SHARP R410BK, R-410BW Service Manual

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Page 1

R-41 OBK

SERVICE MANUAL

S48Mil OR41 OBE

MICROWAVE OVEN MODELS

R-410BK / R-410BW

In the interest of user-safety the oven is to be restored to its original condition and only the parts identical to those specified should be used.

WARNING TO SERVICE PERSONNEL: Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with the following parts may result in a severe, possibly fatal electrical shock.(High Voltage Capacitor,

High Voltage Power Transformer, Magnetron,

High Voltage Rectifier Assembly, High Voltage

Harness etc..)

R-41 OBK R-41 OBW

SECTION

PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICE TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY. Before Servicing Warning to Service Personnel ForewordandWarning Specifications

Generallnformation .........................................................................

KeyUnitLayout Operation Servicing and Troubleshooting Guide TestProcedures Touch Control Outline Component Replacement and Adjustment Procedure Microwave Measurement Procedure Wiring/Schematic Diagram

Parts .....................................................................................

Packing and Accessories

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SHARP ELECTRONICS CORPORATION

PAGE

........... Inside Front Cover

Inside Front Cover

1 2 3 4 5 6 8

IO 18 22 28 29 34 38

Service Headquarters: Sharp Plaza, Mahwah, New Jersey, 07430-2135

Page 2

R-41 OBK R-41 OBW

Do not operate or allow the oven to be operated with the door open. 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.

Before turning on microwave power for any service test or inspection within the microwave gen-

( )

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

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

(d)

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

A microwave leakage check to verify compliance with the Federal Performance Standard

( )

should be performed on each oven prior to releasing oven to the owner.

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 @ I-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 DHHS immediately.

(RD21101U)

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

(RD81001 U)

Page 3

SERVICE MANUAL

SHARR

R-41 OBK R-41 OBW

Microwave Ovens R-41 OBK/R-41 OBW

Foreword

This manual has been prepared to provide Sharp

Electronics Corporation personnel with complete operation and service information for Sharp microwave oven models R-41 OBWR-41 OBW.

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

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

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 are no other visible signs of damage to the

oven.

DANGER

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

Fan motor.

All of the parts marked ages more than 250V.

Removal of the outer case cabinet gives access to volt-

age above 25OV. All of the parts marked “A” on parts list may cause undue

microwave exposure, by themselves, or when they are

damaged, loosened or removed.

“*” on parts list are used at volt-

Specifications

General Information

Key Unit Layout

Troubleshooting / Test Procedures

and Adjustment

Microwave Measurement

Wiring / Schematic Diagram

Sharp Electronics Corporation

Sharp Plaza

Mahwah, New Jersey 07430-2135

Page 4

R-41 OBK R-41 OBW

WARNING TO SERVICE PERSONNEL

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

(EXAMPLE) High Voltage Capacitor, High Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc.. Read the Service Manual carefully and follow all instructions.

Before Servicing

Don’t Touch ! Danger High Voltage

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

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

WARNING:RISK OF ELECTRICAL SHOCK. DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE SERVICING.

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

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

Disconnect the power supply cord and then remove

outer case cabinet.

Open the door and block it open. Discharge the high voltage capacitor.

Disconnect the leads to the primary of the power

transformer.

Ensure that the leads remain isolated from other

5. components and oven chassis by using insulation tape. After the above procedure, reconnect the power sup-

6. ply cord.

When the testing is completed

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

2. Open the door and block it open. Discharge the high voltage capacitor.

Reconnect the leads to the primary of the power transformer. Re-install the outer case cabinet.

Reconnect the power supply cord after the outer

6. case cabinet is installed.

Start the oven and check all functions.

After repairing

1. Reconnect all leads removed from components dur-

ing testing.

Re-install the outer case (cabinet).

Reconnect the power supply cord after the outer

case is installed.

Reconnect the power supply cord after the outer

case is installed.

Run the oven and check all functions.

Microwave ovens should not be operated empty. To test

for the presence of microwave energy within a cavity,

place a cup of cold water on the oven turntable, close the door and set the power to HIGH and set the microwave

timer for two (2) minutes. When the two minutes has

elapsed (timer at zero), carefully check to see if the wa-

ter is hot. If the water remains cold, carry out Before

Servicing procedure and re-examine the connection 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 the microwave leakage test should be carried out.

Page 5

R-41 OBK R-41 OBW

Item

Power Requirements

Power Output

Case Dimensions

Cooking Cavity

1.3 Cu.Ft.

Control Complement

Description

120 Volts 14 Amperes 1650 Watts 60 Hertz Single phase, 3 wire grounded

1100 watts (IEC-705 Test Procedure) Operating frequency of 2450 MHz

Width 2111&” Height 123/i’ (including feet) Depth 1731~”

Width 15” Height 817/& Depth 163/t,’ Tray Size 141/i’ Diameter

Touch Control System Clock (I:00 - 12:59) Timer (0 - 99 min. 99 sec.) Microwave Power for variable cooking

Repetition Rate;

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

P-HI

P-90 . . . . . . . . . . . . . . . . .

P-80 . . . . . . . . . . . . . . . . . approx. 80% of full power

P-70 (MED HIGH) . . . . approx. 70% of full power

P-60 . . . . . . . . . . . . . . . . .

P-50 (MED) . . . . a.. . . . approx. 50% of full power

P-40 . . . . . . . . . . . . . . . . * approx. 40% of full power

P-30 (MED LOW) . . . . .

P-20 . . . . . . . . . . . . . . . . .

P-IO . . . . . . . . . . . . . . . . . approx. 10% of full power

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

approx. 90% of full power

approx. 60% of full power

approx. 30% of full power approx. 20% of full power

Oven Cavity Light Safety Standard

FEATURES

Instant Action Compu Defrost(3) Minute Plus Timer/Clock Popcorn Variable Power (10) 4 Stage Cooking

Yes

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

Page 6

R-41 OBK R-41 OBW

GENERAL INFORMATION

Grounding Instructions

This oven must be fully grounded at all times. This appliance must be connected to a 120 volt, 60 Hz, AC only, 15 Ampere or more 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.

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

Where a two-pronged wall-receptacle is encountered, it

is the personal responsibility and obligation of the cus-

tomer to contact a qualified electrician and have it re-

placed with a properly polarized and grounded threepronged wall receptacle or use a grounding adaptor. If

an extension cord must be used, it should be a 3=wire,

15 ampere minimum cord.

Grounded Grounded Receptacle Box

3 Pronged Plug

3 Pronged Receptacle

Receptacle Box

Grounding Screw

Do not under any circumstances cut or remove the round grounding prong from this plug.

Oven Diagram

1. Digital display

2. Auto-Touch control panel

3. Door open button

4. Door latches

5. Removable turntable support

6. Removable turntable

7. Oven lamp

8. Oven door with see through window

9. Waveguide cover

10. Power Cord

Page 7

Key Unit Layout

a. Indicators. b. Lighted digital display. c. SNACKS/COOKING/REHEATING pad.

Touch to cook or reheat popluar items using a pre-set time constant.

d. COMPU DEFROST pad.

Touch to defrost certain foods. e. Number selection pads. f. TIMER/CLOCK pad.

Touch to set clock and minute timer function. g. START/MINUTE PLUS pad.

Touch to start oven or Touch to cook for 1 minute at 100% power or to increase cooking time.

h. STOP/CLEAR pad.

Touch to erase during programming. Touch once to stop operation of oven during cooking. Touch twice to cancel cooking program.

i. POWER LEVEL pad.

Touch to select microwave power setting.

R-41 OBK R-41 OBW

INSTANT ACTION

To adjust quantity-touch pad again

I I

I I I I I

1 Ground meat 2 Steaks/chops

3 Chicken pieces

1 I

I f I I

1 2

5 6

POWER

LEVEL

CLEAR

STOP

MINUTE PLUS /

TIMER CLOCK

START

Page 8

R-41 OBK R-41 OBW

OPERATION

Description of Operating Sequence

The following is a description of component functions

during oven operation:

interlock relay and is mechanically associated with

the door so that it functions as follows:

Off Condition

Closing the door activates the door sensing switch and secondary interlock switch. In this condition, the monitor switch contacts are opened. When the oven is

plugged in, 120 volts AC is supplied to the control unit

(see schematic diagram). The display flashes 88:88. To

set any program or set the clock, first touch the STOP/

CLEAR pad. The display clears and “ : ” appears and the

control unit counts every minute.

