Sharp R-880F, R-880FS Service Manual

Page 1

R-880F(S)

TABLE OF CONTENTS

Page

CAUTION, MICROWAVE RADIATION.................................................................................................... 1

WARNING.................................................................................................................................................1

PRODUCT SPECIFICATIONS ................................................................................................................ 2

GENERAL INFORMATION.......................................................................................................................2

APPEARANCE VIEW .............................................................................................................................. 3

OPERATION SEQUENCE....................................................................................................................... 4

FUNCTION OF IMPORTANT COMPONENTS ....................................................................................... 8

SERVICING ..............................................................................................................................................8

TROUBLESHOOTING GUIDE ...............................................................................................................10

TEST PROCEDURE.............................................................................................................................. 12

TOUCH CONTROL PANEL ASSEMBLY ..............................................................................................20

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE.................................................. 26

MICROWAVE MEASUREMENT ........................................................................................................... 32

WIRING DIAGRAM................................................................................................................................ 33

PICTORIAL DIAGRAM .......................................................................................................................... 37

POWER UNIT CIRCUIT .........................................................................................................................38

CONTROL PANEL CIRCUIT ..................................................................................................................39

PRINTED WIRING BOARD ....................................................................................................................40

PARTS LIST .......................................................................................................................................... 41

S8209R880FPJS

DOUBLE GRILL

CONVECTION

MICROWAVE OVEN

MODEL R-880F(S)

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

SER VICE MANU AL

SHARP CORPORATION

DOUBLE GRILL CONVECTION

Sensor

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R-880F(S)

Page 3

R-880F(S)

SERVICE MANUAL

DOUBLE GRILL

CONVECTION

MICROWAVE OVEN

R-880F(S)

GENERAL IMPORTANT INFORMATION

This Manual has been prepared to provide Sharp Corp. Service engineers with Operation and Service Information.

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

CAUTION

MICROWAVE RADIATION

Service engineers should not be exposed to the microwave energy which may radiate from the magnetron or other microwave generating devices if it is improperly used or connected. All input and output microwave connections, waveguides, flanges and gaskets must be secured. Never operate the device without a microwave energy absorbing load attached. Never look into an open waveguide or antenna while the device is energized.

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 engineers.

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

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

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

Never operate the Top and/ or Bottom heater with the oven outer cabinet removed. (Because air flow is eliminated, and the excess heat generated on adjacent components). It can cause permanent damage or a fire.

SHARP CORPORATION

OSAKA, JAPAN

PRODUCT SPECIFICATIONS

GENERAL INFORMATION

APPEARANCE VIEW

OPERATING SEQUENCE

FUNCTION OF IMPORTANT COMPONENTS

SERVICING AND TROUBLESHOOTING GUIDE

TEST PROCEDURE

TOUCH CONTROL PANEL

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

MICROWAVE MEASUREMENT

WIRING DIAGRAM

PARTS LIST

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R-880F(S)

GENERAL INFORMATION

WARNING

THIS APPLIANCE MUST BE EARTHED

IMPORTANT

THE WIRES IN THIS MAINS LEAD ARE COLOURED IN ACCORDANCE WITH THE FOLLOWING CODE:

GREEN-AND-YELLOW : EARTH BLUE : NEUTRAL BROWN : LIVE

PRODUCT DESCRIPTION

SPECIFICATION

ITEM DESCRIPTION

Power Requirements 230 - 240 Volts

50 Hertz Single phase, 3 wire earthed

Power Consumption Microwave cooking 1.6 kW

Top Heater mode 1.3 kW

Grill cooking

Bottom heater mode 0.9 kW Top and Bottom heater mode

2.1 kW

Convection cooking 2.1 kW

Power Output

900 W nominal of RF microwave energy (IEC Test Procedure) Operating frequency 2450 MHz

Grill heater Power Output (Top heater)

1200 W (600 W x 2) Bottom heater Power Output 800 W Case Dimensions Width 520 mm

Height 309 mm including foot

Depth 502 mm Cooking Cavity Dimensions Width 352 mm

Height 207 mm

Depth 368 mm Turntable diameter 325 mm Control Complement Touch Control System

Clock (1:00 - 12:59) / Timer (0 - 99 minutes and 99 seconds)

Microwave Power for Variable Cooking

Repetition Rate;

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

70%..................................................................... approx. 70% of FULL Power

50%..................................................................... approx. 50% of FULL Power

30%..................................................................... approx. 30% of FULL Power

10%..................................................................... approx. 10% of FULL Power

Mix cooking

High Mix Top Heater ........................... Top heater with 70% microwave power

Low Mix Top Heater............................ Top heater with 50% microwave power

High

Mix

Bottom Heater ..................... Bottom heater with 70% microwave power

Low

Mix

Bottom Heater ...................... Bottom heater with 10% microwave power

Grill Cooking ............... Top heater mode/

Buttom

heater mode/ Top and Buttom

heater mode

Convection cooking.......................................... 40˚C to 250˚C temperature control

HELP pad, MULTI COOK pad, CONVIENIENCE/PIZZA pad

REHEAT SENSOR pad, EASY DEFROST pad

SENSOR INSTANT ACTION pads, MIX pad, GRILL pad, CONVEC pad

REHEAT pad, LESS (")/MORE (') pads, POWER LEVEL pad

NUMBER AND TEMPERATURE pads, STOP/CLEAR pad

CLOCK pad, INSTANT COOK/START pad Set Weight Approx. 20 kg

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R-880F(S)

APPEARANCE VIEW

1. TOP HEATER SYMBOL The symbol will light when the top heater is in use.

2. BOTTOM HEATER SYMBOL The symbol will light when the bottom heater is in use.

3. CONVECTION SYMBOL The symbol will light during convection cooking.

A. HELP PAD

Press to select auto start, information guide on/off, child lock, demonstration modes or info on pads. Press to obtain cooking information.

B. MULTI COOK PAD

Press to select Multi Cook mode.

C. CONVIENIENCE/PIZZA PAD

Press to select 6 popular menus.

D. REHEAT SENSOR PAD

Press to select 3 popular Re-heat menus.

E. EASY DEFROST PAD

Press to defrost meat by entering weight.

F. SENSOR INSTANT ACTION PAD

Press once to cook or reheat 6 popular menus.

G. MIX PAD

Press to select Mix cooking.

H. GRILL PAD

Press to select Grill cooking.

I. CONVEC PAD

Press to select Convection cooking.

J. REHEAT PAD

Press to reheat the oven prior to cooking.

K. LESS (")/MORE (') pads

Press to adjust the doneness of food in one minute increments during cooking or to increase/ decrease the time whilst programming the automatic operations.

L. POWER LEVEL PAD

Press to select microwave power setting. If not pressed, HIGH is automatically selected.

M. NUMBER AND TEMPERATURE PADS

Press to enter cooking times, clock time, convection temperature, weight or quantity of food.

N. STOP/CLEAR PAD

Press to clear during programming. Press once to stop operation of oven during cooking; Press twice to cancel cooking programme.

O. CLOCK PAD

Press to set clock time.

P. INSTANT COOK/START PAD

Press once to cook for 1 minute on HIGH or increase by 1 minute multiples each time this pad is pressed during manual cooking. Press to start oven after setting programs.

OVEN

1. Oven lamp

2. Top heaters (Grill heaters)

3. See through door

4. Door hinges

5. Door safety latches

6. Door seals and sealing surfaces

7. Bottom heater

8. Oven cavity

9. Turntable motor shaft

10.Ventilation openings

11.Waveguide cover

12.Door opening button

13.Control panel

14.Digital display

15.Power supply cord

16.Outer cabinet

17.Menu label

NOTE:

1. Ensure that the bottom heater is in the lowest position as shown the figure, as it is possible to move it up and down to help with cleaning.

2. Place the turntable support over the turntable motor shaft on the floor of the cavity.

3. Then place the turntable on to the turntable support.

TOUCH CONTROL PANEL

Turntable Turntable

support

High rack

Low rack

Turntable motor shaft

Bottom heater

COOK

HELP

INDICATOR

2 3

B D

N O

C E

J L

NOTE: Some one-touch cooking features such as "Instant Cook" are disabled after three minutes when the

oven is not in use. These features are automatically enabled when the door is opened and closed or the STOP/ CLEAR pad is pressed.

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R-880F(S)

OPERATION SEQUENCE

OFF CONDITION

Closing the door activates the 1st. latch switch and 2nd. interlock relay control switch.

IMPORTANT: When the oven door is closed, the contacts COM-NC of the monitor switch must be open. When the microwave oven is plugged in a wall outlet (230 - 240V 50Hz), the line voltage is supplied to the noise filter and the control unit.

Figure O-1 on page 33

1. The oven display will show " SHARP MICRO- WAVE OVEN " .

2. Press the STOP/CLEAR pad. The oven display will show " : ".

3. Set the clock as follows. 3-1. Press the CLOCK pad once. 3-2. Enter the time of day by perssing the number

pads.

3-3. Start the clock by pressing the CLOCK pad.

NOTE:

1. If you do not set the clock, " : " will appear on the display. When the operation of the oven is finished, " : " will appear on the display instead of the time of day.

2. The oven can be also used when the clock is not set.

3. When the oven door is opened, the oven lamp does not come on.

MICROWAVE COOKING CONDITION

100% (HIGH) COOKING

Enter a desired cooking time by pressing the number pads and start the oven by pressing START pad.

Function sequence Figure O-2 on page 33

CONNECTED COMPONENTS RELAY Convection motor RY1 High voltage transformer RY2 Grill heater (Top) RY3 Bottom heater RY4 Fan motor, RY5 Oven lamp, Turntable motor RY6

1. The line voltage is supplied to the primary winding of the high voltage transformer. The voltage is converted to about 3.3 volts A.C. output on the filament winding and high voltage of approximately 2000 volts A.C. on the secondary winding.

2. The filament winding voltage (3.3 volts) heats the magnetron filament and the high voltage (2000 volts) is sent to the voltage doubling circuit, where it is doubled to negative voltage of approximately 4000 volts D.C..

3. The 2450 MHz microwave energy produced in the magnetron generates a wave length of 12.24 cm. This energy is channelled through the waveguide (transport channel) into the oven cavity, where the food is placed to be cooked.

4. When the cooking time is up, a signal tone is heard and the relays RY2 + RY5 + RY6 go back to their home position. The circuits to the oven lamp, high voltage transformer, fan motor and turntable motor are cut off.

5. When the oven door is opened during a cooking cycle, the switches come to the following condition.

Switch Contact Condition

During Oven Door

Cooking Open(No cooking) 1st. latch switch COM-NO Closed Opened 2nd.

interlock relay

control

switch

COM-NO Closed Opened

Monitor Switch COM-NC Opened Closed

The circuit to the high voltage transformer, fan motor, oven lamp and turntable motor are cut off when the 1st. latch switch and 2nd. interlock relay control switch are made open. Shown in the display is remaining time.

6. MONITOR SWITCH CIRCUIT The monitor switch is mechanically controlled by the oven door, and monitors the operation of the 1st. latch switch and the 2nd. interlock relay RY2.

6-1. When the oven door is opened during or after the

cycle of a cooking program, the 1st. latch switch and 2nd. interlock relay control switch must open their contacts first. After that the contacts (

COM-NC) of the

monitor switch can be closed.

6-2. When the oven door is closed, the contacts (COM-

NC) of the monitor switch must be opened. After that the contacts of the 1st. latch switch and 2nd. interlock relay control switch are closed.

6-3. When the oven door is opened and the contacts of the

1st. latch switch and 2nd. interlock relay RY2 remain closed, the fuse F10A will blow, because the monitor switch is closed and a short circuit is caused.

70% (MEDIUM HIGH), 50% (MEDIUM), 30% (MEDIUM LOW), 10% (LOW COOKING)

When the microwave oven is preset for variable cooking power, the line voltage is supplied to the high voltage transformer intermittently within a 32-second time base through the relay contact which is coupled with the current-limiting relay RY2. The following levels of microwave power are given.

SETTING

Note: The On/Off time ratio does not exactly correspond

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

GRILL COOKING CONDITIONS

The oven has three grill cooking condition. They are the TOP HEATER mode, BOTTOM HEATER mode and TOP AND BOTTOM HEATER mode.

TOP HEATER MODE In this mode, the food is cooked by the top heaters. Press

the GRILL pad once and then enter the cooking time by pressing the number pads. When the START pad is pressed, the following operations occur:

Figure O-3(a) on page 34

100%

32 sec. ON

70%

Approx. 70%

100%

24 sec. ON 8 sec. OFF

14 sec. OFF

20 sec. OFF

26 sec. OFF

50% Approx. 50%

18 sec. ON

30%

Approx. 30%

12 sec. ON

10% Approx. 10%

6 sec. ON

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R-880F(S)

1. The relay RY3 + RY5 + RY6 are energized.

2. The numbers of the digital read-out start the count down to zero.

3. Then the top heaters, turntable motor, oven lamp and fan motor are energized.

4. Now, the food is grilled by the top heaters.

5. Upon completion of the selected cooking time, audible signal sounds and the contacts of relays RY3 + RY6 are opened, then the top heaters, turntable motor and oven lamp are de-energized. But the relay RY5 stays closed and the fan motor operates for 5 minutes. But if the cooking time is less than 2 minutes the relay RY5 will not stay close.

BOTTOM HEATER MODE In this mode, the food is cooked by the bottom heater.

Press the GRILL pad twice and then enter the cooking time by pressing the number pads. When the START pad is pressed, the following operations occur:

Figure O-3(b) on page 34

1. The relay RY4 + RY5 + RY6 are energized.

2. The numbers of the digital read-out start the count down to zero.

3. Then the bottom heater, turntable motor, oven lamp and fan motor are energized.

4. Now, the food is grilled by the bottom heater.

5. Upon completion of the selected cooking time, audible signal sounds and the contacts of relays RY4 + RY6 are opened, then the bottom heating elements, turntable motor and oven lamp are de-energized. But the relay RY5 stays closed and the fan motor operates for 5 minutes. But if the cooking time is less than 2 minutes the relay RY5 will not stay close.

TOP AND BOTTOM HEATER MODE In this mode, the food is cooked by both the top heaters

and bottom heater. Press the GRILL pad three times and then enter the cooking time by pressing the number pads. When the START pad is pressed, the following operations occur:

Figure O-3(c) on page 35

1. The relay RY3 + RY4 + RY5 + RY6 are energized.

2. The numbers of the digital read-out start the count down to zero.

3. Then the top heaters, bottom heater, turntable motor, oven lamp and fan motor are energized.

4. Now, the food is grilled by the top heaters and the bottom heater.

5. Upon completion of the selected cooking time, audible signal sounds and the contacts of relays RY3 + RY4 + RY6 are opened, then the top heating elements, bottom heating element, turntable motor and oven lamp are de-energized. But the relay RY5 stays closed and the fan motor operates for 5 minutes. But if the cooking time is less than 2 minutes the relay RY5 will not stay closed.

GRILL MIX COOKING CONDITION The oven will cook food by supplying grill heaters (top

heaters or Bottom heater) and microwave energy alternately within a 48 seconds time base. And the oven has four programmed cooking mode.

HIGH MIX TOP GRILL MODE AND LOW MIX TOP GRILL MODE

In these modes, the food is cooked by the top heaters and the microwave energy. Press the MIX pad once for HIGH MIX TOP GRILL mode. Press the MIX pad twice for LOW MIX TOP GRILL mode. And then enter the cooking time by pressing the number pads. When the START pad is pressed, the following operations occur:

Figure O-5(a) on page 36

1. The relay RY5 + RY6 are energized.

2. The numbers of the digital read-out start the count down to zero.

3. The turntable motor, oven lamp and fan motor are energized.

4. The relay RY2 + RY3 are energized alternately within a 48 seconds time base by the control unit.

5. The top heaters operate through the relay RY3 is energized. And the high voltage transformer operates through the relay RY2 is energized.

