Sharp R-8320E Service Manual

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Page 1

SHARP SERVICE MANUAL 9

KASMY82101 R J’M

SHARP

CONVECTION MICROWAVE OVEN .

R-8320E

In the interest of user-safety the set should be restored to its original

condition and only parts identical to those specified be used.

SHARP CORPORATIOltl l

Page 2

SERVICE MANUAL

SHARP

R-8320E

FOREWORD

This Manual has been prepared to provide Sharp Service Personnel with complete Operation and Service Information

for the Sharp Convection Microwave Oven, R-8320E.

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

CAUTION

MICROWAVE RADIATION

Personnel 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.

SHARP CORPORATION

OSAKA, JAPAN

PRODUCT DESCRIPTION

,*,<-;,

OPERATING

‘,.rx.:.

INSTRUCTIONS

^ I__ .”

x ,” ;,;

I :I

OPERATION

kg&$

,,~T*gg

SERVICING

PANEL ASSEMBLY

c2 REPLACEMENT AND

.“?

ADJUSTMENT

PARTS LIST

Page 3

TABLE OF CONTENTS

Page

FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..l

CAUTION, MlROWAVE RADIATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

THUMB INDEX..................................................................l

CHAPTER I PRODUCT DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Explanation of Microwave Cooking and Convection Cooking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

CHAPTER II OPERATING INSTRUCTIONS . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Operation of Auto-TouchTM Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . .6

Auto-TouchTM Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Auto-TouchTM Operation Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Operation for Clock Setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Operation for Microwave Cooking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Introduction to Convection Cooking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I3

Accessories...................................................................13

ConvectionHeating.............................................................l3

Convection Broiling. . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . .I4

MixCooking.-.................................................................i5

MixRoasting.................................................................15

MixBaking....................................................................16

Operation for Convection Cooking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Operation for Mix Cooking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Operation for Special Function Cooking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Operation for Auto Start Cooking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Operation for Memory Cooking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

CHAPTER Ill OPERATION

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Normal Cooking Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Description of Operating Sequence (Australia Model). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

OffCondition.....................................................,.......31

Microwave Cooking Condition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . .32

HighCooking.........................................................32

Medium High, Medium or Medium Low/Defrost Cooking . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Convection Cooking Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Preheating Condition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Convection Cooking Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Automatic Mix Cooking Condition. . . . . . . . . . ~ . . . . . . . ., . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Description of Operating Sequence (South Africa Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . .38

I /

OffCondition.............................................................38

Microwave Cooking Condition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

HighCooking.........................................................38

Medium High. Medium or Medium Low/Defrost Cooking . . . . . . . . . . . . . . . . . . . . . . . . . . . ..38

Convection Cooking Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Preheating Condition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . .39

Convection Cooking Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . ,3g

Automatic Mix Cooking Condition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . , . . . . . .40

Description and Function of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . , . . . . .44

0venh-w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...44

Cooling Fan Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

I ’

Turntable Motor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . .44

Thermistor...............................................................44

Magnetron Thermt! Cut-out. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

CookRelay..............................................................44

Page 4

HeaterRelay..

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

..$4

StopSwitch..............................................................4 4

Door Open Mechanism.

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

.44

Convection Cooking System

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

.45

HeatingElement...........................................................4 5

Upper and Lower Latch Switches.

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

.45

Monitor Switch (Australia Model).

.............................................. .46

PowerTransformer.........................................................4 6

Voltage Doubler Circuit

..................................................... .46

MagnetronTube...........................................................4 6

Damper Operation.

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

.47

RelayUnit...............................................................4 8

CHAPTER IV SERVICING

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

..5 1

Troubleshooting Guide.

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

.51

Off Condition.

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

.51

Microwave Cooking Condition.

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

.52

Convection Cooking Condition

................................................ .53

Test Procedures.

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

.54

Magnetron Assembly Test.

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

.54

Power Transformer Test.

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

.55

RectifierTest.............................................................5 5

High Voltage Capacitor Test

.................................................. .56

Upper Latch Switch Test

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

.56

Lower Latch Switch Test

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

.56

MonitorSwitchTest........................................................5 6

BlownFuse..............................................................5 7

Magnetron Therm0 Cut-out Test

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

.57

Cook Relay or Heater Relay Test.

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

.57

StopSwitchTest...........................................................5 7

Touch Control Panel Assembly Test

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

.57 Heating Element Test.

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

.58

ThermistorTest...........................................................5 8

Damper Motor Test.

.................................. _

.................... .58

Damper Switch Test.

....................................................... .58

RelayUnitTest............................................................5 9

CHAPTER V TOUCH CONTROL PANEL ASSEMBLY

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

.60

Outline of Touch Control Panel ....................................................

.60

KeyUnit................................................................6 0

ControlUnit..............................................................6 0

Description of LSI.

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

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

.63

LSI (l-l : IX2107YA). ......................................................

.63

LSI (l-l: IX2075YA). ...............................

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

.69

Power Source Circuit ............................................................

.75

/3Circuit..

................................................................ ..7 6

ACLCircuit..................................................................7 6

BuzzerCircuit.................................................................7 6

Thermistor Sensor Circuit.

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

.77

Indicator Circuit.

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

.78

Servicing....................................................................7 9

Checker.....................................................................B 0

UseofChecker............................................................8 0

Connection Method.

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

.80

External of Checker.

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

.81

Checker Circuit Diagram.

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

.82

TestProgram.................................................................8 3

Troubleshooting Guide.

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

.87

Adjustment of Thermistor Sensor Circuit. ............................................. .97

Page 5

CHAPTER VI COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

.........

.98

Warning.....................................................................g 8

Outer Case Removal.

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

.99

High Voltage Components Removal .................................................

.99

Relay Unit, Cook Relay or Heater Relay Removal.

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

.99

Turntable Motor Removal. .......................................................

100

Magnetron Assembly Removal.

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

100

Cooling Fan Motor Removal

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

100

Convection Motor Removal.

........

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

.I00

Damper Motor and Damper Switch Removal

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

105

Heating Element or Convection Fan Removal.

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

105

Oven LampRemoval...........................................................lO 6

Upper Latch Switch and Monitor Switch (Australia Model) Removal.

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

106 Lower Latch Switch Removal

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

106 Upper Latch Switch, Lower Latch Switch and Monitor Switch (Australia Model)

Adjustment

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

..I0 7

Control Panel Assembly and Components Removal

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

108 Door Replacement and Adjustment

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

110

MICROWAVE MEASUREMENT PROCEDURE . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I1 1

SCHEMATIC DIAGRAM (Australia Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I12

PICTORIAL DIAGRAM (Australia Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I13

PICTORIAL DIAGRAM (South Africa Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I 15

SCHEMATIC DIAGRAM (South Africa Model)

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

.I17

PRINTED WIRING BOARD (Control Unit)

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

118

CONTROL PANEL AND RELAY UNIT CIRCUIT

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

119

PRINTED WIRING BOARD (Relay Unit). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

PACKING AND ACCESSORIES . . . . . . . .

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

122

PARTS LlST..................................................................l23

Page 6

CHAPTER I

PRODUCT DESCRIPTION

EXPLANATION OF MICROWAVE COOKING AND CONVECTION COOKING

The Sharp Convection-Microwave oven uses microwave energy and the sheath heater to produce heat in the food to be cooked. Unlike conventional ovens, microwave energy will cook foods without applying external heat.

Microwaves which are short electromagnetic waves of RF

(radio frequency) energy, pass through materials such as glass, paper, china, and most plastics. Materials such as metal and aluminum foil tend to reflect microwaves and may be used only as recommended in the cooking instructions.

ITEMS

Power Requirements

Microwave Output Power

Convection Output Power

Case Dimensions

Width

Height Depth

Cooking Cavity Dimensions

Width Height Depth

Turntable diameter

Control Complement

Weight

Materials with a high moisture content, like most foods, will absorb microwave energy. As the microwave energy, at a frequency of 2,450 Megahertz enters the food, the

molecules align themselves with the energy. However, cooking by microwave energy only, produces no brown-

ing or searing (unless cooking a roast of sufficient thickness). This microwave oven is, therefore, equipped with a sheath heater to provide browning of the food. The combination of the heater plus high-speed circulation of air by a circulating fan around the food provides fast cooking and browning of foods conventionally with or without the addition of microwave energy.

SPECIFICATIONS

DESCRIPTIONS

220/24OV

50 Hz Single phase, 3 wire earthed

650 W (2 litre water load)

I .5

627 mm 408 mm including feet 480 mm

395 mm 256 mm 422 mm 376 mm

Touch Control System Cook Pad and Stop Pad Timer: 99 min. 99 sec. Clock Microwave Power for Variable Cooking Repetition Rate:

High . . . . . . . . . . . .

.Full

Power throughout the cooking time

Med High. . . . . . . .. .24

sec. ON, 8 sec. OFF, approx. 70% of high

Med . . . . . . . . . . . .

.I8 sec. ON, I4 sec. OFF, approx. 50% of high

Med Low/Defrost . .

. .I2 sec. ON, 20 sec. OFF, approx. 30% of high

Convection Temperature Control Range:

40°C, 70°C,

IO’C, 130°C,

50°C,

180°C,

200°C, 220°C, 230°C,

25O’C.

Approx. 34 kg

Page 7

CHAPTER I I

OPERATING INSTRUCTIONS

OPERATION OF AUTO-TOUCHTM CONTROL PANEL

This Auto-Touch Convection Microwave Oven uses a microprocessor, the electronic brain that provides a wide variety of cooking programs which could not be achieved by conventional control methods. The operation of the oven is controlled by touching the appropriate pads arranged on the surface of the control panel. The lighting digital readout will display the cooking time, convection temperature,

memory or time of day, and indicators show the variable cooking setting or cooking function you have programmed.

An audible entry signal tone should be heard each time you touch the control panel to make a correct entry. If you do not hear this sound,

you have not used enough pressure in touching the pad,

you have made more entries than the control panel will accept,

3) you have made an incorrect entry.

In addition to the entry signal tone, an audible signal will sound for approximately 2 seconds at the

end of the cooking cycle. The following pages give complete instructions for using the Auto-Touch control system. Please use

these instructions and practice programming the oven step by step until you are thoroughly familiar with its operation.

In giving directions, examples of foods have been used so that you may become familiar with the

practical uses for these features.

However, we suggest that

yocr

first practice operating the oven with

one cup of water in a glass measuring cup inside rather than food.

Do not operate the oven empty.

* You cannot program the oven if the door is not closed tightly. *

During cooking, the program cannot be changed until the STOP pad is touched.

All functions are locked in to prevent accidental changes.

Multiple Sequence Cooking

This Auto Touch Convection Microwave Oven can be programmed for multiple cooking sequences for microwave, convection and combination convection microwave. Some of the sequences you might use in cooking include:

FIRST SEQUENCE SECOND SEQUENCE THIRD SEQUENCE

FOURTH SEQUENCE

Microwave Microwave

Microwave

-e

Microwave

Convection

Microwave

Preheat

Convection

Preheat

Convection

Preheat

Auto Mix

Preheat

Convection Microwave

Check your Sharp Carousel Convection Microwave Cookbook for ideas on when to use multiple sequence cooking.

Page 8

AUTO-TOUCHm

CONTROL PANEL

MEM

AUTO

220~

MED

19 I=II

MEDMGH

XONVECTION

FAN

SYMBOL

LIGHTED DIGITAL DISPLAY

Shows readout of cooking time, convection temperature or time of day.

INDICATORS

Indicator lights for Convection

(CONV),

Variable Cooking,

Cook, Mix, Memory

(MEM)

and Auto Start (AUTO).

PROGRAM SELECTOR PADS

Touch to set Auto Start/Clock, Memory

Entry and Memory Recall.

-NUMBER AND TEMPERATURE SELECTION (CONVECTION) PADS

Touch to enter cooking times, clock time or convection temperature (convection).

FUNCTIONS PADS

Touch to select microwave varibale power settings and automatic convection microwave setting. If no function pad is touched, HIGH is automatically selected.

-TIMER

PAD

Touch to set minute timer.

CLEAR PAD

Touch to erase cooking program.

COOK PAD

Touch to start operation.

STOP PAD

Touch to stop operation of oven during cooking.

Page 9

AUTO-TOUCHTM OPERATION CHECK

Clock

1. Plug the power cord into a three-pronged electrical outlet (240V for

Australia/220V

for South

Africa, 50Hz, 10 amp or more, AC only).

2. The digital display will show

88:88

and flash on and off every second. Touch the CLEAR

pad once and

1-1

will appear. The timer will begin counting up each minute. After one

minute the display will show

]::3]

1. Place the turntable inside the oven cavity. When the door is opened, the oven lamp comes on automatically.

2. Place one cup of room temperature water in a glass measuring cup on the turntable inside the oven. Do not attempt to operate the oven without the turntable in place.

3. Close the door securely. Oven lamp will go out.

4. Program the oven to cook three minutes at HIGH. Touch the number pads in the following sequence: 3 , 0 , 0 .

5. Touch COOK pad to activate the oven. The cooling fan will start, the turntable will begin to

rotate and the oven lamp will light.

6. After three minutes, an audible signal will sound and the unit will turn off.*

7. The water should be bubbling if operating normally.

“When the door is opened during the cooking process, the timer automatically stops. The

timer and cooking process start again when the door is closed and COOK pad is touched.

(

Convection

(

1. Place the turntable inside the oven cavity.

When the door is opened, the oven light comes on

automatically.

2. Close door securely. Oven light will go out.

3. Program the oven to preheat to 70°C. Touch CONVECTION pad followed by 70°C pad.

4. Touch COOK pad.

The red Convection Fan Symbol in the display will flash on and off

and the display will show

(ICI..

The oven light and fan will come on, the turntable will

begin rotating and preheating will begin.

5. When the oven temperature reaches

7O”C,

the Convection Fan Symbol will stop flashing and will begin rotating. An audible signal will sound 4 times. The oven will then begin temperature holding operation.

6. The oven will automatically hold the temperature at

70°C

for 15 minutes. After this time has

elapsed, an audible signal will sound 4 times and the unit will turn off.

’

7. The oven cavity will be hot if operating normally.” Avoid touching oven surface and door as intense heat could cause burns.

8. If the door is opened or STOP pad is touched during the preheating operation, the selected preheat temperature is displayed but preheating will stop. The oven will continue preheating

when the door is closed and COOK pad is touched.

9. If

the door is opened or STOP pad is touched during the temperature holding operation,

the program is cancelled and the display will return to time of day.

“lf

the oven emits an odor, program the oven to preheat to 250°C to “burn off” odor. Touch

CONVECTlON

pad, 250°C pad and COOK pad. This is a non-toxic odor common to new

appliances.

Page 10

OPERATION FOR CLOCK SETTING

This oven functions as a clock to keep the time of day. To set the clock, follow this procedure. When oven is plugged in, the display will

show-f:,

flashing on and off every second. Touch the

CLEAR pad;

1x1

will appear.

Suppose you want to enter the correct time of day

12:30

(A.M. or P.M.)

Step

Procedure

Pad Order Display

Touch CLOCK pad,

Enter the correct time of day by

touching the numbers in sequence.

3. 1 Touch CLOCK pad

again.

1 m

The clock is now set and will keep the time of day.

If power to the unit is interrupted, the display will

intermittently show

im]

after the power is reinstated. To reset the clock, touch CLEAR

pad and

then repeat the steps above. NOTE: This is a 12 hour clock.

1-1

will appear in the readout if you attempt to enter an in-

correct clock time. For example, if *you attempt to enter 8:61

or13:00,-1

indicating

an error will appear. To

erase[EcCj

touch CLEAR pad. If you accidentally touch more

than 4 number pads, the last 4 numbers you have touched will appear on the display.

Page 11

OPERATION FOR MICROWAVE COOKING

Throughout This Carousel Convection Microwave Cookbook you will find step by step directions for each recipe. Basic instructions follow:

1. Make sure the oven is plugged into a 3-pronged, grounded 240V

(Australia)/220V

(South Africa),

50 Hz, 10 amp household circuit. When oven is plugged in, the display will show

(61

,flashing

on and off each second. Touch the CLEAR pad;

will appear.

2. Always make certain the metal turntable is seated and in place. The oven should not be used without the turntable in place, and it should never be restricted so that it cannot rotate.

3. The Variable Cooking Control on your Sharp Convection Microwave Oven allows you to select the amount of microwave energy and the rate of cooking or defrosting. There are four levels or settings

for cooking: HIGH, MED HIGH, MED and MED LOW/DEFROST. Your cookbook explains the

use of this feature.

4. Be sure to select the recommended power level before beginning to cook. Refer to Operation of Auto-Touch Control Panel for proper procedure. If you do not touch a setting on the Variable Cooking Control panel, the oven will automatically cook at HIGH. Each recipe in your cookbook gives instructions for the setting best suited for that particular food category. As you become more familiar with the use of the Variable Cooking Control and microwave cooking, you will be able to judge which power level to use for various foods.

5. If food does not seem to be heating properly, check the indicator immediately above the lighted digital display. Be sure the Variable Cooking Control is on the proper setting.

6. The oven is programmed by touching the appropriate Auto-Touch pads.

[ ToCookat

High

]

Many foods are cooked at HIGH (100% power) for best results. The Variable Cooking Control allows you to seledt the rate of microwave cooking, but the oven will automatically operate at HIGH if no Variable Cooking Control pad is touched.

If you wish to cook at HIGH, it is not necessary to touch

the HIGH pad. For other Variable Cooking Control levels, the desired setting must be entered.

Suppose you want to heat 2 cups coffee for 1 minute 30 seconds at HIGH.

Step

Procedure

Enter desired cooking time.

Touch the COOK pad.

Pad Order

Display

[4o"cij

COOK

The cooking time will count down to zero.

When the timer reaches zero, the indicators will go out

and an audible signal will sound. The time of day will reappear on the display. Microwave energy will

stop.

Page 12

To Cook by Variable Cooking Control

This microwave oven has four preset power levels.

Approximate percentage of

microwave power.

(Full Power)

100%

IGH

(Roast)

70%

(Simmer)

50%

MED LOW/DEFROST (Defrost)

30%

Some foods give best results when cooked more slowly at a lower cooking power. Your cookbook will

indicate

the recommended variable setting for each recipe. See your Sharp Carousel Convection Micro-

wave Cookbook for guidelines on how to use the Variable Cooking Control.

Suppose you want to heat soup for 2 minutes 15 seconds at MED

HIGH.

Step

Procedure

Pad Order

Display

Enter desired cooking time.

2. Select desired Variable Cooking Control setting.

Touch the COOK pad.

The cooking time will count down to zero. When the timer reaches zero, all indicators will go out and an audible signal will sound. The time of day will reappear on the display.

NOTE: If you accidently touch the wrong Variable Cooking Control pad, immediately touch the

correct pad. The last pad touched will be the setting the oven accepts, For example, if

you

touch

MEDpad

and then immediately touch MED HIGH pad, the oven will cook at

MED

HIGH.