Cooking Condition

Program desired cooking time and Variable Cooking

Control by touching the NUMBER pads and the Power

Level pad of the Variable Cooking Control. When

START is touched, the following operations occur:

The relay contacts are closed and components connected to the relays (RY-1 and RY-2) are turned on. (For details, see table below.)

Relay

RY-1 Oven Lamp/Turntable Motor/Fan Motor RY-2 Power Transformer

120 volts AC is supplied to the primary winding of the power transformer and is converted to approximately 3.4 volts AC on the filament winding and approximately 2400 volts AC on the high voltage winding.

The filament winding voltage heats the magnetron

3. filament and the high voltage is sent to a voltage doubler circuit.

The microwave energy produced by the magnetron is channeled through the waveguide into the cavity feed-box and into the cavity where the food is cooked.

Upon completion of the cooking cycle, the power

5. transformer, oven lamp and cooling fan are turned off and the generation of microwave energy is terminated.

When the door is opened during a cook cycle, the

6. monitor switch, door sensing switch, secondary interlock switch and primary interlock relay are activated with the following results. The turntable motor, cooling fan motor and the high voltage components are de-energized. The oven lamp remains on and the digital readout displays the time still remaining in the cook cycle when the door was opened.

The monitor switch is electrically monitoring the op-

7. eration of the secondary interlock switch and primary

Components

When the door opens from a closed position, the

( )

secondary interlock switch and primary interlock relay open their contacts, then the monitor switch contacts close.

When the door is closed from the open position,

(b)

the monitor switch contacts first open and the contacts of the secondary interlock switch close.

If the secondary interlock switch and the primary interlock relay contacts are closed when the door is opened, the monitor switch contacts form a short circuit through the monitor fuse, secondary interlock switch and primary interlock relay causing the monitor fuse to blow.

Power Level P-O to P-90 Cooking

When Variable Cooking Power is programmed, 120 volts AC 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

P - HI (HIGH) (100% power)

P - 90

(approx. 90% power) 30 sec. 2 sec.

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

P - 70 (MED, HIGH)

(approx. 70% power) 24 sec. 8 sec.

P - 60

(approx. 60% power)

P - 50 (MED) (approx. 50% power)

P - 40 (approx. 40% power)

P - 30 (MED, LOW) (approx. 30 % power)

P - 20 (approx. 20% power)

P- 10 (approx. 10% power)

P-O (0% power)

On Time

32 sec. 0 sec.

22 sec.

18 sec.

16 sec. 16 sec.

12 sec. 20 sec.

8 sec.

6 sec.

0 sec. 32 sec.

The ON/OFF time ratio does not correspond with the percentage of microwave power, because approximate-

ly 2 seconds are needed for heating the magnetron filament.

Off Time

IO sec.

14 sec.

24 sec.

26 sec.

Page 9

DESCRIPTION AND FUNCTION OF COMPONENTS

R-41 OBK R-41 OBW

Cooling Fan Motor

The cooling fan motor drives a blade which draws exter-

nal cool air. This cool air is directed through the air vanes surrounding the magnetron to cool the magnetron. This air is channeled through the oven cavity to re-

move steam and vapors given off from the heating foods. It is then exhausted through exhaust vents in the

oven cavity.

Oven Temperature Fuse

The oven temperature fuse located on the top of the

oven cavity is designed to prevent damage to the unit if the foods in the oven catch fire due to over heating pro-

duced by improper setting of cook time or failure of control unit.

Under normal operation, the oven temperature fuse re-

mains closed. However, when abnormally high temper-

atures are reached within the oven cavity, the fuse will

open at 144”C, causing the oven to shut down.

Note: This is a fuse and it does not reset.

Magnetron Temperature Fuse

The magnetron temperature fuse located on top of the

magnetron duct is designed to prevent damage to the

magnetron if an over heated condition develops in the tube due to cooling fan failure, obstructed air ducts, dirty

or blocked air intake, etc.

Under normal operation, the magnetron temperature fuse remains closed. However, when abnormally high temperatures are reached within the magnetron the fuse will open at 144OC, causing the oven to shut down.

Note: This is a fuse and it does not reset.

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 and secondary interlock switch fail to open when the door is opened.

Monitor Switch Functions

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

When the door is closed, the monitor switch contacts are first opened and then the door sensing switch and the secondary interlock switch contacts close.

Note: When opening the door, each of these

switches operate inversely.

If the door is opened and the primary interlock relay and secondary interlock switch contacts fail to open, the monitor fuse blows simultaneously with closing of the monitor switch contacts.

Before replacing a blown monitor fuse, test the primary interlock relay, door sensing switch, monitor switch and secondary interlock switch for proper operation. (Refer to section “Test Procedures”.)

Door Open Mechanism

The door is opened by pushing the open button on the control panel. When the open button is pushed, the open button

pushes up the switch lever, and then the switch lever

pushes up the latch heads. The latch heads are moved upward and released from the latch hook. Now the door will open.

Door Sensing / 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 circuit to all components, except the oven lamp. A cook cycle cannot take place until the door is firmly closed thereby activating both interlock switches. The primary interlock system consists of the door sensing switch and the primary interlock relay located on the control panel circuit board.

Latch Heads

Monitor Switch

Secondary Interlock Switch

NOTE: MONITOR FUSE AND MONITOR SWITCH

ARE REPLACED AS AN ASSEMBLY.

Page 10

R-41 OBK

R-41 OBW

SERVICING

When troubleshooting the microwave oven, it is helpful to follow the sequence of operation in performing the checks.

Many of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which will be found in the “Test Procedure” section.

ondary interlock switch

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

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

2. Open the door and block it open.

3. Discharge the 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 insulated tape.

6. After the above procedure install the outer case cabinet and reconnect the power supply cord.

and monitor switch for proper operation.

(Refer to “Test Procedure”

sec-

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 the high voltage capacitor.

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

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.

Troubleshooting Guide

Off Condition

Problem

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

Monitor fuse blows when power is applied.

Display does not illuminate when Shorted or open wiring

power cord is plugged in.

Display does not operate properly Primary interlock relay or door sens- Procedure E when STOP/CLEAR button is ing switch touched.

Oven lamp does not light with door Shorted or open wiring opened.

Shorted power cord or wire harness

Shorted power cord or wire harness Secondary interlock or monitor

switch

Monitor switch or monitor fuse Oven temperature fuse Control unit

Control unit

Key unit unit

Monitor fuse Oven temperature fuse Oven lamp or socket Control unit

Relay (RYI)

Possible Cause

Check or replace

Procedure E

Check or replace Procedure E Procedure F Procedure G

Procedure G Procedure K Check or replace Procedure E Procedure F Check or replace Procedure G Procedure H

Test Procedure

Page 11

Troubleshooting Guide

R-41 OBK R-41 OBW

Cook Condition

Problem

Oven lamp does not light at all. Shorted or open wiring

Oven lamp or socket Control unit

Oven lamp lights, but fan motor and Shorted or open wiring Check or replace turntable motor do not operate.

Oven does not go into cook cycle when START button is touched.

Oven seems to be operating but 1 Shorted or open wiring 1 Check or replace

little or no heat is produced in oven

load. (incompletely cooked or not cooked at all at the end of cook cycle.) 1 Rectifier assembly ( Procedure C

Oven goes into a cook cycle but ex- 1 Shorted or open wiring tremely uneven heating k produced -Turntable motor -

in oven load (food).

Oven does not cook properly when Shorted or open wiring Check or replace

programmed for Cooking Power

P-50 (MED.) mode. (Operates

properly on Cooking Power P-HI

(HIGH) mode.)