6. The relationship between the top heating elements and magnetron operations are as follows.

Note: The On/Off time ratio does not exactly correspond

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

7. Upon completion of the selected cooking time, audible signal sounds and the contacts of relays RY2 + RY3 + RY6 are opened, then the top heaters, high voltage transformer, turntable motor and oven lamp are deenergized. At the end of the convection cycle, if the cavity air temperature is above 120˚C, the circuit to RY5 will be maintained (by the thermistor circuit) to continue operation of the cooling fan motor until the temperature drops below 104˚C, at which time the relay will be de0energized, turning off the fan motor.

HIGH MIX BOTTOM GRILL MODE AND LOW MIX BOTTOM GRILL MODE

In these modes, the food is cooked by the bottom heater and the microwave energy. Press the MIX pad three (3) times for HIGH MIX BOTTOM GRILL mode. Press the MIX pad four (4) times for LOW MIX BOTTOM GRILL mode. And then enter the cooking time by pressing the number pads. When the START pad is pressed, the following operations occur:

Figure O-5(b) on page 36

1. The relay RY5 + RY6 are energized.

2. The numbers of the digital read-out start the count down to zero.

3. The turntable motor, oven lamp and fan motor are

36 SEC. 12 SEC.

LOW MIX TOP GRILL mode

HIGH MIX TOP GRILL mode

MICROWAVE POWER

= APPROX. 70%

MICROWAVE POWER

= APPROX. 50%

OFF

26 SEC. 22 SEC.

OFF

(MICRO.)

TOP HEATERS

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R-880F(S)

NOTE:

1. In case of Automatic operations, the limitations of power output are not carried out.

2. In case that the STOP/CLEAR pad is pressed or the oven door is opened during cooking, the limitations of power output are carried out after the total cooking time beyond the specified cooking time.

3. In case of the two or more same cooking modes are carried out, the limitations of power output are carried out after the total cooking time beyond the specified cooking time.

4. In case of the two or more different cooking modes are carried out, the specified cooking time is started to count from the point when the cooking mode is changed.

5. If the cooking mode has the power level display, the power level is also displayed when the limitations of power output are carried out.

CONVECTION COOKING CONDITION

PREHEATING CONDITION

Press the PREHEAT pad and then select preheating temperature by pressing the temperature pad. When the START pad is touched, the following operations occur:

Figure O-4 on page 35

1. The coils of shut-off relays RY1+RY5+RY6 are energized, the oven lamp, cooling fan motor, turntable motor and convection motor are turned on.

2. The coil of heater relays RY3+RY4 are energized by the CPU unit and the main supply voltage is added to the top and bottom heaters.

3. When the oven temperature reaches the selected preheat temperature, the following operations occur:

3-1. The heater relays RY3+RY4 de-energized by the

CPU unit temperature circuit and thermistor, opening the circuit to the top and bottom heaters.

3-2. The oven will continue to function for 30 minutes,

turning the top and bottom heaters on and off, as needed to maintain the selected preheat temperature. The oven will shut-down completely after 30 minutes.

CONVECTION COOKING CONDITION

When the preheat temperature is reached, a beep signal will sound indicating that the holding temperature has been reached in the oven cavity. Open the door and place the food to be cooked in the oven. Press the CONVECTION pad and then enter the cooking temperature by pressing the temperature pad. And then enter the cooking time by pressing the NUMBER pads. When the START pad is touched, the following operations occur:

1. The numbers of the digital read-out start the count down to zero.

2. The oven lamp, turntable motor, cooling fan motor and convection motor are energized.

3. The relays(RY3 and RY4) are energized (if the cavity temperature is lower than the selected temperature) and the main supply voltage is applied to the heating element to return to the selected cooking temperature. The top heaters and the bottom heater work in accordance with the following table while the heaters are energized.

energized.

4. The relay RY2 + RY4 are energized alternately within a 48 seconds time base by the control unit.

5. The bottom heater operate through the relay RY4 is energized. And the high voltage transformer operates through the relay RY2 is energized.

6. The relationship between the top heating elements and magnetron operations are as follows.

Note: The On/Off time ratio does not exactly correspond

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

7. Upon completion of the selected cooking time, audible signal sounds and the contacts of relays RY2 + RY4 + RY6 are opened, then the bottom heater, high voltage transformer, turntable motor and oven lamp are deenergized. At the end of the convection cycle, if the cavity air temperature is above 120˚C, the circuit to RY5 will be maintained (by the thermistor circuit) to continue operation of the cooling fan motor until the temperature drops below 104˚C, at which time the relay will be de-energized, turning off the fan motor.

AUTOMATIC OPERATIONS

This oven has the following automatic operations;

MULTI COOK CONVIENIENCE/PIZZA

EASY DEFROST Thease will automatically compute the cooking mode and the cooking time. And the oven will cook or defrost the food according to the special cooking sequence.

LIMITATIONS OF POWER OUTPUT IN MANUAL OPERATION

After the same cooking mode is carried out for more than the specified cooking time, the power output is automatically reduced by turning the control relays on and off intermittently, as shown in the table below. This is to protect the oven door against temperature rising.

Specified cooking Limited power Time base

Cooking mode time (minutes) output (%) (seconds)

Microwave 100% Power

20 70 32

Top heaters 30 50 48 Bottom heater 15 50 48 Top browner and

10 (Top) 50 48

Bottom browner

10 (Bottom) 50 48

or Oven cooking

26 SEC. 22 SEC.

LOW MIX GRILL BOTTOM GRILL mode

HIGH MIX GRILL BOTTOM GRILL mode

MICROWAVE POWER

= APPROX. 50%

MICROWAVE POWER

= APPROX. 10%

40 SEC.8 SEC.

OFF

(MICRO.)

BOTTOM HEATER

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R-880F(S)

Selected Temp- Top Heaters Bottom Heater erature (˚C) Power (%) Power (%)

250 40 40 230 40 40 220 40 40 200 30 70 180 20 70 160 10 70 150 10 70 130 10 60

70 10 40 40 10 30

4. Upon completion of the cooking time, the audible signal will sound, and oven lamp, turntable motor, cooling fan motor and convection motor are de-energized. At the end of the convection cycle, if the cavity air temperature is above 120˚C, the circuit to (RY5) will be maintained (by the thermistor circuit) to continue operation of the cooling fan motor until the temperature drops below 104˚C, at which time the relay will be deenergized, turning off the fan motor. Relay (RY1) will however, open as soon as the convection cycle has ended, turning off the convection fan motor.

ABSOLUTE HUMIDITY SENSOR (AH SENSOR) COOKING CONDITION

In case where the AH sensor is used (REHEAT SENSOR or SENSOR INSTANT ACTION), the foods are cooked in microwave cooking mode or grill cooking mode without figuring time, power level or quantity. When the oven senses enough steam from the food, it relays the information to its microprocessor which will calculate the remaining cooking time and power level needed for best results. When the food is cooked, water vapour is developed. The sensor “senses” the vapour and its resistance increases gradually. When the resistance reaches the value set according to the menu, supplementary cooking is started. The time of supplementary cooking is determined by experiment with each food category and inputted into the LSI. An example of how sensor works:

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

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

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

AH SENSOR COOKING SEQUENCE

1. In case the AH sensor cooking condition is started, the coil of shut-off relays (RY5+RY6) are energized, the oven lamp and cooling fan motor are turned on, but the power transformer is not turned on.

NOTE: The oven should not be operated on AH SENSOR

COOKING immediately after plugging in the unit. Wait t wo minutes before cooking on AH SENSOR COOKING CONDITION.

2. After about 16 seconds, the cook relay (RY2) is energized. The power transformer is turned on, microwave energy is produced and first stage is started. The 16 seconds is the cooling time required to remove any vapour from the oven cavity and sensor. (Figure O-2)

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

touch STOP/CLEAR pad. There is a menu which the oven operates in grill cooking mode.

When the sensor detects the vapour emitted from the food, the display switches over to the remaining cooking time and the timer counts down to zero. At this time, the door may be opened to stir food, turn it or season, etc.

NOTE: In case where a small quantity of food is cooked,

the oven will stop without displaying the remaining cooking time. In case of "Reheat Pie" of Sensor Instant Action, the relay (RY2) is turned off and power transformer is turned off. And then the relays (RY3 + RY4) are energized. The top and bottom heaters are turned on.

4. When the timer reaches zero, an audible signal sounds. The shut-off relay (RY5+RY6) and cook relay (RY2) are de-energized and the power transformer, oven lamp, etc. are turned off.

FIRE SENSING FEATURE (MICROWAVE MODE)

This model incorporates a sensing feature which will stop the oven's operation if there is a fire in the oven cavity during microwave cooking. This accomplished by the LSI repeatedly measures the voltage across the temperature measurement circuit (thermistor) during it's 32-seconds time base comparing the obtained voltage measurements. If the most recent voltage measured is 700mV grater than the previous voltage measured, the LSI judges it as a fire in the oven cavity and switches off the relays to the power transformer, fan motor turntable motor and the oven lamp. The LSI also stops counting down. Please refer to the following section for a more detailed description.

Operation

Please refer to the timing diagrams below.

1. The thermistor operates within a 32-seconds time base and it is energized for three (3) seconds and off for 29 seconds. Two (2) seconds after the thermistor is energized, the voltage across the temperature measurement circuit is sampled by the LSI and twenty one (21) seconds after the thermistor is cut off the LSI turns on the cooling fan for six (6) seconds.

2. The above procedure is repeated. If the difference between the first voltage measured (in step 1) and the voltage measured when the procedure is repeated (step 2) is greater than 700mV the LSI makes the

MICROWAVE

AH SENSOR

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R-880F(S)

DOOR OPEN MECHANISM

The door can be opened by pushing the open button on the control panel. When the open button is pushed, the switch lever is moved upward, operating the latch head. The latch head is moved upward and released from the latch hook. Now, the door can be opened.

Figure D-1. Door Open Mechanism

FUNCTION OF IMPORTANT COMPONENTS

judgment that there is a fire in the oven cavity and will switch off the relays to the power transformer, fan motor, turntable motor and the oven lamp. The LSI also stops counting down.

3. Once the fire sensor feature has shut the unit down, the programmed cooking cycle may be resumed by pressing the "START" pad or the unit may be reset by pressing the "CLEAR" pad.

IMPORTANT: During sensor cooking operation, the fire sensing operation sequence will not begin until the AH sensor has detected vapours and initiated a sensor cooking cycle. This is because the operation of the convection fan would interfere with the AH sensor's vapour detection.

ON/OFF TIME RATIO

In grill cooking, convection cooking or mix cooking, the top heaters, bottom heater or magnetron operate whithin a 48 second time base. The following table is the ON / OFF time ratio at each power output of the top heaters, bottom heater or magnetron.

POWER OUTPUT ON TIME OFF TIME

100% 48 sec. 0 sec.

90% 44 sec. 4 sec. 80% 40 sec. 8 sec. 70% 36 sec. 12 sec. 60% 32 sec. 16 sec. 50% 26 sec. 22 sec. 40% 22 sec. 26 sec. 30% 16 sec. 32 sec. 20% 12 sec. 36 sec. 10% 8 sec. 40 sec.

1ST. LATCH SWITCH AND 2ND. INTERLOCK RELAY CONTROL SWITCH

1. When the oven door is closed, the contacts (COM-NO) of each switch must be closed.

2. When the oven door is opened, the contacts (COMNO) of each switch must be opened.

MONITOR SWITCH

1. When the door is closed, the contacts (COM-NC) must be opened.

2. When the door is opened, the contacts (COM-NC) must be closed.

3. If the oven door is opened and he contacts (COM-NO) of the 1st. latch switch and 2nd. interlock relay (RY2) fail to open, the fuse F10A blows immediately after closing the contacts (COM-NC) of the monitor switch.

CAUTION: BEFORE REPLACING A BLOWN FUSE F10A

TEST THE 1ST. LATCH SWITCH, 2ND. INTERLOCK RELAY (RY2) AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER “TEST PROCEDURE”).

CONVECTION

MOTOR

THERMISTOR

Sensing

Voltage

OFF

023243032 (sec.) 64 (sec.)

3 sec.

Sensing the voltage across temperature measurement circuit.

6 sec.

Latch Hook

Latch Heads

Door

1st. Latch Switch

Monitor Switch

Switch Lever

2nd. Interlock Relay Control Switch

Page 11

R-880F(S)

NOISE FILTER

The noise filter assembly prevents radio frequency interference that might flow back in the power circuit.

TOP HEATERS

The top heaters are located on the top of the oven cavity assembly. The top heaters send out heat to grill foods.

BOTTOM HEATER

The bottom heater is located on the floor of the oven cavity assembly. The bottom heater sends out heat to grill foods.

ONVECTION COOKING SYSTEM

This oven is designed with a hot air heating system where food is not directly heated by the top and bottom heaters, but is heated by forced circulation of the hot air produced by the top and bottom heaters. The air heated by the top and bottom heaters is circulated through the convection passage provided on the outer casing of the oven cavity by means of the convection fan which is driven by the convection motor. It then enters the inside of the oven through the vent holes provided on the left side of the oven. Next, the hot air heats the food on the turntable and leaves the oven cavity through the vent in the oven cavity left side wall. Without leaving the oven, this hot air is reheated by the top and bottom heaters, passes through the convection passage and enters the inside of the oven cavity again, in a continuing cycle. In this way, the hot air circulates inside the oven cavity to raise its temperature and, at the same time, comes into contact with the food being cooked. When the temperature inside the oven cavity reaches the selected temperature, the top and bottom heaters are de-energized. When the temperature inside the oven cavity drops below the selected temperature, the top and bottom heaters are energized again. In this way, the inside of the oven cavity is maintained at approximately the selected temperature. When the convection time reaches 0, the top and bottom heaters are deenergized and the convection fan stops operating and the oven shuts off. Upon completion of the cooking time, the audible signal will sound, and oven lamp, turntable motor, cooling fan motor and convection motor are de-energized. At the end of the convection cycle, if the cavity air temperature is above 120˚C, the circuit to RY5 will be maintained (by the thermistor circuit) to continue operation of the cooling fan motor until the temperature drops below 104˚C, at which time the relay will be de-energized, turning off the fan motor. Relay RY1 will however, open as soon as the convection cycle has ended, turning off the convection fan motor. This will now cool.

FUSE F10A 250V

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

2. This fuse blows when the 1st. latch switch and 2nd. interlock relay (RY2) remain closed with the oven door open and when the contacts (COM-NC) of monitor switch closes.

FUSE 15A

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

HIGH VOLTAGE FUSE

The high voltage fuse blows when the high voltage rectifier or the magnetron is shorted.

THERMAL CUT-OUT 125˚C (MG)

This thermal cut-out protects the magnetron against overheating. If the temperature goes up higher than 125˚C because the fan motor is interrupted or the ventilation openings are blocked, the thermal cut-out will open and line voltages to the high voltage transformer will be cut off and the operation of the magnetron will be stopped.

THERMAL CUT-OUT170˚C (OVEN)

The thermal cut-out located on the top of the oven cavity is designed to prevent damage to the oven if the foods in the oven catch fire due to over heating produced by improper setting of the cooking time or failure of control unit. Under the normal operation, the oven thermal cut-out remains closed. However, when abnormally high temperature are reached within the oven cavity, oven thermal cut-out will open at 170˚C causing the oven to shut down. The thermal cut-out will cut back in at 155˚C.

THERMISTOR

The thermistor is a negative temperature coefficient type. The temperature in the oven cavity is detected through the resistance of the thermistor, and then the control unit causes the heating element relay to operate, thus the current to the heating element is turned ON/OFF.

TURNTABLE MOTOR

The turntable motor drives the turntable roller assembly to rotate the turntable.

FAN MOTOR

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

CONVECTION MOTOR

The convection motor drives the convection fan and provides the heated air.

Page 12

R-880F(S)

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

IMPORTANT: If the oven becomes inoperative because

of a blown fuse F10A in the 1st. latch switch - 2nd. interlock relay(RY2)- monitor switch circuit, check the 1st. latch switch, 2nd. interlock relay(RY2) and monitor switch before replacing the fuse F10A.