-e

Page 13

To Cook at Multiple Sequence

Suppose you want to program the oven to cook at HIGH and reduce to MED HIGH.

Check the microwave recipe section of This Carousel Convection Microwave Cookbook for ideas on when to use multiple sequence cooking. You can set 4 sequences.

* Suppose you

want to roast beef for 5 minutes at HIGH, and then continue to cook for 30 minutes

at MED HIGH.

Procedure

Pad Order

Display

Enter desired time for first cooking sequence.

Select first Variable Cooking Control setting.

3. Enter desired time for second cooking sequence.

4. Select second Variable Cooking Control setting.

Touch the COOK pad.

The timer begins to count

down. When it reaches zero.

When the timer reaches zero, all indicator lights will go out and an audible signal will sound. The time of day will reappear on the display.

NOTE: If HIGH isselected

asthe

final sequence, it is not necessary to touch HIGH pad. If HIGH

is programmed as the first, second or third sequence, HIGH pad must be touched.

Page 14

INTRODUCTION TO CONVECTION COOKING

Convection cooking is a not-so-new form of food preparation that has been used by professional chefs for three decades for roasting and baking.

Hot air is circulated throughout the oven cavity by a high speed fan. The constantly moving air surrounds the food to quickly heat the outer portion, thereby sealing in moisture and natural juices. This “sealing-in” process results in more

flavorful

foods cooked

in less time and in many cases at a reduced temperature.

The oven can be filled to capacity, using

both the turntable and the baking rack, with no increase in cooking time.

While all foods that are roasted, baked or broiled benefit from convection cooking, the added microwave feature of your new oven makes it possible to cook a wide range of foods in combination - that

is with convection, then microwaves or vice-versa.

This section of the Operation Manual explains the use of the oven for Convection heating alone and

combination cooking. Please use it as a guide along with the Carousel Convection Microwave cookbook.

ACCESSOR!ES

The following accessories were designed especially for use in the Sharp Convection Microwave Oven. The racks are for convection or combination cooking only; do not use for microwave cooking alone.

Do not substitute similar types of racks for these specially designed ones.

Baking Rack

Broiling Trivet

This rack is used for two-levels cooking,

Used for roasting or broiling to allow

such as layer cakes, muffins, cookies, etc.

juices to drain away from food.

CONVECTION HEATING

Some foods are best when cooked using convection heating alone. These are foods which often have

a cooking time of 15 minutes or less and usually need quick crisping and browning. These include:

Appetizers -frozen, pastry-type, or other Biscuits and rolls - dairy case, brown n’serve, your recipe Brownies -mix, your recipe Biscuits

mix, slice n’bake, frozen, your recipe Cream puffs, puff pastry, turnovers, etc. Fish sticks - frozen, breaded Muffins

mix, your recipe Pie crust - frozen, mix, your recipe Pizza

fresh, frozen, or your recipe

Souff

Basic Convection Heating Procedure

1. Consult recipe or package directions for temperature and time.

2. Preheat oven if required by recipe or package directions.

3. Food may be cooked directly on turntable if appropriate, or on two levels using baking rack and appropriate baking vessel. Example: Fish sticks may be cooked directly on turntable. Muffins may be cooked on 2 levels using the baking rack and two

&muffin

baking pans.

4. Check for doneness at the end of cooking time.

Page 15

/Helpful

1. Do not cover turntable or baking rack with aluminum foil.

It interferes with the flow of air that

cooks food.

2. If food is not done when checked after cooking time, let stand in oven one or two minutes to complete cooking.

3. Round pizza pans are excellent cooking utensils for many convection-only items. Choose pans that do not have extended handles.

Recommended Cooking Utensils

Sharp Carousel metal turntable

Baking rack Metal baking pans Paper board containers usable in oven

Aluminum foil containers

Heat resistant glass Corning Ware@

CONVECTION BROILING

This Convection Microwave Oven wil broil meats, fresh or frozen to perfection! As in conventional cooking, broiling time will vary with thickness as well as weight. For best results use the directions

that follow.

Basic Convection Broiling Procedure

1. Preheat oven 10 minutes at 250°C.

2. Prepare and season meat on both sides, as desired.

3. Place meat on broiling trivet or turntable.

4. Consult broiling chart in your Sharp Carousel Convection Microwave Cookbook; set timer for correct cooking time.

5. Turning meat over is not necessary.

6. Test for doneness; slit center of meat, check for desired

color;

red - rare, pink - medium, gray

well done.

jHelpfulHints

1. Do not cover broiling trivet with aluminum foil.

It interferes with the flow of air that cooks food.

2. For faster clean up spray trivet and turntable with nonstick vegetable spray.

3. To eliminate excess fat in broiling, use broiling trivet.

4. Broiling may be done ahead of time, then individual portions sliced and reheated with microwave power (MEDIUM setting) as needed.

5. Hot dogs cooked on the broiling trivet may be turned over to give an even, grilled appearance.

Recommended Broiling Utensils

Sharp recommends only the use of the metal Carousel turntable, and the broiling trivet and baking

rack accessories that are included with the oven,

Page 16

MIX COOKING

With the exception of those foods that cook best by convection heating alone, most foods are well suited to mix cooking using either the LOW MIX or HIGH MIX setting.

The marriage of convection and microwave cooking produces juicy roasts, moist and tender cakes and fine textured breads, all with just the right amount of browning and crispness.

MIX ROASTING

Mix roasting in the Sharp Convection Microwave Oven is a simple task when you follow the instruc-

tions given below. The results are juicy, crisp browned meats done to your liking.

Basic Roasting Procedure

1. Place meat directly on the turntable or on the metal broiling trivet, or in a shallow roasting pan on the turntable, as you prefer.

2. Season, as desired.

3. Consult chart in your Sharp Carousel Convection Microwave Cookbook for roasting temperature and timing.

4. Program oven for appropriate cooking time and mix setting. Change temperature if recipe requires.

5. Check for desired doneness using a meat thermometer.

If desired, a dual safe microwave/conven-

tional thermometer may be inserted in the meat at the

beginning

cooktime.”

6. Let meat stand tented with to 15-10 minutes before slicing.

A dual safe thermometer is specially designed to withstand high temperature and can safely be used

with heat or microwaves. Do not use conventional meat thermometers for mix cooking and do not

use microwave only thermometers for mix cooking.

Helpful Hints

1. If roasting frozen meat, insert dual safe meat thermometer halfway through cooking time.

2. Thin sections of meat, and wingtips and legs of poultry that may overcook, can be shielded with

small pieces of aluminum foil.

3. Less tender cuts of beef can be roasted and tenderized using oven cooking bags.

4. For true roasting, and fewer calories, use metal broiling trivet to hold meat out of its juices.

5. If gravy is desired, roast in glass utility dish, remove meat to carving board, then microwave gravy.

Recommended Roasting Utensils

Sharp Carousel metal turntable Broiling trivet

Shallow metal roasting pans

Aluminum foil containers Heat resistant glass

Corning Ware@

Page 17

MIX BAKING

Baking with the Sharp Convection Microwave Oven is fast and simple. Using convection heat first gives baked goods their structure and, of course, their browned appearance; finishing with microwaves cooks the inside to a perfect doneness in a shorter time.

Basic Mix Baking Procedure

1. Consult Mix Baking techniques in your Sharp Cookbook for baking temperature.

2. Program oven for appropriate cooking time and mix setting. Change temperature if recipe requires.

3. Set Convection Cooking time.

4. Check for doneness after microwave time has elapsed.

If not completely done, let stand

few minutes to complete cooking.

in oven a

Recommended Baking Utensils

Sharp Carousel metal turntable

Baking rack

Broiling trivet Metal baking pans Paper board containers usable in oven

Aluminum foil containers Heat resistant glass Corning Ware@

Note

During mix baking some metal baking utensils may cause arcing when they come in contact with the turntable, oven walls or accessory racks. Arcing is a discharge of electricity that occurs when microwaves come in contact with metal.

If arcing occurs when using a fluted tube pan, place a heat resistant dish (Pyrex pie plate, glass pizza’ dish or dinner plate) between the pan and the turntable.

If arcing occurs with other metal baking

utensils, discontinue their use for mix cooking.

Page 18

OPERATION FOR CONVECTION COOKING

This oven can also be used for both Convection and Automatic Convection Microwave Cooking.

During convection heating, hot air is circulated throughout the oven cavity to brown and crisp foods

quickly and evenly. The oven should not be used without the metal turntable in place and it should never be restricted so

that it cannot rotate.

You may remove the turntable when preheating the oven or when preparing

food to be cooked directly on the turntable; cookies, for example, biscuits.

To Preheat

This Auto-Touch Convection Microwave Oven allows you to preheat to the desired temperature by touching a temperature pad. Whenever you want to automatically preheat the oven, no “time” is entered. The oven will signal when its ready.

Suppose you want to preheat to 150°C.

Step Procedure

Pad Order

Display

Touch the CONVECTION pad.

riii-Aq

Enter the desired preheating tem- peratu re.