Oven goes into COMPU DEFROST Magnetron Procedure A

but food is not defrosted well

Cooling fan motor Check or replace Turntable motor Check or replace Shorted or open wiring

Primary interlock system

1 Monitor fuse 1 Procedure E

Magnetron or oven temperature

fuse

Relay (RYI)

Magnetron Power transformer Procedure B

H.V. capacitor Primary interlock system

Low voltage 1 Dirty oven cavity 1 Check 1 Wrong operation I Check

Control unit

Wrong operation Check

I Low voltage I Check

Dirty oven check

Compu Defrost

Possible Cause

Check or replace Check or replace Procedure G

Check or replace

Procedure E

Procedure F

Procedure H

Procedure A

Procedure D Procedure E

1 Check or replace

Check or replace Check

Procedure G

Check

Procedure J

Test Procedure

Page 12

R-41 OBK R-41 OBW

Procedure Letter

A .

Magnetron Assembly Test

1. Disconnect the power supply cord, and then remove outercase cabinet.

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

4. To test for an open filament, isolate the magnetron from the high voltage circuit. A continuity check

5. To test for a shorted magnetron, connect the ohmmeter leads between the magnetron filament

6. Reconnect all leads removed from components during testing.

7. Re-install the outercase cabinet.

8. Reconnect the power supply cord after installing the outer case cabinet.

9. Run the oven and check all functions. MICROWAVE OUTPUT POWER

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

HIGH VOLTAGES ARE PRESENT DURING THE COOK CYCLE, SO EXTREME CAUTION SHOULD BE OBSERVED Power output of the magnetron can be measured by performing a water temperature rise test. This test should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following components or wiring: high voltage rectifier, high voltage capacitor and power transformer. This test will require a 16 oz. (453~~) measuring cup and an accurate mercury thermometer or thermocouple type temperature tester. For accurate results, the following procedure must be followed:

Component Test

across the magnetron filament leads should indicate less than IQ.

leads and chassis ground. This test should indicate an infinite resistance. If there is little or no resistance, the magnetron is grounded (shorted) and must be replaced.

Fill the measuring cup with 16 oz. (453~~) of tap water and measure the temperature of the water with a thermometer or thermocouple temperature tester. Stir the thermometer or thermocouple through the water until the temperature stabilizes. Record the temperature of the water. Place the cup of water in the oven. Operate oven on HIGH selecting 62 seconds cook time. Allow the water to heat. 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. Subtract the cold water temperature from the hot water temperature. The normal result should be 38” to 78°F (21 O to 42.6OC) rise in temperature. If the water temperatures are accurately measured and are 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 cook time. Because cooking time can be adjusted to compensate for power output, the magnetron tube assembly should be replaced only if the water temperature rise test indicates a power output well beyond the normal limits. The test is only accurate if the power supply line voltage is 120 volts and the oven cavity is clean.

B . Power Transformer

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

2. Open the door and block it open.

3. Discharge the 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 Q and the resistance of the high voltage coil should be approximately 1 OOQ; the resistance of the filament coil should be less than IQ.

5. Reconnect all leads removed from components during testing.

6. Re-install the outercase cabinet.

7. Reconnect the power supply cord after installing the outer case cabinet.

8. Run the oven and check all functions.

Note: High voltages are present at the high voltage terminal, so do not attempt to measure the fila-

ment and high voltage.

Page 13

R-41 OBK R-41 OBW

Procedure Letter

. High Voltage Rectifier Test

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

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

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

5. Reconnect all leads removed from components during testing.

6. Re-install the outer case cabinet.

7. Reconnect the power supply cord after installing the outer case cabinet.

8. Run the oven and check all functions.

Note: Be sure to use an Ohm-Meter that will supply a forward bias voltage of more than 6.30 Volts.

High Voltage Capacitor Test

(Discharge the high voltage capacitor before touching any oven components or wiring.)

1. Disconnect the power supply cord, and then remove outercase.

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

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 terminal using an ohmmeter. Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate continuity initially and once the capacitor is charged an open circuit.

If the above is not the case, check the capacitor with an ohmmeter to see if it is shorted between

each terminal and case. If it is shorted, replace the capacitor.

5. Reconnect all leads removed from components during testing.

6. Re-install the outercase (cabinet).

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

8. Run the oven and check all functions.

Component Test

Secondary Interlock Switch Test

1. Disconnect the power supply cord, and then remove outercase.

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

4 Isolate the switch and connect the ohmmeter to the common (COM) and normally open (NO) termi-

nal 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. Re-install the outercase (cabinet).

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

8. Run the oven and check all functions.

Primary Interlock System Test

Door Sensing Switch

1. Disconnect the power supply cord, and then remove outercase.

2. Open the door and block it open.

3. Discharge the 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 door sensing switch.

5. Reconnect all leads removed from components during testing.

6. Re-install the outercase (cabinet).

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

8. Run the oven and check all functions.

Page 14

R-41 OBK R-41 OBW

TEST PROCEDURES

Procedure Letter Component Test

. Continued

Primary Interlock Relay CRY-21

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

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

4. Disconnect two (2) wire leads from the relay on the printed circuit board in the control panel assembly. The relay is located on the bottom portion of the circuit board on the backside of the control panel assembly. Connect an ohmmeter to the male terminals and observe the meter reading. The relay contacts should be open. or the circuit board.

5. Reconnect all leads removed from components during testing.

6. Re-install the outer case cabinet.

7. Reconnect the power supply cord after installing the outer case cabinet.

8. Run the oven and check all functions.

Monitor Switch Test

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

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

4 Disconnect the oven from the power supply.

Before performing this test, make sure that the secondary interlock switch and primary interlock relay are operating properly referring to the above Switch Test Procedure. Disconnect the wire lead from the monitor switch (NC) terminal. Check the monitor switch operation by using the ohmmeter as follows: When the door is open, the meter should indicate a closed circuit. With the door open, take a screw driver and push in the monitor switch actuator located through the lower latch hole on the faceplate of the cavity. The meter should indicate a open circuit.

If improper operation is indicated, the monitor switch may be defective and should be replaced. After testing the monitor switch, reconnect the wire lead to the monitor switch (NC) terminal and check continuity of the monitor circuit.

5. Reconnect all leads removed from components during testing.

6. Re-install the outer case cabinet.

7. Reconnect the power supply cord after installing the outer case cabinet.

8. Run the oven and check all functions.

If the relay contacts are closed, replace the primary interlock relay

WhiteWires Connected to Common Terminal

Monitor Switch

Page 15

R-41 OBK R-41 OBW

Procedure Letter

E. Continued

Open Monitor Fuse

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

2. Open the door and block it open.

3. Discharge the high voltage capacitor. 4 If the monitor fuse is open, perform the tests for the primary interlock system, secondary interlock

switch and the monitor switch according to the procedure outlined in this section. Adjust or replace the secondary interlock and door sensing switches.

5. Reconnect all leads removed from components during testing.

6. Re-install the outer case cabinet.

7. Reconnect the power supply cord after installing the outer case cabinet.

8. Run the oven and check all functions.

Temperature Fuses

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

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

4. A continuity check across either of the temperature fuse terminals should indicate a closed circuit unless the temperature of the magnetron temperature fuse reaches 144°C or the oven cavity fuse reaches 144°C. An open magnetron temperature fuse indicates overheating of the magnetron assembly while an open oven fuse indicates overheating of the oven cavity. If a temperature fuse indicates an open circuit, exchange that temperature fuse and check for a restricted air duct, stricted air flow to the magnetron and oven cavity through the vent holes of the oven cavity, especially the air duct and cooling fan assembly.

3. Reconnect all leads removed from components during testing.

6. Re-install the outercase cabinet.

7. Reconnect the power supply cord after installing the outer case cabinet.

8. Run the oven and check all functions.

Component Test

re-

. 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 can not be performed with only a voltmeter and ohmmeter. In this service manual, the touch control panel assembly is divided into two

control units, Control Unit and Key Unit. Troubleshooting by unit replacement is described according

to the symptoms indicated.

