Sharp R772M-003 Schematic

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SERVICE MANUAL

MICROWAVE OVEN WITH TOP

AND BOTTOM GRILLS

SERVICING

PRODUCT SPECIFICATIONS

R-772(W)M/ R-772(G)M

GENERAL IMPORTANT INFORMATION

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

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

WARNING

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.

WARNING

Never operate the oven until the following points are ensured. (A) The door is tightly closed. (B) The door brackets and hinges are not defective. (C) The door packing is not damaged. (D) The door is not deformed or warped. (E) There is not any other visible damage with the oven.

Servicing and repair work must be carried out only by trained service engineers.

GENERAL INFORMATION

APPEARANCE VIEW

OPERATING SEQUENCE

FUNCTION OF IMPORTANT COMPONENTS

TROUBLESHOOTING GUIDE AND TEST PROCEDURE

TOUCH CONTROL PANEL

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

MICROWAVE MEASUREMENT

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

Removal of the outer wrap gives access to potentials above 250V.

All the parts marked “∆” on parts list may cause undue microwave exposure, by themselves, or when they are damaged, loosened or removed.

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

SHARP CORPORATION

OSAKA, JAPAN

WIRING DIAGRAM

PARTS LIST

SERVICING

WARNING TO SERVICE PERSONNEL

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

REMEMBER TO CHECK 3D

1) Disconnect the supply.

2) Door opened, and wedged open.

3) Discharge high voltage capacitor.

WARNING: AGAINST THE CHARGE OF THE HIGH-

VOLTAGE CAPACITOR

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

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

3D checks and

REMEMBER TO CHECK 4R

1) Reconnect all leads removed from components during testing.

2) Replace the outer case (cabinet).

3) Reconnect the supply.

4) Run the oven. Check all functions.

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

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

3D checks and re-examine the connections to

PRODUCT DESCRIPTION

SPECIFICATION

ITEM DESCRIPTION

Power Requirements 230 - 240 Volts / 50 Hertz / Single phase, 3 wire earthed Power Consumption Microwave cooking 1.6 kW Approx. 7.2 A

Oven cooking 1.5 kW Approx. 6.5 A

Top Grill mode ...................... 1.05 kW Approx. 4.2 A

Grill cooking Bottom Grill mode................. 0.55 kW Approx. 2.2 A

Top and Bottom mode ......... 1.55 kW Approx. 6.5 A

Dual cooking

Power Output

Top Grill heating element Power Output Bottom heating element Power Output Case Dimensions Width 520 mm Height 309 mm (including foot) Depth 436 mm Cooking Cavity Dimensions Width 349 mm Height 207 mm Depth 357 mm Turntable diameter 325 mm Control Complement Touch Control System

900 W nominal of RF microwave energy (measured by method of IEC 705) Operating frequency 2450 MHz

1.0 kW

0.5 kW

Clock (1:00 - 12:59) / Timer (0 - 99 minutes 90 sec.) Microwave Power for Variable Cooking

Repetition Rate;

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

70 (MEDIUM HIGH) ......................... approx. 70% of FULL Power

50 (MEDIUM) ................................... approx. 50% of FULL Power

30 (MEDIUM LOW).......................... approx. 30% of FULL Power

10 (LOW) ......................................... approx. 10% of FULL Power

Oven temperature control range:

200˚C, 180˚C, 160˚C, 130˚C, 100˚C, 70˚C and 40˚C

Micro and Top Grill ............... 2.55 kW Approx. 11.2 A

Micro and Bottom Grill ............ 2.1 kW Approx. 9.2 A

TIME keys, BREAKFAST key, PIZZA key, AUTO COOK key, AUTO DEFROST key, WEIGHT keys LESS/MORE keys, DUAL /GRILL key, MICROWAVE POWER LEVEL key STOP/CLEAR key, START/AUTO MINUTE key, WEIGHT CONVERSION key, AUTO START/CLOCK key,

Set Weight Approx. 20 kg

GENERAL INFORMATION

THIS APPLIANCE MUST BE EARTHED

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

INSTANT COOK keys

OVEN (˚C) key, GRILL key

TIMER key

WARNING

IMPORTANT

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

APPEARANCE VIEW

OVEN

1. Control panel

2. Oven lamp

3. Grill heating element (Top Grill)

4. Door opening button

5. Waveguide cover

6. Oven cavity

7. Turntable motor shaft

COOK indicator showing oven in operation.

TOP GRILL indicator.

BOTTOM GRILL indicator

MICROWAVE indicator.

WEIGHT indicators.

