingly.

[3] Soldering

As the melting point of lead-free solder (Sn-Ag-Cu) is higher and has poorer wettability, (ﬂ ow), to prevent damage to the land of the PWB, extreme care should be taken not to leave the bit in contact with the PWB for an extended period of time. Remove the bit as soon as a good ﬂ ow is achieved. The high content of tin in lead free solder will cause premature corrosion of the bit. To reduce wear on the bit, reduce the temperature or turn off the iron when it is not required.

Leaving different types of solder on the bit will cause contamination of the different alloys, which will alter their characteristics, making good soldering more difﬁ cult. It will be necessary to clean and replace bits more often when using lead-free solder. To reduce bit wear, care should be taken to clean the bit thoroughly after each use.

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CHAPTER 11. COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

[1] WARNING

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 Rectiﬁ er Assembly, High Voltage Harness etc..

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WARNING:

1. Disconnect the power supply cord.

2. Make sure that a deﬁ nite “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;

1. Door does not close ﬁ rmly.

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 manners.

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, High voltage rectiﬁ er assembly.

2) Hot parts:

Oven lamp, Magnetron, Power transformer and Oven cavity.

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 ﬁ tted.

3) Sharp edge: Bottom plate, Oven cavity, Waveguide ﬂ ange, 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:

11 - 1

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[2] OUTER CASE REMOVAL

To remove the outer case, procedure as follows.

1. Disconnect the power supply cord.

2. Open the oven door and block it open.

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

4. Remove the remaining three (3) screws from the upper portion of the rear and two (2) screws along the right side of outer case.

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

6. Lift entire outer case from the unit.

CAUTION: DISCONNECT OVEN FROM POWER SUPPLY

BEFORE REMOVING OUTER CASE.

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.

Special screw

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

[3] MAGNETRON REMOVAL

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

2. Open the oven door and block it open.

3. Discharge high voltage capacitor.

4. Remove the two (2) screws holding the air duct to the oven cavity.

5. Release the air duct from the oven cavity.

6. Disconnect the wire leads from magnetron.

7. Remove the four (4) screws holding the magnetron to the waveguide.

8. Remove the magnetron from waveguide.

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

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

[4] HIGH VOLTAGE COMPONENTS REMOVAL (HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY)

To remove the components, proceed as follows.

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

2. Open the oven door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the high voltage wire (white) of the power transforme from high voltage capacitor.

5. Disconnect the H.V. wire of the H.V. rectiﬁ er assembly from the magnetron.

6. Disconnect the ﬁ lament lead (red) of the power transformer from the H.V. capacitor.

7. Remove one (1) screw holding capacitor holder to bottom plate.

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

9. Disconnect the terminal of high voltage rectifier assembly from high voltage capacitor.

10. Now the H.V. rectiﬁ er assembly and H.V. capacitor should be free.

CAUTION: WHEN REPLACING HIGH VOLTAGE RECTIFIER ASSEMBLY, ENSURE THAT THE CATHODE

(GROUND) CONNECTION IS SECURELY FIXED TO THE CAPACITOR HOLDER WITH A GROUNDING SCREW.

CAUTION: D O N O T R EPLACE ONLY HIGH VOLTAGE

RECTIFIER. WHEN REPLACING IT, REPLACE HIGH VOLTAGE RECTIFIER ASSEMBLY.

[5] POWER TRANSFORMER REMOVAL

1. REMOVAL

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

2. Open the oven door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the wire leads (main wire harness) from power transformer.

5. Disconnect the filament lead (red) of the power transformer from magnetron.

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

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

8. Remove the transformer.

9. Now the power transformer is free.

2. REINSTALL

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

2. Secure transformer with four (4) screws to the bottom plate (two screws from upper side and two screws from bottom side).

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

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

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[6] POSITIVE LOCK CONNECTOR (NO-CASE TYPE) REMOVAL

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Push the lever of positive lock® connector.

5. Pull down on the positive lock CAUTION: WHEN CONNECTING THE POSITIVE LOCK

connector.