Before testing

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

2. Open the door and block it open.

3. Discharge the 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 insulated tape.

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

Page 16

R-41 OBK R-41 OBW

TEST PROCEDURES

Procedure Letter

Continued

Touch Control Panel Assembly Test

1. Key Unit

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

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

4. Check unit ribbon connection before replacement.

5. Reconnect all leads removed from components during testing.

6. Re-install the outercase (cabinet).

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

8. Run the oven and check all functions. The following symptoms indicate a defective key unit. Replace the key unit. a) When touching the pads, a certain pad produces no signal at all. b) When touching a number pad, two figures or more are displayed. c) When touching the pads, sometimes a pad produces no signal.

If the key unit is defective.

1. Disconnect the power supply cord, and then remove outercase cabinet.

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

4. Replace the key unit.

5. Reconnect all leads removed from components during testing.

6. Re-install the outercase 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.

2-l In connection with pads.

2-2 In connection with indicators.

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

When testing is completed,

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

4. Reconnect all leads removed from components during testing.

5. Re-install the outercase cabinet.

6. Reconnect the power supply cord after installing the outer case cabinet.

7. Run the oven and check all functions.

Component Test

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.

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

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

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

Page 17

Procedure Letter Component Test

H. Relay Test

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

2. Open the door and block it open.

3. Discharge the 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 insulated tape.

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

7. Check voltage between Pin No. 1 of the 2 pin connector (A) and the common terminal of the relay

RY2 on the control unit with A.C. voltmeter. The meter should indicate 120 volts. If not, check oven

circuit.

RY-1 and RY-2 Relay Test

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

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

DC. voltage not indicated . . . . . . . . . . . . . . . . . . . Check diode which is connected to the relay

R-41 OBK R-41 OBW

coil. If diode is good, control unit is defective.

1 Relay Symbol / Operational Voltage 1 Connected Components

RY 1 ( Approx. 13.0 V DC ( Oven lamp/Turntable motor/Cooling fan motor

RY2 ( Approx. 12.0 V DC Power transformer

8. Disconnect the power supply cord.

9. Open the door and block it open.

IO. Discharge the 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 installing the outer case cabinet.

14. Run the oven and check all functions.

1. Foil pattern on the printed wiring board Test

To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary

on the PWB, which acts as a fuse.

1 Foil Pattern check and repairs

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

2. Open the door and block it open.

3. Discharge the 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 Jl and solder.

2 Pattern at “a” and “b” are broken * Insert the coil RCILF~ 0 O~YAZZ between “c” and “d”.

Page 18

R-41 OBK R-41 OBW

TEST PROCEDURES

Procedure Letter

I . Continued

Procedures to be taken when the foil pattern of the printed wiring board (PWB) is open

. Make a visual inspection of the varistor burn

damage and test the transformer with an ohm-

meter for the presence of layer short-circuit

(check the primary coil resistance which is approximately 575 Q & 15%). If any abnormal condition is detected, replace the defective

pan(s)-

6. Reconnect all leads removed from components during testing.

7. Re-install the outercase (cabinet).

8. Reconnect the power supply cord after installing the outer case cabinet.

9. Run the oven and check all functions.

2. Follow the troubleshooting guide given below. repairs are finished.

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

2. Open the door and block it open.

3. Discharge the 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 insulated tape.

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

7. Follow the troubleshooting guide given below for repair.

Component Test

If indicator does not light up after above check and

Steps Occurrence

The rated AC voltage is not present between

Pin No.1 of the 2-pin connector (A) and the

common terminal of the relay RYI .

2 The rated AC voltage is present at primary

side of low voltage transformer.

Cause or Correction

Check supply voltage and oven power cord

Low voltage transformer or secondary circuit defective. Check and repair.

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

9. Open the door and block it open.

10. Discharge the 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 cabinet is installed.

14.Run the oven and check all functions.

Page 19

TEST PROCEDURES

Procedure Letter Component Test

R-41 OBK R-41 OBW

Compu Defrost Test

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

2. Close the door, touch the “COMPU DEFROST” pad twice and touch the number pad “5”. Then touch the “START” pad.

3. The oven is in “COMPU DEFROST” cooking mode.

4. The oven will operate as follows:

Weight 1st Stage 2nd Stage 3rd Stage

Level Time

0.5 70%

Level Time Level

45sec. 0% 50 sec. 50%

Time Level

30 sec. 30% 35 sec.

4th Stage

Time

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

Key Unit Test

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

2. Open the door and block it open.

3. Discharge the high voltage capacitor.

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

5. Reconnect all leads removed from components during testing.

6. Re-install the outer case cabinet.

7. Reconnect the power supply cord after installing the outer case cabinet

8. Run the oven and check all functions.

If the door sensing switch is good,

If the control unit does

G8 G7 G6 G5

0 G

START

MINUTE

PLUS

POWER

LEVEL

COMPU

DEFROST

CLOCK

FRESH

VEGETABLE

ROLL/MUFFIN

KEY UNIT

REHEAT

CASSEROL

ROLL/MUFFIN

G4 G3 G2

BEVERAGE

DINNER

Page 20

R-41 OBK R-41 OBW

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 Control Unit consists of Power Unit and LSI unit).

The principal functions of these units and their related

signals are explained below.

Key Unit

The key unit is composed of a matrix. Signals generated

in the LSI are sent to the key unit through P73, P81, P82, P83, P90 and P91. When a key pad is touched, a signal is completed

through the key unit and passed back to the LSI through

P60-P63 to perform the function that was requested.

Control Unit

The Control unit consists of the following:

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

2. ACL Circuit A circuit to generate a signal which resets the LSI to the initial state when power is applied.

Buzzer Circuit

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

Door Sensing Switch

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

Relay Circuit

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

Indicator Circuit

This circuit consists of 12 segmenets and 3 com-

mon electrodes using a liquid Crystal Display.

Back Light Circuit

A circuit to drive the back light (Light emmitting diodes LDI -LD5).

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.

1 Symbol /Voltage 1 Application

vc - 5v

LSI (ICI),

Page 21

DESCRIPTION OF LSI

LSI

The I/O signals of the LSI are detailed in the following table.

R-41 OBK R-41 OBW

Signal

SEG 0

SEG 11

R60

R61

R62

R63

AINO

‘UN1 -AIN

vss

R70

I/O Description

OUT Segment data signal.

OUT Magnetron high-voltage circuit driving signal.

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

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

SEG 0 . . . . . . . . . . . . . . . . . . . . S12 SEG 6 . . . . . . . . . . . . . . . . . . . . . S6

SEG 1 . . . . . . . . . . . . . . . . . . . . Sll SEG 7 . . . . . . . . . . . . . . . . . . . . . S5

SEG 2 . . . . . . . . . . . . . . . . . . . . SIO SEG 8 . . . . . . . . . . . . . . . . . . . . . S4

SEG 3 . . . . . . . . . . . . . . . . . . . . . S9 SEG 9 . . . . . . . . . . . . . . . . . . . . . S3

SEG 4 . . . . . . . . . . . . . . . . . . . . . S8

SEG 5 . . . . . . . . . . . . . . . . . . . . . S7

SEG IO . . . . . . . . . . . . . . . . . . . . . S2

SEGII . . . . . . . . . . . . . . . . . . . . . Sl

IN Signal coming from touch-key.

When either G-12 line on key matrix is touched, a corresponding signal out of R73. R81 -R83 and R90-R91 will be input into R60. When no key is touched, the signal is held at “H” level.

IN Signal similar to R60.

When either G-l 1 line on key matrix is touched, a corresponding signal will be inputted into R61.

Signal similar to R60.

When either G-l 0 line on key matrix is touched, a corresponding signal will be inputted into R62.

Signal similar to R60.

When either G-9 line on key matrix is touched, a corresponding signal will be inputted into R63.

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

Door close ‘I” level signal (OV) Door open “H” level (5V).

IN Terminal to change functions according to the Model.

By using the A/D converter contained in the LSI, DC voltage in accordance with the Model in

operation is applied to set up its cooking constant.

IN Power source voltage: + 5V

VSS voltage of power source circuit input.

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

PULSE OUT

___--___--____- -- ---

P-HI

PFbl

+TE ;’ 24 sec.