TROUBLESHOOTING GUIDE

REMEMBER TO CHECK 3D

1) Disconnect the supply.

2) Door opened, and wedged open.

3) Discharge high voltage capacitor. WARNING: AGAINST THE CHARGE OF THE

HIGH-VOLTAGE CAPACITOR.

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, of the connecting lead of the high-voltage rectifier) against the chassis with the use of an insulated screwdriver.

Sharp recommend that wherever possible fault-finding is carried out with the supply disconnected. It may in, some cases, be necessary to connect the supply after the outer case has been removed, in this event carry out 3D checks and then disconnect the leads to the primary of the high voltage transformer. Ensure that these leads remain isolated from other components and the oven chassis. (Use insulation tape if necessary.) When the testing is completed carry out 3D checks and reconnect the leads to the primary of the high voltage transformer.

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.

SERVICING

WARNING TO SERVICE PERSONNEL

Microwave ovens contain circuitry capable of producing very high voltage and current. Contact with following parts will result in electrocution. High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier assembly, High voltage harness.

REMEMBER TO CHECK 4R

1) Reconnect all leads removed from components during testing.

2) Replace the outer case (cabinet).

3) Reconnect the supply.

4) Run the oven. Check all functions.

Microwave ovens should not be run empty. To test for the presence of microwave energy within a cavity, place a cup of cold water on the oven turntable, close the door and set the power level to HIGH (100%) and set the microwave timer for two (2) minutes. And push the start key. When the two minutes has elapsed (timer at zero) carefully check that the water is now hot. If the water remains cold carry out 3D checks and re-examine the connections to the component being tested.

Page 13

R-880F(S)

Fuse 15A blows when power cord is plugged into wall outlet.

Fuse F10A blows when the door is opened.

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

"SHARP MICRO- OVEN" does not appear in display when power cord is

plugged into wall outlet.

Display does not operate properly when STOP/CLEAR pad is pressed.

Oven does not start when the INSTANT COOK/ START pad is pressed.

(Display operates.)

Oven lamp does not light. (Turntable motor operates.)

Fan motor does not operate. (Oven lamp lights.)

Turntable motor does not operate. (Oven lamp lights.)

Oven or electrical parts does not stop when cooking time is 0 or

STOP/CLEAR pad is pressed.

Oven goes into cook cycle but shuts down before end of cooking cycle.

Oven seems to be operating but little or no heat is produced in oven load.

Oven does not operating properly during variable cooking condition

except 100% cooking condition.

Top heaters do not operate.

Bottom heater does not operate.

Oven seems to be operating but little or no heat is produced in oven load.

(Microwave power does not seem to be generated properly.)

Top heaters do not operate.

Bottom heater does not operate.

Temperature is lower or higher than preset.

Convection motor does not operate.

Oven stops after 4 minutes 15 sec..

Oven is in sensor cooking condition but AH sensor does not end 1st.

stage or does not stop cooking cycle or the oven stops soon.

CONDITION

PROBLEM

MAGNETRON

HIGH VOLTAGE TRANSFORMER

H.V. RECTIFIER ASSEMBLY

HIGH VOLTAGE CAPACITOR

1ST. LATCH SWITCH

MONITOR SWITCH

2ND. INTERLOCK RELAY CONTROL SWITCH

THERMAL CUT-OUT 125˚C

THERMAL CUT-OUT 170˚C

FUSE F10A

FUSE 15A

NOISE FILTER

FAN MOTOR

TURNTABLE MOTOR

CONVECTION MOTOR

TOP HEATERS

BOTTOM HEATER

THERMISTOR

HIGH VOLTAGE FUSE

TOUCH CONTROL PANEL

KEY UNIT

RELAY RY1

RELAY RY2

RELAY RY3

RELAY RY4

RELAY RY5

RELAY RY6

FOIL PATTERN ON P.W.B.

AH SENSOR

POWER SUPPLY CORD

OVEN LAMP

SHORTED WIRE HARNESS

OPENED WIRE HARNESS

MIS-ADJUSTMENT OF SWITCHES

A BCDEEEFFGHI JJJKKLMNOPPPPPPQR

MIX

COOKING

CONDITION

CONVECTION

COOKING

CONDITION

AH. SENSOR

OFF

CONDITION

COOKING

CONDITION

(COMMON MODE)

MICROWAVE

COOKING

CONDITION

GRILL

COOKING

CONDITION

POSSIBLE CASE

AND

DEFECTIVE PARTS

Page 14

R-880F(S)

A MAGNETRON TEST

TEST PROCEDURES

PROCEDURE

LETTER COMPONENT TEST

CARRY OUT 3D CHECKS. Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal. To test for an open circuit filament use an ohmmeter to make a continuity test between the magnetron

filament terminals, the meter should show a reading of less than 1 ohm. To test for short filament to anode condition, connect ohmmeter between one of the filament terminals

and the case of the magnetron (ground). This test should be indicated an infinite resistance. If a low or zero resistance reading is obtained then the magnetron should be replaced.

MICROWAVE OUTPUT POWER (1 litre load)

The following test procedure should be carried out with the microwave oven in a fully assembled condition (outer case fitted). Microwave output power from the magnetron can be measured by IEC Test Procedure, i.e. it is measured by how much power the water load can absorb. To measure the microwave output power in the microwave oven, the relation of calorie and watt is used. When P(W) heating works for t(second), approximately P x t/4.187 calorie is generated. On the other hand, if the temperature of the water with V(ml) rises ∆T (°C) during this microwave heating period, the calorie of the water is V x ∆T.

Measuring condition:

1. Container The water container must be a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm and an outside diameter of approximately 190 mm.

2. Temperature of the oven and vessel The oven and the empty vessel are at ambient temperature prior to the start the test.

3. Temperature of the water The initial temperature of the water is (10±1)°C.

4. Select the initial and final water temperature so that the maximum difference between the final water temperature and the ambient temperature is 5K.

5. Select stirring devices and measuring instruments in order to minimize addition or removal of heat.

6. The graduation of the thermometer must be scaled by 0.1°C at minimum and be an accurate thermometer.

7. The water load must be (1000±5) g.

8. “t” is measured while the microwave generator is operating at full power. Magnetron filament heatup time is not included.

NOTE: The operation time of the microwave oven is “t + 3” sec. (3 sec. is magnetron filament heat-up time.)

Measuring method:

1. Measure the initial temperature of the water before the water is added to the vessel. (Example: The initial temperature T1 = 11°C)

2. Add the 1 litre water to the vessel.

3. Place the load on the centre of the shelf.

4. Operate the microwave oven at HIGH for the temperature of the water rises by a value ∆ T of (10 ± 2) K.

5. Stir the water to equalize temperature throughout the vessel.

6. Measure the final water temperature. (Example: The final temperature T2 = 21°C)

7. Calculate the microwave power output P in watts from above formula.

NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL WHILE THE OVEN IS IN OPERATION.

The formula is as follows;

P x t / 4.187 = V x ∆ T+ 0.55 x mc (T2-T0)

(W) = 4.187 x V x ∆T / t + 0.55 x mc (T2-T0)/t

Our condition for water load is as follows:

Room temperature (T0) ... around 20°CPower supply Voltage.............. Rated voltage

Water load..................................1000 g Initial temperature (T1) ...................... 10±1°C

Heating time.............................. 47 sec. Mass of container (mc) ......................... 330 g

T2............................ Final Temperature P = 90 x ∆T+ 0.55 x mc(T2-T0)/47

Page 15

R-880F(S)

Initial temperature .................................................................................................. T1 = 11°C

Temperature after (47 + 3) = 50 sec ...................................................................... T2 = 21°C

Temperature difference Cold-Warm.......................................................................∆T1 = 10C

Measured output power

The equation is “P = 90 x ∆T” ...................................................... P = 90 x 10°C = 900 Watts

JUDGMENT: The measured output power should be at least ± 15 % of the rated output power.

CAUTION: 1°C CORRESPONDS TO 90 WATTS. REPEAT MEASUREMENT IF THE POWER IS

INSUFFICIENT.

TEST PROCEDURES

PROCEDURE

LETTER COMPONENT TEST

1000g

T1˚C

T2˚C

Heat up for 50 sec

B HIGH VOLTAGE TRANSFORMER TEST

WARNING: High voltage and large currents are present at the secondary winding and

filament winding of the high voltage transformer. It is very dangerous to work near this part when the oven is on. NEVER make any voltage measurements of the high-voltage circuits, including the magnetron filament.

C HIGH VOLTAGE RECTIFIER ASSEMBLY TEST

HIGH VOLTAGE RECTIFIER TEST CARRY OUT 3D CHECKS.

Isolate the high voltage rectifier assembly from the HV circuit. The high voltage rectifier can be tested using an ohmmeter set to its highest range. Connect the ohmmeter across the terminal B+C of the high voltage rectifier and note the reading obtained. Reverse the meter leads and note this second reading. The normal resistance is infinite in one direction and more than 100 kΩ in the other direction.

CARRY OUT 4R CHECKS. NOTE: FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER, THE BATTERIES OF

THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE AT LEAST 6 VOLTS, BECAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE SHOWN IN BOTH DIRECTIONS.

CARRY OUT 3D CHECKS. Disconnect the leads to the primary winding of the high voltage transformer. Disconnect the filament and secondary winding connections from the rest of the HV circuitry. Using an ohmmeter, set on a low range, it is possible to check the continuity of all three windings. The following readings should be obtained:-

a. Primary winding ................................ approximately 1.7 Ω

b. Secondary winding .......................... approximately 118 Ω

c. Filament winding......................................... less than 1 Ω

If the readings obtained are not stated as above, then the high voltage transformer is probably faulty and should be replaced. CARRY OUT 4R CHECKS.

HIGH VOLTAGE RECTIFIER

D HIGH VOLTAGE CAPACITOR TEST

CARRY OUT 3D CHECKS. A. Isolate the high voltage capacitor from the circuit.

B. Continuity check must be carried out with measuring instrument which is set to the highest

resistance range.

Page 16

R-880F(S)

TEST PROCEDURES

PROCEDURE

LETTER COMPONENT TEST

E SWITCH TEST

CARRY OUT 3D CHECKS. Isolate the switch to be tested and using an ohmmeter check between the terminals as described in the following table.

Table: Terminal Connection of Switch

Plunger Operation COM to NO COM to NC

Released Open circuit Short circuit Depressed Short circuit Open circuit

COM; Common terminal, NO; Normally open terminal NC; Normally close terminal

If incorrect readings are obtained, make the necessary switch adjustment or replace the switch. CARRY OUT 4R CHECKS.

F THERMAL CUT-OUT TEST

CARRY OUT 3D CHECKS. Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make a continuity

test across the two terminals as described in the below.

Table: Thermal Cut-out Test

Temperature of "ON" Temperature of "OFF" Indication of ohmmeter

Parts Name condition (closed circuit). condition (open circuit). (When room temperature

(˚C) (˚C) is approx. 20˚C.) Thermal cut-out 125˚C This is not resetable type. Above 125˚C Closed circuit Thermal cut-out 170˚C Cuts back in at 155˚C. Above 170˚C Closed circuit

If incorrect readings are obtained, replace the thermal cut-out. An open circuit thermal cut-out (MG) indicates that the magnetron has overheated, this may be due

to resistricted ventilation, cooling fan failure or a fault condition within the magnetron or HV. circuit. An open circuit thermal cut-out (OVEN) indicates that the food in the oven cavity may catch fire, this

may be due to over heating produced by improper setting of the cooking timer or failure of the control panel.

CARRY OUT 4R CHECKS.

G BLOWN FUSE F10A

CARRY OUT 3D CHECKS.

If the fuse F10A is blown when the door is opened, check the 1st. latch switch, 2nd. interlock relay and monitor switch.

If the fuse F10A is blown, there could be a short or ground in electrical parts or wire harness. Check them and replace the defective parts or repair the wire harness.

CARRY OUT 4R CHECKS.

CAUTION: Only replace fuse F10A with the correct value replacement.

C. A normal capacitor shows continuity for a short time (kick) and then a resistance of about 10MΩ after

it has been charged. D. A short-circuited capacitor shows continuity all the time. E. An open capacitor constantly shows a resistance about 10 MΩ because of its internal 10MΩ

resistance. F. When the internal wire is opened in the high voltage capacitor shows an infinite resistance. G. The resistance across all the terminals and the chassis must be infinite when the capacitor is

normal. If incorrect reading are obtained, the high voltage capacitor must be replaced.

CARRY OUT 4R CHECKS.

Page 17

R-880F(S)

CARRY OUT 3D CHECKS. Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two

terminals as described in the table below.

Table: Resistance of Motor

Motors Resistance Fan motor Approximately 290 Ω Turntable motor Approximately 15 kΩ Convection motor Approximately 293 Ω

If incorrect readings are obtained, replace the motor. CARRY OUT

4R CHECKS.

TEST PROCEDURES

PROCEDURE

LETTER COMPONENT TEST

H BLOWN FUSE 15A

J MOTOR WINDING TEST

CARRY OUT 3D CHECKS. Disconnect the leads from the terminals of noise filter.

Using an ohmmeter, check between the terminals as described in the following table.

MEASURING POINTS INDICATION OF OHMMETER

Between N and L Approx. 680 kΩ Between terminal N and WHITE Short circuit

Between terminal L and RED Short circuit If incorrect readings are absorbed, replace the noise filter unit. CARRY OUT

4R CHECKS.

I NOISE FILTER TEST

CARRY OUT 3D CHECKS.

If the fuse 15A is blown, there could be a short or ground in electrical parts or wire harness. Check them and replace the defective parts or repair the wire harness.

CARRY OUT 4R CHECKS.

CAUTION: Only replace fuse 15A with the correct value replacement.

K TOP HEATERS AND BOTTOM HEATER TEST

CARRY OUT 3D CHECKS. Before carrying out the following tests make sure the heater is cool completely.

1. Resistance of heater.

Disconnect the wire leads to the heater to be tested. Using ohmmeter with low resistance range. Check the resistance across the terminals of the heater as described in the following table.

Table: Resistance of heater

Parts name Resistance Top heaters Approximately 24 Ω x 2 = 48 Ω Bottom heater Approximately 72 Ω

2. Insulation resistance. Disconnect the wire leads to the heater to be tested. Check the insulation resistance between the heater terminal and cavity using a 500V - 100MΩ insulation tester. The insulation resistance should be more than 10 MΩ in the cold start.

If the results of above test 1 and/or 2 are out of above specifications, the heater is probably faulty and should be replaced.

CARRY OUT 4R CHECKS.

N WHT

RED

Page 18

R-880F(S)

TEST PROCEDURES

PROCEDURE

LETTER COMPONENT TEST

L THERMISTOR TEST

1. CARRY OUT 3D CHECKS.

2. Disconnect connector-D from the control unit. Measure the resistance of the thermistor with an ohmmeter. Connect the ohmmeter leads to Pin No’s D1 and D3.

Room Temperature Resistance 68˚F(20˚C) - 86˚F(30˚C) Approx. 293kΩ - 184KΩ

3. If the meter does not indicate above resistance, replace the thermistor

4. CARRY OUT 4R CHECKS.

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 units, Control Unit and Key Unit, and also the Control unit is divided into two units, CPU unit and Power unit, and troubleshooting by replacement is described according to the symptoms indicated.

1. Key Unit Note : Check key unit ribbon connection before replacement. 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.

2. Control Panel The following symptoms indicate a defective control unit. Before replacing the control unit. perform the key unit test (Procedure O) to determine if control unit is faulty.

2-1 In connection with pads

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

2-2 In connection with indicators

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

2-3 Other possible troubles 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. d) Proper temperature measurement is not obtained.