CONNECTORS TO THE TERMINALS,

INSTALL THE POSITIVE LOCK

LEVER FACES YOU.

SO THAT THE

Figure C-1. positive lock® connector

[7] CONTROL PANEL ASSEMBLY REMOVAL

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the leads from the control unit.

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

6. Now, the control panel assembly is free.

[8] GRAPHIC SHEET AND MEMBRANE SWITCH REPLACEMENT

1. 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. Remove the two (2) screws holding the control unit to the control panel frame. And remove the control unit.

6. Remove the rubber connector from the long slit on the control panel frame.

7. Tear away the graphic sheet from the control panel frame.

8. Tear away the membrane switch from the control panel frame.

2. REINSTALL

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

2. Tear the backing paper from the new membrane switch.

3. Insert the ribbon cable of the membrane switch into the slit of the control panel frame.

4. Adjust the upper edge and right edge of the membrane switch to the small depression on the surface of the control panel frame.

5. Attach the membrane switch to the control panel frame by rubbing with a soft cloth not to scratch.

6. Tear the backing paper from the new graphic sheet.

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

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

9. Tear the small backing paper from the ribbon cable of the membrane switch.

10. Attach the ribbon cable to the control panel frame rear side.

11. Place the edge of the membrane switch’s ribbon cable on the lower portion of the liquid crystal display.

12. Insert the rubber connector into the long slit on the control panel frame.

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

NOTE: Do not contact the contact surface of the ribbon

cable (edge) and the rubber connector directly with your ﬁ ngers. 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.

Positive lock connector

Lever

Terminal

Push

Pull down

Large depression

Figure C-2. Graphic Sheet and Membrane Switch Replacement

Small backing paper

Ribbon cable

Graphic sheet

Control panel frame

Membrane switch

Slit

Small depression

11 - 3

Liquid crystal display

Ribbon cable of membrane switch

Long slit

Control panel frame (Rear side)

Contact surface

Rubber connector

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[9] POWER SUPPLY CORD REPLACEMENT

1. REMOVAL

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Remove the single (1) screw holding the green wire to the oven cavity back plate.

5. Disconnect the leads of the power supply cord from the noise ﬁ lter, referring to the Figure C-3(a).

6. Release the moulding cord stopper of the power supply cord from the square hole of the oven cavity back plate, referring

2. REINSTALL

1. Insert the moulding cord stopper of power supply cord into the square hole of the rear cabinet, referring to the Figure C-3 (b).

2. Install the earth wire lead of power supply cord to the oven cavity back plate with one (1) screw and tight the screw.

3. Connect the gray wire leads of power supply cord to the noise ﬁ lter correctly, referring to the Pictorial Diagram.

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

to the Figure C-3(b).

7. Now, the power supply cord is free.

Screw

Green Wire

Gray Wire

Connect the wire lead which has the black case to the terminal "L" of the noise filter.

Figure C-3(a) Power Supply Cord Replacement Figure C-3(b) Power Supply Cord Replacement

Power Supply Cord

Oven Cavity Back Plate

Noise Filter

Power Supply

Moulding Cord Stopper

DER

T HW

Oven Cavity Back Plate

Cord

Square Hole

[10] TURNTABLE MOTOR REMOVAL

1. 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.

5. Disconnect wire leads from turntable motor.

(See “Positive lock connector removal”)

6. Remove one (1) screw holding turntable motor to oven cavity.

7. Remove the TTM packing from the turntable motor.

8. Now, the turntable motor is free.

[11] COOLING FAN MOTOR REMOVAL

1. REMOVAL

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Disconnect the wire leads from the fan motor.

5. Remove the 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 ANY PIECES DO NOT ENTER

THE GAP BETWEEN THE ROTOR AND THE STATOR OF THE FAN MOTOR. BECAUSE THE ROTOR IS EASY TO BE SHAVEN BY PLIERS AND METAL PIECES MAY BE PRODUCED.