(ON and OFF times for other power level)

Signal to sound Buzzer (2.0 kHz).

0.1 sec.

H: GND

B: completion sound

Page 22

R-41 OBK R-41 OBW

Signal Description

R72

I/O

OUT

Oven lamp, fan motor and turntable motor driving signal.

To turn on and off shut off relay RYI. The square waveform voltage is delivered to the RY-1

driving circuit and RY-2 control circuit.

16.7 msec.

During Cooking

R73 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is inputted to R60-R63 terminal while one of G8 line keys on key matrix is touched.

INT2 Signal synchronized with commercial power source frequency.

This is the basic timing for time processing of LSI.

16.7 msec.

R81

OUT

Key strobe signal.

Signal applied to touch-key section. A pulse signal is inputted to R60-R63 terminal while one of G7 line keys on key matrix is touched.

R82 OUT

Key strobe signal.

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

R83 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is inputted to R60-R63 terminal while one

of G5 line keys on key matrix is touched.

R90 OUT

Key strobe signal.

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

R91 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is inputted to R60-R63 terminal while one

of G3 line keys on key matrix is touched. R92 OUT Terminal not used. XIN Internal clock oscillation frequency setting input.

The internal clock frequency is set by applying the ceramic filter oscillatior circuit with respect

to XOUT terminal.

OUT XOUT Internal clock oscillation frequency control output.

Output to control oscillation input of XIN.

RESET IN Auto-clear terminal.

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

“L” level the moment power is supplied, at this time the LSI is reset. Thereafter set at “H” level.

HOLD

VLC Signal synchronized with commercial power source frequency.

IN/OUT

Connected to GND.

Signal similar to VSS.

COMI

OUT Common data signal: COMI.

Connected to LCD (Pin No. Cl).

COM2

OUT

Common data signal: COM2.

Connected to LCD (Pin No. C2).

COM3

OUT Common data signal: COM3.

Connected to LCD (Pin No. C3).

COM4

VDD

OUT

Terminal not used.

Power source voltage input terminal

Connected to GND.

Page 23

SERVICING

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. fluenced by surrounding high voltage power sources, 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, practice the following

guidelines:

I. When storing and transporting LSI, thoroughly wrap

them in aluminum foil. Also wrap all PW boards in aluminum foil.

2. When soldering, the technician should use a grounding strap as shown in the figure and use a grounded soldering iron and work table.

Shapes of Electronic Components

Transistor 2SB1238

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 pan-

el is available either from the power line of the oven itself or from an external power source.

Servicing The Touch Control Panel With The Oven Power Supply

The high voltage transformer of the microwave oven

is still live during servicing and presents a hazard.

When checking the performance of the touch control panel, put the outer cabinet on the oven to avoid touch-

ing the high voltage transformer or unplug the primary terminal (connector) of the high voltage transformer to turn it off; the end of such connector must be insulated with an insulating tape. After servicing, be sure to reconnect the leads to their original locations.

1. On some models, the power supply co touch control panel and the oven itself

For this reason, it is easily in-

e 0

e=?

Approx. 1 MQ

Transistor

DTD143ES

rd between the

is so short that

R-41 OBK R-41 OBW

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.

2. On some models, the power supply cord between the touch control panel and the oven proper is long enough that they may be separated from each other.

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

Servicing The Touch Control Panel With An External Power Supply

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

Servicing Tools

Tools required to service the touch control panel assem-

bly.

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

2. Oscilloscope: Single beam, DC-IOMHz type or more advanced model.

3. Hand tools.

frequency range:

Other Precautions

1. Before turning on the power source of the control unit, remove the aluminum 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 aluminum 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.

Be sure to use specified components where high pre-

cision is required.

Page 24

R-41 OBK R-41 OBW

COMPONENT REPLACEMENT/ADJUSTMENT PROCEDURE

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

Example High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness

etc..

ergy. Please follow the

instructions below before operating the oven.

1. Disconnect the power supply cord.

2. Visually check the door and cavity face plate for damage (dents, cracks, signs of arcing etc.).

Carry out any remedial work that is necessary before

operating the oven.

Do not operate the oven if any of the following condi-

tions exist;

1. Door does not close firmly.

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

3. The door gasket or seal is damaged.

4. The door is bent or warped.

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

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

7. There is visible damage to the oven. Do not operate the oven:

1. Without the RF gasket (Magnetron).

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

3. If the door is not closed.

4. If the outer case cabinet is not fitted.

To prevent electric shock, take the following precautions.

1. Before wiring.

1) Disconnect the power supply cord.

2) Open the door and block it open.

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

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

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

2) Hot parts: Oven lamp, Magnetron, High voltage Transform-

er and oven cavity.

3) Sharp edge: Bottom plate, oven cavity, waveguide, flange,

chassis support and other metallic plate.

4) Movable parts (to prevent a fault) Fan blade, Fan motor, Switch , Switch lever, and 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 Wiring Diagram.

Page 25

COMPONENT REPLACEMENT / ADJUSTMENT PROCEDURE

Please refer to “OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS” When carrying out any of the following removal procedures:

Outer Case Removal

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

1. Disconnect power supply cord before removing outer case cabinet.

2. Discharge the high voltage capacitor before touching any oven components or wiring.

To remove the outer case, proceed as follows.

1. Disconnect the power supply cord.

Open the oven door and block it open.

3. Remove the two screws (2) from the upper and lower

Power Transformer Removal

4. Remove the two screws (2) from the rear of outer case.

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

6. Lift entire case from the unit.

When replacing the outer case, the 2 special Torx screws must be reinstalled in the same locations.

R-41 OBK R-41 OBW

Disconnect the power supply cord and remove outer

case cabinet.

Open the oven door and block it open.

Discharge high voltage capacitor.

Disconnect wire leads of the main wire harness and H.V. wire from power transformer. Disconnect the lead from magnetron filament.

5. Disconnect the leads of the power transformer from

6. high voltage capacitor.

Remove the four (4) screws holding the transformer

to base plate.

Remove the transformer.

High Voltage Rectifier and High Voltage

Capacitor Removal

When replacing the high voltage rectifier and high volt-

age capacitor, the ground side terminal of the high

voltage rectifier must be secured firmly with a ground-

ing screw.

Disconnect the power supply cord and remove outer

1. case cabinet.

Open the oven door and block it open.

2. Discharge high voltage capacitor.

3. Remove one (1) screw holding the capacitor band

4. and the high voltage rectifier assembly to the base

9. Now the power transformer is free. Re-install

Rest transformer on baseplate with its primary terminals toward oven face plate.

Secure transformer with four (4) screws to baseplate.

Re-connect the wire leads (primary and high volt-

age) to transformer and filament leads of transformer to magnetron and high voltage capacitor. Refer to “Wiring Diagram”.

Re-install outercase cabinet and check that oven is

operating properly.

plate.

5. Disconnect the wire lead of high voltage rectifier as-

6. Disconnect terminals of rectifier assembly from ca-

. . _ _.

sembly trom the magnetron.

pacitor and magnetron. High voltage rectifier assem-

bly is now free.

Do not replace only high voltage rectifier. When replacing it, replace the entire high voltage rectifier assem bly.

(RDA1504U)

Magnetron Removal

Disconnect the power supply cord and remove outer

1. case cabinet.

Open the oven door and block it open. Discharge high voltage capacitor.

Disconnect wire leads from the magnetron.

Remove the one (1) screw holding chassis support

5. to magnetron and magnetron duct. Slide the magnetron duct slightly so that two (2) screws at left hand

side of the magnetron appear. Carefully remove the four (4) screws holding magne-

tron to waveguide flange.

Remove the magnetron with care so that the magnetron antenna is not hit by any metal objects around the tube.

Now, the magnetron is free.

Page 26

R-41 OBK R-41 OBW

Magnetron Installation

Install magnetron assembly to the waveguide flange

ating properly.

with care to prevent damage to the magnetron tube.

Secure the magnetron with four (4) screws. Hold the chassis support to the magnetron and mag-

3. netron duct with one (1) screw. Connect wire leads to the magnetron .