O KEY UNIT TEST

N CONTROL PANEL ASSEMBLY TEST

M HIGH VOLTAGE FUSE TEST

CARRY OUT 3D CHECKS. If the high voltage fuse is blown, there could be a short in the high voltage rectifier or the magnetron. Check them and replace the defective parts and the high voltage fuse.

CARRY OUT 4R CHECKS. CAUTION: ONLY REPLACE HIGH VOLTAGE FUSE WITH THE CORRECT VALUE REPLACEMENT.

If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is marking good contact, verify that the 2nd. interlock relay control switch operates properly; that is the contacts are closed when the door is closed and open when the door is open. If the 2nd. interlock relay control switch is good, disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the 2nd. interlock relay control switch is closed (either close the door or short the 2nd. interlock relay control switch connecter). Use the Key unit matrix indicated on the control panel schematic and place a jumper wire between the pins that correspond to the STOP/CLEAR pad marking

Page 19

R-880F(S)

TEST PROCEDURES

PROCEDURE

LETTER COMPONENT TEST

momentary contact. If the control unit responds by clearing with a beep the key unit is faulty and must be replaced. If the control unit does not respond, it is a faulty and must be replaced. If a specific pad does not respond, the above method may be used (after clearing the control unit) to determine if the control unit or key pad is at fault.

CARRY OUT 3D CHECKS. Remove the outer case and check voltage between Pin No. 1 of the 3 pin connector (A) and the

common terminal of the relay RY6 on the control unit with an A.C. voltmeter. The meter should indicate 230-240 volts, if not check oven circuit.

Relay Test Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation, grill operation, convection operation or mix operation.

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

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

control unit is defective.

RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS

RY1 Approx. 24.0V D.C. Convection motor RY2 Approx. 24.0V D.C. High voltage transformer RY3 Approx. 24.0V D.C. Grill heaters (Top) RY4 Approx. 24.0V D.C. Bottom heater RY5 Approx. 24.0V D.C. Fan motor RY6 Approx. 24.0V D.C. Oven lamp / Turntable motor

CARRY OUT 4R CHECKS.

P RELAY TEST

PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD (PWB) IS OPEN

To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit on the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given below for repair. Problem: POWER ON, indicator does not light up.

CARRY OUT 3D CHECKS.

STEPS OCCURRENCE CAUSE OR CORRECTION

The rated AC voltage is not present between

Check supply voltage and oven power cord.

Pon No. 1 of the 3-pin connector (A) and the. common terminal of the relay RY6.

The rated AC voltage is present at primary Low voltage transformer or secondary circuit defective. side of low voltage transformer. Check and repair.

3 Only pattern at "a" is broken.

*Insert jumper wire J1 and solder. (CARRY OUT 3D CHECKS BEFORE REPAIR.)

4Pattern at "a" and "b" are broken.

*Insert the coil RCILF2003YAZZ between "c" and "d". (CARRY OUT 3D CHECKS BEFORE REPAIR.)

09876

G 8 G 7 G 6 G 5 G 4 G 3 G 2 G 1

G12 G11 G10 G 9

HELP

Pasta

160˚C 150˚C 130˚C 70˚C 40˚C

250˚C 230˚C 220˚C 200˚C 180˚C

Rice

EASY

DEFROST

PREHEAT

Fresh

Vegetables

Frozen

Vegetables

CONVENIENCE

/PIZZA

INSTANT

COOK/ START

REHEAT SENSOR

CONVEC

Jacket Potato

Reheat

Pie

POWER

LEVEL

GRILLCLOCK

MIX

STOP/

CLEAR

MULTI

COOK

LESS

CARRY OUT 4R CHECKS.

Page 20

R-880F(S)

NOTE: *At the time of these repairs, make a

visual inspection of the varistor for burning damage and examine the transformer with tester for the presence of layer short circuit (check primary coil resistance). If any abnormal condition is detected, replace the defective parts.

CARRY OUT 4R CHECKS.

TEST PROCEDURES

PROCEDURE

LETTER COMPONENT TEST

Checking the initial sensor cooking condition

(1) The oven should be plugged in at least two minutes before sensor cooking. (2) Room temperature should not exceed 35˚C. (3) The unit should not be installed in any area where heat and steam are generated. The unit should

not be installed, for example, next to a conventional surface unit. Refer to the "INSTALLATION Instructions" .

(4) Exhaust vents are provided on the back of the unit for proper cooling and air flow in the cavity. To

permit adequate ventilation, be sure to install so as not to block these vents. There should be some space for air circulation.

(5) Be sure the exterior of the cooking container and the interior of the oven are dry. Wipe off any

moisture with a dry cloth or paper towel.

(6) The Sensor works with food at normal storage temperature. For example, chicken pieces would

be at refrigerator temperature and canned soup at room temperature.

(7) Avoid using aerosol sprays or cleaning solvents near the oven while using Sensor settings. The

sensor will detect the vapor given of by the spray and turn off before food is properly cooked.

(8) After the oven is started on sensor cooking condition, if the sensor has not detected the vapor of

the food, ERROR will appear and the oven will shut off.

Water load cooking test

Make sure the oven has been plugged in at least five minutes before checking sensor cook operation. The cabinet should be installed and screws tightened. (1) Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup. (2) Place the container on the center of tray in the oven cavity. (3) Close the door. (4) Touch Fresh vegetables pad. Now, the oven is in the sensor cooking condition and "FRESH",

"VEGETABLES", "SENSOR" and "COOKING" will appear in the display.

(5) The oven will operate for the first 16 seconds, without generating microwave energy. When the AH sensor is defective (open or short), ERROR will appear in the display immediately.

If ERROR appears check sensor wire connections and/or AH sensor. NOTE: ERROR will appear if the door is opened or STOP/CLEAR pad is touched during first stage of

sensor cooking.

(6) After approximately 16 seconds, microwave energy is produced, and the display should start to

count down the remaining cooking time and oven should turn off after water is boiling (bubbling). If the oven does not turn off, replace the AH sensor or check the control unit, refer to explanation below.

TESTING METHOD FOR AH SENSOR AND/OR CONTROL UNIT

To determine if the sensor is defective, the simplest method is to replace it with a new replacement sensor. (1) Disconnect oven from power supply and then remove outer case. (2) Discharge the high voltage capacitor. (3) Remove the AH sensor. (4) Install the new AH sensor. (5) Re-install the outer case. (6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:

6-1. Fill approximately 200 milliliters (7.2 oz) of tap water in a 1000 milliliter measuring cup.

R AH SENSOR TEST

CN - A

VRS1

FAN

(J1)

Page 21

R-880F(S)

TEST PROCEDURES

PROCEDURE

LETTER COMPONENT TEST

6-2. Place the container on the center of tray in the oven cavity. 6-3. Close the door. 6-4. Touch Fresh Vegetables pad. 6-5. The control panel is in automatic Sensor operation. 6-6. The display will start to count down the remaining cooking time, and the oven will turn off

automatically after the water is boiling (babbling).

If new sensor dose not operate properly, the problem is with the control unit.

CHECKING CONTROL UNIT

(1) Disconnect oven from power supply and then remove outer case. (2) Discharge the high voltage capacitor. (3) Disconnect the wire leads from the cook relay. (4) Disconnect the sensor connector that is mounted to lower portion of control panel. (5) Then connect the dummy resistor circuit (see fig.) to the sensor connector of control panel. (6) Reconnect the oven to the power supply and check the sensor cook operation, proceed as follows:

6-1. Touch Fresh Vegetables pad. 6-2. The control panel is in the sensor cooking operation. 6-3. After approximately 1 minute and 15 seconds, push plunger of select switch. This condition

is same as judgement by AH sensor.

6-4. After approximately 3 seconds, the oven stops. If the above is not the case, the control unit is probably defective. If the above is proper, the AH sensor is probably defective.

R1,R2 : 22Ω ± 1% 1/2W

R3 :4.3kΩ ± 5% 1/4W R4 :1MΩ ± 5% 1/4W

Sensor Dummy Resistor Circuit

Plunger

NC NO

COM

R3 R4

1 2 3

F-1 F-2

F-3

To connector (F) on Control Unit.

CONNECTOR

Page 22

R-880F(S)

TOUCH CONTROL PANEL ASSEMBLY

OUTLINE OF TOUCH CONTROL PANEL

4) Reset Circuit

A circuit to generate a signal which resets the LSI to the initial state when power is supplied.

5) Buzzer Circuit

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

6) 2nd. Interlock Relay Control Switch A switch to "tell" the LSI if the door is open or closed.

7) Relay Circuit

To drive the magnetron, grill heaters, bottom heater, convection motor, fan motor, turntable motor, convection motor and light the oven lamp.

8) Back Light Circuit

A circuit to drive the back light (Light emitting diodes LD1 - LD10).

9) Indicator Circuit

This circuit consists of 2 line, 7-digits, 45-segments and 5-common electrodes using a Liquid Crystal Display.

10) Temperature Measurement Circuit : (OVEN THER-

MISTOR)

The temperature in the oven cavity is sensed by the thermistor. The variation of resistance according to sensed temperature is detected by the temperature measurement circuit and the result applied to LSI. The LSI uses this information to control the relay and display units.

11) Absolute Humidity Sensor Circuit

This circuit detects the humidity of a food which is being cooked, to control its automatic cooking.

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 CPU unit.)

The principal functions of these units and signals communicated among them are explained below.

Key Unit

The key unit is composed of a matrix, signals generated in the LSI are sent to the key unit from P40, P41, P72, P73 P74, P75, P76 and P77. When a key pad is touched, a signal is completed through the key unit and passed back to the LSI through P44 - P47 to perform the function that was requested.

Control Unit

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

1) LSI

This LSI controls the temperature measurement signal, AH sensor signal, key strobe signal, relay driving signal for oven function and indicator signal.

2) Power Source Circuit

This circuit generates voltage necessary in the control unit.

Symbol Voltage Application

VC -5.2V LSI(IC1)

3) 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.

DESCRIPTION OF LSI

LSI

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

Pin No. Signal I/O Description

1C1INTerminal not used. 2 VL1 IN Power source voltage input terminal.

Standard voltage for LCD. 3-5 AN7-AN5 IN Heating constant compensation terminal. 6 AN4 IN Terminal not used. 7 AN3 IN Temperature measurement input: OVEN THERMISTOR.

By inputting DC voltage corresponding to the temperature detected by the

thermistor, this input is converted into temperature by the A/D converter built

into the LSI.

Page 23

R-880F(S)

8 AN2 IN Input signal which communicates the door open/close information to LSI.

Door closed; "H" level signal. Door opened; "L" level signal.

9 AN1 IN AH sensor input.

This input is an analog input terminal from the AH sensor circuit, and connected to the A/D converter built into the LSI.

10 AN0 IN Used for initial balancing of the bridge circuit (absolute humidity sensor). This

input is an analog input terminal from the AH sensor circuit, and connected to the A/D converter built into LSI. This input is an analog input terminal from the AH sensor circuit, and connected to the A/D converter built into the LSI.

11 P57 OUT Timing signal output terminal for temperature measurement(OVEN

THERMISTOR).

"H" level (GND) : Thermistor OPEN timing. "L" level (-5V) : Temperature measuring timing. (Convection cooking)

12 P56 OUT Signal to sound buzzer.

A: key touch sound. B: Completion sound. C: When the temperature of the oven

cavity reaches the preset temperature in the preheating mode, or when the preheating hold time (30 minutes) is elapsed.

13 P55 OUT Timing signal output terminal for temperature measurement(OVEN

THERMISTOR).

"H" level (GND) : Thermistor OPEN timing.

"L" level (-5V) : Temperature measuring timing. (Convection cooking) 14-18 P54-P50 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor). 19 P47 IN Signal coming from touch key.

When any one of G12 line keys on key matrix is touched, a corresponding signal

from P40, P41, P72, P73, P74, P75, P76 and P77 will be input into P47. When no

key is touched, the signal is held at "L" level. 20 P46 IN Signal similar to P47.

When any one of G11 line keys on key matrix is touched, a corresponding signal

will be input into P46. 21 P45 IN Signal similar to P47.

When any one of G10 line keys on key matrix is touched, a corresponding signal

will be input into P45. 22 P44 IN Signal similar to P47.

When any one of G9 line keys on key matrix is touched, a corresponding signal will

be input into P44. 23 INT1 IN Terminal not used. 24 INT0 IN Signal to synchronized LSI with commercial power source

frequency(50Hz).

This is basic timing for time processing of LSI.

25 P41 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal

while one of G8 line key on matrix is touched. 26 P40 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal

while one of G7 line key on matrix is touched. 27 P77 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal

while one of G6 line key on matrix is touched. 28 P76 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal

while one of G5 line key on matrix is touched. 29 P75 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47

terminal while one of G4 line key on matrix is touched.

Pin No. Signal I/O Description

H: GND

0.12 sec

2.4 sec

1.2 sec

20 msec.

H : GND

L (-5V)

Page 24

R-880F(S)

Pin No. Signal I/O Description

30 P74 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G3 line key on matrix is touched.

31 P73 OUT

Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G2 line key on matrix is touched.

32 P72 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G1 line key on matrix is touched.

33 P71 OUT Oven lamp and turntable motor driving signal(Square Waveform : 50Hz).

To turn on and off shut-off relay (RY6). The square waveform voltage is delivered to the relay (RY6) driving circuit.

34 P70 IN Connected to VC. 35 RESET IN

Auto clear terminal.

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

36 P81 OUT Magnetron high-voltage circuit driving signal.

To turn on and off the cook relay (RY2). In 100% operation, the signals hold "L" level during microwave cooking and "H" level while not cooking. In other cooking modes (70%, 50%, 30%, 10%) the signal turns to "H" level and "L" level in repetition according to the power level.

37 P80 OUT Grill heaters (TOP HEATER) driving signal.

To turn on and off the grill heaters relay (RY3). "L" level during grill (TOP GRILL, TOP AND BOTTOM) cooking, Convection cooking or Mix top grill cooking, "H" level otherwise. The heater relay turns on and off within a 48 second time base in accordance with the special program in LSI.

38 XIN IN Internal clock oscillation frequency input setting.

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

39 XOUT OUT Internal clock oscillation frequency control output.

Output to control oscillation input of XOUT.

40 VSS IN Power source voltage: -5V.

VC voltage of power source circuit input.

41 P27 OUT Bottom heater driving signal.

To turn on and off the bottom relay (RY4). "L" level during grill (TOP AND BOTTOM) cooking, Convection cooking or Mix bottom cooking, "H" level otherwise. The heater relay turns on and off within a 48 second time base in accordance with the special program in LSI.

During cooking

20 msec.

ON/OFF time ratio in Micro cooking (a. 32second time base)

ON/OFF time ratio in Micro cooking (a. 48second time base)

MICRO ON OFF COOK

100% 32 sec. 0 sec.

70% 24 sec. 8 sec. 50% 18 sec. 14 sec. 30% 12 sec. 20 sec. 10% 6 sec. 26 sec.

MICRO ON OFF COOK

100% 48 sec. 0 sec.

70% 36 sec. 12 sec. 50% 26 sec. 22 sec. 30% 16 sec. 32 sec. 10% 8 sec. 40 sec.

Power output ON time OFF time

100 % 48 sec. 0 sec.

90 % 44 sec. 4 sec. 80 % 40 sec. 8 sec. 70 % 36 sec. 12 sec. 60 % 32 sec. 16 sec. 50 % 26 sec. 22 sec. 40 % 22 sec. 26 sec. 30 % 16 sec. 32 sec. 20 % 12 sec. 36 sec. 10 % 8 sec. 40 sec.

Power output ON time OFF time

100 % 48 sec. 0 sec.

90 % 44 sec. 4 sec. 80 % 40 sec. 8 sec. 70 % 36 sec. 12 sec. 60 % 32 sec. 16 sec. 50 % 26 sec. 22 sec. 40 % 22 sec. 26 sec. 30 % 16 sec. 32 sec. 20 % 12 sec. 36 sec. 10 % 8 sec. 40 sec.