2. REINSTALL

1. Re-install the TTM packing.

2. Re-install the turntable motor with the TTM packing with the single (1) screw to the oven cavity bottom plate.

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

4. Insert the tab of the turntable motor cover into the hole of the bottom plate.

5. Re-install the turntable motor cover to the bottom plate with one (1) screw.

TTM packing

Turntable motor

Figure C-4. TTM packing Installation

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 assembly 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.

CAUTION: DO NOT RE-USE THE REMOVED FAN BLADE

BECAUSE THE HOLE (FOR SHAFT) MAY BE LARGER THAN NORMAL.

10.Now, the fan motor is free.

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Page 28

2. 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 ﬂ at 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.

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CAUTION: DO NOT HIT THE FAN BLADE STRONGLY WHEN INSTALLED BECAUSE THE BRACKET MAY BE

TRANSFORMED.

MAKE SURE THAT THE FAN BLADE ROTATES

SMOOTH AFTER INSTALLED.

MAKE SURE THAT THE AXIS OF THE SHAFT IS

NOT SLANTED.

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

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

Coil

Stator

Gap

Bracket

Rotor

Groove joint pliers

Rear View

Axis

Shaft

Stator

Rotor

Side View

These are the positions that should be pinched with pliers.

Table

Shaft

Center of bracket

[12] DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL

1. REMOVAL

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

2. Open the door and block it open.

3. Discharge high voltage capacitor.

4. Remove the control panel assembly, referring to section of CONTROL PANEL ASSEMBLY REMOVAL.

5. Remove the switch lever from the oven cavity.

6. Disconnect wire leads from the switches.

7. Remove two (2) screws holding latch hook to oven ﬂ ange.

8. Remove latch hook assembly from oven ﬂ ange.

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

10. Switch is now free.

2. REINSTALL

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

2. Secure latch hook (with two (2) mounting screws) to oven ﬂ ange.

3. Re-connect wire leads to each switch. Refer to pictorial diagram.

4. Install the switch lever to the oven cavity.

5. Reinstall the control panel assembly to the oven cavity.

6. Reconnect wire leads to the control unity, referring to the pictorial diagram.

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

[13] DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT

1. 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 ﬂ ange.

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 ﬁ rmly.

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.

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2. After adjustment, check the following.

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

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

3. Monitor switch contacts close when door is opened.

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

[14] DOOR REPLACEMENT

Door

Latch Heads

Switch Lever

Figure C-5. Latch Switch Adjustments

Latch Hook

Door Sensing Switch

Monitor Switch

Secondary Interlock Switch

1. 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 corner portion of door panel as shown in Figure C-6 to free engaging parts.

4. Pry the choke cover by inserting a putty knife in order shown in ﬁ gure C-6.

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.

Choke Cover

Door Frame

Putty Knife

Figure C-6. Door Disassembly

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

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

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

10. Now, door panel with sealer ﬁ lm is free.

11. Tear sealer ﬁ lm from door panel.

12. Now, door panel is free.

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

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

15. Remove door screen from door frame.

16. Now, door screen is free.

2. REINSTALL

1. Re-install door screen to door frame.

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

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

4. Put sealer ﬁ lm on door panel. Refer to “Sealer Film” and ﬁ gure C-8, on how to handle the new ﬁ lm.

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

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

NOTE: After any service to the door;

1) Make sure that door sensing switch, secondary

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

2) An approved microwave survey meter should be used to assure compliance with proper microwave radiation emission limitation standards.

3. 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 air-tight, 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.