8. Grill heating element (Bottom Grill)

9. Door seals and sealing surfaces

10.Ventilation openings

11.Outer cabinet

12.Power supply cord

13.Turntable

14.Rack

CONTROL PANEL

DEFROST indicator.

COOK

LBSKGOZ

DEFROST

AUTO

AUTO indicator, showing auto cooking on progress. DIGITAL DISPLAY.

LESS/MORE indicators. % percentage microwave power level indicator.

TIME keys. Use to select cooking time.

BREAKFAST key.

AUTO COOK key.

WEIGHT keys.

GRILL key. Press to select Grill.

OVEN (˚C) key.

MICROWAVE POWER LEVEL key. Press to select microwave power level.

STOP/CLEAR key. Press once to stop a programme, and/or twice to cancel a programme.

TIMER key

WEIGHT CONVERSION key

BREAKFAST

MIXED GRILL

OVEN CHIPS

1 Chilled Ready Meals 1 Frozen Ready Meals 3 Roast Beef / Lamb 3 4 Roast Pork 4 Minced Meat 5 Roast Poultry 5 Bread

R-772

BAKED POTATOES

PIZZA

CHICKEN PTNS

CRISPY CRUMB FOODS

FRESH VEG.

1 Meat Joint 2 Poultry

Chicken Ptn, Steak, Chops

PIZZA key. Press to cook pizza.

INSTANT COOK keys.

AUTO DEFROST key.

LESS/MORE keys. Press to shorten or lengthen heating time.

DUAL GRILL key. Press to select Dual Grill.

START/AUTO MINUTE key. Press to start a programme. Press to cook on (HIGH) for 1 minute or increase time during cooking in multiples of 1 minute.

AUTO START/CLOCK key. Use to set the clock.

OPERATION SEQUENCE

OFF CONDITION

Closing the door activates the monitored latch switch and the stop switch.

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

Figure O-1 on page 29

1. The control unit is not energized. The display shows nothing (Fig. O-1 (a)).

2. Open the door. The contacts (COM-NC) of the monitored latch switch are closed and the control unit is energized. Then contacts of relays RY1 and RY5 are closed, and the oven lamp will light and the display will show "ENERGY SAVE MODE" (Fig. O-1(b)).

3. Close the door. The contacts (COM-NC) of the monitored latch switch are opened and the contacts of relay RY1 are opened and the oven lamp will be turned off. The display will show " . 0". (Fig. O-1(c)).

NOTE: Energy save mode

1. If the oven has not been used for more than 2 minutes, the contacts of the relay RY5 will be opened and the control unit will be not energized. Open and close the door, the control unit will resume.

2. If the clock is set, this energy save mode does not work.

MICROWAVE COOKING CONDITION

HIGH COOKING

Enter a desired cooking time by touching the TIME keys and start the oven by touching START key.

Function sequence Figure O-2 on page 30

CONNECTED COMPONENTS RELAY Oven lamp, Turntable motor RY1 High voltage transformer RY2 Fan motor RY6

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

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

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

4. When the cooking time is up, a signal tone is heard and the relays RY1 + RY2 + RY6 go back to their home position. The circuits to the oven lamp, high voltage transformer, fan motor and turntable motor are cut off.

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

Switch Contact Condition

Monitored latch switch

Stop switch

Monitor Switch

COM-NO Closed Opened COM-NC Opened Closed COM-NO Closed Opened COM-NO Closed Opened COM-NC Opened Closed

During Oven Door Cooking Open(No cooking)

The circuit to the high voltage transformer is cut off when the contacts of relay RY2, and the contacts (COM-NO) of the monitored latch switch and monitor switch are made open. The circuit to the fan motor is cut off when the relay RY6 is made open. The circuit to the turntable motor is cut off when the contacts (COM-NO) of the monitored latch switch are made open. The relay RY2 and RY6 are made open when the door is opened. The oven lamp remains on even if the oven door is opened after the cooking cycle has been interrupted, because the relay RY1 stays closed. Shown in the display is remaining time.

6. MONITOR SWITCH CIRCUIT The monitor switch is mechanically controlled by the oven door, and monitors the operation of the monitored latch switch.

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

cycle of a cooking program, the monitored latch switch and stop switch must open their contacts (COM-NO) first.

And

the contacts (COM-NC) of the monitored latch switch SW1 are made closed. After that the contacts (COM-NC) of the monitor switch can be closed and the contacts (COM-NO) of monitor switch are made open.