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

When replacing the magnetron, be sure that the R.F. gasket is in place and that the mounting screws are tightened securely.

Control Panel Assembly Removal

Disconnect the power supply cord and remove outer case cabinet.

Open the oven door and block it open.

Discharge high voltage capacitor.

Disconnect wire leads from panel components.

Remove the one (1) screw holding the control panel.

Re-adjust the clip holding panel assembly to oven flange.

7. Remove control panel assembly by sliding it upward. Now, individual components can be removed.

NOTE:

Before attaching a new key unit, remove remaining adhesive on the control panel frame surface completely with alcohol. When attaching the key unit to the control panel frame, adjust the upper edge and right edge of the key unit to the correct position of the control panel. Stick the key unit firmly to the control panel frame by

rubbing with soft cloth.

Oven Lamp and Lamp Socket Removal

Disconnect the power supply cord and remove outer case cabinet.

Open the oven door and block it open.

Discharge high voltage capacitor.

Pull the wire leads from the oven lamp socket with the flat type small screw driver.

Remove the oven lamp socket from the magnetron duct by turning the socket counterclockwise. Pushing the small tab of magnetron locating the left hand

side of lamp socket.

6. Pull the wire leads from the oven lamp socket by pushing the terminal hole of the oven lamp socket

with the small flat type screw driver.

7. Remove the oven lamp from the oven lamp socket by

turning the oven lamp.

8. Now, the oven lamp and lamp socket are free.

Note: (orange) wires must be connected to the terminal with

blue mark on the lamp socket.

Turntable Motor Removal

motor cover by snipping off the material in four corners.

Do not drop the turntable motor cover into the oven after cut-

ting the bridges. Because it will damage the wire leads of the

motor and it is difficult to remove it out of the oven.

1. Disconnect the power supply cord.

2. Remove turntable and turntable support from oven cavity.

3. Lay the oven on its backside. Remove the turntable 7. Now turntable motor is free.

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

Disconnect wire leads from turntable motor.

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

(RDA1305U)

TURNTABLE

Turntable motor cover removal

CUll-ING PLIER

BASE PLATE

TURNTABLE

MOTOR

COVER

SCREW Supplied with

replacement motor

/’

I I

Turntable motor cover re-insta

DOOR

Page 27

COMPONENT REPLACEMENT / ADJUSTMENT PROCEDURE

Turntable Motor Re-install

R-41 OBK R-41 OBW

Remove any sharp edges on the turntable motor

cover and the base plate with cutting pliers.

Insert the edge of motor cover into tab on the base plate.

Cooling Fan Motor Removal

Disconnect the power supply cord and remove outer

1. case cabinet. Open the oven door and block it open.

2. Discharge the high voltage capacitor.

3. Disconnect the wire leads from the fan motor.

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

5. back plate of the oven cavity.

Remove the fan blade from the fan motor shaft ac-

6. cording to the following procedure.

a) Hold the edge of the rotor of the fan motor by using

a pair of groove joint pliers.

Make sure that no pieces metal enter the gap between

the rotor and the stator of the fan motor because the

rotor is easily shaven by pliers and metal pieces may

i be produced. Do not touch the pliers to the coil of the

fan motor because the coil may be cut or injured. Do

not disfigure the bracket by touching with the pliers.

b) Remove the fan blade from the shaft of the fan mo-

tor by pulling and rotating the fan blade with your

hand.

c) Now, the fan blade will be free.

3. Secure motor cover with one (1) screw to base plate.

INSTALLATION

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

a. Hold the center of the bracket which supports the

shaft of the fan motor on the flat table.

b. Apply the screw lock tight into the hole (for shaft) of

the fan blade.

c Install the fan blade to the shaft of the fan motor by

pushing the fan blade with a small, light weight, ball peen hammer or rubber mallet.

Do not hit the fan blade hard when installing because

the bracket may be disfigured.

Make sure that the fan blade rotates smooth after installation. Make sure that the axis of the shaft is not slanted.

2. Install the fan motor to the back plate of the oven cav-

ity with two (2) screws.

3. Connect the wire leads to the fan motor, referring to the wiring diagram.

Do not use this removed fan blade again because the hole (for shaft) may become bigger than a standard one.

Coil

lide

View

0 0

These are the positions which should be pinched with pliers

Page 28

R-41 OBK R-41 OBW

COMPONENT REPLACEMENT/ADJUSTMENT PROCEDURE

Door Sensing Switch /Secondary Interlock Switch and Monitor Switch Adjustments

Disconnect the power supply cord and remove outer case cabinet.

Open the oven door and block it open.

Discharge the 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.

Loosen the two (2) screws holding the latch hook to the oven cavity front flange.

With the door closed, adjust the 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 heads should be less than

0.5mm. The vertical position of the latch hook should be placed where the door sensing switch and the secondary interlock switch have activated with the door closed. Secure the screws with washers firmly.

Make sure of the door sensing switch operation. If the door sensing switch has not activated with the door closed, loosen the screw and adjust the latch hook position.

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

Note: After adjustments, make sure of the following:

1. In and out play of the door remains less than 0.5mm when in the latched position. Check the upper position of the latch hook by pushing and pulling the upper portion of the door.

Then check lower portion of the latch hook, by pushing

and pulling the lower portion of the door toward the oven face. Both results (play of the door) should be

less than 0.5mm.

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

Monitor switch contacts close when door is opened. Re-install outer case and check for microwave leakage around the door with an approved microwave survey meter. (Refer to “Microwave Measurement Procedure.“)

Door Sensing Switch /Secondary Interlock Switch and Monitor Switch Removal

Disconnect the power supply cord and remove outer case cabinet.

The door sensing and secondary interlock switches

interrupt the circuit before the door can be opened. Discharge high voltage capacitor.

Disconnect wire leads from switches, fuse and connectors from control panel.

Remove one (1) screw holding control panel to oven cavity faceplate.

Slide control panel assembly upward and remove from cavity faceplate.

Open oven door.

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

Remove latch hook from oven flange by lifting up on flexible tab and pushing latch hook back.

1 O.Locate the flexible retaining tabs on the latch hook.

11. Push tab inward and rotate switch counterclockwise to release switch.

Note: For monitor switch, lift switch over boss while ro-

tating counterclockwise.

12Switch is now free.

Page 29

DOOR DISASSEMBLY

R-41 OBK R-41 OBW

Removal

1. Disconnect the power supply cord.

2. Push the open button and 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 the figure below to free engaging parts .

4. Pry the lever and lift up the choke cover by inserting

a putty knife in the order as shown in the figure below.

5. Release choke cover from door panel.

6. Now choke cover is free from door panel.

7. Release two(2) pins of door panel from two (2) holes

of upper and lower door hinges by lifting up.

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

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

and remove door frame.

1 O.Now, door panel with sealer film is free.

11 .Tear sealer film from door panel.

12.Now, door panel is free. 13Slide latch head upward and remove it from door

frame and latch head.

14.Now latch head and latch spring are free. 15Remove door screen from door frame.

16.Now, door screen is free.

Re-Install

Re-install door screen to door frame.

Re-install latch spring to the head. Re-install latch spring to the door frame. Re-install door panel to door frame by fitting eight (8)

tabs of door frame to eight (8) holes of door panel.

Put sealer film on door panel. Refer to “Sealer Film Installation” and on how to handle the new film. Catch two (2) pins of door panel on two (2) holes of

upper and lower door hinge. Re-install choke cover to door panel by snapping on

to the door panel.

Note: After any service to the door

(A)Make sure that door sensing switch, secondary

Interlock switch, primary Interlock relay and monitor

switch are operating properly.

(Refer to section “Test Procedures”.)

(B)An approved microwave survey meter should be

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

After adjustment, make sure of the following:

1. Door latch heads smoothly catch latch hook through latch holes, and also latch head goes through the center of the hole.