3. Touch COOK pad.

r-=--j

~~~~t~~tur-;

Convection Fan Symbol will

flash on and off.

When oven temperature rises above

4O”C,

the actual oven temperature will appear on display. When the oven reaches the programmed temperature, the Convection Fan Symbol will stop flashing and begin rotating and an audible signal will sound 4 times.*

*At this point the oven is preheated,

Food may be placed in the oven and the oven programmed. If the oven door is not opened, the oven will begin temperature holding operation. The oven will automatically hold at the preheat temperature for 15 minutes. After this time has elapsed, an audible signal will sound 4 times and the oven will turn off. All indicators will go out. Whenever the door is

opened or the STOP pad is touched during this 15 minutes period, the program is cancelled and the display will return to the time of day.

Page 19

To Cook by Convection

This Au to-Touch

Convection

Microwave Oven can be

programmed

for ten

different

convection

cooking temperatures for up to 99 minutes, 99 seconds.

Suppose you want to cook at 200°C for 25 minutes.

Step

Procedure

Pad Order Display

Enter desired cooking time.

2. Touch CONVECTION pad.

Enter desired temperature.

4. Touch COOK pad.

If you

wish to check the tem-

perature you set at any time

during cooking, touch

CON-

VECTION

pad.

Convection Fan Symbol will

rotate and the cooking time will count down to zero.

The oven temperature will

appear on the display as long

as the CONVECTION pad is

touched. The oven will continue to count down to zero during this time.

When timer reaches zero, an audible signal will sound and the time of day will reappear on the display

The fan will remain on until the oven cavity has been cooled.

Page 20

To Preheat and Cook by Convection at the Same Temperature

This Convection Microwave Oven can be programmed to combine preheating and convection cooking or preheating and automatic mix cooking operations.

Suppose you want to preheat to 180” C and bake biscuits at 180°C for 15 minutes.

Step

Procedure

Pad Order

Display

Touch Convect ion pad.

rCO”IYLCTIONI

]

2. Touch desired preheat temperature pad.

pg=Tgq

Enter desired cooking time.

:,.,i

p+gZj

-~ co

Touch CONVECTION pad again.

rii-&q

5. Touch COOK pad.

(Ex.)

Oven temperature is lower

than 40°C.

(,,,,

Convection Fan Symbol will flash on and off.

When the oven reaches the programmed temperature, the Convection Fan Symbol will stop flashing and begin rotating and an audible signal will sound 4 times. The oven will then begin temperature holding operation.

The oven will automatically hold at the

desired temperature for 15 minutes. This will allow time to finish preparing the food to

be cooked. You may open the door anytime during this holding time.

6. .Push the Door Open button.

7. Place food in oven. Close door.

Touch COOK pad.

EII

I:,.,,1

Convection Fan Symbol will rotate

The cooking time will count down to zero, When the timer reaches zero, all indicators will go out and an audible signal will sound. The time of day will reappear on the display. The fan will remain on until the oven cavity has been cooled.

Page 21

To Preheat and Cook by Convection at a Different Temperature

Suppose you want to preheat to 200°C and bake a cake at 180°C for 40 minutes.

Step

Procedure

Pad Order

Display

Touch Convection pad.

p&q

‘-‘“C

2. Touch desired preheat temperature pad.

Enter desired cooking time.

p-q

pJ$q

4. Touch CONVECTION pad again.

pizq

5. Touch desired temperature pad.

[

~.,

6. Touch COOK pad. (Ex.) Oven temperature is lower

than 40°C.

r-=--j

p-----q

Convection Fan Symbol will flash on and off.

When the oven reaches the programmed temperature, the Convection Fan Symbol will stop flashing and begin rotating and an audible signal will sound 4 times. The oven will

then begin temperature holding operation.

The oven--will automatically hold at the desired temp.erature for 15 minutes. This will allow time to finish preparing the food to be cooked. YOU may open the door anytime during this holding time.

Push the Door Open button.

Place food in oven. Close door.

Touch COOK pad.

COOK

Convection Fan Symbol will rotate

‘L, ---I-:-- AZ---

‘II . .

_ _

. .

all i

nd icators

will go out and

nt: cooking

rime

WIII

count down to zero. When the timer reaches zero,

an audible signal will sound. The time of day will reappear on the display. The fan will remain on until the oven cavity has been cooled.

Page 22

OPERATION FOR MIX COOKING

This Convection Microwave Oven has two preprogrammed settings that make it easy to cook with both convection heat and microwaves automatically.

The LOW MIX/BAKE pad is preprogrammed for 150°C with 10% microwave power, while the HIGH

MIX/ROAST pad is preprogrammed for 200°C with 30% microwave power. On both of these settings the convection heating system and the microwave system automatically alternate to give you fast, even cooking. The convection temperature setting of either pad can be changed to accomodate a wide

variety of foods.

information.

See your Sharp Carousel Convection Microwave Cookbook for complete cooking

To Cook by Mix Settings

Suppose you want to roast lamb for 50 minutes on HIGH MIX/ROAST.

Step

Procedure

Enter desired cooking time.

Touch HIGH MIX/ROAST pad.

3. Touch COOK pad.

Pad Order

p-fggq jl

COOK

Display

11 I-l

II I7

-’ 1-I

I-1 1-t

1-1

l-1

I-1 1-t

COOK

MIX

Convection

Fan Symbol will rotate.

The cooking time will count down to zero.

When the timer reaches zero, the indicators will go out

and an audible signal will sound.

Thetime

of day will reappear on the display.

The fan will remain on until the oven

cavity’has

been cooled.

NOTE:

TO cook on LOW MIX/BAKE setting, use the above’procedure, touching LOW MIX/BAKE

pad in Step 2.

Page 23

To Change Convection Temperature of Mix Settings

You may want to change the preprogrammed temperature of LOW

MlXrSAKE

or HIGH MIX/

ROAST settings. Check your Sharp Carousel Convection Microwave Cookbook for ideas on when to

change the temperature.

SUPPOSE

YOU

want to bake bread for 30 minutes on

LOW

MIX/BAKE

180°C changing from 150”~.

Step

Procedure

Pad Order

Display

Enter desired cooking time.

pj$q

io125oocjj

2. Touch LOW MIX/BAKE pad.

pi-j

-:5,,-

3. Touch 180°C pad.

-1

4. Touch COOK pad.

COOK

Convection Fan Symbol will

rotate, and the cooking time

If you wish to check the temper-

will count down to zero.

ature you set at any time during cooking, touch CONVECTION pad.

FCONVfCTlDN

yr:gl

The oven temperature will

appear on the display as long as CONVECTION pad is touched.

The oven will continue to count down to zero during this time.

When the timer reaches zero, an audible signal will sound and the time of day will reappear on the display. The fan will remain on until the oven cavity has been cooled.

NOTE: TO cookon HIGH

MIX/ROASTsetting,

use the above procedure, touching HIGH MIX/ROAST

pad in Step 2.

Page 24

To Preheat and Cook by Mix Settings

This Convection Microwave Oven can be programmed to combine preheating and automatic mix cooking operations. You will want to preheat at the same temperature as the automatic mix tempe-

rature; that is 150°C for the LOW MIX/BAKE setting or 200°C for the HIGH MIX/ROAST setting.

Suppose you want to preheat to 200°C and bake an apple pie for 35 minutes at HIGH MIX/ROAST

200” c.

Step

Procedure

Pad Order Display

Touch Convection pad.

2. Touch desired preheat temperature pad.

Enter desired cooking time.

4. Touch HIGH MIX/ROAST pad.

5. Touch COOK pad.

(Ex.) Oven temperature is lower than 40°C.

Convection Fan Symbol will

flash on and off. When the oven reaches the programmed temperature, Convection Fan Symbol will stop flashing and begin rotating and an audible signal will sound 4 times. The oven will’ then begin temperature holding operation.

The oven will automatically hold at the desired temperature for 15 minutes. This will allow time to finish preparing the food to be cooked. You may open the door anytime during this holding time.

6. Push the Door Open button.

Place food in oven. Close door.

Touch COOK pad.

Convection Fan Symbol will rotate.

The cooking time will count down to zero; When the timer reaches zero, all indicators will go out and an audible signal will sound. The time of day will reappear on the

display.

The fan will remain on until the oven cavity has been cooled.

NflTF* TO

nreht+at and

cook

on LOW MIX/BAKE setting.

use

the above Drocedure, tou&ina

Page 25

OPERATION FOR SPECIAL FUNCTION COOKING

This Convection Microwave has three special function keys to simplify programming. These include

BROIL, SLOW COOK and PROOF.

Preheating is automatic when BROIL setting is used. Only actual cooking time is entered; the

oven signals when it is preheated to 250°C.

Suppose you want to broil a steak for 15 minutes.

Step

Procedure

Pad Order

Display

Enter maximum broiling time using convection broiling chart in your Sharp Carousel Convection Microwave Cookbook.

2. Touch BROIL pad.

3. Touch COOK pad.

(Ex.)

Oven temperature is lower

than 40°C.

Convection Fan Symbol will flash on and off.

When

th$

oven reaches the programmed temperature, Convection Fan Symbol will stop flashing and begin rotating and an audible signal will sound 4 times. Oven will maintain 250°C for 15 minutes after signal sounds and Convection Fan

Symbol begins to rotate.

If the oven door is not opened within 15 minutes, the oven

will automatically turn off.

4. Open the door and place food’ in oven. Usually food is placed on the broiling trivet.

Close oven door and touch COOK pad.

Convection

FanSymbolwilI

rotate

The cooking time will count down to zero.

When the timer reaches all indicators will go out and

en audible signal will sound. The time of day will

reappear on the

display,

The fan will remain on until the oven cavity has been cooled. NOTE: While timer is set for the maximum

broiling time as directed in Step 1, check food at minimum time recommended in the chart. This will eliminate the need to completely reprogram the oven if additional cooking time is needed. Simply close the oven door and touch COOK pad to continue the cooking,

Page 26

The SLOW COOK setting is preset for 130°C for 4 hours. It is designed for foods which cook longer

than 99 minutes, 99 seconds at 130°C or less. Foods such as baked beans or marinated chuck steak

are

best cooked slowly at low temperatures.

SLOW COOK feature expands

the

lengthof

cooking

time to a maximum of 4 hours at 130°C or lower.

It adds to the overall versatility of your new Convection Microwave Oven. When using this setting, no cooking time is entered; you will need to time food manually.

Suppose you want to cook baked beans at 130°C.

Step1

Procedure

1. I Touch SLOW COOK pad.

2. ’ Touch COOK pad.

Pad Order

Display

:h.

pszq 1 ICON”

/,=;’ &ic 1

Convection Fan Symbol will begin to rotate. Alter 4 hours an audible signal will sound.

Suppose you want to change oven temperature to any of

4O”C, 70°C

110°C and 130°C e

Step

Procedure

Display

1. I Touch SLOW COOK pad.

CoNV

( 3 s

I I

Enter desired oven temperature if you want to change from 130°C.

’

Touch COOK pad.

Convection Fan Symbol

will

begin to rotate. After 4 hours an audible signal will sound.

If the oven door is opened or STOP pad is touched during SLOW COOK cycle, the program

will be cancelled and the oven will turn off.

or stir.

If you need to check food, open the oven door and check

After closing the door, touch SLOW COOK pad, lower temperature if needed, and COOK pad

to reactivate the oven.

If a temperature setting above 130°C is

entered,lEE]indicating

an error will appear on the display.

CLEAR pad must be touched before reprogramming the oven.

Page 27

The PROOF cycle is designed for raising or proofing bread dough. It is preset at 40°C for 30 minutes.

See the Convection Microwave Baking and Dessert section of your Sharp Carousel Convection Microwave Cookbook for proofing directions.

Suppose you want to proof dough of loaf bread.

Step

Procedure

Place dough in a well-greased bowl or loaf pan; cover with damp

cloth.

Place dough in oven.

Close door. Touch PROOF pad.

Touch COOK pad.

Pad Order

Display

CONV

=if I-i

)I ri

,f 1-r

I-t B-4

Fan Symbol will begin rotating.

The cooking time will count down to zero. When the timer reaches zero, all indicators will go out and an audible signal will sound. The time of day will reappear on the display.

The fan will remain on until the oven cavity has been cooled.

NOTE: To check oven temperature during PROOF cycle, touch CONVECTION pad. 1

*c: #!I?q

will appear on display.

Page 28

OPERATION FOR AUTO START COOKING

If YOU

wish to

program

your

oven

to automatically begin cooking at a designated time of day, a limit of

time setting is maximum 12 hours.

Suppose you want to start cooking a roast for 50 minutes on HIGH MIX/ROAST at

4:30

p.m.

Before setting, check to make sure the clock is showing the correct time of day.

Step

Procedure

Pad Order

Display

Enter the desired start time.

Touch AUTO START pad.

3. Enter the desired cooking time.

The colon will flash on and off.

4. Select desired HIGH MIX/ROAST setting.

Touch COOK pad.

Suppose you are setting at

1:OO

p.m.

It comes at

4:30

p.m.

Convection Fan Symbol will rotate.

The cooking

time

will

count down

to zero. When the timer reaches zero, all indicators will go out and

an audible signal will sound. The time of day will reappear on the display.

Page 29

NOTE: The Auto Start feature can be used for any of the programs described on the previous pages,

including:

1) cooking by time using the Variable Cooking Control

2) multiple sequence cooking

3) defrosting

4) convection cooking

5) memory cooking

To Check Auto Start Time

Once you have correctly programmed the oven for Auto Start, the correct time of day (not the

Auto Start time) will appear on the display. To check the time of day you have programmed the oven

begin cooking, follow these steps:

Suppose you have already set the Auto Start time at

4:30

p.m.

Step

Procedure

Pad Order Display

Touch AUTO START pad.

[&iq

The colon will flash on and off.

Checking the Auto Start time will not interfere with the operation of the oven. The oven will still

start at the designated time of day and perform the cooking sequences you have programmed.

To cancel Auto Start, simply touch STOP pad and then CLEAR pad.

(

Minute Timer

The Auto-Touch control panel can be used as a timer for timing up to 99 minutes, 99 seconds. There

is no cooking involved.

Suppose you want to time a 3 minutes long distance phone call.

Step

Procedure

Pad Order Display

Enter desired time.

2. Touch TIMER pad.

The timer will begin counting down to zero. When the timer reaches zero, the signal will sound. The time of day will reappear on the display.

To cancel the minute timer during operation, simply touch CLEAR pad and the time of day will reap pear.

Page 30

OPERATION FOR MEMORY COOKING

This Microwave Oven has one memory bank to allow you to preset one frequently used cooking program. The oven “memorizes” these instructions and can recall this information whenever needed. This feature can be used for frequently prepared foods such as scrambled eggs, heating coffee or baby bottles or special recipes children like to cook.

It can also be used for more complicated multiple

sequence cooking and convection microwave cooking.

You can program the oven ahead and another family member or even the baby sitter can cook dinner by simply touching one panel to recall instructions.

Suppose you prepare two scrambled eggs every morning,

If two scrambled eggs cooked for 2 minutes 20 seconds at MED HIGH are exactly as you like them.

Step

Procedure

Pad Order

Display

Enter desired cooking time.

2. Select desired Variable Cooking setting.

3. / When you are touching MEMORY

’

ENTRY pad.

The time of day will reappear on the display and MEMORY indicator will go out.

That information (2 minutes, 20 seconds at MED HIGH) now becomes the program stored in the

memory bank. This information

wili

remain in the memory bank indefinitely unless power to the unit

is interrupted or you elect to change the program.

You can erase this information simply by pro-

gramming over it using the procedure outlined above. NOTE: The Minute Timer and the Auto Start time cannot be programmed into the Memory.

Page 31

To Cook by Memory

To use the information stored in the memory bank.

Suppose you have already stored the cooking program 2 minutes 20 seconds at MED HIGH in the

memory bank.

Step

Touch MEMORY RECALL pad.

Procedure

Touch COOK pad.

Pad Order

MEMORY

RECALL

Display

M. HIGH

The information stored in the memory bank will be repeated until COOK or CLEAR pad is touched.

Cook indicator will light and the timer will count down to zero.

When the timer reaches zero, all

indicators will go out and an audible signal will sound.

The time of day will reappear on display.

NOTE: The oven can be started immediately after touching MEMORY RECALL pad. It is not

necessary to wait for the memorized cooking program to be reviewed before touching COOK pad.

The Memory can be used for any of the programs described on the previous pages, including:

1) cooking by time using the Variable Cooking Control

2) one to four step cooking (up to four sequences)

3) defrosting

4) convection cooking

At times you may forget exactly what information is stored in the memory bank or simply want to check if the oven has been programmed correctly.

Suppose the memory bank has been programmed for 5 minutes at MED LOW/DEFROST, and

followed by 2 minutes at HIGH.

step

Procedure

Pad Order

Display

Touch MEMORY RECALL pad.

piq

Then

-1

The cooking sequence will be repeated

until COOK or

CLEAR pad is touched.

2. Touch CLEAR pad.

Time of day will reappear on

display.

Page 32

CHAPTER Ill

OPERATION

NORMAL COOKING SEQUENCE

MICROWAVE COOKING

Place the food to be cooked in the oven and close the

door firmly.

2. Set the touch control for desired condition by touching the NUMBER and Variable Selection pads. The HIGH indicator will light.

3. Touch the “COOK” pad. The COOK indicator light will glow indicating the oven

is in the cook cycle and the oven lamps, cooling fan motor and turntable motor will come on. Note:

If the oven door is opened or the “STOP” pad is touched during the cooking operation, the

oven will go out of the cook cycle (no

microwave energy) and the time display will

stop. This is done so the exact cooking time

remains on the display.

To restore cooking operation, the door must

be closed and the “COOK” pad must be touch-

ed again.

4. At the end of the cook cycle, the COOK and HIGH indicator lights will go out, and audible signal will sound for a few seconds. The oven will stop supplying the microwave energy. The cooling fan motor, oven lamps and turntable motor will go off.

CONVECTION COOKING

(Example: Preheat the oven at

70°C)

1. Place the turntable in the oven and close the door firmly.

2. Set the convection temperature by touching the CONVECTION and

70°C

pads.

The CONV indicator and 70 C wil appear on display.

3. Touch the “COOK” pad. The Convection Fan Symbol on display will flash on and off, and display will show LO C. The COOK indicator will glow indicating the oven is in the convection cycle, and the oven lamps, cooling fan motor, turntable motor and convection motor will come on.

Note:

If the door is opened or “STOP” pad is

touched during the preheating operation, the

oven will go out of the preheating cycle (no heater energy) and the temperature display will stop. This is done so the exact preheating temperature remains on the display. To restore preheating operation, the door must be closed and “COOK” pad must be touched again.

4. A beep will sound four times to signal when oven temperature has reached 70°C (and the Convection Fan Symbol will stop flashing and begin to rotate).

5. Place the food to be cooked in the oven and close the door firmly.

6. Set the convection cooking time by touching the

NUMBER pads and touching the “CONVECTION”

and

“7O’C”

pads, and “COOK” pad must be touched again. The convection cooking time now counts down to zero.

7. At the end of the convection cook cycle, the COOK and CONV indicator will go out, and an audible signal will sound for a few seconds. The oven will stop the convection cooking operation.

The cooling fan motor, oven lamps, turntable motor and

convection motor will also go off.

DESCRIPTION OF OPERATING SEQUENCE

(Australia Model)

The following is a complete description of component function during the three stages of oven operation.

OFF CONDITION

touch the “CLE-AR” pad. This will cancel

“88:88”

and

1:OO

will appear on the display and count up every one

minute.

2. A signal is input to the control unit, energizing the coil of shut-off relay (RY4).

Closing the door activates both door latch switches: upper

RY4 contacts close, completing a circuit to the damper

latch switch and lower latch switch. (In this condition, the

motor.

monitor switch is opened)

The damper motor now operates moving the damper to

The stop switch on the control panel is activated by the

the open position, thereby closing the contacts of the

door lever.

damper switch

which

inputs a signal to the control

When oven is plugged in, the 240 volts A.C. is supplied

unit.

to the transformer on the relay unit, and the transformer is energized. But no components in the oven will operate

The coil of shut-off relay (RY4) is de-energized,

open-

ing its contacts, thereby turning off the damper motor.

except damper motor which will run until the damper is fully open. (Figure 1)

A display will show a flashing “88:88”.

Note:

When the door is opened by pushing the

door open button, the oven lamps and cooling fan motor come on.

To set any program or set the clock, you must first

Page 33

MICROWAVE COOKING CONDITION

1. HIGH COOKING Program desired cooking time and Variable Cooking

Control by touching the NUMBER pads and the “HIGH”

pad of the Variable Cooking Control. When the

“COOK” pad is touched, the following operations occur: (Figure 2) l-l

l-2

l-3

l-4

l-5

l-6

l-7

l-8

l-9