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

NC) of the monitor switch must be opened and the contacts (COM-NO) of monitor switch must be closed. After that the contacts (COM-NO) of the monitored latch switch and the stop switch are made closed. the contacts (COM-NC) of the monitored latch switch are made open

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

(COM-NO) of the monitored latch switch remain closed, the fuse F8A will blow. Because the relay RY1 and monitor switch are closed and a short circuit is caused.

MEDIUM HIGH, MEDIUM, MEDIUM LOW, LOW COOKING

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

900W (HIGH)

MEDIUM

630W

450W (MEDIUM) Approx. 50%

MEDIUM

270W

90W (LOW) Approx. 10%

32 sec. ON

24 sec. ON 8 sec. OFF

HIGH

18 sec. ON

12 sec. ON

LOW

6 sec. ON

Approx. 70%

14 sec. OFF

20 sec. OFF

Approx. 30%

26 sec. OFF

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

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

GRILL COOKING CONDITION

TOP GRILL (Figure O-3a)

In this condition the food is cooked by the top grill heating element. Programme the desired cooking time by touch-

And

100%

OPERATION SEQUENCE

ing the TIME keys and touh the GRILL key once. When the STARTkey is touched, the following operations occur:

1. The numbers on the digital readout start the count down to zero.

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

3. The relay RY3 is energized and the main supply voltage is applied to the top grill heating element.

4. Now, the food is cooked by the top grill heating element.

BOTTOM GRILL (Figure O-3b)

In this condition the food is cooked by bottom grill heating element energy. Programme the desired cooking time by touching the TIME keys and touh the GRILL key twice. When the STARTkey is touched, the following operations occur:

1. The numbers on the digital readout start the count down to zero.

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

3. The relay RY4 is energized and the main supply voltage is applied to the bottom grill heating element.

4. Now, the food is cooked by the bottom grill heating element.

TOP AND BOTTOM GRILL (Figure O-3c)

In this condition the food is cooked by top and bottom grill heating elements energy. Programme the desired cooking time by touching the TIME keys and touh the GRILL key three times. When the STARTkey is touched, the following operations occur:

1. The numbers on the digital readout start the count down to zero.

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

3. The relay RY4 is energized and the main supply voltage is applied to the bottom grill heating element.

4. The relay RY3 is energized and the main supply voltage is applied to the top grill heating element.

5. Now, the food is cooked by the top and bottom grill heating elements.

OVEN COOKING CONDITION

PRE-HEATING (Figure O-4)

Programme the desired oven temperature by touching OVEN (˚C) key. When the STARTkey is touched, the following operations occur:

1. The coil shut-off relays RY1 and RY6 are energized, the oven lamp, cooling fan motor and turntable motor are turned on.

2. The coil shut-off relays RY3 and RY4 are energized by control unit and the main supply voltage is added to the top and bottom heating elements.

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

3-1. The coil shut-off relays RY3 and RY4 are energized

by control unit temperature circuit and thermistor, opening the circuit to the top and bottom grill heating elements.

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

turning the top and bottom heating elements on and off, as needed to maintain the selected pre-heat temperature. The ovenwill shut-down completely after 30 minutes.

NOTE: The fan motor will be turned on and off at

preheating. And the convection motor will be turned off at preheating. See "Power setting" on page 9.

OVEN COOKING (Figure O-4)

When the pre-heat temperature is reached, a beep signal will sound indicating that the holding the temperature has been reached in the oven cavity. Open the door and place the food to cooked in the oven. Program desired cooking time by touching the TIME keys and program oven temperature by touching the OVEN (˚C) key . When the START key is touched, the following operations occur:

1. The numbers on the digital readout start the count down to zero.

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

3. The relays RY3 and RY4 are energized (if the cavity temperature is lower than selected temperature) and the main supply voltage is applied to the top and bottom heating elements to return to the selected cooking temperature.

Upon completion of the cooking time, the audible signal will sound, and the oven lamp, turntable motor, cooling fan motor, top and bottom heating elements are de-energized. At the end of cooking cycle, if the cavity air temperature rise above 120˚C, the circuit to the relay RY6 will be maintained (by the thermistor circuit) to continue operation of the cooling fan motor until temperature drops below 105˚C, at that time the relay RY6 will be de-energized, turning off the fan motor.