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Slit choke of door panel

Hinge

Upper Oven Hinge

Lower Oven Hinge

Upper Oven Hinge

Lower Oven

Figure C-7. Door Replacement

Choke Cover

4. SEALER FILM

1. Put the adhesive tape on the backing ﬁ lm of the sealer ﬁ lm as shown in Fig. C-8

2. Tear the backing ﬁ lm by pulling the adhesive tape.

3. Put the pasted side of the sealer ﬁ lm on the door panel

Sealer film

Figure C-8. Sealer film

Backing film

Adhesive tape

11 - 7

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CHAPTER 12. CIRCUIT DIAGRAMS

[1] Pictorial Diagram (Figure S-1)

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Figure S-1 Pictorial Diagram

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12 - 1

Page 32

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12 - 2

[2] Control Panel Circuit (Figure S-2)

Figure S-2 Control Panel Circuit

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[3] Printed Wiring Board (Figure S-3)

Figure S-3. Printed Wiring Board

12 - 3

Page 34

PARTS LIST

HOW TO ORDER REPLACEMENT PARTS

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MICROWAVE OVEN

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

1. MODEL NUMBER

2. REF. NO.

3. PART NO.

4. DESCRIPTION

CONTENTS

[1] OVEN PARTS

[2] DOOR AND CONTROL PANEL PARTS

MODEL

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Parts marked “*” may cause undue microwave exposure. Parts marked “S” are used in voltage more than 250V.

INDEX

■

TOP PAD ASSEMBLY

FPADBA585WRKZ

INTO THE OVEN CAVITY

TRAY PAD ASSY

(CPADBA287WRKZ)

DOOR PROTECTION SHEET

SPADPA580WRE0

6-5 INSTRUCTION BOOK

6-1 TURNTABLE TRAY

FOAMSHEET for R-231NW

SPAKHA014WREZ

6-2 TURNTABLE SUPPORT

MICROWAVE OVEN

Not replaceable items.

POLYETHYLENE BAG

SSAKHA014WRE0

PLASTICSHEET for R-231NW

SPADPA615WREZ

BOTTOM PAD ASSEMBLY

FPADBA586WRKZ

PACKING CASE

SPAKCE807WREZ

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

Page 35

R-231NW

[1] OVEN PARTS

2-1

7-8

4-8

6-1

4-5

4-11

4-10

7-8

4-6

1-10

7-1

7-6

7-2

7-3

7-4

4-9

7-8

1-8

7-6

4-17

4-1

7-10

7-1

6-4

1-3

7-7

1-13

1-7

1-1

1-12

7-7

4-7

7-1

4-3

7-11

1-6

7-11

7-6

4-14

4-4

4-12

6-2

7-8

2-3

2-2

7-1

7-8

1-9

1-11

4-13

2-3

7-8

1-2

1-1

4-2

1-4

7-1

7-8

7-7

4-16

1-5

7-3

4-15

Page 36

R-231NW

PARTS LIST

KNAR ECIRPYT’Q NOITPIRCSED EDOC STRAP .ON

[1] OVEN PARTS

ELECTRONIC PARTS

FA2hctiws gnisnes rooD /hctiws kcolretni yradnoceS0ERW580AM-WSQ 1-1 1-1 QSW-MA137WRE0 Secondary interlock switch/ Door sensing switch (Interchangeable) 2 AH 1-1 QSW-MA147WRE0 Secondary interlock switch/ Door sensing switch (Interchangeable) 2 --

FA1 hctiws rotinoM0ERW680AM-WSQ 2-1

HA1)elbaegnahcretnI( hctiws rotinoM0ERW831AM-WSQ2-1

1) --elbaegnahcretnI( hctiws rotinoM0ERW841AM-WSQ2-1 QA1 droc ylppus rewoPZERW801ADCCAF 3-1

1-4 FH-DZA128WRKZ High voltage recti? RA1 yssa re

WA1 roticapac egatlov hgiHZZRW933AZQ-CR 5-1 XA1 rotom naFZZRW334AETOMR 6-1 VA1)elbaegnahcretnI( rotom naF0ERW643AETOMR6-1