The COOK and HIGH indicators light. The numbers of the digital readout start counting down to zero. The coil of shut-off relay (RY2) is energized. A. The relay contacts (A) close to provide a

current path to the oven lamps.

B. The relay contacts (B) close to provide a

current path to the turntable motor. The coil of shut-off relay (RY3) is energized. The relay contacts close to provide a current path

to the cooling fan motor.

The coil of cook relay is energized by the con-

trol unit and relay unit.

The relay contacts close to provide a current path to the power transformer. The 240 volts A.C. is supplied to the primary winding of the power transformer and is converted

to 3.15 volts A.C. output on the flament winding.

The 3.15 volts A.C. output from filament winding heats the magnetron filament. The 2400 volts A.C. output from the high vottage

winding of the power transformer is sent to a voltage doubler circuit consisting of a high voltage

capacitor and a rectifier. The 2400 volts A.C. is converted to approximately 4000 negative. D.C. voltage (peak to peak) by

the voltage doubler circuit and sent to the magnetron tube assembly. The negative 4000 volts D.C. is applied to the cathode of the magnetron tube. This causes the magnetron to oscillate and produce the 2450 MHz cooking frequency. The RF energy produced by the magnetron tube is channeled through the waveguide into the cavity

feedbox,

and then into the cavity where

the food is placed to be cooked.

l-10 Upon completion of the cooking time, the

following results will occur:

A. The shut-off relay (RY2) will be de-ener-

gized, de-energizing the oven lamps and the turntable motor.

B. The shut-off relay (RY3) will be de-ener-

gized, de-energizing the cooling fan motor.

C. The cook relay will be de-energized, opening

the circuit to the power transformer stop-

ping the generation of microwave energy by

the magnetron.

D. The COOK and HIGH indicators will go out,

and the time of day will reappear.

The end of cooking signal will sound, and the

oven will revert OFF condition.

l-l 1. The monitor switch is electrically monitoring the

operation of the upper latch switch and is mechanically associated with the door so that it will function in the following sequence.

(1) When the door opens from closed position,

the upper and lower latch switches first operate to open their contacts, and then the monitor switch contacts close.

(2) When th

edoor is closed from open position, the monitor switch contacts first open, and then the contacts of the upper and lower latch switches close.

In case the upper latch switch fail with it contacts closed when the door is opened, closing of the monitor switch contacts will form a short circuit through the fuse and upper latch switch, causing the fuse to blow,

2. MEDIUM HIGH,

MEDIUM or MEDIUM LOW/

DEFROST COOKING

Program disired cooking time by touching the number pad or pads and “MED HIGH”, “MED” or “MED LOW/

DEFROST” pad of variable cooking control. When the “COOK” pad is touched, the following operations occur: 2-1.

2-2.

2-3.

HIGH

MED

HIGH

MED

The shut-off relays (RY2 and RY3) and cook relay are energized. The COOK and selected

Variabie

Cooking Control indicators light. The 240 volts A.C. is supplied to the power transformer intermittently through the cook relay contacts which is operated by the control unit within a 32 second time base. The microwave power operation is as follows:

-32

sec.------H

sec.

MICROWAVE POWER

OFF

=Approx. 70%

-18

sec.

14 sec.

-+OFF

MICROWAVE POWER

=Approx. 50%

MICROWAVE POWER

=Approx.

30%

Note:

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

becausee

approx. 2 seconds are needed for

heating of the magnetron filament.

Page 34

CONVECTION COOKING CONDITION

PREHEATING CONDITION

Program desired convection temperature by touching the

“CONVECTION” pad and the temp. pad. When the “COOK” pad touched, the following operations occur: (Figure 3)

1. The COOK and CONV indicators light.

2. LO C appears in the display and Convection Fan Symbol flashes on and off. 40 C appears in the display when oven temperature has

reached 4O’C.

3. The coil of shut-off relay (RY4) is energized by the control unit. 3-l.

The relay contacts close to provide a current path to the damper motor.

3-2. The damper motor is energized and damper is

moved to the closed position, opening the damper switch contacts.

3-3. The opening of the damper switch contacts sends

a signal to the control unit de-energizing shut-off

relay (RY4) and opening the circuit to the damp-

er motor.

4. The coil of shut-off relay (RY2) is energized. 4-l. The relay contacts (A) close to provide a current

path to the oven lamps.

4-2. The relay contacts (B) close to provide a current

path to the turntable motor.

5. The coil of shut-off relay (RY3) is energized. The relay contacts close to provide a current path to the cooling fan motor.

6. The coil of shut-off relay

(RYl )

is energized. The relay contacts close to provide a current path to the convection motor.

7. The coil of heater relay is energized by the control unit.

8. The heater relay contacts close to provide a current path to the heating element.

9. The 240 volts A.C. is supplied to the heating element.

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

10-l. The Convection Fan Symbol stops flashing on

and off, and begins to rotate.

10-2. The heater relay is de-energized by the control

unit temperature circuit and thermistor,

open-

ning the circuit to the heating element.

10-3

A beep signal will sound four times.

The preheat temperature has been reached.

10-4. The oven will continue to function for 15

minutes, turning on and off, as needed to main-

tain the selected preheat temperature.

The oven will shut-down completely after 15

minutes.

CONVECTION COOKING CONDITION

When the preheat temperature is reached, a beep signal will sound four times 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. Then program desired cooking time and convection temperature by touching the NUMBER pad, “CONVECTION” pad and Temperature pad. When the “COOK” pad is touched, the following operations occur:

1. The COOK, Convection Fan Symbol and CONV indicators light.

The numbers of the digital readout start the count down to zero.

2. The oven lamps, turntable motor, cooling fan motor

and convection motor are energized.

The heating element is not energized. But, if the oven temperature was lower than the selected temperature, the heater relay is energized, and the 240 volts A.C. is supplied to the heating element to return to the selected cooking temperature. When the selected temperature is reached, the heater is de-energized, but the other components remain in operation.

4. Upon completion of the cooking time, the audible signal will sound, and oven lamps, turntable motor, cooling fan motor and convection motor are

de-

energized. At that time if the oven temperature is approximately

120°C

or above, the shut-off relay

(RY3) remains ON (judged at the control unit by

thermistor operation) and the cooling fan motor

continues to operate cooling the oven cavity. Or, when the oven temperature reaches approximately 120°C or above at the completion of cooking

time, the same operation as described above will take

place, the cooling fan will continue to run. When the oven temperature drops below approximately 80°C, the contacts of the shut-off relay (RY3) open and the cooling fan motor is de-energized, and the

oven will revert to the OFF condition. The heater will’ cycle on and off to maintain the selected temperature.

At the end of the convection cook cycle, shut-off relay (RY4) is energized turning on the damper motor.

The damper is returned to the open position, closing the damper switch contacts which send a signal to the control unit, de-energizing shut-off relay (RY4).

Page 35

AUTOMATIC MIX COOKING CONDITION

Program desired cooking time and temperature by touch-

ing the number pads and the “LOW MIX/BAKE” or “HIGH

MIX/ROAST” pad. When the “COOK” pad is touched, the following operations occur:

1. The COOK and MIX indicators light, and Convection Fan Symbol will rotate. The numbers of the digital readout start the count down to zero.

2. The shut-off relay (RY4) is energized. The damper door closes from the open position.

3. The shut-off relays

(RYI,

RY2 and RY3) are energized, energizing the oven lamps, turntable motor, cooling fan motor and convection motor.

4. The heater relay is energized. The 240 volts

AC.

is supplied to the heating element.

5. Now, the oven is in the convection cooking condition.

LOW MIX

BAKE

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

6-l. The 240 volts A.C. is supplied to the heating

element and power transformer alternately.

6-2. The heating

element operates through the heater relay contacts and the power transformer operates through the cook relay contacts.

6-3. These are operated by the control unit within

a 32 second time base.

The relationship between the convection and microwave

power operations are as follows.

Note:

The ON/OFF time ratio does not correspond with the percentage of microwave power, because approx. 2 seconds are needed for heating of the magnetron filament.

6 sec.

l--y-

26 sec.

/ON i

MICROWAVE POWER

=Approx. 10%

I I

!ON

CONVECTION TEMPERATURE

=I 5o”c

set

‘---i--

20 sec.

-_i

ION

HIGH MIX

ROAST

iON

-a

32 sec.

MICROWAVE POWER

=Approx. 30%

CONVECTION TEMPERATURE

=200°c

Note :

During alternate

Microwave/Convection operation, the convection heater is energized only if the cavity temperature drops below the set temperature.

Page 36

240-50Hz

P-5

TH:

THERM ISTt

SCHEMATIC

NOTE: CONDITION

OF OVEN

1. DOOR CLOSED

2. CLOCK APPEARS ON DISPLAY

/7 n C-IVFN

AbjfJ

v-h.- -,,a.

UPPER

LATCH

SWITCH

MONITOR SWITCH

TURNTABLE

MOTOR

STOP

SWITCH

I DAMPER

MOTOR

HEATER iCOOK

,RELAY IRELAY

-----

I I

ZOOLING

FAN MOTOR

IEATING

LEMENT

HEATER RELAY

CONTACTS

---m-----

----

FUSE

MlOA

LOWER LATCH

SWITCH

MAGNETRON THERM0

CUT-OUT

COOK

RELAY

CONTACTS

POWER TRANSFORMEF

HIGH

FECTIFIER

VOLTAGE

=#‘L+

----

MAGNETRON

Figure 1 Oven Schematic-Off Condition

(Australia Model)

Page 37

240%50Hz

TH:

THERMISTO

SCHEMATIC

NOTE: CONDITION OF

OVEN

1. DOOR CLOSED

2. COOKING TIME PROGRAMMED

3. VARIABLE COOKING CONTROL “HIGH”

4. “COOK” PAD TOUCHED

I-URNTABLE

‘/lOTOR

STOP

c1y c2t

I ,

DAMP% - -J

SWITCH

I DAMPER

MOTOR

s-m--

iHEATER

iCOOK

,RELAY IRELAY

ELEMENT

HEATER RELAY

CONTACTS

------__

RECTIFIER VOLTAGERECTIFIER VOLTAGE

FUSE

MlOA

LOWER

LJTCH

SWITCH

MAGNETRON THERM0 CUT-OUT

COOK

RELAY

CONTACTS

POWER TRANSFORMER

L-

------I

MAGNETRON

Figure 2. Oven Schematic-Microwave Cooking Condition

(Australia Model)

Page 38

240~50Hz

TH : , THERMISTOR

SCHEMATIC

NOTE: CONDITION

OF OVEN

1. DOOR CLOSED

2. CONVECTION PAD TOUCHED

3. DESIRED TEMP. PAD TOUCHED

4. “COOK” PAD TOUCHED

I I

r-------

TURNTABLE MOTOR

STOP

,,,,,:;L-J

SWITCH

I I

iLEMENT

HEATER RELAY

CONTACTS

L- -

---- ___

FUSE

MlOA

LOWER

LATCH

)

SWITCH

MAGNETRON

THERM0

CUT-OUT

COOK

-I

RELAY

‘CONTACTS

----

POWER

TRANSFORMEf

MAGNETRON

Figure 3. Oven Schematic-Convection Cooking Condition

(Australia Model)

Page 39

DESCRIPTION OF OPERATING SEQUENCE

(South Africa Model)

The following is a complete description of component function during the three stages of oven operation.

OFF CONDITION

Closing the door activates both door latch switches: upper latch switch and lower latch switch. The stop switch on the control panel is activated by the door lever. When oven is plugged in, the 220 volts A.C. is supplied to the transformer on the relay unit, and the transformer is energized. But no components in the oven will operate except damper motor which will run until the damper is fully open. (Figure 4)

1. A display will show a flashing “88:88”. To set any program or set the clock, you must first touch the “CLEAR” pad. This will cancel “88:88” and

1:OO

will appear on the display and count up every one

minute.

2. A signal is input to the control unit, energizing the coil of shut-off relay (RY4).

RY4 contacts close, completing a circuit to the damper motor.

The damper motor now operates moving the damper to the open position, thereby closing the contacts of the damper switch which inputs a signal to the control

unit.

The coil of shut-off relay (RY4) is de-energized, open-

ing its contacts, thereby turning off the damper motor.

Note:

When the door is opened by pushing the door open button, the oven

lamps

and cooling fan

motor come on.

MICROWAVE COOKING CONDITION

1. HIGH COOKING Program desired cooking time and Variable Cooking Control by touching the NUMBER pads and the “HIGH” pad of the Variable Cooking Control. When the “COOK” pad is touched, the following

operations occur: (Figure 5)

1-l

The COOK and HIGH indicators light. The numbers of the digital readout start counting down to zero.

l-2 The coil of shut-off relay (RY2) is energized.

A. The relay contacts (A) close to provide a

current path to the oven lamps.

B. The relay contacts (B) close to provide a

current path to the turntable motor.

l-3

The coil of shut-off relay (RY3) is energized.

The relay contacts close to provide a current path to the cooling fan motor.

l-4

The coil of cook relay is energized by the con-

trol unit and relay unit. The relay contacts close to provide a current

path to the power transformer.

l-5 The 220 volts A.C. is supplied to the primary

winding of the power transformer and is converted to 3.15 volts A.C. output on the filament winding.

l-6 The 3.15 volts A.C. output from filament wind-

ing heats the magnetron filament.

1-7

The 2400 volts A.C. output from the high voltage winding of the power transformer is sent to a voltage doubler circuit consisting of a high voltage capacitor and a rectifier. The 2400 volts A.C. is converted to approximately 4000 negative D.C. voltage (peak to peak) by the voltage doubler circuit and sent to the magnetron tube assembly.

l-8 The negative 4000 volts D.C. is applied to the

cathode of the magnetron tube. This causes the magnetron to oscillate and produce the 2450 MHz cooking frequency.

l-9

The RF energy produced by the magnetron tube is channeled through the waveguide into the cavity

feedbox,

and then into the cavity where

the food is placed to be cooked.

l-10 Upon completion of the cooking time, the

following results will occur: A.

The shut-off relay (RY2) will be de-ener-

gized, de-energizing the oven lamps and the

turntable motor.

The shut-off relay (RY3) will be de-ener-

gized, de-energizing the cooling fan motor.

The cook relay will be de-energized, opening

the circuit to the power transformer stop-

ping the generation of microwave energy by

the magnetron.

The COOK and HIGH indicators will go out, and the time of day will reappear.

The end of cooking signal will sound, and the oven will revert OFF condition.

MEDIUM HIGH, MEDIUM or MEDIUM LOW/

DEFROST- COOKING Program disired cooking time by touching the number

pad or pads and “MED HIGH”, “MED” or “MED LOW/ DEFROST” pad of variable cooking control. When the

“COOK” pad is touched, the following operations occur: 2-l.

The shut-off relays (RY2 and

RY3)

and cook relay

are energized.

2-2. The COOK and selected Variable Cooking

Control indicators light.

2-3. The 220 volts A.C. is supplied to the power

transformer intermittently through the cook relay contacts which is operated by the control unit within a 32 second time base. The microwave power operation is as follows:

Page 40

MICROWAVE POWER

At-i

=Approx.

70%

MED

d-14 sec.

MICROWAVE POWER

-cl

8 sec.

-+OFF

=Approx. 50%

MICROWAVE POWER

=Approx.

30%

Note:

The ON/OFF time ratio does not correspond with the percentage of microwave power, because approx. 2 seconds are needed for heating of the magnetron filament.

CONVECTION COOKING CONDITION

PREHEATING CONDITION

Program desired convection temperature by touching the “CONVECTION” Pad and the temp. pad. When the “COOK” pad touched, the following operations occur: (Figure 6)

1. The COOK and CONV indicators light.

2. LO C appears in the display and Convection Fan Symbol flashes on and off.

40 C appears in the display when oven temperature

has reached 40°C.

3. The coil of shut-off relay (RY4) is energized by the

control unit. 3-l. The relay contacts close to provide a current

path to the damper motor.

3-2. The damper motor is energized and damper is

moved to the closed position, opening the

damper switch contacts.

3-3. The opening of the damper switch contacts sends

a signal to the control unit de-energizing shut-off

relay (RY4) and opening the circuit to the damp-

er motor.

4. The coil of shut-off relay (RY2) is energized. 4-l. The relay contacts (A) close to provide a current

path to the oven lamps.

4-2. The relay contacts (B) close to provide a current

path to the turntable motor.

5. The coil of shut-off relay (RY3) is energized. The relay contacts close to provide a current path to the cooling fan motor.

The coil of shut-off relay (RY 1) is energized.

The relay contacts close to provide a current path to

the convection motor.

7. The coil of heater relay is energized by the control unit.

8. The heater relay contacts close to provide a current path to the heating element.

The 220 volts A.C. is supplied to the heating element.

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

10-l. The Convection Fan Symbol stops flashing on

and off, and begins to rotate.

10-2. The heater relay is de-energized by the dontrol

unit temperature circuit and thermistor,

open-

ning the circuit to the heating element.

10-3. A beep signal will sound four times.

The preheat temperature has been reached.

10-4. The oven will continue to function

minutes, turning on and off, as needed

tain the selected preheat temperature.

The oven will shut-down completely minutes.

CONVECTION COOKING CONDITION

for 15

main-

after 15

perature by touching the NUMBER pad, “CONVEC-

TION” pad and Temperature pad. When the “COOK” pad is touched, the following operations occur:

The COOK, Convection Fan Symbol and CONV indicators light. The numbers of the digital readout start the count

down to zero.

The oven lamps, turntable motor, cooling fan motor and convection motor are energized. The heating element is not energized. But, if the oven temperature was lower than the selected temperature, the heater relay is energized, and the 220 volts A.C.

is supplied to the heating element to return to the selected cooking temperature. When the selected temperature is reached, the heater is de-energized, but the other components remain in operation.

Upon completion of the cooking time, the audible signal will sound, and oven lamps, turntable motor, cooling fan motor and convection motor are

de-

energized. At that time if the oven temperature is approximately

12OO.C

or above, the shut-off relay

(RY3) remains ON (judged at the control unit by thermistor operation) and the cooling fan motor continues to operate cooling the oven cavity. Or, when the oven’ temperature reaches approximately

120°C or above at the completion of cooking time, the same operation as described above will take place, the cooling fan will continue to run. When the oven temperature drops below approximately

80°C,

the contacts of the shut-off relay (RY3) open and the cooling fan motor is de-energized, and the oven will revert to the OFF condition. The heater will cycle on and off to maintain the selected temperature.

Page 41

At the end of the convection cook cycle, shut-off relay (RY4) is energized turning on the damper motor. The damper is returned to the open position, closing the damper switch contacts which send a signal to the control unit, de-energizing shut-off relay (RY4).

AUTOMATIC MIX COOKING CONDITION

Program desired cooking time and temperature by touching the number pads and the “LOW MIX/BAKE” or “HIGH MIX/ROAST” pad. When the “COOK” pad is touched, the following opera-

tions occur:

1. The COOK and MIX indicators light, and Convection Fan Symbol will rotate. The numbers of the digital

readout start the count down to zero.

2. The shut-off relay (RY4) is energized. The damper door closes from the open position.

3. The shut-off relays

(RYl,

RY2 and RY3) areenergized, energizing the oven lamps, turntable motor, cooling fan motor and convection motor.

4. The heater relay is energized.

The 220 volts A.C. is supplied to the heating element.

5. Now, the oven is in the convection cooking condition.

6. When the oven temperature reaches the selected temperature, the following operations occur: 6-1. The 220 volts A.C. is supplied to the heating

element and power transformer alternately.

6-2. The heating

element operates through the heater relay contacts and the power transformer operates through the cook relay contacts.

6-3. These are operated by the control unit within

a 32 second time base.

The relationship between the convection and microwave power operations are as follows.

Note:

The ON/OFF time ratio does not correspond with the percentage of microwave power, because approx. 2 seconds are needed for heating of the magnetron filament.

6 sec.

IF---y

26 sec.

[ON

MICROWAVE POWER

=Approx. 10%

LOW MIX

BAKE

!ON

CONVECTION TEMPERATURE

=15o”c

20 sec.

-1 I

I .

MICROWAVE POWER

(MICRO.)

OFF

=Approx.

30%

HiGH MIX

ROAST

ION

I I

CONVECTION TEMPERATURE

=200°c

32 sec.

------A

Note:

During alternate

Microwave/Convection operation, the convection heater is energized only if the cavity temperature drops below the set temperature.

Page 42

220V-50Hz

I I I

LINE

BYPASS

CAPACITOR J-,

TH: THERMISTOR

SCHEMATIC

NOTE: CONDITION

OF OVEN

1. DOOR CLOSED

2. CLOCK APPEARS ON DISPLAY

r------- 1

OVEN LAMP

UPPER LATCH SWITCH

TURNTABLE

.-l

,AMP:zL -

SWITCH I

I DAMPER

-----

IHEATER

iCOOK

,RELAY IRELAY

I I f I

---___

ELEMENT

HEATER RELAY

CONTACTS

L--------.

L-L--T----A----A

MAGNETRONMAGNETRON

Figure 4. Oven Schematic-Off Condition

(South Africa Model)(South Africa Model)

, 3

FUSE

MIOA

FJiss

CAPACITOR

LOWER LATCH SWITCH

.MAGNETRON

THERM0 CUT-OUT

COOK

RELAY

‘CONTACTS

POWER TRANSFORMER

Page 43

220V-50Hz

I I

r-------

FUSE

MlOA

LINE BYPASS

CAPACITOR

LATCH

)

SWITCH

T”nh’TAn’

I UlllY I HISLIZ

MOTOR

-M--, f

STOP SWITCH

H2r -1

IT’T-

I ILJ

;rn

I I

TH:

THERMISTO

vMAGNETRON

THERM0

CUT-OUT

IDAMP%

-J

SW ITCH

SCHEMATIC

LEMENT

HEATER RELAY

CONTACTS

--------_

NOTE: CONDITION OF

OVEN

1. DOOR CLOSED

2. COOKING TIME PROGRAMMED

3. VARIABLE COOKING CONTROL “HIGH”

4. “COOK” PAD TOUCHED

COOK

RELAY

CONTACTS

---

I I

POWER TRANSFORMER

I-

HIGH

RECTIFIER VOLTAGE

I-

L-

---I

MAGNETRON

Figure 5. Oven Schematic-Microwave Cooking Condition

(South Africa Model)

Page 44

220V-50Hz

LINE

BYPASS

CAPACITOR

TH:

THERMISTOF

SCHEMATIC

NOTE: CONDITION

OF OVEN

1. DOOR CLOSED

2. CONVECTION PAD TOUCHED

3. DESIRED TEMP. PAD TOUCHED

4. “COOK” PAD TOUCHED

r-------

TURNTABLE

--I

SWITCH

H2-- - 1

I-

I I

: I

-4 i

IKT-““‘I llK:TAY I ‘-1

1 1

; DAMP&L - J 1

SWITCH

iLEMENT

HEATER RELAY

CONTACTS

---w-m-__

POWER TRANSFORMEI?

FUSE

MlOA

--IL

LINE

BYPASS

CAPACITOR

LOWER LATCH SWITCH

MAGNETRON THERM0 CUT-OUT

COOK

RELAY

CONTACTS

HIGH

RECTIFIER VOLTAGE

;

MAGNETRON

Figure 6. Oven Schematic-Convection Cooking Condition

(South Africa Model)

Page 45

DESCRIPTION AND FUNCTION OF COMPONENTS

OVEN LAMP

The oven cavity lamp illuminates the interior of the oven so that the food being cooked can be examined visually through the door window without having to open the door.

COOLING FAN MOTOR The cooling fan motor drives a blade which draws cooling air through the oven base. This cooling air is directed through the air venes surrounding the magnetron and cools the magnetron assembly. Most of the air is then exhausted directly through the back vents. However, a portion of this air is channeled through the cavity to remove steam and vapors given off from the heating foods.

It is then exhausted at the top of the oven cavity into a condensation compartment. This fan motor operates during both microwave and convection cooking.

TURNTABLE MOTOR The turntable motor rotates the turntable located on the bottom of oven cavity, so that it works to cook the foods on the turntable evenly, during both microwave and convection cooking.

THERMISTOR The thermistor of 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 heater relay to operate, thus the current to the

heating element is turned ON/OFF.

MAGNETRON THERM0 CUT-OUT The

therm0

cut-out located on the magnetron assembly,

is designed to prevent damage to the magnetron if an

overheated condition develops in the tube due to cooling fan failure, obstructed air ducts, dirty or blocked air intake, etc. Under normal operation, the

therm0

cut-out remains

closed. However,

when abnormally high temperature

within the magnetron approaches a critical level, the

therm0 cut-out will interrupt the circuit to the power trans-

former, and will interrupt the cook cycle. When the magnetron has cooled to safe operating temperature, the

therm0

cut-out closes and the cook cycle will resume.

COOK RELAY The cook relay is mounted on the front portion of the relay chassis.

The coil of the cook relay is energized by the control unit and relay unit, thereby closing its contacts which provide a current path to the power transformer. The cook relay is activated by 12 volts D.C. supplied from control unit and relay unit.

HEATER RELAY

The heater relay is mounted on the back portion of the relay chassis. The coil of the heater relay is energized by the control unit and relay unit, thereby closing its contacts which provide a current path to the heating element. The heater relay is activated by 12 volts D.C. supplied from the control unit and relay unit.

STOP SWITCH The stop switch is located on the open device of the control panel assembly and activated by the door lever. When the open button is depressed while the oven is in cook cycle (microwave or convection cooking), the stop switch contacts open to de-energize the shut-off relays and cook or heater relay circuit in the control unit and relay unit.

DOOR OPEN MECHANISM The door can be opened by pushing the open button on

the control panel, refer to Figure 7. When the open button is pushed, the open plate on the open device pushes in the door lever on the door, operat-

ing the latch head linkage. The lower and upper latch heads are moved upward, and are released from the lower

and upper latch hooks.

Now, the door can be opened.

Lever

Open

Button Device

Figure 7 Door Open Mechanism

Page 46

CONVECTION COOKING SYSTEM

This oven is designed with a hot air heating system where food is not directly heated up by the heating element, but

is instead heated by forced circulation of the hot air produced by the heating element. The air heated by the heating element 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 oven through the vent holes provided on the top and

left side of the oven. Next, the hot air heats up the food on the turntable and leaves the oven cavity through the vent in the

center

of the oven cavity ceiling. Without leaving the oven, this hot air is reheated by the heating element, 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 then drops

preset temperature, the heating element is de-energized. When the temperature inside the oven cavity then drops below the preset temperature, the heating element is energized again. In this way, the inside of the oven cavity is maintained at approximately the preset temperature.

When the convection time reaches 0, the heating element

is de-energized and the convection fan stops operating. Although the damper will open and the cooling fan motor normally turn off when the convection time reaches “0”, if the temperature of oven has reached approximately

120°C

or higher at that time (or later) the cooling fan motor will continue to operate, cooling the oven.. Pushing in ambient air through the vent holes in the damper

section, the cooling fan motor circulates it through the oven and then exhausts it out through the rear vent and condensate compartment. Once the oven temperature has been lowered to a approximately

80°C,

the cooling fan

motor stops operating.

Convect Passage

Heating

Convection

Element

Fan

Convection Fan

Belt

-7

ior

Convection Motor

HEATING ELEMENT The heating element is located above the top of the oven cavity as illustrated in Figure 8. It is intended to heat air

driven by the convection fan. The heated air is kept in the oven and forcedly circulated and reheated by the heating element.

UPPER AND LOWER LATCH SWITCHES The upper latch switch is mounted in the upper latch hook and the lower latch switch is mounted in the lower latch

hook. They are activated by the latch heads on the door.

When the door is opened, the switches interrupt the circuit

to all components except the oven lamps and cooling fan

motor.

A cook cycle cannot take place until the door is firmly closed thereby activating both latch switches.

Note:

The monitor switch is provided on Australia Model.

Latch

Hlead

Latch

Hook

iI Upper

Latch

‘11

Switch

Lower Latch

Latch

Head

”

Lower

Latch

Switch

iitor tch

Figure 9.

Latch Switches and Monitor Switch

Figure 8.

Page 47

MONITOR SWITCH (AUSTRALIA MODEL) The monitor switch mounted on the upper latch hook is activated (the contacts opened) by the latch head on the

door while the door is closed. This switch is intended to

render the oven inoperative by means of blowing the fuse

when the contacts of the upper latch switch fail to open

when the door is opened.

Functions;

1. When the door is opened, the monitor switch contacts close (to ON condition) due to their being normally closed. At this time the upper and the lower latch switches are in OFF condition (contacts open) due to

their being normally open contact switches.

2. As the door goes to a closed position, the monitor switch contacts are first opened and then the upper and

lower latch switches contacts close. (In case of opening

the door, each of these switches operate inversely.)

3. If the door is opened and the upper latch switch contacts fail to open, the fuse blows simultaneously with the closing of the monitor switch contacts.

CAUTION: BEFORE REPLACING A BLOWN FUSE,

TEST THE UPPER LATCH SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO THE TEST PROCEDURE ON PAGE 56.)

POWER TRANSFORMER The transformer consists of three windings: primary, filament and high voltage.

During a cook cycle, the

220/240

volts A.C. applied to the primary winding of the transformer through the cook relay contacts is converted to 3.15 volts A.C. on the filament winding and approximately 2400 volts A.C. on the high voltage winding. The 3.15 volts A.C. voltage heats the magnetron filament. This causes the tube cathode to readily emit the electrons necessary for tube conduction whenever the negative 4000 D.C. voltage is applied to the cathode.

WITHOUT

MAGNETIC

FIELD

ELECTRONS

CATHODE

ANODE+

1’

Figure 10. Basic Magnetron

The 2400 volts A.C. voltage is fed to the voltage doubler circuit.

VOLTAGE DOUBLER CIRCUIT The voltage doubler circuit consists of a rectifier and a capacitor. The 2400 volts A.C. from the high voltage wind-

ing of the power transformer is applied to the voltage doubler circuit, where it is rectified and converted to approximately 4000 volts negative D.C. needed for

magnetron operation.

Rectifier: The rectifier is solid state device that allows current flow in one direction, but prevents current flow in the opposite direction. This acts as rectifier changing alternating current into pulsating D.C.

High voltage capacitor:

The capacitor is able to store energy on one half of the power cycle and release it along with the transformer output to produce approx. 4000 negative D.C. volts to the magnetron.

MAGNETRON TUBE

The basic magnetron tube is a cylindrical cathode within a cylindrical anode surrounded by a magnetic field. When the cathode is heated by the filament winding of the power transformer, electrons are given off by the cathode. These negatively charged electrons are

attacted

to the more positive anode of the tube when the negative 4000 D.C. voltage is applied to the cathode. Ordinarily, the electrons would travel in a straight line from the cathode to the anode as shown in Figure 10. But the addition of a magnetic field, provided by permanent magnets surrounding the anode, causes the electrons to take

an orbital path between the cathode and anode, Figure 11. As the electrons approach the anode, they travel past the small resonant cavities that are part of the anode. Interaction occurs, causing the resonant cavities to oscillate at the very high frequency of 2450 megahertz. This RF energy is radiated from the magnetron antenna into the waveguide into the cooking cavity

feedbox,

and finally into the

cooking cavity where food has been placed to be cooked.

WITH

MAGNETIC

FIELD.

ANODE--/

+ATHODE

COOKI

NG LOAD-/

without Magnetic Field

Figure 11. Basic Magnetron with Magnetic Field

Page 48

DAMPER OPERATION Usually, the damper is open position except during the convection cooking. Damper position is set automatically by damper motor,

damper switch, motor cam and damper arm

,lever.

These components are operated according to the signal that judges the microwave cooking or convection cooking operation in the control unit.

Microwave Cooking:

Damper is in the open position. Because a portion of cooling air is channeled through the cavity to remove steam and vapors given off from the heating foods.

It is then exhausted at the top of the oven cavity into a condensation compartment.

Convection Cooking: Damper is in the closed position, so that no hot air will be allowed to leak out the oven cavity, Figure 8.

Damper Operation

1. When power supply cord is plugged in: l-l. When power supply cord is plugged in, a signal

is sensed in the control unit, and operates the

shut-off relay (RY4).

Damper Arm Lever

Motor Cam.

nPmnO*

Cwi+t-h

Damper Motor’

Mounting Bracket

Figure 12 Damper Operation

l-2. Contacts of shut-off relay (RY4) close and

supljly

220/240

volts A.C. to the damper motor. The damper motor is energized, opening the damper door.

l-3. When damper is moved to the open position by the

motor cam and arm lever, damper switch is closed

(ON position).

l-4. The signal of damper switch is re-sensed in the

control unit and shut-off relay (RY4) is turned off.

l-5. The 220/240 volts A.C. to the damper motor is stop-

ped and the motor turns off.

2. When oven is microwave cooking: Damper is in the open position.

3. When oven is convection cooking:

3-l. Damper motor is energized by touching the con-

vection, temperature and COOK pads.

3-2. When damper is in the closed position (damper

switch is OFF), its signal is sensed by the control

unit, and shut-off relay (RY4) is de-energized.

3-3. The damper is held in the closed position during

the convection cooking operation.

3-4. At the end of the convection cooking, the shut-off

relay (RY4) is energized, and damper is returned to

the open position.

Control

Unit

L- --

--- --

’

l-1 13

LEL-i

04%

----__

Damper Switch

Figure 13 Damper Motor Circuit

Page 49

RELAY UNIT

The relay unit is composed of transformer, buzzer, relays, printed wiring board, etc. This unit generates voltage necessary in the control unit from the A.C. line voltage. The cook, heater relays and shut-off relays of the printed Operational circuit is as follows:

1. When the 220/240 volts A.C. is supplied, the signal of D5 terminal (LSI: l-l) goes to “H” level (usually at “L” level).

The terminal (D-6) on the relay unit become F-3 (OUT) voltage through the driver IC (IR-2403) and shut-off relay (RY4) is energized. The damper motor is energized through the shut-off relay (RY4) contacts.

Note; If the damper is at the open position (damper

switch is ON), the signal of terminal D5 goes

“L” level and the damper motor is de-energized.

2. During microwave cooking, the signal of terminal

Dl,

D2 and 04 on LSI (l-l) goes to “H” level and shut-off relays (RY2 and RY3) are energized. The components which are connected to the relay contacts are energized. Also, the cook relay is energized.

During convection cooking, the signal of terminal DO, D2, D3 and D4 on LSI (l-l) goes to

“H”

level and shut-

off relays

(RYl,

RY2 and RY3) are energized. The components which are connected to the relay contacts are energized. Also, the heater relay is energized.

Relationship between pin Nos. and Connections

CONNECTOR”

CONNECTOR D”

Pin No.

I/O

Pin No.

I/O

DESCRiPTlON

C-l

Input the A.C. Line voltage:

220/24OV 50Hz

c-2

IN 1. These terminals are connected to the transformer.

2. The transformer coverts

22OV/24OV

A.C. to 17.4 volts A.C. output

on the secondary winding.

3. The secondary A.C. voltage is rectifier to a smoothing circuit.

4. Control panel is operated on the D.C. voltage that is supplied.

----- -----

------------

-----------

--------

D-2

D-4

OUT

This voltage supply to the DC-DC converter circuit into the control unit.

----------

-----------

OUT

Signal synchronized with commercial power source frequency Signal of commercial frequency is supplied to the p circuit in the control

unit.

D-5

This signal will be changed in the ,0 circuit to the square wave that is the basic timing for all of time processing.

-------------

----------

-------

Signal to sound buzzer

Signal coming from D2 terminal of LSI (l-2).

Key touch sound:

Approx. 0.1 sec.

Approx. 2.5 kHz, approx. 0.1 sec.

-----------------

GND

-15v

Completion Sound:

(Cook or

convec.

time)

Approx. 2.5 kHz, approx. 2 sec.

Approx. 2sec.

________-__--_-

-GND

-15v

Completion Sound:

(Reached the preheating temp.)

Approx. 2.5 kHz, approx. 1 sec. ON, 1 sec. OFF four times.

Approx. lsec. Approx. 1 sec.

GND

-lsv

Page 50

DESCRIPTION

Cook relay, heater relay and shut-off relays driving voltage. When the driver IC (IR-2403) is turned on by the “H” level signal from

the LSI (l-l), cook relay, heater relay and shut-off relays are energized by this driving voltage.

Connected to GND.

_________ ---------------------------

Cook Relay driving signal. To turn the cook relay on and off.

In HIGH cooking mode operation, one circuit of the driver IC (IR-2403) is closed (ON) during cooking and supplies the D-3 (OUT) voltage to the cook relay coil, and the cook relay is turned on. When not cooking, the

IC is turned off and the relay is not energized. In other cooking modes (MED HIGH, MED, MED LOW/DEFROST), one circuit of the driver IC (IR-2403) is cycled on and off according to the power setting.

__-_-___----------------------

Heater Relay driving signal. To turn the heater relay on and off.

In Convection cooking operation, one circuit of the driver IC (IR-2403) is closed (ON) during cooking and supplies the D-3 (OUT) voltage to the heater relay coil and the heater relay is energized, when oven tempera-

ture is below the set temperature, and driver IC (I R-2403) is open (OFF) when oven temperature is higher than set temperature.

Shut-off relay

(RYl)

driving signal.

To turn on the shut-off relay

(RYl).

One circuit of the driver IC (I R-2403) is closed (ON) and supplies the

D-3 (OUT) voltage to the shut off relay

(RYl)

energizing the relay and

turning on the convection fan motor. Shut-off relay (RY2) driving signal. To turn on the shut-off relay (RY2).

One circuit of the driver IC (IR-2403) is closed (ON) and supplies the

D-3 (OUT) voltage to the shut off relay (RY2) energizing the relay and

turning on the turntable motor and the oven cavity lamps.

Shut-off relay (RY3) driving signal.

To turn on the shut-off relay (RY3).

One circuit of the driver IC (I

R=2403)

is closed (ON) and supplies the

D-3 (OUT) voltage to the shut off relay (RY3) energizing the relay and

turning on the cooling fan motor. Shut-off relay (RY4) driving signal. To turn on the shut-off relay (RY4).

One circuit of the driver IC (IR-2403) is closed (ON) and supplies the D-3 (OUT) voltage to the shut-off relay (RY4) to operate the damper motor when cooking condition is changed from convection to microwave or from microwave to convection, and also when power supply cord is initially plugged in or the end of convection cooking.

OR “D’

--m-

XTOR

--m-

CONNEC’

Pin No.

OUT

D-3

E-2 F-2

-----

--------

D-10

E-l OUT

OUT

D-8

F-l

A-2

OUT

D-l 1

B-2

OUT

D-9

B-3

OUT

B-4

OUT

D-7

OUT

D-6

B-l

Page 51

4VDD

DC-DC

-”

CONVERTER

FUSE

Heater of display tube

POWER SUPPLY

220/240\ 50Hz

1 1-3

(lR2403)

LSI

l-l

RYI

A-l

R21

8.2K

797

Q20

RY2

A683f

TURNTABLE MOTOR

I I

747

I I f

I 37 I

’

I I

MOTOR

(DAMPER)1

RELAY UNIT

CONTROL UNIT

Figure 14

Page 52

CHAPTER IV

SERVICING

TROUBLESHOOTING GUIDE

When troubleshooting the convection 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

proce-

dure letter which will be found in the “Test Procedures”

section.

IMPORTANT (Australia model only)

: If the oven becomes inoperative because of

a blown fuse in the upper-monitor switch circuit, check the upper latch switch and monitor switch before replacing the fuse.

PROBLEM

POSSIBLE CAUSE

TEST PROCEDURE OR

CORRECTION

OFF CONDITION

Home fuse blows when power cord

Shorted wire in power cord or wire

is plugged into wall receptacle.

harness.

Replace cord or check wiring.

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

Shorted wire in power cord or wire harness.

Defective monitor switch. (Australia Model)

Replace power cord or check and

repair wire harness.

Procedure G.

88:88 does not appear in display

No power at outlet.

(

Check home fuse.

when power cord is first plugged

into wall outlet.

Blown fuse.

Procedure H.

Open wire in power cord, wiring harnes, or wiring between control panel assembly units.

Replace or repair wiring.

Defective control unit.

Procedure L.

Defective relay unit.

Procedure

Display does not operate

Defective key unit.

Procedure L.

I properly when CLEAR key is touched. (Buzzer should sound

Defective control unit.

Procedure L.

and time of day should appear

in display.)

Defective relay unit.

Procedure Q.

Oven lamps do not light with

door opened.

No power in home. Open wire in power cord or wire

harness.

Check wall outlet.

Replace same or repair wiring.

Defective oven lamp.

Replace both lamps.

Defective lower latch switch.

Procedure F.

Open or loose wire connection to the

above components.

Check wiring.

Blown fuse.

Procedure H.

Page 53

TROUBLESHOOTING GUIDE (CONT’D)

PROBELM

POSSIBLE CAUSE

TEST PROCEDURE OR

CORRECTION

MICROWAVE COOKING CONDITION

Oven lamps do not light in cook cycle.

(Does light when door is opened)

Defective contacts (A) of shut-off relay (RY2) on relay unit.

Defective control unit.

Procedure

Procedure L.

Oven lamps do not light at all.

Burned out bulb.

Replace.

Open wiring to oven lamp.

Check and repair wiring.

Oven lamps light, but turntable motor do not operate.

Defective contacts (B) of shut-off relay (RY2) on relay unit.

Procedure Q.

Cook indicator lights on display

Defective turntable motor. Defective control unit.

Replace.

Procedure L. but cooling fan motor do not operate.

Defective contacts of shut-off relay (RY3) on relay unit.

Procedure Q.

Defective cooling fan motor. Open or loose wiring between above

components.

Replace.

Check and repair wiring.

Oven does not go into a cook

cycle when COOK key is touched.

Primary and/or secondary interlock switches defective or out of adjustment.

Procedures E and F.

Defective magnetron therm0 cut-out.

Procedure I. Defective cook relay. Defective control unit.

Procedure J.

Procedure L. Defective key unit.

Procedure L.

Defective relay unit.

Open or loose wiring to above components.

Procedure Q.

Check and repair wiring.

Oven seems to be operating

Defective magnetron therm0 cut-out.

Procedure I.

but little or no heat is produced in oven load.

(Food incompletely cooked or

Defective relay unit.

)

Procedure Q.

qot

cooked at all at end of

zook

cycle)

Defective cook relay. Defective power transformer.

Procedure J. Procedure 8.

Defective rectifier.

Procedure C.

Defective high voltage capacitor.

Procedure D. Defective control unit. Open or loose wiring to above

components.

Procedure L.

Check and repair wiring.

&en

goes into a cook cycle but

extremely

uneven heating is

3roduced

in oven load (food).

Turntable motor does not operate.

Refer to proceeding turntable

motor problem.

Page 54

TROUBLESHOOTING GUIDE (CONT’D)

PROBELM

POSSIBLE CAUSE

TEST PROCEDURE OR

CORRECTION