Page 25

R-880F(S)

Pin No. Signal I/O Description

42 P26 OUT Convection motor driving signal.

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

"L" level during CONVECTION; "H" level

otherwise. (Relay RY1 does not turn on

at preheating mode.) 43 P25 OUT

Fan motor driving signal.

To turn on and off the fan motor relay

RY5. "L" level during cooking, or for 5

minutes after grill cooking or Mix cooking

for a while after convection. "H" level

otherwise. 44 P24 OUT Terminal not used. 45 P23 OUT Common data signal: COM5.

Connected to LCD (Pin No. 37) 46-48 P22-P20 OUT Segment data signal.

Connected to LCD. No connection in LCD. 49-50 P17-P16 OUT Segment data signal.

Connected to LCD. No connection in LCD. 51-80 SEG39-SEG10 OUT Segment data signal.

Connected to LCD.

The relation between signals are as follows:

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

SEG 0 (90) ....................SEG45 (51) SEG23 (67).................SEG17 (17)

SEG 1 (89) ....................SEG44 (50) SEG24 (66).................SEG16 (16)

SEG 2 (88) ....................SEG43 (49) SEG25 (65).................SEG15 (15)

SEG 3 (87) ....................SEG42 (48) SEG25 (65).................SEG15 (32)

SEG 4 (86) ....................SEG41 (47) SEG26 (64).................SEG14 (14)

SEG 5 (85) ....................SEG40 (46) SEG27 (63).................SEG13 (13)

SEG 6 (84) ....................SEG39 (45) SEG28 (62).................SEG12 (12)

SEG 7 (83) ....................SEG38 (44) SEG29 (61).................SEG11 (11)

SEG 8 (82) ....................SEG37 (43) SEG30 (60).................SEG10 (10)

SEG 9 (81) ....................SEG31 (31) SEG31 (59)...................SEG 9 ( 9)

SEG10 (80) ...................SEG30 (30) SEG32 (58)...................SEG 8 ( 8)

SEG11 (79) ...................SEG29 (29) SEG33 (57)...................SEG 7 ( 7)

SEG12 (78) ...................SEG28 (28) SEG34 (56)...................SEG 6 ( 6)

SEG13 (77) ...................SEG27 (27) SEG35 (55)...................SEG 5 ( 5)

SEG14 (76) ...................SEG26 (26) SEG36 (54)...................SEG 4 ( 4)

SEG15 (75) ...................SEG25 (25) SEG37 (53)...................SEG 3 ( 3)

SEG16 (74) ...................SEG24 (24) SEG38 (52)...................SEG 2 ( 2)

SEG17 (73) ...................SEG23 (23) SEG39 (51)...................SEG 1 ( 1)

SEG18 (72) ...................SEG22 (22) P16 (50) ......................SEG32 (38)

SEG19 (71) ...................SEG21 (21) P17 (49) ......................SEG33 (39)

SEG20 (70) ...................SEG20 (20) P20 (48) ......................SEG34 (40)

SEG21 (69) ...................SEG19 (19) P21 (47) ......................SEG35 (41)

SEG22 (68) ...................SEG18 (18) P22 (46) ......................SEG36 (42)

81 SEG9 OUT Segment data signal.

Connected to LCD. No connection in LCD. 82-90 SEG8-SEG0 OUT Segment data signal.

Connected to LCD. Signal is similar to SEG39. 91 VCC IN Connected to GND. 92 VREF IN Connected to GND. 93 AVSS IN Connected to VC.

94 COM3 OUT Common data signal: COM4.

Connected to LCD (Pin No. 36). 95 COM2 OUT Common data signal: COM3.

Connected to LCD (Pin No. 35). 96 COM1 OUT Common data signal: COM2.

Connected to LCD (Pin No. 34). 97 COM0 OUT Common data signal: COM1.

Connected to LCD (Pin No. 33). 98-99 VL3-VL2 IN Power source voltage input terminal.

Standard voltage for LCD. 100 C2 IN Terminal not used.

OFF

During

cooking

GND

(Convection)

OFF

During cooking or for 5 minutes after grill, mix or for awhile after convection.

GND

Page 26

R-880F(S)

(1)Structure of Absolute Humidity Sensor

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

(2)Operational Principle of Absolute Humidity Sensor

The figure below shows the basic structure of an absolute humidity sensor. A bridge circuit is formed by two thermistors and two resistors (R1 and R2). The output of the bridge circuit is to be amplified by the operational amplifier. Each thermistor is supplied with a current to keep it heated at about 150˚C (302˚F), the resultant heat is dissipated in the air and if the two thermistors are placed in different humidity conditions they show different degrees of heat conductivity leading to a potential difference between them causing an output voltage from the bridge circuit, the intensity of which is increased as the absolute humidity of the air increases. Since the output is very minute, it is amplified by the operational amplifier.

(3)Detector Circuit of Absolute Humidity Sensor Cir-

cuit

This detector circuit is used to detect the output voltage of the absolute humidity circuit to allow the LSI to control sensor cooking of the unit. When the unit is set in the sensor cooking mode, 16 seconds clearing cycle occurs than the detector circuit starts to function and the LSI observes the initial voltage available at its AN1 terminal.

ABSOLUTE HUMIDITY SENSOR CIRCUIT

With this voltage given, the switches SW1 to SW5 in the LSI are turned on in such a way as to change the resistance values in parallel with R107 ~ R111 of IC2. Changing the resistance values results in that there is the same potential at both F-3 terminal of the absolute humidity sensor and AN0 terminal of the LSI. The voltage of AN1 terminal will indicate about -2.5V. This initial balancing is set up about 16 seconds after the unit is put in the Sensor Cooking mode. As the sensor cooking proceeds, the food is heated to generate moisture by which the resistance balance of the bridge circuit is deviated to increase the voltage available at AN1 terminal of the LSI. Then the LSI observes that voltage at AN1 terminal and compares it with its initial value, and when the comparison rate reaches the preset value (fixed for each menu to be cooked), the LSI causes the unit to stop sensor cooking; thereafter, the unit goes in the next operation automatically. When the LSI starts to detect the initial voltage at AN1 terminal 16 seconds after the unit has been put in the Sensor Cooking mode, if it is not possible to balance, of the bridge circuit due to disconnection of the absolute humidity sensor, ERROR will appear on the display and the cooking is stopped.

1) Absolute humidity sensor circuit

ventilation opening for sensing

Sensing part (Open vessel)

Sensing part (Closed vessel)

Thermistors

SW1 SW2

SW3 SW4

SW5

P54

P53

P52 P51 P50

LSI (IC1)

AN0

AN1

620k

300k 150k

75k

37.4k

17 18

47k

IC2

10k

0.01uF

0.015uF

0.01uF

VA : -15V

R90

C101

C102

C103

C104

F-2

1.8k

F-1

F-3

3.57k

3.32k

VC : -5V

0.1

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

R107 R108

R112

R105

360k

R102

R101

R103

R104

D101

R109 R110

R111

R106

Operational amplifier

Output voltage

S : Thermistor open vessel

C : Thermistor closed vessel

Absolute humidity (g/m )

Output voltage

Absolute humidity vs, output voltage characterist

Page 27

R-880F(S)

1. Precautions for Handling Electronic Components

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

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

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

2. Shapes of Electronic Components

3. Servicing of Touch Control Panel

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

(1)Servicing the touch control panel with power

supply of the oven :

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

Therefore, before checking the performance of the touch

control panel,

1) Disconnect the power supply cord, and then remove

outer case.

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Disconnect the leads to the primary of the power

transformer.

5) Ensure that these leads remain isolated from other

components and oven chassis by using insulation tape.

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

After checking the performance of the touch control panel,

1) Disconnect the power supply cord.

2) Open the door and block it open.

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

transformer.

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

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

is installed.

6) Run the oven and check all functions.

SERVICING

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

touch control panel and the oven itself is so short that the two can't be separated.

For those models, check and repair all the controls (sensor-related ones included) of the touch control panel while keeping it connected to the oven.

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

touch control panel and the oven proper is long enough that they may be separated from each other. For those models, 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).

4. Servicing Tools

Tools required to service the touch control panel assembly.

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

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

3) Others: Hand tools

5. Other Precautions

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

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

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

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

5) Be sure to use specified components where high precision is required.

Transistor 2SB1238

Transistor KRC243M

approx. 1M ohm

Page 28

R-880F(S)

1. Disconnect the oven from power supply.

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

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

Carry out any remedial work that is necessary before operating the oven. Do not operate the oven if any of the following conditions exist;

1. Door does not close firmly.

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

3. The door gasket or seal or damaged.

4. The door is bent or warped.

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

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

7. There is visible damage to the oven.

Do not operate the oven:

1. Without the RF gasket (Magnetron).

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

3. If the door is not closed.

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

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

WARNING FOR WIRING

To prevent an electric shock, take the following manners.

1. Before wiring,

1) Disconnect the power supply.

2) Open the door and wedge the door open.

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

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

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

2) Hot parts: Oven lamp, Magnetron, Grill heaters, Bottom

heater, High voltage transformer and Oven cavity.

3) Sharp edge: Bottom plate, Oven cavity, Waveguide flange, Chassis support and other metallic plate.

4) Movable parts (to prevent a fault) Fan blade, Fan motor, Switch, Switch lever, Open button, Turntable motor, Convection motor.

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

4. Insert the positive lock connector certainly until its pin is locked. And make sure that the wire leads should not come off even if the wire leads is pulled.

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

OUTER CASE REMOVAL

To remove the outer case proceed as follows.

1. Disconnect oven from power supply.

2. Open the oven door and wedge it open.

3. Remove the two (2) screws holding the back plate to the oven cavity rear plate.

4. Remove the back plate.

5. Remove the five (5) screws from rear and along the side edge of case.

6. Slide the entire case back about 3cm to free it from

retaining clips on the cavity face plate.

7. Lift the entire case from the oven.

8. Discharge the H.V. capacitor before carrying out any further work.

9. Do not operate the oven with the outer case removed.

N.B.; Step 1, 2 and 8 form the basis of the 3D checks.

CAUTION: DISCHARGE HIGH VOLTAGE CAPACITOR

BEFORE TOUCHING ANY OVEN COMPONENT OR WIRING.

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

WARNING: Avoid possible exposure to microwave energy. Please follow the instructions below before

operating the oven.

HIGH VOLTAGE COMPONENTS REMOVAL

(HIGH VOLTAGE CAPACITOR, HIGH VOLTAGE RECTIFIER ASSEMBLY AND HIGH VOLTAGE FUSE)

To remove the components, proceed as follows.

1. CARRY OUT 3D CHECKS.

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

3. Disconnect the high voltage fuse from the high voltage transformer.

4. Now, the high voltage fuse is free.

5. Remove one (1) screw holding earth side terminal of

Page 29

R-880F(S)

HIGH VOLTAGE TRANSFORMER REMOVAL

1. CARRY OUT 3D CHECKS.

2. Disconnect the filament leads of high voltage transformer from high voltage capacitor and the magnetron.

3. Disconnect the high voltage fuse from the high voltage transformer.

4. Disconnect the main wire harness from the high volt-

age transformer.

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

6. Remove the transformer.

7. Now the high voltage transformer is free.

1. CARRY OUT 3D CHECKS.

2. Release the tabs of air intake duct from the chassis support and the oven cavity.

3. Disconnect the high voltage wire of the high voltage rectifier assembly and filament lead of the transformer from the magnetron.

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

5. Move the air intake duct to left.

6. Carefully remove four (4) screws holding magnetron to

waveguide, when removing the screws hold the magnetron to prevent it from falling.

7. Remove the magnetron from the waveguide with care so the magnetron antenna is not hit by any metal object around the antenna.

CAUTION: WHEN REPLACING THE MAGNETRON,

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

MAGNETRON REMOVAL

POSITIVE LOCK® CONNECTOR (NO-CASE TYPE) REMOVAL

1. CARRY OUT 3D CHECKS.

2. Push the lever of positive lock® connector.

3. Pull down on the positive lock® connector. CAUTION: WHEN CONNECTING THE POSITIVE

LOCK® CONNECTORS TO THE TERMINALS, INSTALL THE POSITIVE LOCK

CONNECTOR SO THAT THE LEVER FACES YOU

Figure C-1 Positive lock® connector

11.Release the two (2) tabs of the LCD holder holding the CPU unit to the LCD holder.

12.Remove the LCD holder from the CPU unit.

13.Remove the two (2) screws holding the power unit to the control panel frame.

14.Release the four (4) tabs of the control panel frame holding the power unit to the control panel frame.

1 5. Now, the control unit (CPU unit + Power unit) is free. NOTE: 1. Before attaching a new key unit, wipe off re-

maining adhesive on the control panel frame surfaces completely with a soft cloth soaked in alcohol.

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

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

CONTROL PANEL ASSEMBLY

1. CARRY OUT 3D CHECKS.

2. Disconnect the main wire harness, thermistor harness, AH sensor harness and the switch harness from the power unit and control unit.

3. Straighten the tab of the oven cavity front flange holding the tab of the control panel frame.

4. Lift up the control panel assembly.

5. Now, the control panel assembly is free.

CONTROL UNIT

Disconnect the flat ribbon cable from the connector CN-G.

7. Remove the two (2) screws holding the CPU unit to the control panel frame.

8. Release the four (4) tabs of the control panel frame holding the CPU unit to the control panel frame.

9. Release the liquid crystal display (LCD) from the LCD holder.

10.Now, the LCD sheet is free.

CONTROL PANEL ASSEMBLY REMOVAL

the high voltage rectifier assembly.

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

7. Release the capacitor holder from the fan duct.

8. Remove the capacitor from the capacitor holder.

9. Now, high voltage rectifier assembly and the capacitor should be free.

CAUTION: WHEN REPLACING HIGH VOLTAGE

RECTIFIER ASSEMBLY, ENSURE THAT THE CATHODE (EARTH) CONNECTION IS SECURELY FIXED TO THE CAPACITOR HOLDER AND BASE PLATE WITH AN EARTHING SCREW.

Terminal

Push

Pull down

Lever

Positive lock® connector

Page 30

R-880F(S)

REMOVAL

1. CARRY OUT 3D CHECKS.

2. Remove the one (1) screw holding the noise filter to the chassis support.

3. Release the noise filter from the tab on the fan duct.

4. Disconnect the wire leads from the fan motor.

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

6. Remove the one (1) screw holding the fan duct to the oven cavity rear plate.

7. Release the tabs of the capacitor holder from fan duct.

8. Remove the fan duct from the oven.

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

1) 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.

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

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

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

3) Now, the fan blade will be free.

CAUTION:

• Once the fan blade has been removed, it

must be replaced with a new one.

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

11.Now, the fan motor is free.

INSTALLATION

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

screws.

2. Fix the fan blade to the fan motor shaft according to

the following procedure.

1) Hold the centre of the bracket which supports the shaft of the fan motor on a flat table.

2) Install the fan blade to the shaft of fan motor by pushing the fan blade with a small, light weight, ball peen hammer or rubber mallet.

CAUTION:

• Do not hit the fan blade when installing it

because the bracket may be deformed.

• Make sure that the fan blade rotates smoothly

after installation.

FAN MOTOR REPLACEMENT

1. CARRY OUT 3D CHECKS.

2. Now, the back plate with the sub back plate should be removed.

3. Disconnect the connector CN-F from the control unit.

1. CARRY OUT 3D CHECKS.

2. Now, the back plate with the sub back plate should be removed.

3. Disconnect the connector CN-D from the control unit.

4. Remove the one (1) screw holding the air duct to the oven cavity rear plate.

5. Remove the air duct assembly from the oven cavity rear plate.

THERMISTOR REMOVAL

6. Remove the one (1) screw holding the thermistor angle to the oven cavity rear plate.

7. Remove the thermistor angle together with thermistor from the oven.

8. Straighten the tab of the thermistor angle holding the thermistor to the thermistor angle.

9. Remove the thermistor from the thermistor angle.

AH SENSOR ASSEMBLY REMOVAL

4. Remove the two (2) screws holding the AH sensor assembly to air duct assembly.

5. Now, the AH sensor assembly is free.

1. CARRY OUT 3D CHECKS.

2. Now, the back plate with the sub back plate should be removed.

3. Disconnect the wire leads from the convection motor.

4. Remove the two (2) screws holding the conv. thermal cover to the oven cavity rear plate.

5. Remove the four (4) screws holding the convection duct to the oven cavity rear plate.

6. Remove the convection duct assembly from the oven cavity rear plate.

7. Remove the one (1) nut and the two (2) washers holding the convection fan to the convection motor shaft.

8. Remove the convection fan.

Remove the three (3) screws holding the convection

CONVECTION MOTOR REMOVAL

duct to the conv. thermal cover.