1) --elbaegnahcretnI( rotom naF0ERW653AETOMR6-1 FB1 nortengaMZZRW933AZM-VR 7-1

HB1)elbaegnahcretnI( nortengaMZZRW833AZM-VR7-1

1p ALmal nevOZZRW690ATPMLR8-1

NA1 rotom elbatnruTZZRW252ADTOMR 9-1

WA1)elbaegnahcretnI( rotom elbatnruT0ERW681ADTOMR9-1

TA1)elbaegnahcretnI( rotom elbatnruTZZRW462ADTOMR9-1

GA1 )nevO( Cº051 esuf erutarepmeT0ERW410AT-SFQ 01-1 FB1 remrofsnart egatlov hgiHZZRW847A-NRTR 11-1 FB1)elbaegnahcretnI( remrofsnart egatlov hgiHZZRW727A-NRTR11-1 FB1)elbaegnahcretnI( remrofsnart egatlov hgiHZZRW827A-NRTR11-1

WA1redloh esuFZKRW414AFBWPF21-1

FA1 A3.6T esuF0ERW700AB-SFQ 31-1

CABINET PARTS

EB1tenibac esac retuOZPRW859AUBACG 1-2

SA1 etalp mottoBZWRW773A-IADG 2-2

FA2 tooFZERW401APGELG 3-2

OVEN PARTS

LA1 kooh hctaLZFRW441A-KOHP 1-4

1 r AFedloh roticapaC2ZPRW861AKDNBL 2-4

GA1 edalb naFZFRW350AJNAFN 3-4

1 t AFcud naF2ZWRW809A-CUDP 4-4

GB1 ytivac nevOZTRW155A-NVOF 5-4

1 t AFroppus sissahC2ZPRW762AFGNAL 6-4

GA1 revel hctiwSZFRW142APVELM 7-4

GA1 revoc ediugevaWZERW914APVOCP 8-4

NA1 tcud riAZPRW909A-CUDP 9-4

EA1 gnikcap MTT0FRW480AGCAPP 01-4

BA1 noihsuC0PRW105AUSUCP 11-4

FA1 noihsuCZERW466AGSUCP 21-4

DA1 noihsuCZERW166AGSUCP 31-4

EA1 noihsuCZPRW516AGSUCP 41-4

BA1 noihsuC0PRW872AUSUCP61-4

MISCELLANEOUS

MA1 elbatnruT0FRW430A-TNTN 1-6

RA1 troppus elbatnruTZKRW101APLORF 2-6

GA1 lebal noituac SHHDZRRW072AAUACT 4-6

SCREWS, NUTS AND WASHERS

BA1 mm8 x mm4 : wercS00K80P047SPHX 1-7

AA1 mm8 x mm4 : wercS00001P047STEX 2-7

CA5 wercs laicepS00080P047SPHX 3-7

AA2 wercs laicepS0ERW2500ZC-XL 4-7

CA3 wercs laicepS0ERW370AZC-XL 6-7

AA4 mm8 x mm4 : wercS0VR80P047STHX 7-7

AA71 mm8 x mm4 : wercS00080P047STOX 8-7

2 w ACercs laicepS0ERW070AZC-XL11-7

* *

Page 37

R-231NW

[2] DOOR AND CONTROL PANEL PARTS

5-1

5-2

5-7

5-6

5-3

3-1-1

3-1

3-1-2

5-5

5-4

3-5

3-6

3-4

3-8

3-7

6-5

6-6

3-3

3-2

Page 38

R-231NW

NO. PARTS CODE DESCRIPTION Q’TY PRICE RANK

[2] DOOR AND CONTROL PANEL PARTS

CONTROL PANEL PARTS

3-1 FPNLCC029WRKZ Control panel frame with key unit 1 3-1-1 PSHEPB414WREZ Graphic sheet 1 3-1-2 QSW-KA053DRZZ Membrane switch 1 AQ