MICROWAVE COOKING CONDITION (CONT’D)

Oven does not cook properly when Defective control unit.

Procedure L.

programmed for MED LOW/

DEFROST, MED or MED HIGH

Defective key unit.

Procedure L.

cooking powers. Open or loose wiring between above

(Operates properly on HIGH)

components.

Check and,repair wiring.

CONVECTION COOKING CONDITION

CONV indicator lights but oven does not go into cook cycle when cook pad is touched.

CONV indicator lights, but heating element does not heat.

Temperature in the oven cavity is lower or higher than preset.

Defective key unit,

Procedure L.

Defective thermistor.

Procedure N.

Open wiring in circuit to above

Check wiring.

components.

Defective heating element

Procedure M.

Defective heater relay.

Procedure J.

Defective relay unit.

Procedure

Defective control unit.

Procedure L.

Open or loose wire connection to the above components.

Check wiring.

Defective magnetron therm0 cut-out.

Procedure I

Defective heating element.

Procedure M.

Defective control unit.

Procedure L.

Defective convection motor.

Replace.

Defective thermistor.

Procedure N.

Defective damper motor.

Procedure 0.

Defective damper switch.

Procedure P.

Defective drive mechanism of convection

Check.

fan.

Page 55

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

MAGNETRON ASSEMBLY TEST

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

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

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

Power output of the magnetron can be measured by performing a water temperature rise test. This test should only be used if above tests do not indicate a faulty magnetron and there is no defect in the following components or wiring: rectifier, high voltage capacitor and power transformer.

MICROWAVE OUTPUT POWER

Microwave output power from the magnetron can be measured by way of substitution, i.e. it can be measured by using water load how much it can be absorbed by the water load. 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-t/4.2

calorie is generated. On the other

hand, if the temperature of the water with V (ml) rises AT

(“C)

during this microwave heating

period, the calorie of the water is V-AT. The formular is as follows;

p _

4.2.V-AT

---

(WI

Our condition for the water load is as follows;

water load . . . .

.2000

Heating time. . .

.120

seconds (2 minutes)

p7ix-j

Measuring method;

1. Put the water load of two (2) litres on the

center

of the oven shelf. The water load should be arranged in two (2) Pyrex beakers, the size of which is one (1) litre, and be placed at right and left, side by side, on the oven shelf.

2. Measure the temperature of water before heating and also after heating during two minutes by microwave, and calculate the temperature rise. The temperature rise should be the average of temperature differences measured in each beaker.

3. The output power should be calculated as follows. In case the measuring result is not satisfactory, execute the measurement several times and judge

the result from the synthetic point of view.

Microwave output power should be within

+15%

of the nominal one.

Page 56

PROCEDURE

LETTER

TEST PROCEDURES (CONT’D)

COMPONENT TEST

Calculation of output power;

Microwave output power . . . . .P (W) = 70 x AT (“C)

AT =

(ATL + ATR)

: average temperature rise

ATL = (Q2 - TLJ ATR = (TRY -TRY 1

TL2

: water temperature after heating in left beaker

TLI :

water temperature before heating in left beaker

TR2 : water temperature after heating in right beaker TRl

: water temperature before heating in right beaker

Measuring condition; As the microwave output is affected by several conditions, the measurement should be made carefully with following attentions.

1. Initial temperature of salt water should be 20 f l°C. (The salt water should be contained bon (1) percent of salt.) Well and quickly stir the water and the temperature measurement should be

done immediately after heating.

2. The graduation of thermometer should be scaled by 0.1 “C at minimum and an accurate mercury thermometer is recommended.

3. Water container should be one (1) litre beaker made of Pyrex glass and its diameter approxi-

mately 12 cm.

4. Room temperature should be around 20°C.

5. Power supply voltage should be 220/240 volts.

POWER TRANSFORMER TEST

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

Disconnect the primary input terminals and measure the resistance of the transformer with an ohmmeter. Check for the continuity of the coils with the ohmmeter. On the RX1 scale, the resistance of the primary coil should be less than 1.1 ohm (22OV)/1.2 ohm (24OV) and the resistance of high

voltage coil should be approximately 105 ohms: and the resistance of filament coil should be less than 1 ohms. With 220/240 volts AC applied to the primary winding, the voltage across the filament winding should be approximately 3.15 volts A.C. (HIGH VOLTAGES ARE PRESENT TO HIGH VOLTAGE TERMINAL, SO EXTREME CAUTION SHOULD BE OBSERVED.)

RECTIFIER TEST

DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY

OVEN COMPONENTS OR WIRING.

Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance across the terminals and observe, reverse the leads to the rectifier terminals and observe meter

reading. If a short is indicated in both directions, or if an infinite resistance is read in both directions, the rectifier is probably defective and should be replaced.

Page 57

TEST PROCEDURES (CONT’D)

PROCEDURE

LETTER

COMPONENT TEST

HIGH VOLTAGE CAPACITOR TEST

DISCljARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY

OVEN COMPONENTS OR WIRING.

If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads and check for short or open between the terminals using an ohmmeter. Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate

continuity for a short time and should indicate an open circuit once the capacitor is charged. If the

above is not the case, check the capacitor with the ohmmeter to see if it is short circuited between

the terminals. If it is short circuited, replace the capacitor.

UPPER LATCH SWITCH TEST

The upper latch switch can be checked with an ohmmeter. Isolate the switch and then connect the

meter leads to the common (COM) and normally open (NO) terminals of the switch. The meter

should indicate an open circuit with the door opened and a closed circuit with the door closed,

In case improper operation is indicated, make the necessary switch adjustment or replacement.

LOWER LATCH SWITCH

,TEST

Isolate the switch and connect the ohmmeter leads to the common

(COM)

and normally open (NO) terminals of the switch. The meter should indicate an open circuit with the door opened and a closed circuit with the door closed.

W)th

the meter leads connected to the common

(COM)

and normally closed (NC) terminals of the switch, it should indicate a closed circuit with the door opened and an open circuit with the door closed.

In case improper operation is indicated, make the necessary switch adjustment or replacement.

MONITOR SWITCH TEST

(Australia Model)

Before performing this test, make sure that the upper latch switch is operating properly referring the

Test Procedure “E”. Connect one ohmmeter lead to one of the fuse terminals, and the other lead to the power transformer terminal to which the white wire from the wiring harness is connected,

When the door is open, the meter should indicate a closed circuit.

When the monitor switch lever of the upper latch hook is pushed by the screw-driver through

the upper latch hole on

the,

front plate of the oven cavity with the door opened (in this condition

the plunger of the monitor switch is pushed in), the meter should indicate an open circuit.

In case improper operation is indicated, replace the defective switch.

POWER TRANSFORMER

OHMMETER

Page 58

TEST PROCEDURES (CONT’D)

PROCEDURE

LETTER

COMPONENT TEST

BLOWN FUSE

If the fuse in the upper latch switch and monitor switch (Australia) circuit is blown when the door

is opened, check the upper latch switch and monitor switch before replacing the blown fuse (Refer

to Test Procedure E and

G).

In case the fuse is blown by an improper switch operation, replace the

defective switch and fuse at the same time.

Replace just the fuse if the switches operate normally.

CAUTION: REPLACE BLOWN FUSE 10 AMPERE FUSE,

PART NO.

QFS-CQOOlYBEO

MAGNETRON THERM0 CUT-OUT TEST

A continuity check across the therm0 cut-out terminals should indicate a closed circuit unless the

temperature of the therm0 cut-out reaches approximately 104°C. The therm0 cut-out resets auto-

matically at approximately 79°C. An open therm0 cut-out indicates overheating of the magnetron assembly. Check for restricted air flow to the magnetron through the opening in the chassis, especially the cooling duct.

COOK RELAY OR HEATER RELAY TEST

Disconnect the wire leads from relay coil terminals. A continuity check of the cook relay coil should indicate approximately 160 ohms. Supply the 12 volts D.C. to the relay coil terminals, and then check if there is a continuity between the contacts of relay.

STOP SWITCH TEST

Isolate the stop switch and connect the ohmmeter leads to the common

(COM)

and normally open (NO) terminals of the switch. The meter should indicate an open circuit with the open button pushed and a closed circuit with the open button released. In case improper operation is indicated, replace the stop switch.

TOUCH CONTROL PANEL ASSEMBLY TEST

The touch control panel consists of circuits including semiconductors such as LSI,

ICs,

etc. Therefore, unlike the convectional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter. For test procedure or troubleshooting guide, refer to the CHAPTER V “TOUCH CONTROL PANEL ASSEMBLY”.

Page 59

TEST PROCEDURES (CONT’D)

PROCEDURE

LETTER

COMPONENT TEST

HEATING ELEMENT TEST

Make sure the heating element is fully cooled and test the followings;

a. Disconnect wire leads and measure the resistance with an ohmmeter. On the R x 1 scale, the

resistance between the heating element terminals should be approximately 9.6 ohms.

b. Disconnect wire leads and measure the insulation resistance with

500V-lOOMa

insulation

resistance meter.

The insulation resistance between heating element terminal and cavity should be more than

0.5MSX

THERMISTOR TEST

Disconnect leads from the thermistor and remove the thermistor. Measure the resistance of the thermistor with an ohmmeter.

Resistance

High0

Room Temp.

COM.- High

COM. - Low

Low

20°C - 30°C

Approx.

322 -

165kSZ

68 -

35kS2

Cornmo” 0

If the meter does not indicate these resistance, replace the thermistor.

THERMISTOR

DAMPER MOTOR TEST’

When the power cord is plugged into the wall receptacle, the 220/240 volts A.C. is supplied to the damper motor and the motor operates until the damper is opened and the damper switch closes.

Then the damper motor stops operating.

If the damper motor does not operate, check for input voltage by A.C. volt-meter at the motor.

1. Disconnect the power cord from the wall receptacle.

2. Disconnect the 2-pin connector of motor and connect the meter leads to the 2-pin connector of main wire harness.

3. Reconnect the power cord into the wall

receptalcle.

220/240

volts A.C. is indicated at the 2-pin connector, replace the motor.

Not indicated, check the wire harness and the relay unit.

DAMPER SWITCH TEST

Disconnect the wire leads from the switch terminals and connect the ohmmeter leads to the common (COM) and normally open (NO) terminals of the switch.

When switch actuator is pushed by the damper motor cam, the meter should indicate a closed

circuit.

2. When the power cord is plugged into the wall receptacle, the damper motor operates and damper cam starts rotate. Then switch actuator is released and meter should indicate an open circuit.

In case jmproper operation is indicated, replace the damper switch.

Page 60

TEST PROCEDURE

(CONT’D)

PROCEDURE

LETTER

COMPONENT TEST

RELAY UNIT TEST

The relay unit consists of circuits including-relays, buzzer, transformer, etc. Plug power cord into wall receptacle, the display “88:88” will be flashing.

Remove the outer case and check voltage between pins C-l and C-2 on the relay unit with an A.C. voltmeter. The meter should indicate 220/240 volts, if not check oven circuit. If 220/240 volts is indicated but oven components such as the oven lamp, turntable motor, fan motor, convection motor, damper motor, high voltage components and heating element do not operate properly. Set a microwave or convection cooking program and touch cook pad.

1. Oven lamp and turntable motor does not operate. Check voltage between Pin Nos. C-l and

B-2

or B-3 with an A.C. voltmeter.

2201’240 volts A.C. indicated . . . . - . . . . . . . Defective oven components.

220/240 volts A.C. not indicated . . . . . . . . . Defective shut-off relay RY-2.

(Shut-off relay RY-2 does not operate.) . . . .

. (See shut-off relay test or control unit.)

2. Cooling fan motor does not rotate. Check voltage between pin Nos. C-l and B-4 with an A.C. voltmeter.

220/240 volts A.C. indicated . . . . . . . . . . . . Defective oven components.

220/240 volts A.C. not indicated . . . . . . . . . Defective shut-off relay RY-3.

(Shut-off relay RY-3 does not operate.) . - . .

. (See shut-off relay test or control uinit.)

3. Damper motor does not rotate. Check voltage between Pin Nos. C-l and B-l with an A.C. voltmeter.

220/240 volts A.C. indicated . . . . . . . . - . . . Defective oven components.

220/240 volts A.C. not indicated . . . . . .

. . . Defective shut-off relay RY-4.

(Shut-off relay RY-4 does not operate.) . . . .

(See shut-off relay test or control unit.)

4. Convection motor does not rotate.

Check voltage between Pin Nos. C-l and A-2 with an A.C. voltmeter.

220/240 volts A.C. indicated . . . . . . . . . . . . Defective oven components.

220/240 volts A.C. not indicated . . . . . .

. . . Defective shut-off relay RY-1.

(Shut-off relay RY-1 does not operate.) . . . .

. (See shut-off relay test or control unit.)

Shut-off Relay Test Check voltage at the relay coil with a D.C. voltmeter during the cooking operation (microwave or

convection).

12 volts D.C. indicated . . . . . . . . . . . . . . . . . . Defective shut-off relay

12 volts D.C. not indicated . . . . . . . . . . . .

. . . Check the diode which connected to the relay

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

Page 61

CHAPTER V

TOUCH CONTROL ASSEMBLY

OUTLINE OF TOUCH CONTROL PANEL

The touch control section mainly consists of the following units as shown in the block diagram.

(1) Key unit

(2) Control unit

Exchange of signals between each unit is indicated by the arrows in the block diagram. The principal functions of these units and the signals communicated among them are explained below.

Key Unit The key unit is composed of kind of matrix circuits; in which, when one of signals Sq - S7 generated by the

LSI

(IX21

07YA) operates the key, it is given to the

LSI

(IX2107YA)

as one of signals

Ke-K6.

It consists of keys made of conductive rubber and printed circuit board.

Control Unit Control unit consists of two

LSls (IX2107YA,

IX2075YA),

converter circuit, fl circuit, ACL circuit, buzzer circuit, thermistor sensor circuit and indicator circuit.

I) LSI

(IX2107YA)

This LSI controls the thermistor sensor signal, key touch and relay unit control signal for oven function.

2) LSI

(IX2075YA)

This LSI effects the control of the indicator circuit and control of the buzzer signal.

3) Converter Circuit This circuit generates voltages [VDD (for IX2107 YA) :

-15V,

VDD’ (for IX2075YA) = VBB:

-lOV,

vp:

-25V,

VG:

-3OVI

necessary in the control

unit.

4) fl Circuit The p 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 the commercial frequency.

5) ACL Circuit

The circuit to generate signals resetting the

LSls

(IX2107YA, IX2075YA)

to the initial state when

power is supplied.

6) Buzzer Circuit The part responsive to signals from the LSI

(IX2075YA)

emit audible sounds (key touch

sound and completion sounds).

7) Thermistor Sensor Circuit The temperature in the oven cavity is sensed by the thermistor. The variation of resistance according to sensed

temperature is detected by the thermistor sensor

circuit and the result applied to LSI. The result of detecting is given to LSI

(lX2107YA)

controlling the relay and display.

8) Stop Switch The switch to “tell” open or closed condition of

the oven door to the LSI

(IX2107YA).

9) Indicator Circuit This circuit consists of

6-digits,

6-segments (Convec-

tion Fan symbol),

7-segments

display, four cooking mode indicators, CONV indicator, and the following indicators using fluorescent display.

COOK, MIX, MEM and AUTO

The method of display is by dynamic drive using

Dl 1 through D15 as digit selecting signals. The

LSI

(IX2075YA)

output terminals of each indicator

are as follows.

- R23r R30 - R33

: 7 segment signals

: 4 mode power

level indicators (M.

LOW, MED, M.

HIGH and HIGH)

: MIX, MEM and AUTO

: COOK

: CONV

: Convection Fan

Symbol

Page 62

BLOCK DIAGRAM

INI C-

POWER SUPPLY

220/24OV 50Hz

(HI C.

POWER SOURCE CIRCUIT

--IT-

RY-4

D-l

-i-

-T

RY-2

D-8

- --

Ft-

RY-3

D-

D-l

j c”kJlT 1

COOK RELAY

E-l

IMGJ

E-2 D.C. LINE (GNDI

F-2

HEATER RELAY F-l (HEATER)

-a

--I

A-l

CONVECTION

A-2 MOTOR fti. FAN)

TURNTABLE MOTOR (TTMI

B-2

OVEN LAMP

a-3

(0.L.)

COOLING

a-4 FAN MOTOR (COOLING FANI

I-1: IX2107YA (M58841-924SP)

DAMPER

B-1 MOTOR (DAMPER)

THERMISTOR

DAMPER STOP

SWITCH SWITCH

Figure 15. Block Diagram

Page 63

K DIAGRAM

INDICATOR CIRCUIT

R31

R30

Z--2-

R23

R22

CONTROL UNIT

R12 ^_.

,-,i!Jl+b

I I I I II

--r---l I I I I I I

KEY UNIT

G-l 1

MED LOW

I(- BROIL

MED

~ COOK

MED

DEFROST

HIGH

CLEAR

G-9

A- TlMER ,+$J PROOF STOP ,r-j&-j &, &.

IG-aI I I-’

HIGH MIXi MEMORYIMEMORY

- , -, - - - -. .

I\ /1 SLOW

LOW MIX

COOK

BAKE

ENTRY

G-4

G-l G-2

I I

: IX2107YA ~M5884i-024w

f:lIl I

I I I ’

I I

5. Block Diagram

Page 64

DESCRIPTION OF

LSI

LSI (I-1:

IX2107YA)

The I/O signals of the LSI

(IX2107YA)

are detailed in the following tables,

421

K13

K12

Kll

K7 K2

KlO

LSI

I-1

IX2107YA

(M58841 024SP)

03 02 Dl

XIN

XOUT

s7 s3 S6 s2 s5

VDD

CNVss

Figure 16.

Relationship between pin Nos. and Signals (LSI:

lX2107YA)

Page 65

Pin No.

Signal

I/O

Description

Connected to GND (0 volt).

To change over power source frequency.

60 Hz area: “H” level (OV: GND) 50 Hz area: “L” level (-15V: VDD)

Note:

Normally connected to “H” level (GND) by jumper wire.

DlO

To change over temperature indicate mode (“FPC)

unit: “H” level (OV: GND)

‘C

unit: “L” level (-15V: VDD)

Note:

Normally connected to “L” level (VDD) by printed pattern.

T’4

OUT

Terminal not used. Connected to

GND.

VREF

IN Reference voltage input terminal

A reference voltage applied to the A/D converter in the LSI

(IX2107YA)

to convert the oven temperature detected by the thermistor at A/D. The reference voltage is generally maintained at -6.4 to

-6.8V.

f(13

Temperature measurement input.

By inputting DC voltage corresponding to the temperature detected by the thermistor, this input is converted into temperature by the A/D converter in which LSI

(IX2107YA)

is built in.

The following is the relationship between signals and detected temperatures.

K13

(Low temperature measurement) . . . .

.40°C, 70°C

K 9 (High temperature measurement). . . . .l

10°C, 130°C, 150°C, 180°C,

200°C,

220°C,

230°C,

250°C

IN Signal coming from touch-key.

When either one of

[=I

151

-1

1-1

key is touched,

a corresponding signal out of S7 - S4 will be input into

KS.

When no key is touched , the signal is held at “L” level

(-15V).

Signal similar to

K5.

When either one of

(-1

, /llso”cll ,

[ml

[-COOK]

key

totid,

a corresponding signal will be input into

K1.

IN Signal similar to

K5.

When either one of p] ,

-1

-12oo”cJj

key is touched, a correspond-

ing signal will be input into

Ko.

Signal similar to

K5.

When either one of

[El

141

ISTOP]

or [CONVECTION)

key

is touched,

a corresponding signal will be input into

Kq.

13 K

Terminal not used.

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

Damper opened:

“H” level signal (OV: GND)

Damper closed:

“L” level signal (-15V: VDD)

Page 66

Pin No.

Signal

I/O

Description

Signal

synchronized

with commercial power source frequency.

This is the basic timing for all time processing.

Signal similar to

K5.

When either one of

fggq

, [lllo”cl] ,

key is touched,

a corresponding signal will be input into

K3.

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

Door closed:

“H” level signal (OV)

Door opended:

“L” level signal

(-15V)

Signal similar to

K5.

When either one of

-123oDc]j

key is touched, a

corresponding signal will be input

K2.

IN Signal similar to

Ks.

When either one of

(K]

[I1Bo”c11 ,[E]

key is touched, a

corresponding signal will be input

K6.

20 RESET

Terminal not used. Auto-clear terminal.

Signal is input to reset the LSI to the initial state when power is supplied. Temporarily set to “H” level the moment power is supplied, in this time the

LSI is reset. Thereafter set “L” level

(-15V).

21 22 23 24

25 26

27 28

vss INT

CNVss

V DD

Connected to GND.

Terminal not used. Connected to GND.

IN Power source voltage:

-15V

Voltage of power source circuit is input.

OUT

Data output port with respect to R

o. terminal of LSI (l-2: IX2075YA)

OUT

Key strobe signal. Signal applied to touch-key section. A pulse signal is generated while

jMEENMpRRy *

/~OIUVKTION;

-COOK]

1-1

key is being touched.

OUT

Data output port with respect to R. 1 terminal of LSI (l-2:

IX2075YA).

OUT

Key strobe signal. Signal applied to touch-key section. A pulse signal is generated while

jT-Gq

JPROOF]

lSTOPJj

j7IZOO”Clj

[a1220”Cl]

-1

key is being touched.

OUT

Data output port with respect to R

terminal of LSI (l-2: IX2075YA).

Page 67

Pin No.

Signal

I/O

Description

OUT

Key strobe signal.

Signal applied to touch-key section.

A pulse signal is generated while

161

[21

[ml

,101,

1-1

m[Iso”Cll

key is being touched.

OUT

Data output port with respect to

R03

terminal of LSI (1-2: IX2075YA).

OUT

Key strobe signal. Signal applied to touch-key section. A pulse signal is generated while

po(

/MEDI

1-1

ICOOK/

JHIGH] I