2. Deviation of door alignment from horizontal line of cavity face plate is less than 1 .O mm.

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

4. Install the outer case cabinet and check for microwave leakage around the 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 the oven cavity during the cooking cycle. This function does not require that the door be air tight, moisture tight, or light tight. Therefore, the occasional appearance of moisture, light or sensing of gentle warm air movement around the oven door is not abnormal and does not indicate leakage of microwave energy from the cavity.

Sealer Film Installation

1. Put adhesive tape on the backing film of the sealer film as shown below.

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

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

Page 30

R-41 OBK R-41 OBW

MICROWAVE MEASUREMENT PROCEDURE

After adjustment of the door, switches are completed in TERLOCK SWITCH TEST and MICROWAVE LEAKAGE TEST must be performed to assure compliance with DHHS (CDRH) Performance Standards for Microwave Ovens.

Interlock Switch Test

Make sure that the door sensing switch, secondary interlock switch and monitor switch are operating properly by checking with an ohmmeter. Refer to the “Test Procedure” of the door sensing switch, secondary interlock switch and monitor switch.

Microwave Leakage Test

Requirements

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

Safety interlock switches.

Primary interlock relay and door sensing switch will prevent microwave radiation emissions in excess of the requirement as above mentioned, secondary interlock switch shall prevent microwave radiation emission or more from the external surface of the oven.

Preparation For Testing

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

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

in excess of 5 mWcm* at any point 5cm

interlock

dividu

ally or col ectively, a IN-

and monitor

2. Place the oven tray in the oven cavity.

3. Place the load of 275 & 15ml(9.8 oz.) of tap water initially at 20 + 5’C (68OF) in the center of the oven cav-

ity. The water container shall be a low form of 600 ml (20 oz.) beaker with an inside diameter of approximately

8.5 cm (3 % in.) and made of an electrically nonconductive material such as glass or plastic. The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any leakage is measured accurately.

4. Set the cooking control on High.

5. Close the door and put the oven into a cook cycle for several minutes. survey is completed, replace it with 275ml of cool water.

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

(2.5cm/sec.) along the gap, watching for the maximum indication of 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 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 per-

mitted by the closed latch assembly.

4. Measure carefully at the point of the highest leakage and make sure that the highest leakage is no greater than 4 mW/cm* to allow for measurement uncertainty, and that the secondary interlock switch does turn the oven OFF before any door movement.

If the water begins to boil before the

Note: Survey instruments that comply with the require-

ment for instrumentation 21 CFRI 030.1 O(c)(3)(i),

standa

as prescribed by the performance microwave ovens must be used for testing

rd for

Note: After servicing, record data on service invoice

and microwave leakage report.

Page 31

RED

12OVAC

60Hz

GRYNVHT

Door Closed, Cook Off Condition

MAGNETRON

RED

N.C.

TEMP.

,xE Note 5

1 ’

RED

MONITOR SWITCH

H.V. CAPACITOR

- -

TRANSFORMER

--I

F7.v.

RECTIFIER

7 fi

,-I

MAGNETRON

MONITOR

FUSE

I I

rI I

h t!

GRND

CAVITY

TEMP.

FUSE

BLK

RY-1

: i 1

COM.

- _ -

- -

N.O.

.-- T

INTERLOCK

DOOR SENSING SWITCH

RY-2

PRIMARY

RELAY

GRN

RED

COM.

WHT

SECONDARY INTERLOCK SWITCH

NOTES:

1. Circuits subject to change without notice.

2. Wire color code applies to primary circuits only, not to low-voltage or secondary circuits.

3. Power supply cord terminal marked “N” must be connected to the neutral (Gray & white) wire.

4. Power supply cord grounding screw must be kept tight at all times.

5. The hot (red) wire must be connected to the (finish lead) terminal of the power transformer.

6. Terminal with blue mark on lamp socket must be connected to the (orange) wire.

Schematic Diagram

WHT

Note 2

Page 32

I 0 n

m u 0

IGRYJ

WHT

Door ’ @

corn.

Sensing Switch

Secondary interlock

- Hot

- Neutral

Note 1

n.0.

GRN

Ground

Oven Cavity

RED

Monitor Fuse

II III I II III1 I II

CN-B

BLK

HIGH VOLTAGE SECTION

WHT

Temp. Fuse

Turntable Motor

H.V. Capacitor

Oven Lamp

GRY WHT

NOTES:

1. Power supply terminal marked “ Neutral ” must be connected to the Netural (White/Gray) wires.

2. Terminal with Blue mark on the lamp socket must be connected to the wire ‘I Orange”.

3. The hot (red) wire must be connected to the (finish lead) terminal of the power transformer.

Blue Mark

Note 2

Wiring Diagram

Page 33

R-41 OBK R-41 OBW

TURNTABLE

MOTOR

OVEN LAMP

FAN MOTOR

[Al j+

[A2j-

LDl-LD5 :

LDl LD2 LD3 LD4 LD5

GND

da.

VR ( ::

INT

I I

BUZZER

TURNTABLE

RYI

Q3 DTDI 43ES

SPl

RC: Q 1k I

1 IV U.Ul\

MOTOR

OVEN LAMP

C6]

FAN MOTOR

MICRO

DOOR SWITCH

NOTE

- : IF NOT SPECIFIED, 1/4w + 5%

,---- : IF NOT SPECIFIED, lSS270

Power Unit Circuit

Page 34

R-41 OBK

R-41 OBW

3 4 5 6

L c 2

Aszln 10’

I-

5 6

Page 35

R-41 OBK R-41 OBW

1 2

4 5 6

Printed Wiring Board of Power Unit

1 2

4 5

Page 36

R-41 OBK R-41 OBW

PARTS LIST

Contact your nearest SHARP Parts Distributor to order.

For location of SHARP Parts Distributor, Please call Toll-Free;

I-800-BE-SHARP

Ref No. Part No.

I§ I

Description / Qty 1 Code 1

Electrical

l- 1 RC-QZBO18MREO l- 2 FH-DZBOO8MRYO M H.V. Diode assembly

l- 3 QSOCLBO06MREO M Oven lamp socket l- 4 RLMPTAO68WREO M Oven lamp l- 5 RMOTEA346WREO l- 6 QFSHDBOO3MREO M Fuse block 1- 7 FFS-BAOlG/KIT M Monitor switch (V-16G-2C25) & Fuse assembly

l- 8 QSW-MAllOWREO M Sec. l- 9 l-10 RV-MZA255WREO l-11 RMOTDA229/KIT 1-12 RTRN-BO6OMREO 1-13 FACCDB003MRE0 1-14 QW-QZBOlGMREO 1-15 FW-VZBl47MREO M Main wire harness 1-16

QFS-TBO06MREO M Temperature fuse (144'C)

FW-VZBl25MRE0 M Stop switch harness

M H.V. Capacitor

M Fan motor

(2OA-250VAC)

interlock & Door sensing switch (V-166G-3C25)

M Magnetron

M T.T. Motor

M Power transformer

M Power cord M H.V. wire A (Transformer - Capacitor)

Oven

2- 1 LBNDKB007MRP0 M H.V. Capacitor band 2- 2 LANGTBO28MRPO 2- 3 PHOK-BO13MRFO M Latch hook

2- 4 GDAI-B05OMRPO M Base plate 2- 5 GLEGPBO03MRF0

2- 6 MLEVPBOl6MRFO M Latch lever 2- 7 PDUC-BO73MRP0 2- 8 NFANPBOOlMREO M Fan blade 2- 9 PDUC-B043MRF0 M Fan duct

2-10 ------------------- - Oven cavity (Not a reolaceable Dart) 2-11 PCOVPB037MRP0

2-12 GCABUBO64MRPO 2-12 GCABUBO58MRPOA M Outer case cabinet 2-13 FROLPB024MRKO 2-14 NTNT-AO95WRE0 M T.T. Tray

2-15 PPACGB014MRF0 2-16 PCUSGB033MRP0 M Base plate cushion

2-17 PCUSUBO42MRPO

M Chassis support

M Foot

M Magnetron duct

M Waveguide cover M Outer case cabinet

M T.T. Roller assembly

M T.T. Motor packing

M Air flow cushion

(R-410BK) (R-410BW)