3-2 JBTN-B308WRFZ Open button 1 AG

3-3 MSPRCA050WRE0 Open button spring 1 AB

3-4 DPWB-A482DRKZ Control unit 1 BH

3-5 QCNC-A023WRZZ Rubber connector 1 AE

3-6 RLCDSA105DRZZ Liquid crystal display 1 AQ

3-7 XEPS730P08XS0 Screw ; 3mm x 8mm 2 AB

3-8 PCUSUA633WREZ Cushion 1 AE

DOOR PARTS

5-1 FDORFA397WRTZ Door panel assembly 1 BB

5-2 GWAKPB262WRRZ Door frame 1 AW

5-3 HPNL-A926WRRZ Door screen 1 AS

5-4 LSTPPA205WRFZ Latch head 1 AF

5-5 MSPRTA187WRE0 Spring 1 AC

5-6 PSHEPA782WREZ Sealer ﬁ lm 1 AG

5-7 GCOVHA424WRFZ Choke cover 1 AK

MISCELLANEOUS

6-5 TINSEB205WRRZ Instruction book 1

6-6 FW-VZC044WREZ Main wire harness 1 AQ

Page 39

R-231NW

KNAR ECIRPYT’Q NOITPIRCSED EDOC STRAP .ON

[2] DOOR AND CONTROL PANEL PARTS

CONTROL PANEL PARTS

1t AXinu yek htiw emarf lenap lortnoCZKRW920CCLNPF1-3 1t ANeehs cihparGZERW414BPEHSP 1-1-3

QA1 hctiws enarbmeMZZRD350AK-WSQ 2-1-3 GA1nottub nepOZFRW803B-NTBJ 2-3 BA1 gnirps nottub nepO0ERW050ACRPSM 3-3 HB1 tinu lortnoCZKRD284A-BWPD 4-3 EA1 rotcennoc rebbuRZZRW320A-CNCQ 5-3 QA1 yalpsid latsyrc diuqiLZZRD501ASDCLR 6-3 BA2 mm8 x mm3 ; wercS0SX80P037SPEX 7-3 EA1 noihsuCZERW336AUSUCP 8-3

DOOR PARTS

BB1 ylbmessa lenap rooDZTRW793AFRODF 1-5

WA1emarf rooDZRRW262BPKAWG 2-5 SA1neercs rooDZRRW629A-LNPH 3-5 FA1 daeh hctaLZFRW502APPTSL 4-5 CA1gnirpS0ERW781ATRPSM 5-5

5-6 PSHEPA782WREZ Sealer ? GA1 ml

KA1 revoc ekohCZFRW424AHVOCG 7-5

MISCELLANEOUS

1 koob noitcurtsnIZRRW502BESNIT 5-6

QA1 ssenrah eriw niaMZERW440CZV-WF 6-6

Page 40

R-231NW

KNAR ECIRPYT’Q NOITPIRCSED EDOC STRAP .ON

[2] DOOR AND CONTROL PANEL PARTS

CONTROL PANEL PARTS

1t AXinu yek htiw emarf lenap lortnoCZKRW920CCLNPF1-3 1t ANeehs cihparGZERW414BPEHSP 1-1-3

DOOR PARTS

BB1 ylbmessa lenap rooDZTRW793AFRODF 1-5

WA1emarf rooDZRRW262BPKAWG 2-5 SA1neercs rooDZRRW629A-LNPH 3-5 FA1 daeh hctaLZFRW502APPTSL 4-5 CA1gnirpS0ERW781ATRPSM 5-5

5-6 PSHEPA782WREZ Sealer ? GA1 ml

KA1 revoc ekohCZFRW424AHVOCG 7-5

MISCELLANEOUS

1 k ALoob noitcurtsnIZRRW502BESNIT 5-6

QA1 ssenrah eriw niaMZERW440CZV-WF 6-6

Page 41

R-231NW

INDEX

■

PARTS CODE No.

[ D ]

DPWBFC479WRUZ 2-3-4

[ F ]

FACCDA107WREZ 1-1-3 AU FACCDA108WREZ 1-1-3 -FDORFA397WRTZ 2-5-1 BB FFS-BA026WRKZ 1-1-2 AN FH-DZA114WRKZ 1-1-4 AR FPNLCB845WRKZ 2-3-1 AZ FPNLCB846WRKZ 2-3-1 AZ FPWBFA385WRKZ 1-1-12 AV FROLPA101WRKZ 1-6-2 AR FW-VZC044WREZ 2-6-6 AQ

[ G ]