10.

Remove the convection duct with the conv. air angles from the conv. thermal cover.

11.Remove the thermal insulation.

12.

Remove the one (1) pipe holding the cooling fan to the convection motor shaft.

13.

Remove the cooling fan and the one (1) washer from the convection motor shaft.

14.

Remove the two (2) screws holding the convection motor to the conv. thermal cover.

15.

Remove the convection motor from the conv. thermal cover.

16.

Remove the one (1) ring from the convection motor shaft.

17.

Now, the convection motor is free.

Page 31

R-880F(S)

Removal

1. CARRY OUT 3D CHECKS.

2. Remove the one (1) screw holding the green/yellow wire to the cavity rear plate.

3. Disconnect the leads of the power supply cord from the noise filter, referring to the Figure C-2(a).

4. Release the power supply cord from the oven cavity rear plate.

5. Now, the power supply cord is free.

Re-install

1. Insert the moulding cord stopper of power supply cord into the square hole of the oven cavity rear plate, referring to the Figure C-2(b).

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

3. Connect the brown and blue wire leads of power supply cord to the noise filter correctly, referring to the Pictorial Diagram.

POWER SUPPLY CORD REPLACEMENT

Figure C-2 (a) Replacement of Power Supply Cord Figure C-2(b). Power Supply Cord Replacement

1. Disconnect the oven from the power supply.

2. Remove the turntable motor cover by snipping of material in four corners.

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

4. Disconnect the wire leads from the turntable motor and

TURNTABLE MOTOR REPLACEMENT

remove the two (2) screws holding the turntable motor.

5. Now, the turntable motor is free.

6. After replacement use the one (1) screw provided with the turntable motor assembly to fit turntable motor cover.

NOTE: The one (1) screw to fit the turntable motor cover

should be XHTSD40P08RV0.

OVEN LAMP REMOVAL

1. CARRY OUT 3D CHECKS.

2. Screw the oven lamp from the oven lamp socket off.

3. Pull the wire leads from the oven lamp socket by pushng the terminal hole of the oven lamp socket with the flat type screw driver.

4. Lift up the oven lamp socket from the air intake duct.

5. Now, the oven lamp socket is free.

Rear view Side view

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

3. Install the fan duct to the oven cavity rear plate with the one (1) screw.

4. Insert the tabs of the capacitor holder to the fan duct.

5. Install the capacitor holder to the oven cavity rear plate with the one (1) screw.

6. Install the noise filter to the fan duct and the chassis support with the one (1) screw.

7. Re-connect the wire leads to the fan motor.

Gap

Rotor

Bracket

Stator

Groove joint pliers

Coil

Shaft

Axis

Stator

Rotor

These are the positions that should be pinched with pliers.

Shaft

Table

Center of bracket

Oven lamp socket

Terminal

Wire lead

Terminal hole

Flat type small screw driver

Power Supply Cord

Moulding Cord Stopper

Oven Cavity Rear Plate

Square Hole

Power Supply Cord

Chassis Support

WHT

RED

T1 T2

Screw

Green/Yelow Wire

Brown Wire

Noise Filter

Bule Wire

Oven Cavity Back Plate

Page 32

R-880F(S)

If the 1st. latch switch, 2nd. interlock relay control switch and monitor switch do not operate properly due to a misadjustment, the following adjustment should be made.

1. CARRY OUT 3D CHECKS.

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

3. With the door closed, adjust the latch hook by moving it back and forward or up and down. In and out play of the door allowed by the latch hook should be less than

0.5 mm. The horizontal position of the latch hook should be placed where the monitor switch has activated with the door closed. The vertical position of the latch hook should be placed where the 1st. latch switch and 2nd. interlock relay control switch have activated with the door closed.

4. Secure the screws with washers firmly.

5. Make sure of the 1st. latch switch, 2nd. interlock relay control switch and monitor switch operation. If those switches have not activated with the door closed, two (2) screw holding latch hook to oven cavity front flange and adjust the latch hook position.

After adjustment, make sure of following:

1. In and out play of door remains less than 0.5 mm when

1ST. LATCH SWITCH, 2ND. INTERLOCK RELAY CONTROL SWITCH AND

MONITOR SWITCH ADJUSTMENT

latched position. First check latch hook position, pushing and pulling the door toward the oven face. The results (play of the door) should be less than 0.5mm.

2. The contacts (COM-NO) of the 1st. latch switch and 2nd. interlock relay control switch interrupt the circuit before the door can be opened.

3. The contacts (COM-NC) of the monitor switch close when the door is opened.

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

Figure C-4 Latch Switches Adjustment

GRIL HEATERS (TOP HEATERS) REMOVAL

1. CARRY OUT 3D CHECKS.

2. Remove the one (1) screw holding the exhaust duct to the oven cavity.

2. Remove the exhaust duct from the oven cavity.

4. Disconnect the wire leads from the grill heaters.

5. Lay down the two (2) tabs holding the reflector to the oven cavity.

6. Remove the reflector from the oven cavity by sliding it leftward.

7. Remove the grill heaters and the short terminal together from the oven cavity top plate.

8. Remove the two (2) screws holding the short terminal to the grill heaters.

9. Now the individual grill heaters are free.

BOTTOM HEATER REMOVAL

1. CARRY OUT 3D CHECKS

2. Remove the fan duct from the oven cavity, referring to "FAN MOTOR REPLACEMENT".

3. Disconnect the wire leads from the bottom heater.

4. Remove the two (2) nuts holding the bottom heater with the bottom heater angle and the heat seal spring to the

oven cavity right wall.

5. Remove the two (2) nuts holding the bottom heater with the bottom heater angle and the heat seal spring to the oven cavity left wall.

6. Remove the bottom heater from the oven cavity .

1. CARRY OUT 3D CHECKS.

2. Remove the control panel assembly referring to "CONTROL PANEL ASSEMBLY REMOVAL".

3. Disconnect the leads from all switches.

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

5. Remove the latch hook.

6. Push the retaining tab slightly and remove the switch.

1ST. LATCH SWITCH, 2ND. INTERLOCK RELAY CONTROL SWITCH AND

MONITOR SWITCH REMOVAL

Figure C-3. Switches

Tab

1st. Latch Switch

2nd. Interlock Relay Control Switch

Monitor Switch

Latch Hook

Latch Heads

Door

1st. Latch Switch

Monitor Switch

Switch Lever

2nd. Interlock Relay Control Switch

Page 33

R-880F(S)

Figure C-6. Door Replacement

REMOVAL

1. CARRY OUT 3D CHECKS.

2. Push the open button and open the door slightly.

3. Insert an putty knife (thickness of about 0.5mm) into the gap between the choke cover and door frame as shown in Figure C-5 to free engaging parts.

4. Pry the choke cover by inserting a putty knife as shown in Figure C-5.

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.

Figure C-5. 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 sub assembly is free from oven cavity.

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

10.Release door panel from seven (7) tabs of door frame by sliding door panel downward.

11.Now, door panel is free.

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

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

14.Remove the two (2) screws holding the glass stopper to the door frame.

15.Remove the glass stopper from the door frame.

16.Slide the front door glass left and then slide upwards to release the tabs holding it.

17.Now, the front door glass is free

RE-INSTALL

1. Re-install the front door glass to the door frame as follows.

1) Insert the lower edge of the front door glass into the six (6) tabs of the door frame.

2) Slide the front door glass upwards and insert the upper edge of the front door glass into the five (5) tabs of the door frame.

3) Slide the front door glass righ and insert the right edge of the front door glass into the two (2) tabs of the door frame.

2. Re-install the glass stopper to the door frame as follows.

1) Re-install the glass stopper to the door frame so that the two (2) holes of the glass stopper meet the two (2) pins of the door frame.

2) Hold the glass stopper to the door frame with the two (2) screws.

DOOR REPLACEMENT

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

4. Re-install door panel to door frame by fitting seven (7) tabs of door frame to seven (7) holes of door panel.

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

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

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

Note: After any service to the door; (A) Make sure that 1st. latch switch, 2nd. interlock

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

(B) An approved microwave survey meter should be

used to assure compliance with proper microwave radiation emission limitation standards. (Refer to Microwave Measurement Procedure.)

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 centre 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 lighttight. Therefore, occasional appearance of moisture, light or sensing of gentle warm air movement around oven door is not abnormal and do not in themselves indicate a leakage of microwave energy from oven cavity.

Putty Knife

Door Frame

Choke Cover

Upper Oven Hinge

Lower Oven Hinge

Choke Cover

Slit Choke

Door Panel

Page 34

R-880F(S)

MICROWAVE MEASUREMENT

After adjustment of door latch switches, monitor switch and door are completed individually or collectively, the following leakage test must be performed with a survey instrument and it must be confirmed that the result meets the requirements of the performance standard for microwave oven.

REQUIREMENT

The safety switch must prevent microwave radiation emission in excess of 5mW/cm2 at any point 5cm or more from external surface of the oven.

PREPARATION FOR TESTING:

Before beginning the actual test for leakage, proceed as follows;

1. Make sure that the test instrument is operating normally as specified in its instruction booklet. Important: Survey instruments that comply with the requirement for instrumentations as prescribed by the performance standard for microwave ovens must be used for testing.

Recommended instruments are: NARDA 8100 NARDA 8200 HOLADAY HI 1500 SIMPSON 380M

2. Place the oven tray into the oven cavity.

3. Place the load of 275 ± 15ml of water initially at 20 ± 5˚C in the centre of the oven tray. The water container should be a low form of 600 ml beaker with inside diameter of approx. 8.5cm and made of an electrically non-conductive 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. Close the door and turn the oven ON with the timer set for several minutes. If the water begins to boil before the survey is completed, replace it with 275ml of cool water.

5. Move the probe slowly (not faster that 2.5cm/sec.) along the gap.

6. The microwave radiation emission should be measured at any point of 5cm or more from the external surface of the oven.

mW cm

Microwave leakage measurement at 5 cm distance

Page 35

R-880F(S)

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. MICROWAVE POWER LEVEL PAD PRESSED ONCE(100%).

3. COOKING TIME PROGRAMMED.

4. START PAD TOUCHED.

Figure O-2 Oven Schematic-Microwave cooking Condition

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. : OR CLOCK APPEAR ON DISPLAY.

NOTE: Indicates components with potential above 250 V.

Figure O-1 Oven Schematic-OFF Condition

TTM

OVEN LAMP

FAN MOTOR

CONVECTION

MOTOR

TURNTABLE

MOTOR

H.V. RECTIFIER

CONTROUNIT

COM.

N.O.

COM.

N.O. N.O.

N.O.

LINE BYPASS CAPACITOR

0.0033µF/ 250V

LINE BYPASS CAPACITOR

0.0033µF/ 250V

RESISTOR 10M/ 0.5W

NOISE SUPPRESSION COIL

RESISTOR 680 k/ 0.5W

LINE CROSS CAPACITOR

0.22µ/250V

NOISE FILTER UNIT

THERMISTOR

BRNBLU

G-Y

EARTH

LIVENEUTRAL

RY4

RY3

RY2

RY6

RY5

RY1

CAPACITOR

1.07µF

AC2200V

GRILL HEATER (TOP)

BOTTOM HEATER

MAGNETRON

HIGH VOLTAGE

TRANSFORMER

F1F3F2

1ST. LATCH SWITCH

THERMAL CUT-OUT (MG.)

THERMAL CUT-OUT(OVEN)

FUSE 15A

230 - 240 V

50Hz

HIGH VOLTAGE

FUSE 0.75A

2ND. INTERLOCK

RELAY CONTROL

SWITCH

RY2: 2ND. INTERLOCK RELAY

MONITOR SWITCH

FUSE F10A

AH SENSOR

TTM

OVEN LAMP

FAN MOTOR

CONVECTION

MOTOR

TURNTABLE

MOTOR

H.V. RECTIFIER

CONTROUNIT

COM.

N.O.

COM.

N.O. N.O.

N.O.

LINE BYPASS CAPACITOR

0.0033µF/ 250V

LINE BYPASS CAPACITOR

0.0033µF/ 250V

RESISTOR 10M/ 0.5W

NOISE SUPPRESSION COIL

RESISTOR 680 k/ 0.5W

LINE CROSS CAPACITOR

0.22µ/250V

NOISE FILTER UNIT

THERMISTOR

BRNBLU

G-Y

EARTH

LIVENEUTRAL

RY4

RY3

RY2

RY6

RY5

RY1

CAPACITOR

1.07µF

AC2200V

GRILL HEATER (TOP)

BOTTOM HEATER

MAGNETRON

HIGH VOLTAGE

TRANSFORMER

F1F3F2

1ST. LATCH SWITCH

THERMAL CUT-OUT (MG.)

THERMAL CUT-OUT(OVEN)

FUSE 15A

230 - 240 V

50Hz

HIGH VOLTAGE

FUSE 0.75A

2ND. INTERLOCK

RELAY CONTROL

SWITCH

RY2: 2ND. INTERLOCK RELAY

MONITOR SWITCH

FUSE F10A

AH SENSOR

Page 36

R-880F(S)

Figure O-3(b) Oven Schematic-Grill cooking Condition (BOTTOM HEATER mode)

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. GRILL PAD TOUCHED TWICE.

3. COOKING TIME PROGRAMMED.

4. STRAT PAD TOUCHED.

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. GRILL PAD TOUCHED ONCE.

3. COOKING TIME PROGRAMMED.

4. STRAT PAD TOUCHED.

Figure O-3(a) Oven Schematic-Grill cooking Condition (TOP HEATER mode)

TTM

OVEN LAMP

FAN MOTOR

CONVECTION

MOTOR

TURNTABLE

MOTOR

H.V. RECTIFIER

CONTROUNIT

COM.

N.O.

COM.

N.O. N.O.

N.O.

LINE BYPASS CAPACITOR

0.0033µF/ 250V

LINE BYPASS CAPACITOR

0.0033µF/ 250V

RESISTOR 10M/ 0.5W

NOISE SUPPRESSION COIL

RESISTOR 680 k/ 0.5W

LINE CROSS CAPACITOR

0.22µ/250V

NOISE FILTER UNIT

THERMISTOR

BRNBLU

G-Y

EARTH

LIVENEUTRAL

RY4

RY3

RY2

RY6

RY5

RY1

CAPACITOR

1.07µF

AC2200V

GRILL HEATER (TOP)

BOTTOM HEATER

MAGNETRON

HIGH VOLTAGE

TRANSFORMER

F1F3F2

1ST. LATCH SWITCH

THERMAL CUT-OUT (MG.)

THERMAL CUT-OUT(OVEN)

FUSE 15A

230 - 240 V

50Hz

HIGH VOLTAGE

FUSE 0.75A

2ND. INTERLOCK

RELAY CONTROL

SWITCH

RY2: 2ND. INTERLOCK RELAY

MONITOR SWITCH

FUSE F10A

AH SENSOR

TTM

OVEN LAMP

FAN MOTOR

CONVECTION

MOTOR

TURNTABLE

MOTOR

H.V. RECTIFIER

CONTROUNIT

COM.

N.O.

COM.

N.O. N.O.

N.O.