~~~or[~]

key is being touched.

XOUT

OUT

Internal clock oscillation frequency control output. Output to control oscillation input of

XIN.

XIN

Internal clock oscillation frequency setting input. The internal clock frequency is set by inserting the ceramic filter oscillation circuit with respect to X0 UT terminal.

OUT

CONVECTION MOTOR driving signal. To turn on and off the shut-off relay

(RYI

). “H” level during CONVECTION

COOK; “L” level otherwise.

J=G-=j-------~~

1J:

OUT

Magnetron high-voltage circuit driving signal. To turn on and off the cook relay.

In HIGH operation, the signals holds

“H” level during microwave cooking and

“L” level while not cooking. In other cooking modes (MED HIGH, MED, MED

LOW/DEFROST), the signal turns to “H” level and “L” level in repetition according

to the power level.

-J

HIGH

MED LOW DEFROST

Page 68

Pin No.

Signal

I/O

Description

OUT

Oven light and turntable motor driving signal.

To turn on and off the shut-off relay

(RY2

). “H” level during both microwave and

convection cooking; “L” level otherwise.

OUT

Heating element driving signal.

To turn on and off the heater relay.

“H” level during

canvection

cooking; “L” level otherwise.

))[------“:I,

OUT

Cooling fan motor driving signal.

To turn on and off the shut-off relay ( RY3). “H” level during both microwave and convection cooking; “L” level otherwise,

At the end of the convection cooking:

If oven temperature has reached approx. 1 20°C or higher, the signal holds

“H” level until the oven temperature below than approx. 80°C.

When oven temperature has been lowered to approx.

8O”C,

the signal holds

“L” level.

OUT

Damper motor driving signal.

To turn on and off the shut-off relay ( RY4). “H” level when cooking condition

is changed from convection to microwave or from microwave to convection, and also when power supply cord is initially plugged in or the end of convection cooking; “L” level otherwise.

OUT

Output signal to be used for data suppling with respect to Do terminal of

LSl

(l-2:

IX2075YA).

Input

signal to be used for data reception with respect to

R20

terminal of

LSI (l-2:

IX2075YA).

Page 69

Pin No.

OUT

Signal

I/O

OUT

Description

Magnetron high-voltage circuit and heating element driving signal.

To turn on and off the cook relay by D1 signal and the heater relay by

signal. “H” level during cooking condition; “L” level otherwise.

26 sec.

L-

1 1

HIGH MIX

ROAST

Page 70

LSI (l-2:

IX2075YA)

The I/O signals of the LSI

(lX2075YA)

are detailed in the following tables.

D3 D4

D5 D6

07 08

DlO Dll 012

D13

014

D15

LSI

I-2

IX2075YA

(HD38755A50)

VDISP

VDD

OSCl 18 osc2

02 Dl

DO R33

R32 R31

R30

R23

R22 R21

R20 INTl INTO

R13

R12 Rll RlO

R03

R02

1221

ROO

Figure 17.

Relationship between pin Nos. and Signals (LSI:

IX2075YA)

Page 71

Pin No.

Signal

I/O

Description

OUT

The relation between signals and indicators are as below:

Signal

Indicator

OUT

. . . . . .

ErnM!

OUT

D4......

. . . . . .

OUT

Dg......

OUT

D7......

Dg......

OUT

D9.

. . . . . .

CONV indicator

CONV

indicator lights during convection condition.

“H”

level during convection condition, “L” level otherwise.

Convection Fan Symbol flashes on and off until the oven temperature is reached set temperature.

Signal turns to

“H”

level and

“L”

level in rapid sequence.

Convection Fan Symbol rotates when oven temperature reached at set

temperature.

Signal turns to “H” level and “L” level in rapid sequence.

GND

160

msec.

e-l

_-----

_________

-25~

DIO

Not used. Usually, connected to Vdisp

(--25V)

by pull-down resistor of internal

LSI

(l-2: lX2075YA)

Page 72

Pin No.

Signal

I/O

OUT

Description

Digit selection signal.

The relation between digit signal and digit are as follows:

Digit Signal

Dight

DI1..

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

Colon

D12

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

D13

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

D14

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

D1s

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

Usually, one pulse is output in every p period, and input into the grid of Fluorescent Display.

13.2 msec.

--GND

GND

Dll

44-I

1.2-1.4 msec. I

D12

0.14 msec.

D13

014

1.46 msec.

D15

0.14 msec.

-___--------

GND

- -

--3ov

Page 73

Pin No.

Signal

I/O

Description

D12

OUT

Similar to

D11

To indicate the first digit of Fluorescent Display.

813

OUT

Similar to

D11

To indicate the second digit of Fluorescent Display.

D14

OUT

Similar to

D11

To indicate the third digit of Fluorescent Display.

D15

OUT

Similar to Di

To indicate the fourth digit of Fluorescent Display.

VDISP

Anode (segment) of Fluorescent Display light-up voltage: -25V. Vp voltage of converter circuit is input.

RESET IN

Auto-clear terminal. Signal is input to reset the LSI to the initial slate when power is supplied.

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

(-15V).

VBB

VDD

OSCl

Power source voltage: -1 OV.

-10 volt of converter circuit is input.

Internal clock oscillation frequency setting input.

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

OS&

terminal.

OS&

OUT

Internal clock oscillation frequency control output.

Output to control oscillation input of

OSCl.

TEST

vss

ROO

ROl

Ro2

R03

Terminal not used. Connected to GND.

IN Input signal to be used for data supplying and reception with respect to LSI (l-l:

. IX2107YA) output signal: So -

Ss.

OUT

Signal for lighting of power level indicators.

1.46 msec.

------_

GND

Normally signal similar Vp. Pulse signals are generated when lighting either indicator.

Digit

Signal

-30v

--------GN,,

OOpsec.+-

-25v

-i p-40psec.

1.6 msec.

Page 74

Pin No.

Signal

I/O

Description

Rll

OUT

Signal for lighting MIX, MEM and AUTO indicators. Signal similar to R1

R12

OUT

Signal for lighting COOK indicator.

Normally signal similar Vp. Pulse signal is generated when lighting indicator.

GND-

13.2

msec.

R12

--1-_

-4-L

1.0-1.4

msec.

R13

Not used. Terminal for manufacture test. Usually, connected to

V~rsp (-25V)

by pull-down resistor of internal LSI

(l-2: IX2075YA) By connecting this terminal to the

“GND”, count-up is performed regardless of

signal from l-l

(lX2107YA).

INTO

lNTl

R20

Not used. Connected to GND.

OUT

Output signal to be used for data supplying with respect to D7 terminal of LSI

(l-l: lX2107YA).

R21

OUT

Segment data signals.

R22

OUT

The relation between signals and segments are as follows:

OUT

. Signal

Segment

R33

. . . . ..a

R32 . . . . .

R30

OUT

R31

OUT

R31

. . . . . .c

. . . . .

O-- _. e

38.

R32

OUT

. . . . . .e

R33

OUT

R22

. . . . ..f

1.46 msec.

. . . . . .g

_-------

GND

DIgIt Signal

J-L

-30v

ie;gt

n--------1;:

70psec.+

-4 +

?Opsec.

L-

1.6 msec.

Page 75

Pin No.

Signal

I/O

Description

Input isgnal to be used for data reception with respect to D6 terminal of LSI (l-l:

lX2107YA).

Signal

synchronized

with commercial power source frequency.

This is the basic timing for all time processing.

i&g

GND

--------

,5v

13.2 msec.

OUT

Signal to sound buzzer. A: Key touch sound.

B: Completion sound. C:

End of preheating or hold temperature sound.

0.1 sec.

2 sec.

1 sec. 1 sec.

-----GND

-- -15v

15Opsec.

250psec.

f =-=-

2.5

kHz

T 400x 1o-6

Page 76

POWER SOURCE CIRCUIT

Power Source Circuit on Relay Unit

220/24OV

AC is applied to the primary of the

tranSfOrmer

(T1

) through a filter circuit consisting of

f-1,

and

Cl.

The secondary output of Tl is full-wave rectified by a

bridge circuit of D3 to D6 and smoothed by an electrolytic

capacitor C2 to DC voltage

(approx. -23V).

DC-DC Converter Circuit By switching on power supply, the starting base current

BS) flows to transistor 01 through resistor R3 and the collector currnet (IC) of Ql begins to flow through the primary winding

10-4

of the DC-DC converter transformer

(T2 1.

The current (IC) varies the magnetic flux of the transformer core and induces voltage in the base winding 3-8. The induced voltage is positive

fedback

and produces the

base current (IBF) through resistor

R2,

and the total current is I B = I BS + I BF. Therefore, if the current amplification factor is

hFE,

the

collector current

(Ic)

of Ql increases with time until it

reaches

hFE

x lg. When the collector current (I,) reaches

hFE

x IB, IC is saturated and the base winding voltage induced by the variation of core magnetic flux turns to zero and accordingly Ig turns to zero. Thus the transistor Ql is rapidly turned off. While Ql is on, the diodes 07 and D8 on the secondary output circuit are in reverse polarity and turned off. When Ql is turned

off, the magnetic flux stored in the core begins to reduce and induces voltage on the secondary output terminals. At the time, the base winding retains the

“OFF” v&age

and Ql remains in the “OFF” position.

22Of24OV 50Hz

RELAY UNIT

(D-:

ID-

(D-

Power source circuit

When variation of magnetic flux turns to zero, the above steps are repeated and the collector waveform will be as illustrated in Fig. 19. As a result, when the VDD voltage increases larger than the sum of

ZD1

and ZD2, these are turned on and the base

current runs through

ZD1

and ZD2.

By the above, bias of 02 is changed and ON-time of Ql is controlled, thereby stabilizing the output voltage. C8 and

ClO:

Voltage smoothing capacitors

C7 and

C9:

Corrector

Noise by-pass capacitors

-___--

____ -___----

GND

-23V

Figure 19. Normal Waveform

CONTROL UNIT

ZDl

ZD2

GND

VG I-3OVl

W-VP 3v A.C

DC-DC Converter circuit

Figure 18.

Power Source Circuit and DC-DC Converter Circuit

Page 77

CIRCUIT

Half-wave rectified voltage (VB) from the power source

circuit is applied to the base of

Q40.

The p waveform is generated from the collector of Q42. This is the basic timing for all time processing.

-----___-

_-----_

--------ND

R48

Figure 20. fl Circuit and Waveform

ACL CIRCUIT

By switching on power supply charge current

(iI )

is fed

Cso

through

and generates Zener voltage (Vz).

If Vz exceeds the zener voltage of

ZDSO, ZD5 o

is turned

on and the current iz flows. Thus the base current

(i3 )

flows through the transistor Q50 to turn on 050. By the

turning on of 050, a reset signal is obtained from the

collector.

R50 :: zx D50

RESET

ZD50

R51

-[-J”&iJ’;;

050

c50

R52

i3.

VDD

msec.

Figure 21. ACL Circuit

BUZZER CIRCUIT

The square waveform developed from D2 terminal of LSI

(l-2) is applied to the base of

060

to turn on and off

Q60, and squard waveform voltage (2.5 kHz) is applied to SPI

to generate buzzer sound.

Relay

Unit1 rControl

Unit

I 1

R60

< VDD (-15v)

sp, -

- .GND

I I I I I I I

--15v

15Opsec.

250usec

Figure 22. Buzzer Circuit

Page 78

THERMISTOR SENSOR CIRCUIT

LSI (lX2107YA) has a built-in A/D converter. Analog DC

Accordingly, the temperature detected by THERMISTOR

voltage input to

(LOW TEMP.) or Kg (HIGH TEMP.)

is input to K

(LOW) and Kg (HIGH) input terminal of

terminal is digitally converted into temperature data.

LSI

(lX2107YA)

as analog DC voltage value.

The thermistor sensor circuit is basically constituted by

In case of VREP

Approx. -6.4v - -6.8~

the potential division circuit for

R32

(LOW),

R31

(HIGH)

and THERMISTOR against the standard voltage of

R30

Temperatures 40°C through 1

10°C

are detected by the low

and ZD30.

side of the thermistor and 130°C through 250°C by the high side.

R33

and

VR30

are provided for compensation and fine

adjustment of THERMISTOR (LOW) and

R34,

Rss

and

The following is the relationship between temperatures and

VRs I

are provided for compensation and fine adjustment DC voltages at the input terminal of

LSI (fX2167YA).

of THERMISTOR (HIGH).

THERMISTOR

CONVECTION

TEMP.

1-1

HIGH

130°c

-4.4v

150°c

-3.9v

180°C

-3.lV

2oo”c

-2.6V

220%

-2.ov

230°C

-1.8V

250°C

-1.2v

R30

I-‘

VDD

I I I 1

-Iv I

REF

LSi

R114

lsh c. K13

‘ZD30

R113

R31

D30

vR30

vFt31

R32

l R33 4 ” 1

VI34

w4;-;-

i-1

IX2107YA

THERMISTOR

Figure 23. Thermistor Sensor Circuit

Page 79

INDICATOR

Method of Display Indicator element is Fluorescent Display. Basically, a Fluorescent Display is a triode having a cathode, a grid and an anode. Usually, the cathode of Fluorescent Display is directly heated and the filament serves as cathode.

When a proper voltage is impressed to the filament to heat

it, thermo-electrons are emitted and, with positive voltage

with respect to filament being applied to the anode and grid.

hit against the anode to illuminate the fluorescent body. If the anode or grid voltage is zero or negative against the filament, thermo-electrons can not reach the anode, hence

the fluorescent body is not luminescent.

R21 R22 R23 R30 R31

Pi::

D5 D4

D3 DZ

LSI

lIX2075YA1

D15 014 011 D13 312

CIRCUIT

In this model, the Fluorescent Display g-digits,

7-segments

are used for displaying figures,

6-segments

are used for Convection Fan Symbol and letters. The Fluorescent Display employs the dynamic drive method, when the high level of anode signal and grid signal agree, the corresponding segment displays.

Grid (digi?)

Cathode (filament)

- ------r---_--L----

---- ---- ------T-----

3VA.C.

4’ GC

4 Gl

3.3K

-----__----___

_---

I L

(-3Ov)

Figure 24. Indicator Circuit

Page 80

Relations of between Digit and Segment Signal. The requirements for display are as follows:

1. Specifying digits.

2. Specifying segments. The following signals are responsible for specifying digits.

1st

digit:

D12

2nd

digit:

D13

Colon digit: DI1

3rd

digit:

D14

4th

digit: D1

5th

digit: Connected to GND.

The following signals are responsible for specifying segments.

Segment

Signal

Segment

Signal

Segment

Signal

character

R33

character

CONV

D!2

format

R32

format

M. LOW

,e,

R31

0 l

MED

R30

M. HIGH

Indi-

cator

HIGH

R22

COOK

R21

MIX

Upper colon

R22

MEM

RII

Lower colon

R23

AUTO

*Notes 1. The upper colon is connected to

“f”

segment into the fluorescent

display.

2. The lower colon is connected to

“err

segment into the fluorescent

display.

SERVICING

1. Precautions for Handling Electronic Components This unit uses CMOS IC and CMOS LSI in the integral part of the circuits. When handling these parts, the following precautions should be strictly followed. Compared to bi-polar IC, CMOS IC and CMOS

LSls

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 charged in clothes, etc, and sometimes it is not fully

protected by the built-in protection circuit.

n order to protect CMOS

IC’s

and CMOS

LSl’s,

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

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

approx. 1

MC2

2. Servicing Tools Following tools are required when servicing the touch control panel assembly.

1) Soldering: 30W

(To prevent leaking current, it is recommended to

use a soldering iron with grounding terminal.)

2) Oscilloscope:

Single beam, frequency range: DC

10MHz type or more advanced model

3) Checker:

Exclusively designed checker (refer to

“Checker”)

4) Others: -- Other tools

3. Other Precautions

1) When turning on the power source of the control

unit, remove the aluminum foil applied for preventing

static electricity.

2) Connect the connectors of the indicator and key units to the control unit taking care that the lead wires are not twisted.

3) After aluminum foil is removed, take extra care that abnormal voltage due to static electricity etc. is not applied to the input or output terminals.

4) Attach connectors, electrolytic capacitors, etc. to PW board, taking care that all connections are tight.

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

Page 81

CHECKER

The checker is used when repairing or adjusting the touch control panel assembly and relay unit. When connectors coming from the checker are connected

to respective connectors on the control panel components

or relay unit, A.C. power can be supplied from checker

(including relay unit) to control panel components so that the panel components can be operated, being separated from the oven circuit electrically.

Use of Checker

a) for repairing

for executing test program

“Test Program” is executed by using the checker.

Connection Method

Control Panel Assembly:

1. Connect the 1 l-pin connector @ to the control unit.

2. Connect the

2-pin

connector @ (for stop switch)

to the control unit.

3. Connect the

5-pin

connector @ (for damper

switch and thermistor) to the control unit.

Relay Unit:

1. Connect the

2-pin

connector @ (for stop switch)

to the New control unit.

2. Connect the

5-pin

connector @ (for damper

switch and thermistor) to the New control unit.

3. Connect the

5-pin

connector

to the de-

fective relay unit.

4. Connect the 1 l-pin connector @ of defective relay unit to the New control unit.

Table 1 shows the relation between the indicator lamps of

the checker, energized relays of the relay unit, and LSI

(I-1 ) signals.

Table 1

INDICATOR

OPERATIONAL SIGNAL

LAMP

RELAY

FROM LSI (l-l)

Oven Lamp

RY2

Turntable Motor

Cooling Fan Motor

Convection Motor

Heater

Cook

Damper

RY3

RYl

Operates at

12V D.C

RY4

Note: The damper- indicator light is turned on or off by

the damper motor and damper switch in the checker.

Damper indicator light on: Damper is open posi-

tion

Damper indicator light off: Damper is closed posi-

tion

SENSOR DUMMY RESISTANCE

1 Terr: 1 OPEN

ResistanceDisplay Value

:210 ka2

1% LOC

: 30

ka*O.l%

43c+

4 --

: 6.1

kKZ +O.l% 147C+2C

: 4

kQ*O.l%

OCk2C

: 1.7

kQ20.1%

200C*2C

R(j

: 400

$2 rt

0.1%

25OCX5C

MQ2+

Open judge

Page 82

-3 u--u--l

.-.

lIzlc

-- 11

-PIN CONNECTOR (II

(FROM

RELAY

UNIT1

1 l-PIN I4 (TO CON

- 11

CONNECTOR

IGI

(FROM

KEY UNIT)

5.PIN

WIRE

CONNECTOR

IJI

(TO

THERMISTORI

- -.