GCABUA958WRPZ 1-2-1 BE GCABUA960WRPZ 1-2-1 BE GCOVHA424WRFZ 2-5-7 AK GDAI-A377WRWZ 1-2-2 AS GLEGPA104WREZ 1-2-3 AF GWAKPA978WRRZ 2-5-2 AW GWAKPA980WRRZ 2-5-2 AW

[ H ]

HPNL-A833WRRZ 2-5-3 AS HPNL-A835WRRZ 2-5-3 AS

[ J ]

JBTN-B308WRFZ 2-3-2 AG JBTN-B309WRFZ 2-3-2 AG

[ L ]

LANGFA267WRPZ 1-4-6 AH LBNDKA168WRPZ 1-4-2 AD LSTPPA205WRFZ 2-5-4 AF LX-CZ0052WRE0 1-7-4 AA LX-CZA070WRE0 1-7-3 AC LX-CZA073WRE0 1-7-6 AC LX-EZA042WRE0 1-7-5 AB

[ M ]

MLEVPA241WRFZ 1-4-7 AG MSPRCA050WRE0 2-3-3 AB MSPRTA187WRE0 2-5-5 AC

[ N ]

NFANJA053WRFZ 1-4-3 AG NTNT-A034WRF0 1-6-1 AM

[ P ]

PCOVPA419WREZ 1-4-8 AG PCUSGA615WREZ 1-4-14 AE PCUSGA661WREZ 1-4-13 AD PCUSGA662WREZ 1-4-12 AD PCUSUA501WRP0 1-4-11 AB PCUSUA633WREZ 2-3-8 AE PDUC-A908WRWZ 1-4-4 AR PDUC-A909WRPZ 1-4-9 AN PHOK-A144WRFZ 1-4-1 AL PPACGA176WREZ 1-4-10 AC PSHEPA782WREZ 2-5-6 AG PSHEPB087WREZ 2-3-1-1 AT PSHEPB089WREZ 2-3-1-1 AT

PRICE

RANK

NEW

MARK

PART

RANK

PARTS CODE No.

[ Q ]

QCNC-A014WRZZ 2-3-5 AE QFS-TA014WRE0 1-1-10 AG QSW-KA053DRZZ 2-3-1-2 AQ QSW-MA085WRE0 1-1-1 QSW-MA137WRE0 1-1-1 AH QSW-MA147WRZZ 1-1-1 AG

[ R ]

RC-PZA041WRE0 1-1-5 AS RC-QZA307WRZZ 1-1-5 AX RC-QZA327WRZZ 1-1-5 AT RC-QZA328WRZZ 1-1-5 AS RLCDSA105DRZZ 2-3-6 AQ RLMPTA082WRZZ 1-1-8 AL RLMPTA085WRZZ 1-1-8 AL RLMPTA087WRZZ 1-1-8 AL RMOTDA186WRE0 1-1-9 AW RMOTDA252WRZZ 1-1-9 AN RMOTDA264WRZZ 1-1-9 AT RMOTEA346WRE0 1-1-6 AV RMOTEA356WRE0 1-1-6 -RMOTEA433WRZZ 1-1-6 AX RTHM-A075WRE0 1-1-10 AN RTHM-A119WRE0 1-1-10 AK RTRN-A727WRZZ 1-1-11 BF RTRN-A728WRZZ 1-1-11 BF RV-MZA338WRZZ 1-1-7 BH RV-MZA339WRZZ 1-1-7 --

[ T ]

TCAUAA268WRRZ 1-6-4 AF TCAUAA291WRRZ 1-6-3 AE TINSEB076WRRZ 2-6-5 AM

[ X ]

XEPSD30P08XS0 2-3-7 AA XHPSD40P08000 1-7-7 AA XHPSD40P08K00 1-7-1 AC XHTSD40P08RV0 1-7-2 AA XOTSD40P08000 1-7-8 AA XOTSE40P08000 1-7-9 AA XOTSF40P08000 1-7-9 AA

PRICE

RANK

NEW

MARK

PART

RANK

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