LINE BYPASS CAPACITOR

0.0033µF/ 250V

LINE BYPASS CAPACITOR

0.0033µF/ 250V

RESISTOR 10M/ 0.5W

NOISE SUPPRESSION COIL

RESISTOR 680 k/ 0.5W

LINE CROSS CAPACITOR

0.22µ/250V

NOISE FILTER UNIT

THERMISTOR

BRNBLU

G-Y

EARTH

LIVENEUTRAL

RY4

RY3

RY2

RY6

RY5

RY1

CAPACITOR

1.07µF

AC2200V

GRILL HEATER (TOP)

BOTTOM HEATER

MAGNETRON

HIGH VOLTAGE

TRANSFORMER

F1F3F2

1ST. LATCH SWITCH

THERMAL CUT-OUT (MG.)

THERMAL CUT-OUT(OVEN)

FUSE 15A

230 - 240 V

50Hz

HIGH VOLTAGE

FUSE 0.75A

2ND. INTERLOCK

RELAY CONTROL

SWITCH

RY2: 2ND. INTERLOCK RELAY

MONITOR SWITCH

FUSE F10A

AH SENSOR

NOTE: Indicates components with potential above 250 V.

Page 37

R-880F(S)

SCHEMATIC

NOTE: CONDITION OF OVEN FOR GRILL COOKING

1. DOOR CLOSED.

GRILL PAD THREE TIMES.

3. COOKING TIME PROGRAMMED.

4. STRAT PAD TOUCHED.

Figure O-3(c) Oven Schematic-Grill cooking Condition (TOP AND BOTTOM HEATERS mode)

SCHEMATIC

NOTE: CONDITION OF OVEN FOR GRILL COOKING

1. DOOR CLOSED.

CONVECTION PAD

TOUCHED

TEMPERATURE PAD

TOUCHED

4. COOKING TIME PROGRAMMED.

5. STRAT PAD TOUCHED.

Figure O-4 Oven Schematic-Convection cooking Condition

TTM

OVEN LAMP

FAN MOTOR

CONVECTION

MOTOR

TURNTABLE

MOTOR

H.V. RECTIFIER

CONTROUNIT

COM.

N.O.

COM.

N.O. N.O.

N.O.

LINE BYPASS CAPACITOR

0.0033µF/ 250V

LINE BYPASS CAPACITOR

0.0033µF/ 250V

RESISTOR 10M/ 0.5W

NOISE SUPPRESSION COIL

RESISTOR 680 k/ 0.5W

LINE CROSS CAPACITOR

0.22µ/250V

NOISE FILTER UNIT

THERMISTOR

BRNBLU

G-Y

EARTH

LIVENEUTRAL

RY4

RY3

RY2

RY6

RY5

RY1

CAPACITOR

1.07µF

AC2200V

GRILL HEATER (TOP)

BOTTOM HEATER

MAGNETRON

HIGH VOLTAGE

TRANSFORMER

F1F3F2

1ST. LATCH SWITCH

THERMAL CUT-OUT (MG.)

THERMAL CUT-OUT(OVEN)

FUSE 15A

230 - 240 V

50Hz

HIGH VOLTAGE

FUSE 0.75A

2ND. INTERLOCK

RELAY CONTROL

SWITCH

RY2: 2ND. INTERLOCK RELAY

MONITOR SWITCH

FUSE F10A

AH SENSOR

TTM

OVEN LAMP

FAN MOTOR

CONVECTION

MOTOR

TURNTABLE

MOTOR

H.V. RECTIFIER

CONTROUNIT

COM.

N.O.

COM.

N.O. N.O.

N.O.

LINE BYPASS CAPACITOR

0.0033µF/ 250V

LINE BYPASS CAPACITOR

0.0033µF/ 250V

RESISTOR 10M/ 0.5W

NOISE SUPPRESSION COIL

RESISTOR 680 k/ 0.5W

LINE CROSS CAPACITOR

0.22µ/250V

NOISE FILTER UNIT

THERMISTOR

BRNBLU

G-Y

EARTH

LIVENEUTRAL

RY4

RY3

RY2

RY6

RY5

RY1

CAPACITOR

1.07µF

AC2200V

GRILL HEATER (TOP)

BOTTOM HEATER

MAGNETRON

HIGH VOLTAGE

TRANSFORMER

F1F3F2

1ST. LATCH SWITCH

THERMAL CUT-OUT (MG.)

THERMAL CUT-OUT(OVEN)

FUSE 15A

230 - 240 V

50Hz

HIGH VOLTAGE

FUSE 0.75A

2ND. INTERLOCK

RELAY CONTROL

SWITCH

RY2: 2ND. INTERLOCK RELAY

MONITOR SWITCH

FUSE F10A

AH SENSOR

Page 38

R-880F(S)

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. MIX PAD TOUCHED THREE TIMES/FOUR TIMES.

3. COOKING TIME PROGRAMMED.

4. STRAT PAD TOUCHED.

Figure O-5(b) Oven Schematic-Mix cooking Condition (High Mix Bottom Grill mode / Low Mix Bottom Grill mode)

Figure O-5(a) Oven Schematic-Mix cooking Condition (High Mix Top Grill mode / Low Mix Top Grill mode)

NOTE: The microwave relay RY2 and heater relay RY3 could not turn on simultaneously.

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. MIX PAD TOUCHED ONCE/TWICE.

3. COOKING TIME PROGRAMMED.

4. STRAT PAD TOUCHED.

NOTE: The microwave relay RY2 and heater relay RY4 could not turn on simultaneously.

TTM

OVEN LAMP

FAN MOTOR

CONVECTION

MOTOR

TURNTABLE

MOTOR

H.V. RECTIFIER

CONTROUNIT

COM.

N.O.

COM.

N.O. N.O.

N.O.

LINE BYPASS CAPACITOR

0.0033µF/ 250V

LINE BYPASS CAPACITOR

0.0033µF/ 250V

RESISTOR 10M/ 0.5W

NOISE SUPPRESSION COIL

RESISTOR 680 k/ 0.5W

LINE CROSS CAPACITOR

0.22µ/250V

NOISE FILTER UNIT

THERMISTOR

BRNBLU

G-Y

EARTH

LIVENEUTRAL

RY4

RY3

RY2

RY6

RY5

RY1

CAPACITOR

1.07µF

AC2200V

GRILL HEATER (TOP)

BOTTOM HEATER

MAGNETRON

HIGH VOLTAGE

TRANSFORMER

F1F3F2

1ST. LATCH SWITCH

THERMAL CUT-OUT (MG.)

THERMAL CUT-OUT(OVEN)

FUSE 15A

230 - 240 V

~ 50Hz

HIGH VOLTAGE

FUSE 0.75A

2ND. INTERLOCK

RELAY CONTROL

SWITCH

RY2: 2ND. INTERLOCK RELAY

MONITOR SWITCH

FUSE F10A

AH SENSOR

TTM

OVEN LAMP

FAN MOTOR

CONVECTION

MOTOR

TURNTABLE

MOTOR

HIGH VOLTAGE

FUSE 0.75A

H.V. RECTIFIER

CONTROUNIT

COM.

N.O.

COM.

N.O. N.O.

N.O.

LINE BYPASS CAPACITOR

0.0033µF/ 250V

LINE BYPASS CAPACITOR

0.0033µF/ 250V

RESISTOR 10M/ 0.5W

NOISE SUPPRESSION COIL

RESISTOR 680 k/ 0.5W

LINE CROSS CAPACITOR

0.22µ/250V

NOISE FILTER UNIT

2ND. INTERLOCK

RELAY CONTROL

SWITCH

RY2: 2ND. INTERLOCK RELAY

THERMISTOR

BRNBLU

G-Y

EARTH

LIVENEUTRAL

RY4

RY3

RY2

RY6

RY5

RY1

CAPACITOR

1.07µF

AC2200V

GRILL HEATER (TOP)

BOTTOM HEATER

MAGNETRON

HIGH VOLTAGE

TRANSFORMER

F1F3F2

1ST. LATCH SWITCH

THERMAL CUT-OUT (MG.)

THERMAL CUT-OUT(OVEN)

MONITOR SWITCH

FUSE 15A

FUSE F10A

230 - 240 V ~ 50Hz

AH SENSOR

NOTE: Indicates components with potential above 250 V.

Page 39

R-880F(S)

23456

123456

RED

WHT

THERMAL

CUT-OUT

(OVEN)

THERMAL

CUT-OUT

125

°C(MG)

FAN

MOTOR

CONVECTION

MOTOR

WHT

BLK

WHT

RED

BRN

WHT

HIGH VOLTAGE COMPONENTS

G–Y

BLU

BRN

WHT

RED

NOISE

FILTER

POWER SUPPLY

CORD

WHT

COM

WHT

RED

WHT

N.C.

N.O.

COM.

GRILL HEATER

BOTTOM HEATING

ELEMENT

WHT

ORG

CN-B

WHT

GRY

RED

BRN

BLK

TURNTABLE

MOTOR

MONMITOR

SWITCH

1ST.

LATCH

SWITCH

GRY

WHT

453

RED

ORG

GRY

GRN

GRY

CN-A

NEUTRAL

LIVE

EARTH

15A

F10A

RED WHT

BRN

ORG

GRN

GRY

N.O.

COM.

2ND. INTERLOCK

RELAY CONTROL

SWITCH

RED

ORG

BRN

WHT

BLK

AH SENSOR

RED

WHT

123

CN-F

THERMISTOR

CN-B

SP1

RY6

RY2

RY4

RY3

CONTROL PANEL

CN-A

RY5

CN-D

CN-F

CN-C

CN-G

BLK

BRN

ORG

RY1

RED

BRN

ORG

BLK

CN-D

RED

WHT

MAGNETRON

H.V.

CAPACITOR

H.V.

RECTIFIER

H.V. FUSE

HIGH VOLTAGE

TRANSFORMER

OVEN LAMP

& SOCKET

NOTE:

Neutral (WHT) wire must

be connected to the ter-

minal with black mark on

the oven light socket.

BLACK MARK

Figure S-1. Pictrorial Diagram

Page 40

R-880F(S)

Figure S-2. Power Unit Circuit

23456

123456

–

+ –

–

COM

N.O.

COM

N.O.

COM

N.O.

COM

N.O.

A 3

OVEN LAMP TURNTABLE MOTOR

BOTTOM HEATER

TOP HEATER

MICRO

OVEN THERMISTOR

AC230-240V 50Hz

LED

GND

VC VA

VR INT

BUZZER

FAN MOTOR

CONVECTION MOTOR

N.C.

OVEN THERMISTOR

N.C.

MICRO

OVEN LAMP TURNTABLE MOTOR

BOTTOM HEATER

TOP HEATER

2ND. INTERLOCK RELAY CONTROL SWITCH

FAN MOTOR

CONVECTION MOTOR

Q2 2SB1238

R4 27

R5 4.7k

R3 510 1/2w

R2 680 1/2w

RY5

RY6

RY4

Q3 KRC243M

C5 10µ/35v

RY3

RY2

R6 3.3k

SP1

2SB1238

D1-4 1N4002

VRS1

(J1)

C1 0.1µ/50v

C3 0.1µ/50v

ZD1

R1 2.4k

HZ16-1

D12D11

RY1

D7D10D9D8

C4 10µ/35v

C2 1000µ/35v

10G471K

A 1

B 2 B 1D 3 D 1

C12

C13

C17

C 7

C11

C 8

C14

C 6

C16

C15

C 5

C 4

C 9

C 1

C 3

C 2

C10

NOTE : IF NOT SPECIFIED, 1/4w ± 5%

: IF NOT SPECIFIED, 1SS270A

A 5

Page 41

R-880F(S)

23456

123456

C 4

INT

GND

BUZZER

: IF NOT SPECIFIED, 1/10 ± 5%

NOTE

LED

FAN

MOTOR

CONVECTION

MOTOR

OVEN LAMP

TURNTABLE

MOTOR

TOP

HEATER

BOTTOM

HEATER

2ND. INTERLOCK

RELAY CONTROL

SWITCH

OVEN

THERMISTOR

MICRO

C 2

G12 G11 G10 G 9

G 8

160˚C

150˚C

130˚C

70˚C

40˚C

250˚C

230˚C

220˚C

200˚C

180˚C

HELP

CONVEC

POWER

LEVEL

Jacket

Potato

Rice

Reheat

Pie

EASY

DEFROST

REHEAT

SENSOR

MULTI

COOK

STOP/

CLEAR

Fresh

Vegetables

Frozen

Vegetables

CONVENIENCE

/PIZZA

MIX

INSTANT COOK

START

CLOOK

Pasta

PREHEAT

GRILL

LESS

G 7 G 6 G 5 G 4 G 3 G 2 G 1

C 3

C 5

C 1

C10

C 9

C15

C 6

C 8

C14

C 7

C12

C13

C17

C11

–

SEG10

C 1

51 1

VL1

AN7

AN6

AN5

AN4

AN3

AN2

AN1

AN0

P57

P56

P55

P54

P53

P52

P51

P50

P47

P46

P45

P44

P41

P40

P77

P76

P75

P74

P73

C 2

VL2

VL3

COM0

COM1

COM2

COM3

AVSS

VREF

VCC

SEG0

SEG1

SEG2

SEG3

SEG4

SEG5

SEG6

SEG7

SEG8

SEG9

P72

P71

P70

SEG45

SEG44

SEG43

SEG42

SEG41

SEG40

SEG39

SEG38

SEG37

SEG36

SEG35

SEG34

SEG33

SEG32

COM5

COM4

SEG15

SEG31

SEG30

SEG29

SEG28

SEG27

SEG26

SEG25

SEG24

SEG23

SEG22

SEG21

SEG20

SEG19

SEG18

SEG17

SEG16

SEG15

SEG14

SEG13

SEG12

SEG11

SEG10

SEG9

SEG8

SEG7

SEG6

SEG5

SEG4

SEG3

SEG2

SEG1

COM3

COM2

COM1

P81

P80

XIN

XOUT

VSS

P27

P26

P25

P24

P23

P22

P21

P20

P17

P16

RESET

INT1

INT0

SEG11

SEG12

SEG13

SEG14

SEG15

SEG16

SEG17

SEG18

SEG19

SEG20

SEG21

SEG22

SEG23

SEG24

SEG25

SEG26

SEG27

SEG28

SEG29

SEG30

SEG31

SEG32

SEG33

SEG34

SEG35

SEG36

SEG37

SEG38

SEG39

C10 47µ/16v

C11 0.1µ/50v

C13

0.1µ/50v

C21

0.1µ/50v

C12

0.1µ/50v

R15 4.7k

R31 15k

R71 15k R70 15k R69 15k

R82 9.1k

R83 15k

R81 180F

R68 15k

R55 4.7k

IC-1

RH-IZA927DR

R60 15k

R61 15k

R62 15k

R63 15k

R64 15k

R65 15k

R66 15k

R67 15k

(J1)

R11 4.7k

(J13) 4.7k

(J14) 4.7k

(J15) 4.7k

R30 4.7k

R73 100k

R80 150kF

AH SENSOR

R74 100k

R75 100k

R72 100k

C30

C61 330p/50v

C60 330p/50v

C62 330p/50v

C63 330p/50v

R141kR131kR12

ZD10

UDZ4.3B

R10 1k

Q11

DTA143EKA

CF1 4.19MGW

R56

Q40

DTA143EKA

LD1

D22

D23

D30

LD2 LD3 LD4 LD5

LD10 LD9 LD8 LD7 LD6

Q25

DTA143EKA

Q24

DTA143EKA

Q23

DTA143EKA

Q22

DTA123JKA

Q21

DTA123JKA

Q20

DTA123JKA

Q10

2SA1037AK

(J10)

(J11)

(J12)20k

C14

C80

: IF NOT SPECIFIED, 1SS355

: IF NOT SPECIFIED, 0.01µF / 25v

COOK

HELP

C16

IC2

BA4558

0.015µ/25v

C102

C103

C104

IC2

R101

1.8kF

C101

0.1µ/50v

D101

MA152WA

R104 47k

R112 3.57kD

R90 330 1w

R105 3.32kD

R103 10k

R102 360kF

R111 37.4kF

R110 75kF

R109 150k

R108 300k

R107 620k

R106 47k

F 2 F 3F 1

Figure S-3. Control Panel Circuit

Page 42

R-880F(S)

Figure S-4. Printed Wiring Board

23456

123456

DIP

12 1

CN - C

CN - D

CN - B

CN - A

VRS1

FAN

CON

RY1

RY5

LOT NO.