1 1 1 AE 1 1 AR 1 AD 1 AF

2 2 AF 1 1 AP 1 BF 1 1 AC 1 AU 1 AF

1 AB 1 AF 1 AG 1 AQ

4 1 AD 1 AF

1 AC 1 AD 1 -

1 AD 1 AV 1 AV 1 AK 1 1

1 2

3-l 3-1A

3-1B 3-1c 3-1D

c2 c5 01-4

CPWBFB022MRU0 QCNCMA275DRE0

QCNCMA275DRE0 QCNCMA422DREO FW-VZB141MREO

RC-KZAO87DREO VCEAB31EWlO8M

VCEAB31VW106M VHDllESl///-1

Control Panel

Control unit 2-pin connector (CN-A)

2-pin connector (CN-B) g-pin connector (CN-C) Lead wire harness

Capacitor 0.lyF 50V Capacitor 1000pF 35V

Capacitor 10pF 35V Diode (11ESl)

(WH-1)

1 1

2 4

BE AC

AF AC

AB AD

AB AB

Page 37

R-41 OBK R-41 OBW

Ref No. Part No. 5

Description Qty Code

Control Panel

D5-8 LDl-5

42 VS2SB1238//-3 J Transistor (2SB1238) 1 Q3

R3 R4

R5 VRD-B12EF472J J Resistor R6

RYl-2 SPl

VRSl

3-2 LHLD-BOO4MRFO M LED holder 1 AC 3-3 3-3 3-4

3-4 3-5 3-5

3-6 MSPRTAO5OWREO M Button Spring 1 3-7 PSHEPBO23MREO M LED sheet 1 AR

3-8

VHDlSS27OA/-1 J Diode (lSS270A) VHPSLZ381A9-3 J Light emitting diode

VSDTD143ES/-3 J Transistor VRD-B12HF68OJ J Resistor 68OQl/zW VRD-B12EF270J J Resistor 27a'/~W

VRD-B12EF332J J Resistor 3.3kQ 1/4W RRLY-A114DREO J Relay (OJE-SS-124LM)

RALM-AO14DREO J Buzzer RTRNPBO16MREO M Transformer RH-VZAO32DREO J Varistor

FPNLCB169MRKO M Control panel assembly (R-410BK) FPNLCB171MRKO M Control panel assembly (R-410BW) FUNTKB126MREO M Key unit

FUNTKB127MREO M Key unit JBTN-BO65MRFO M Open Button

JBTN-BO68MRFO M Open Button

XEPSD3OPlOXSO M Screw; Control unit mtg.

(DTD143ES)

4.7kQ l/dW

(PKM22EPT)

(104G471K)

(R-410BK) (R-410BW)

(R-410BK) (R-4lOBW)

4 5

1 AC 1 1 1 1

2 AG 1 AG

1 1 AE

1 AX 1 AX 1

1 1

AR AR

AE AE

Door

4- 0 CDORFB213MRKO M Door assembly(R-410BK) 1 BE

4- 0 CDORFB214MRKO M Door assembly(R-4lOBW) 1 BE 4- 1 FCOV-BlOlMRKOA M Door screen assembly (R-410BK) 1 AS 4- 1 FCOV-BlO3MRKOA M Door screen assembly (R-410BW) 1 AU 4- 2 FDORFBO62MRTO M Door panel 1 AW

4- 3 PSHEPBO2lMREO M Sealer film 1 AE 4- 4 GCOVHBO34MRFO M Choke cover 1 AG

4- 5 LSTPPBO2lMRFO M Latch head 1 AE

A ,

4- 6 MSPRTAO46WREO M Latch spring 1 AB 4- 7 HPNL-BO77MREO M Door Screen (R-410BK) 1 AK

4- 7 HPNL-BO78MREO M Door Screen (R-4lOBW) 1 AK

Miscellaneous

5- 1 TCAUABO15MRRO M Monitor caution label 1 5- 2 TCAUABO27MRRO M DHHS caution label 1 AB 5- 3 TCAUABO33MRRO M UL SCREW label 1 5- 4 TINSEBl89MRRO M Operation manual 1 AE

Fasteners

6- 1 LX-BZAO41WREO M Screw; Base plate mtg. 3 6- 2

6- 3 XHTSD4OPl2RVO M Screw; Power cord mtg. 1 6- 4 LX-BZ0081YBEO M Screw; H.V. Capacitor mtg.& Magnetron mtg. 5 6- 5

6- 6 6- 7 XCBSD3OPO8000 M Screw; Temperature fuse mtg. 2

6- 8 ‘XHTSD40P08000 M Screw; Magnetron duct mtg. 2 6- 9 LX-CZAO38WREO M Screw; O.C. Cabinet grnd. 2 6-10 6-11

LX-CZOO52WREO

XOTSD4OPl2000

xCPsD3OPO8000

XHTSD4OPO8RVO M Screw; LX-CZBOllMREO M Screw;

M Screw;

Base plate.

M Screw; T.T. Motor mtg.

Latch hook mtg. & AH sensor duct mtg.

Power transformer mtg., Chassis support &

& AH sensor mtg.

Fan motor mtg. UL O.C. Cabinet

2 2

Page 38

R-41 OBK R-41 OBW

Cavity Assembly

Page 39

R-41 OBK R-41 OBW

1 2 3

Control Panel Assembly

4 5

Door Assembly

r----

____-----_----

---- ------ L

__---------

----

L-_-----__------_-.-.--_--________________________l

1 2 3 4 5 6

\ 1

Page 40

R-4106K R-41 OBW

Wire Harnesses

Packing and Accessories

* Actual harnesses may be different than illustrations.

-1~

* PACKING KIT

* Non-replaceable items.

* PLASTIC BAG

* PACKING CASE

‘980 SHARP CORP. (5M270E) Printed in U.S.A.

SHARP R410BK, R-410BW Service Manual

TABLE OF CONTENTS

WARNING TO SERVICE PERSONNEL

Before Servicing

When the testing is completed

After repairing

GENERAL INFORMATION

Grounding Instructions

Oven Diagram

Key Unit Layout

OPERATION

Description of Operating Sequence

Off Condition

Cooking Condition

DESCRIPTION AND FUNCTION OF COMPONENTS

Cooling Fan Motor

Oven Temperature Fuse

Magnetron Temperature Fuse

Monitor Switch

Monitor Switch Functions

Door Open Mechanism

SERVICING

Troubleshooting Guide

Off Condition

Cook Condition

B . Power Transformer

Primary Interlock System Test

Monitor Switch Test

Open Monitor Fuse

Before testing

Touch Control Panel Assembly Test

H. Relay Test

OUTLINE OF TOUCH CONTROL PANEL

Key Unit

Control Unit

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

2. ACL Circuit A circuit to generate a signal which resets the LSI to the initial state when power is applied.

Buzzer Circuit

Door Sensing Switch

Relay Circuit

Indicator Circuit

Back Light Circuit

Power Source Circuit

DESCRIPTION OF LSI

SERVICING

Precautions for Handling Electronic Components

Shapes of Electronic Components

Servicing of Touch Control Panel

Servicing The Touch Control Panel With The Oven Power Supply

Servicing The Touch Control Panel With An External Power Supply

Servicing Tools

Other Precautions

COMPONENT REPLACEMENT/ADJUSTMENT PROCEDURE

Outer Case Removal

Power Transformer Removal

Magnetron Removal

Magnetron Installation

Control Panel Assembly Removal

Oven Lamp and Lamp Socket Removal

Turntable Motor Removal

Turntable Motor Re-install

Cooling Fan Motor Removal

Door Sensing Switch /Secondary Interlock Switch and Monitor Switch Adjustments

Door Sensing Switch /Secondary Interlock Switch and Monitor Switch Removal

DOOR DISASSEMBLY

Removal

Re-Install

Sealer Film Installation

MICROWAVE MEASUREMENT PROCEDURE

Interlock Switch Test

Microwave Leakage Test

Requirements

Preparation For Testing

Leakage Test

Electrical

Oven

Control Panel

Door

Miscellaneous

Fasteners

1. 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.