BRN

, RED

PNK.’

WHT I

‘,BLK 0 /

Control Panel Assembly

Defective Relay Unit

Figure 25.

Connectiorr Meted

External of Checker

t CHECKER

FOR

R-8320E 1

5-PIN CONNECTOR

QQQQ8QOI

1 l-PIN CONNECTOR

/II

/Ad

---

[CLOSEDJ

5-PIN CONNECTOR

OFF [

;;;$]

OFF

K (

OVEN

TURN-

COOLING

CONVEC HEATER

COOK DAMPER

LAMP

TABLE FAN TION MOTOR MOTOR

MOTOR

--_.---

SENSOR

REG.

0 P.L

A.C. 220124OV

Figure 26. External of Checker

Page 83

Checker Circuit Diagram

- -

MAIN

SWITCH

860

COOK

.‘.

860

HEATER

CONVECTION

MOTOR

TURNTABLE

MOTOR

I r

COOLING FAN MOTOR

DAMPER MOTOR

r I

--L

I-+

I I

SWITCH

1 .5K

DAMPER

SENSOR

EGU

LATOR

SWITCH

SENSOR DUMMY RESISTANCE

/ 2

HIGH

STOP

SWITCH

Figure- 27 Checker Circuit

Diagram

Page 84

TEST PROGRAM

This test program is prepared to check the touch control panel functions, In the event of improper operation, this test program indicates defective places or parts.

How to Use

This checker is provided with the connectors, wire

leads, etc.

1) Use a grounded work bench.

2) Connect the checker to the panel components, referring to the “Connection Method”.

3) Turn OFF the main switch of the checker.

4) Connect the AC cord of the checker to a wall receptacle.

5) Turn on stop switch.

6) Set the main switch of the checker to ON.

By the above procedure, the control panel is ready

for testing.

Remarks on Test Program Phone

Display and checker

CONV M. LOW MED

M. HIGH HIGH

& b

: Key touch sound

T.0.D

: Time of day

: Completion sound

: Light

: Completion sound

% @

: Flashing

for preheat temp.

: Rotating

CHECKER

SENSOR

KEY AND

REG.

CHECKER

r’

CHECK ITEM

SWITCH

OPERATION

DISPLAY

@ COPEM

STOP SWITCH “ON”

I I

MAIN SWITCH “ON”

88888

I)/

I I I , , , , I

,fiL,- * 4 _^^ \

I I

j j 1 )

\r\lLl31 I I

wzG.1

i :

;

(After 13 sec.)

MEMORY

RECALL

/ !

CONVECTION

I I ’

SLOW COOK

1 1

i /

I! I

1.i

Flashing in 1 sec. period.

When damper lamp lights, damper is in

the open position.

Keys are not input until CLEAR pad is Touched. (Operation with 1 min.)

/ I

1 1 I

CLEAR

I /

Ii4

)

AUTO START

CLOCK

Setting the CLOCK.

125 9

1 2 59

AUTO START

’

CLOCK

12:59

CONV

CONVEC-

TION

Check convection cooking.

CONV

250”

5 0 c

Page 85

Remarks on Test Program Phone

0 : Key touch sound

: Completion sound

0 : Completion sound

for preheat temp.

Display and checker

T.0.D

: Time of day

: Light

$$ @

: Flashing

: Rotating

CONV

M. LOW

MED

M. HIGH HIGH

a!!

ouo r7

O 07

9R)

02 02 O 02

COOK

MIX

MEM AUTO

I I I I

CHECKER

SENSOR

KEY AND

r’ r’

REG.

CHECKER

DISPLAY

2 ij

CHECK ITEM

SWITCH

OPERATION

i.u

-I

i5 r-’

r’ z

gbE

g G 8 6 ii!

t;;

COOK

Damper light turn off

after 11 sec.

Cooking does not start.

16@

(LOC)

CONV

COOK

o$g

C.0.0.

Convection fan symbol

COOK

flashing in 1 sec. period.

CONV

@(43"c)-

3c.0.0.

Check temperature

COOK

(43+$C)

CONV

STOP

0 2 5 0 c

CONV

COOK

3Coeeee

COOK CONV

21 @(147OC)

%14

7Ceeeee

Check temperature

COOK

(14722°C)

CONV

Cooling fan motor lamp

STOP

0 2 5 0 c l l

lights

when

oven

tempe-

rature has reached approx.

CONV

120°C

or higher.

COOK

%14

7Ceeeee

COOK CONV

Convection fan symbol is

@(25O"C)

OCeeee

rotating when setting

COOK

temperature is reached.

STOP

346 0

T. 0.

l l

Damper lamp lights automatically. (Ready to microwave

. 4 l

cooking)

@ (LOC)

AUTO START

CLOCK

4 6

Check auto start function

AUTO

and variable cooking

control.

7888 0 7 8

8 8 l

AUTO

MED LOW

M. LOW

DEFROST

’

7 8

8 8 l

AUTO

-I

_--

MED

7 8

8 8 l

AUTO

M.HIGH

MED HIGH

7 8 . 8 8 l

AUTO

HIGH

0 7 8 . 8 8 l

AUTO

CLEAR

I I

lOI

T. 0. D

I I I I I I

IeI

Page 86

Remarks on Test Program Phone

0 : Key touch sound

: Completion sound

0 : Completion sound

for preheat temp.

Display and checker

T.0.D

: Time of day

: Light

e (ID

: Flashing

: Rotating

SENSOR REG. SWITCH

CONV M. LOW MED

M. HIGH HIGH

&c&h

ouo

00 O DO ln

97) !I3 Q O UQ UDI

COOK

MIX

MEM AUTO

KEY AND

MED LOW

M. LOW

DEFROST

151

M. LOW

COOK

COUNT DOWN

4IGH

MIX

ROAST

2 0 0 c

MIX

LOW MI

BAKE

15 @ (200°C)

“,yT;[

i G G

CHECKER

z 5

CHECK ITEMITEM

g E

2 F

8 8I 4

Check microwave cooking.

I I I

Check microwave cooking.

MIX

I0I

MlY

nfil=nn.

lel

1 1

1.11,.

,.ILI”,7

. T. 0. D

CONV

BROIL 0

CLEAR

SLOW c

CLEAR

0 T. 0. D

CONV

:OOK

T. 0. D

PROOF

CONV

The temperature is displayed only while the key in touched.

Page 87

Remarks on Test Program Phone

0 : Key touch sound

: Completion sound

for preheat temp.

Display and checker

T.0.D

: Time of day

: Light

% @

: Flashing

: Rotating

CONV

M. LOW MED

M. HIGH HIGH

&zA u,li u,o O 02 &!g

wJn)

UJ n-u O 1117

n-u

COOK

MIX

MEM

AUTO

-r

CHECKER

-1

i r’

“r

LL 5

.is

fjj

z 2

6Gt-’

E 2 “IO

8 2

I -

I I I I t

I 1 lej 1 1 jel

SENSOR

KEY AND

REG.

CHECKER

SWITCH

OPERATION

CHECK ITEM

DISPLAY

9 L

TIMER

T. 0. D

’

l l

Cl!EAR

-!=--I

1 I I I

, ,

-r

l---M-w

Timer function is operated on relation to stop switch.

T. 0. D

STOP SWITCH “ON

‘*

Check memory bank.

MEMORY

RECALL

MIX

MEM

I / I I I I

I I I I I I

(BLANK)

0 c

MIX

MEM

I 1

1 I

IelI

l-t-t-l

Display of memory bank is repeated until

the CLEAR pad is

touched.

(BLANK)

MIX . MEM

(BLANK)

1 5

0 c

MIX

MEM

(BLANK)

CLEAR

T. 0. D

‘0 @(OPEN)

MAIN SWITCH “OFF”

Page 88

TROUBLESHOOTING GUIDE

This model has the control unit and the separate relay unit, a power supply for driving the control unit. Thus if the control panel operates normally when the test program is run, the relay unit needs to be checked. The following troubleshooting flow charts are prepared for both units. Carry out check in the following order.

Note 1) Check the 1 l-pin connector

(D)

of the relay unit

if the soldering is poor, and the copper foil con-

ductors if they are broken.

2) With the key connectors, manipulate the 1 l-pin connector

(G)

on the control unit by fingers to

check if the soldering is poor.

3) Check other connectors for poor soldering.

g8:8g

does not flash

A. Check converter circuit

B. Check fl circuit

2. All keys fail to transmit input

3. Special matrix group keys fail to transmit input

4. Cook does not start C. Check damper circuit

5. Shut-off relay RYI-

RYq,

cook relay or heater relay

does not operate

6. Buzzer does not sound.

7. Faulty power on reset ( BB-88 lights but does not flash)

8. Faulty display

9. Faulty convection operation

Yes

Defective transformer

develop approx. 23V

(Tl)

Opened 03 to D6 diodes

Faulty C2 or short

terminal (Test Pin)

develop

-15V

Yes

Defective converter

circuit

See A. “Check Converter

Circuit” (Next page)

terminal (Test Pin)

To page 88

Page 89

From page 87

Note:

To measure

fSmoLW9

resistance, remove pin

of fluorescent display

At the time, don’t

Opened filament

Replace

Flourescend Display

apply excessive glass tube root.

force to pin

terminal (Test Pin)

Defective

“p

circuit”

Yes

See B. “Check /3 circuit” (Page 90)

Check and replace

203

Defective

LSI

(l-2)

CF70

To page 89

Page 90

From page 88

Replace T2

See Table

Yes

Is C5 faulty or

Correct soldering.

Replace C5.

ZDl

or ZD2

shot-t circuited?

Replace

ZDl

. ZD2

Replace

. C8

Cl0

.Cll

Are resistances across

See Table

Table 1

Terminal 1

,“,;;;z, /

Replace

1 @ - @ (

3.6~2

Page 91

Defective

Dl,

Poor R40 soldering

Yes

Defective Q40‘

applied to Q41

base?

II-l Poor soldering of R42,

R45, R46 and R48

Yes

Defective

041

applied

to Q42 base?

>l Poor soldering of R43

and R47

Yes

Defective Q42

Poor R44 soldering

ALL KEYS FAIL

TRANSMIT INPUT

Correct soldering.

Yes

Defective

Connector

(H)

2-pin wire connector

stop switch

Page 92

SPECIAL MATRIX GROUP KEYS

FAIL TO TRANSMIT INPUT

(Vertical group

keys)

For example, in case Of BROIL, 6, TIMER and

Correct soldering

HIGH MIX/ROAST.

Cl 00

soldered

normally?

Defective

LSI

(I-1)

(Horizontal group keys

For example, in case of BROIL, MED, MED LOW/ , DEFROST, COOK, HIGH, MED HIGH and CLEAR

Key

connector

(G)

RlOO

Correct soldering

Defective

LSI

(I-1)

Refer to Table 3 for other group keys.

Table 3

Parts related

R104

to vertical

---+

R115

group keys

l Cl00

R105

RlO?

R109

RllO

l Rlll

R112

Parts related

R115

.R115

R115

l R115

R115

to horizonta

*Cl00

l Cl00

l c1oo

-Cl00

*Cl00

group keys

Pin Nos.

BROIL

MED

MED LOW

related to

DEFROST

COOK

HIGH

MED HIGH

CLEAR

RlOO

each keys

7,ll

6, 11

5,ll

4,ll

3, 11

2, 11

1,ll

Pin Nos. related to

+E]

I-&

l R101

each keys -

7,10

6, 10

5, 10

4,lO

3, 10

2, 10

1,lO

Pin Nos.

TIMER

PROOF

SToP

pi&

l-&q

START

related to

R102

each keys

7,g

HIGH MIX

MEMORY

CONVEC-

SLOW

LOW MIX

Pin Nos. -related to

ROAST

ENTRY

RECALL

TION

COOK

BAKE

R103

each keys

5,6

416

Page 93

COOK DOES NOT

START.

Is cooking possible

for about1min.?

Defective

Yes

l Damper circuit

l Damper motor l Shut-off relay

(RY4)

See C.

“Check Damper circuit” (Next page)

motor rotate when

cooking

is started?

Defective

shut-off relay

(RY-2)

Yes

Defective

LSI

(I-1)

Yes

D3 and 05 oppened or

Replace D3 and D5 or

correct soldering.

Page 94

Is 220/24OV AC

Check shut-off

relay MY

circuit

Check damper switch or poor contact of damper switch connector.

Check and replace damper motor

Is normal

voltage

applied

to each relay coil ?

Yes

Defective Relay

to each relay in parallel

Yes

Replace Diode

Yes

Replace D3 and D5 or

correct soldering.

Page 95

BUZZER DOES NOT SOUND

Is normal

waveform (2.5KHz)

applied across pin No. 1 and 5

of relay unit connector

(DI ?

Yes

]No

Is normal

waveform

(2.5KHzI

applied across pin No. 42

(D, 1

LSI (l-2) and “GND”?

Yes

Replace Buzzer

(St’1 1

Defective

050

Wrong constant of

R51, R52 & R53

Poor soldering

Page 96

Faulty display

, .

Yes

Is segment signal of

Yes

Defective

segments of all

degits

A +

Fluorescent Display

Poor soldering

Yes

Are all

segments of

Yes

Is digit signal of

Yes

specific digit not lit up?

Yes

Defective

Fluorescent Display

LSI

(l-2)

FAULTY CONVECTION

OPERATION

Replace Thermistor

To page 96

Page 97

From page 95

l Defective ZD30

Poor.soldering

Yes

Defective VR30, VR31

Poor soldering

Wrong constant of R31,

R32, R33, R34 & R35

Adjustment

Page 98

ADJUSTMENT OF THERMISTOR SENSOR CIRCUIT

Adjust this circuit if necessary in order to measure the temperature of food correctly.

1) When readjustment is necessary The volumes VR30

(10K

ohms) and VR31

(4.7k

ohms)

must be readjusted after replacing the parts identified by

asterisk

(*)

mark given in circuit diagram is replaced.

2) Method of adjustment Adjust in the following procedures.

(1) Turn off the power. (Main switch “OFF”) (2) Connect the checker to the control panel assembly. (3) Set the rotary switch of checker to @ .

(30kS2:

43C

-L

; C)

(4) Turn on the power (Main switch “ON”) and stop

switch “ON”.

(5) Touch CONVECTION, 250°C and COOK pads.

(Then, the temperature will be displayed)

(6) Rotate th

e volume VR30 until the indication turns

“43C z!z 2

o C”

(7) Set the rotary switch of checker to @ (147C

2C).

If “147C k2C” is not indicated, rotate the volume

VR31 until the indication turns to “147C

+2C”.

(8)

Make sure to indicated “LO C” when set the rotary

switch of checker to 0 (LO C.)

(9) Make sure the convection cooking operation is

stopped when set the rotary switch of checker to

@ (open judge).

R30

Il.

. .

< VDD

4.b

VREF

LsI

R114

l-l

ZD30

R113

l z2

ireTy*R35

IX2107Y

(LOW) I

(HIGH)

THERMISTOR

Figure 28. Thermistor Sensor Circuit

Printed Wiring Board (Control Unit)

Page 99

CHAPTER VI

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

WARNING: to avoid possible exposure to microwave

2. There is a broken door hinge or support.

energy;

3. The door gasket or seal is damaged.

Before operating the oven;

4. The door is bent or warped.

1. Make sure that unlatching the door slowly is

ac-

5. There is any defective parts in the interlock, oven

companied

by a click indicating actuation of the latch

door or microwave generating and transmission

switches.

assembly.

2. Check visually the door seal for arcing and damage.

B. Do not operate the oven until after repair if any of the

following conditions exist;

1. Door does not close firmly against the front of appliance.

6. There is any other visible damage to the oven.

C. Do not operate the oven;

Without the RF gasket.

2. If the waveguide and oven cavity are not intact.

3. If the door is not closed.

OUTER

MAINS SUPPLY

CORE

BASE CABINET

DOOR

SWIN

HIGH VOLTAGE

wKRECTIFIER

POkER

TRANSFORMER

CHASSIS

HEATER RELAY

Figure 29.

Outer Case and Chassis Components

Page 100

OUTER CASE REMOVAL

To remove the outer case, refer to Figure 29 and proceed

from the retaining clips on cavity face plate.

as follows:

4. Lift the entire case from the unit.

1. Disconnect the oven from the power supply.

2. Remove the screws from the rear and along the side

CAUTION: DISCHARGE THE HIGH VOLTAGE

CAPA-

edges of the case.

CITOR BEFORE TOUCHING ANY OVEN

3. Slide the entire case back about 1 inch (3 cm) to free it

COMPONENTS OR WIRING.

HIGH VOLTAGE COMPONENTS REMOVAL

(High Voltage Capacitor and Rectifier)

To remove the components, proceed as follows.

5. Now, the capacitor and rectifier are free.

1. Disconnect the oven from the power supply and remove

CAUTION: WHEN REPLACING THE RECTIFIER, THE

the outer case.

EARTH SIDE TERMINAL MUST BE

SECU-

2. Discharge the high voltage capacitor.

RED FIRMLY WITH A EARTHING SCREW.

3. Disconnect the wire leads from the high voltage capacitor,

4. Remove the single (1) screw holding the capacitor holder to the mounting bracket, and remove the capacitor

holder.

POWER TRANSFORMER REMOVAL

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

2. Discharge the high voltage capacitor.

3. Disconnect the wire leads from the power transformer.

4. Disconnect the filament leads from the magnetron and high voltage capacitor.

5. Remove the two (2) screws holding the transformer to

the base cabinet (A).

6. Remove the transformer.

RELAY UNIT, CQOK RELAY OR HEATER RELAY REMOVAL

1. Disconnect the oven from power supply and remove the outer case.

Relay Unit:

2. Discharge the high voltage capacitor.

3. Disconnect the 1 l-pin connector of relay unit from the control unit.

4. Disconnect the 5-pin and

2-pin

connectors from the

relay unit.

5. Remove the two (2) screws holding the relay chassis

support

to the relay chassis and base cabinet (A).

6. Remove the screw holding the relay chassis to the base

cabinet (A).

7. Take off the relay

chasis

from the base cabinet (A).

1. Disconnect the

2-pin

wire connector (E) (black and

brown wire reads) from the cook relay.

2. Disconnect the 2-pin wire connector (F) (blue and gray wire reads) from the heater relay.

3. Remove the four (4) screws holding the relay unit to the relay chassis.

4. Take off the relay unit from the relay chassis hooks. Cook Relay or

Heater Relay:

1. Disconnect the wire leads from the relay.

2. Remove the screw holding the relay to the relay chassis.

3. Take off the relay from the relay chassis

hoqk.