RY6

RY3

T - H

RY4

B - H

RY2

(J1)

D12

MICRO

SP1

D11

ZD1

D10

Page 43

R-880F(S)

PARTS LIST

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

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

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

* * *

∆

* *

ELECTRIC PARTS

1- 1 QSW-MA131WRE0 1st. latch switch, 2nd. interlock relay control switch 2 AG 1- 1 QSW-MA110WRE0

1st. latch switch, 2nd. interlock relay control switch (Interchangeable)

2AH 1- 2 QSW-MA132WRE0 Monitor switch 1 AH 1- 2 QSW-MA111WRE0 Monitor switch (Interchangeable) 1 AH 1- 3 RMOTDA227WRE0 Turntable motor 1 AW 1- 3 RMOTDA228WRE0 Turntable motor (Interchangeable) 1 AU 1- 3 RMOTDA207WRE0 Turntable motor (Interchangeable) 1 AT 1- 4 FH-DZA080WRK0 High voltage rectifier assembly 1 AM 1- 5 RC-QZA215WRE0 High voltage capacitor 1 AY 1- 5 RC-QZA290WRZZ High voltage capacitor (Interchangeable) for prduction use 1-1- 6 RMOTEA361WRE0 Fan motor 1 AW 1- 6 RMOTEA369WRE0 Fan motor (Interchangeable) for prduction use 1-1- 7 FPWBFA355WRKZ Noise filter 1 AY 1- 8 QACCAA049WRZZ Power supply cord 1 AW 1- 8 QACCAA042WRE0 Power supply cord (Interchangeable) 1 AX 1- 8 QACCAA047WRE0 Power supply cord (Interchangeable) 1 AP 1- 9 QFS-BA007WRE0 Fuse 15A 1 AF 1-10 QFS-CA026WRZZ Fuse F10A 1 AH 1-11 QTANNA017WRW0 Short terminal 1 AD 1-12 RHET-A213WRE0 Grill heater (Top heater) 2 AU 1-13 RHET-A212WRE0 Bottom heater 1 BA 1-14 RLMPTA078WRE0 Oven lamp 1 AL 1-14 RLMPTA080WRE0 Oven lamp (Interchangeable) for prduction use 1 -1-15 QSOCLA024WRE0 Oven lamp socket 1 AH 1-15 QSOCLA022WRE0 Oven lamp socket (Interchangeable) 1 AG 1-15 QSOCLA011WRE0 Oven lamp socket (Interchangeable) 1 AH 1-16 RTHM-A109WRE0 Thermal cut out 170˚C OFF / 155˚C ON (Oven) 1 AM 1-16 RTHM-A048WRE0

Thermal cut out 170˚C OFF / 155˚C ON (Oven)(Interchangeable)

1AH 1-17 RTHM-A078WRE0 Thermal cut-out 125˚C (MG.) 1 AK 1-17 RTHM-A098WRE0 Thermal cut-out 125˚C (MG.) (Interchangeable) 1 AK 1-17 RTHM-A116WRE0 Thermal cut-out 125˚C (MG.) (Interchangeable) 1 AK 1-18 RTRN-A573WRE0 High voltage transformer 1 BN 1-19 RV-MZA222WRE0 Magnetron 1 BN 1-19 RV-MZA294WRE0 Magnetron (Interchangeable) 1 BL 1-20 FDTCTA192WRK0 AH sensor assembly 1 AV 1-21 FH-HZA063WRE0 Thermistor 1 AP 1-22 RMOTEA373WRE0 Convection motor 1 AW 1-23 QFS-IA006WRE0 H.V. fuse 0.75A 1 AQ 1-23 QFS-IA008WRZZ H.V. fuse 0.8A (Interchangeable) for prduction use 1--

CABINET PARTS

2- 1 GCABDA097WRW0 Back plate 1 AW 2- 2 GCABUA707WRP0 Outer case cabinet 1 AZ 2- 3 GDAI-A305WRW0 Base plate 1 AX 2- 4 GLEGPA074WRE0 Leg 2 AC

CONTROL PANEL PARTS

3- 1 DPWBFB872WRK0 Power unit (New Zealand only) 1 BE 3- 1A QCNCMA234DRE0 3-pin connector (CN-A) 1 AC 3- 1B QCNCMA275DRE0 2-pin connector (CN-B) 1 AB 3- 1C FW-VZA238DRE0 9pin wire harness (WH-1, WH-2) 2 AK 3- 1D QCNCMA410DRE0 2-pin connector (CN-D) 1 AB C1 RC-KZA087DRE0 Capacitor 0.1 uF 50V 1 AA C2 VCEAB31VW108M Capacitor 1000 uF 35V 1 AF C3 RC-KZA087DRE0 Capacitor 0.1 uF 50V 1 AA C4-5 VCEAB31VW106M Capacitor 10 uF 35V 2 AA D1-4 RH-DZA006PRE0 Diode (1N4002) 4 AD D5-12 VHD1SS270A/-1 Diode (1SS270A) 8 AA Q1-2 VS2SB1238//-3 Transistor (2SB1238) 2 AA Q3 VSKRC243M//-3 Transistor (KRC243M) 1 AB R1 VRD-B12EF242J Resistor 2.4k ohm 1/4W 1 AA R2 VRD-B12HF681J Resistor 680 ohm 1/2W 1 AA R3 VRD-B12HF511J Resistor 510 ohm 1/2W 1 AB R4 VRD-B12EF270J Resistor 27 ohm 1/4W 1 AB R5 VRD-B12EF472J Resistor 4.7k ohm 1/4W 1 AA R6 VRD-B12EF332J Resistor 3.3k ohm 1/4W 1 AA RY1 RRLY-A080DRE0 Relay (OJ-SH-124LM) 1 AG RY2 RRLY-A081DRE0 Relay (VRB24) 1 AL RY3-4 RRLY-A076DRE0 Relay (OMIF-S-124LM) 2 AK RY5 RRLY-A080DRE0 Relay (OJ-SH-124LM) 1 AG RY6 RRLY-A076DRE0 Relay (OMIF-S-124LM) 1 AK SP1 RALM-A014DRE0 Buzzer (PKM22EPT-THAI) 1 AG

Page 44

R-880F(S)

∆ ∆ ∆

∆ ∆

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

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

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

T1 RTRNPA105DRE0 Transformer 1 AS VRS1 RH-VZA032DRE0 Varistor (10G471K) 1 AE ZD1 VHEHZ161///-1 Zener diode (HZ16-1) 1 AA 3- 2 DPWBFC291WRKZ CPU unit 1 BF 3- 3 DPNLCB745WRKZ Control panel frame with key unit 1 BB 3- 3-1 JBTN-B092WRF0 Open button 1 AF 3- 3-2 MSPRCA050WRE0 Open button spring 1 AB 3- 3-3 FUNTKB129WREZ Key unit 1 AX 3- 4 LHLD-A185WRF0 LCD holder 1 AL 3- 5 PSHEPA626WRE0 LED sheet 1 AF 3- 6 XEPSD30P08XS0 Screw; 3mm x 8mm 4 AA

OVEN PARTS

4- 1 DOVN-A517WRY0 Oven cavity 1 BT 4- 2 PHOK-A106WRF0 Latch hook 1 AL 4- 3 FDUC-A338WRK0 Air duct assembly 1 BF 4- 4 PCUSGA389WRP0 Cushion 1 AG 4- 5 LANGQA478WRP0 Turntable motor angle 1 AP 4- 6 MSPRTA186WRE0 Plate spring 1 AE 4- 7 NCPL-A051WRE0 Turntable motor shaft 1 AN 4- 8 PSPA-A109WRE0 Spacer 1 AB 4- 9 LBNDKA136WRP0 HV capacitor holder 1 AQ 4-10 NFANJA041WRE0 Fan blade 1 AF 4-11 PDUC-A697WRF0 Fan duct 1 AM 4-12 GCOVHA388WRW0 Bottom heater cover 1 AF 4-13 GLEGPA071WRF0 Leg 1 AG 4-14 LANGFA191WRW0 Chassis support 1 AN 4-15 PCOVPA340WRW0 Sub back plate 1 AQ 4-16 LFLG-A030WREZ Bearing 1 AM 4-17 MLEVPA226WRF0 Switch lever 1 AF 4-18 MSPR-A004WRE0 Heat seal spring 2 AF 4-19 PCOV-A011WRP0 Bottom heater angle 2 AM 4-20 PCOVPA339WRE0 Waveguide cover 1 AF 4-21 PCUSGA385WRP0 Cushion 1 AH 4-22 PCUSUA190WRP0 Cushion 1 AC 4-23 PCUSUA191WRP0 Cushion 1 AC 4-24 PDUC-A691WRF0 Air intake duct 1 AG 4-25 PDUC-A692WRP0 Exhaust 1 AS 4-26 PDUC-A784WRWZ Air guide 1 AP 4-27 PGLSPA518WRE0 Light glass 1 AZ 4-28 PCUSGA399WRE0 Cushion 1 AF 4-29 PREFHA061WRW0 Reflector 1 BE 4-30 PSHEPA487WRE0 Heater film 1 AA 4-31 PSKR-A358WRP0 Air separate angle 1 AX 4-32 MSPRCA113WRE0 H-spring 2 AC 4-33 PCUSGA420WRP0 Cushion 1 AE 4-34 LANGQA489WRP0 Thermistor angle 1 AW 4-35 NFANMA047WRP0 Convection fan 1 AX 4-36 NFANMA048WRP0 Cooling fan 1 AX 4-37 PCUSUA499WRP0 Cushion 1 AC 4-38 PDUC-A707WRW0 Convection duct 1 AR 4-39 PFPF-A210WRE0 Thermal insulation 1 AM 4-40 PPIPFA030WRE0 Pipe 1 AK 4-41 PSKR-A339WRP0 Convection air angle 2 AX 4-42 PSKR-A345WRW0 Convection motor guide A 1 AU 4-43 PSKR-A346WRW0 Convection motor guide B 1 AR 4-44 PSLDHA140WRW0 Convection thermal cover 1 AQ

DOOR PARTS

5- 1 DDORFA857WRK0 Door panel assembly 1 BB 5- 2 GWAKPA872WRRZ Door frame 1 AY 5- 3 LSTPPA176WRF0 Latch head 1 AN 5- 4 LSTPPA177WRF0 Glass stopper 1 AF 5- 5 MSPRTA187WRE0 Latch spring 1 AC 5- 6 PGLSPA513WRE0 Front door glass 1 AV 5- 7 XCPSD40P08000 Screw : 4mm x 8mm 6 AA 5- 8 GCOVHA387WRF0 Choke cover 1 AS

MISCELLANEOUS

6- 1 FAMI-A099WRM0 High rack 1 AS 6- 2 FAMI-A100WRM0 Low rack 1 AS 6- 3 FSRAHA063WRYZ Turntable support 1 AK 6- 4 NTNT-A092WRH0 Turntable 1 AZ 6- 5 TLABMA584WRR0 Menu label 1 AF 6- 6 TINSEA956WRRZ Instruction book 1 AP

Page 45

R-880F(S)

PACKING AND ACCESSORIES

HOW TO ORDER REPLACEMENT PARTS

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

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

Note: The parts marked "

∆" may cause undue microwave exposure.

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

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

TRAY HOLDER

(SPADFA424WRE0)

TURNTABLE TRAY

HIGH RACK LOW RACK

LAMP CAUTION

COOK BOOK & INSTRUCTION BOOK

TURNTABLE SUPPORT

TRAY PAD

(SPADPA577WRE0)

TOP PAD ASSEMBLY

(FPADBA381WRK0)

BOTTOM PAD ASSEMBLY

(FPADBA382WRK0)

WRAP COVER

(SSAKHA034WRE0)

DOOR PROTECTION SHEET (SPADPA204WRE0)

PACKING CASE

(SPAKCD804WREZ)

Not Replaceable Items.

6- 7 FW-VZB045WRE0 Switch harness 1 AG 6- 8 FW-VZB946WREZ Main wire harness 1 AU 6- 9 TSPCND272WRRZ Rating label 1 AF 6-10 LHLDWA011WRE0 Purse lock M 1 AB 6-11 TCAUHA214WRR0 K caution label 1 AC

SCREWS,NUTS AND WASHERS

7- 1 XFPSD40P08K00 Screw : 4mm x 8mm 12 AA 7- 2 XEPSD40P25000 Screw : 4mm x 25mm 2 AA 7- 3 LX-EZA042WRE0 Special screw 2 AB 7- 4 LX-NZ0061WRE0 Flange nut 4 AA 7- 5 XBPWW30P05K00 Screw : 3mm x 5mm 2 AA 7- 6 XCTWW40P08000 Screw : 4mm x 8mm 8 AB 7- 7 XHPSD30P06000 Screw : 3mm x 6mm 3 AA 7- 8 XHTSD40P08RV0 Screw : 4mm x 8mm 3 AA 7- 9 XOTSD40P12RV0 Screw : 4mm x 12mm 15 AA 7-10 XOTSD40P12000 Screw : 4mm x 12mm 10 AA 7-11 XWSUW40-10000 Washer : 4mm x 1mm 1 AA 7-12 XOTSE40P08000 Screw : 4mm x 8mm 1 AA 7-13 XBTSD40P05000 Screw : 4mm x 5mm 2 AA 7-14 XNEUW40-32000 Nut : 4mm x 3.2mm 1 AA 7-15 XRESE40-06000 Ring : 4mm x 0.6mm 1 AA 7-16 XWHUW40-08000 Washer : 4mm x 0.8mm 1 AA 7-17 XWHUW48-08120 Washer : 4.8mm x 0.8mm 1 AA 7-18 XHPSD40P08K00 Screw : 4mm x 8mm 2 AC 7-19 XCPSD40P08000 Screw : 4mm x 8mm 1 AA

Page 46

R-880F(S)

23456

123456

OVEN AND CABINET PARTS

7-9

7-5

4-1

4-30

7-10

7-9

2-1

6-11

7-9

7-1

7-6

1-10

4-35

4-41

4-38

7-14

7-11

7-16

7-13

4-41

4-25

4-33

4-29

7-10

7-12

4-32

4-19

4-18

1-11

2-2

4-23

4-26

7-4

4-3

1-15

1-9

7-2

1-6

4-11

4-10

7-1

2-4

1-19

7-18

4-9

7-9

7-1

7-9

2-3

1-23

1-5

1-13

1-4

6-4

6-5

6-3

1-1

4-17

4-28

1-18

4-12

4-13

4-19

4-18

4-32

4-16

7-4

7-9

7-19

7-1

4-6

7-1

6-7

4-2

1-2

7-3

1-14

7-10

1-21

4-4

7-13

4-24

4-39

4-21

4-14

1-7

1-17

7-8

7-10

7-7

4-31

7-1

1-8

1-12

1-16

4-27

4-44

4-40

4-34

4-36

7-17

7-7

7-10

4-43

4-42

4-15

1-20

7-8

4-37

7-15

1-22

4-22

7-18

7-1

4-7

1-3

4-5

4-8

4-20

7-6

7-8

Page 47

R-880F(S)

23456

123456

DOOR PARTS

MISCELLANEOUS

CONTROL PANEL PARTS

5-3

5-6

5-4

5-5

5-1

6-9

3-2

5-7

5-2

6-1

6-8

6-10

6-2

Actual wire harness may be different than illustration.

6-7

3-3-1

3-3-3

3-3-2

3-3

3-4

3-5

3-1

3-6

5-7

5-8

Page 48

R-880F(S)

'02SHARP CORP. (8S_CD_E)

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