DUAL COOKING CONDITION

MICROWAVE AND TOP GRILL (Figure O-5a)

Programme the desired cooking time by touching the TIME keys. Touch the DUAL GRILLL key once. Select the microwave power level by touching the MICROWAVE POWER LEVEL key. When the STARTkey is touched, the following operations occur:

1. The numbers on the digital readout start the count down to zero.

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

3. The relay RY3 is energized and the main supply voltage is applied to the top grill heating element.

4. The relay RY2 is energized and the microwave energy is generated by magnetron.

5. Now, the food is cooked by microwave and top grill simultaneously.

MICROWAVE AND BOTTOM GRILL (Figure O-5b)

Programme the desired cooking time by touching the TIME keys. Touch the DUAL GRILL three twice. Select the microwave power level by touching the MICROWAVE POWER LEVEL key. When the STARTkey is touched, the following operations occur:

1. The numbers on the digital readout start the count

OPERATION SEQUENCE

down to zero.

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

3. The relay RY4 is energized and the main supply voltage is applied to the bottom grill heating element.

4. The relay RY2 is energized and the microwave energy is generated by magnetron.

5. Now, the food is cooked by microwave and bottom grill simultaneously.

POWER SETTING

The power setting of the top heating element, bottom heating element and fan motor in the Oven cooking mode and Oven preheating mode is 100%.

ON/OFF TIME RATIO

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

POWER OUTPUT ON TIME OFF TIME

100% 48 sec. 0 sec.

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

AUTOMATIC COOKING

PIZZA BREAKFAST INSTANT COOK AUTO COOK AUTO DEFROST Above functions are automatic cooking. They automatically work out the correct cooking mode and cooking time and/or cooking temperature. They will cook according to the special cooking sequence.

LIMITATIONS OF POWER OUTPUT IN MANUAL OPERATION

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

Cooking mode time (minutes) output (%) (seconds) Microwave (100%) Top grill 30 50 48 Bottom grill 45 50 48 Top grill and 15 (Top) 50 48

Bottom grill 15(Bottom) 50 48

Micro. (100%) 20 (Micro.) 70 48

+ Top grill 15 (Grill) 50 48

U A

Micro. (100%) 20 (Micro.) 70 48

+ Bottom grill 15 (Heater) 50 48

NOTE:

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

2. In case that the stop key is touched or the oven door is opened during cooking, the limitations of power output are not carried out after the total cooking time beyond the specified cooking time.

3. In case of the two or more same cooking modes are carried out, the limitations of power output are not carried out after the total cooking time beyond the specified cooking time.

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

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

Specified cooking Limited power Time base

20 70 32

FUNCTION OF IMPORTANT COMPONENTS

DOOR OPEN MECHANISM

The door can be opened by pushing the open button on the control panel. When the open button is pushed, the open lever is pushes lower latch head on the door upward. The upper latch head is linked with the lower latch head, so now, the door can be opened.

DOOR

LATCH HEADS

LATCH HOOK

(SW2) MONITOR SWITCH

(SW1) MONITORED LATCH SWITCH

(SW3) STOP SWITCH

OPEN LEVER

Figure D-1. Door Open Mechanism

MONITORED LATCH SWITCH

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

2. When the oven door is opened, the contacts (COMNO) of the switch must be opened. And the contacts (COM-NC) must be closed.

STOP SWITCH

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

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

MONITOR SWITCH

The monitor switch is activated (the contacts opened) by the upper latch head on the door while the door is closed. The switch is intended to render the oven inoperative by means of blowing the fuse F8A when the contacts of the monitored latch switch fail to open when the door is opened.

Function

1. When the door is opened, the contacts (COM-NC) of monitor switch close (to the ON condition) due to their being normally closed and contacts (COM-NO) open. At this time the contacts (COM-NO) of monitored latch switch is in the 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 (COM-NC) are opened and contacts (COM-NO) closed and then contacts (COM-NO) of monitored latch switch and stop switch are closed.(On opening the door, each of these switches operate inversely.)

3. If the door is opened and the monitored latch switch contacts (COM-NO) fail to open, the fuse F8A blows immediately after closing of the monitor switch (COMNC) contacts.

CAUTION: BEFORE REPLACING A BLOWN FUSE F8A,

TEST THE MONITORED LATCH SWITCH AND MONITOR SWITCH FOR PROPER OPERATION. (REFER TO CHAPTER “TEST PROCEDURE”).

FUSE 15A 250V

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

FUSE F8A 250V

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

2. The fuse also blows when the monitored latch switch remains closed with the oven door open and when the monitor switch contact (COM-NC) closes.

3. The fuse also blows when the asymmetric rectifier, H.V. rectifier,.H.V. wire harness, H.V. capacitor, magnetron or secondary winding of high voltage transformer is shorted.

TC TRANSFORMER

T/C transformer converts A.C. line voltage into low voltage to drive the control unit.

THERMAL CUT-OUT 125˚C (MG)

This thermal cut-out protects the magnetron against overheat. If the temperature goes up higher than 125˚C because the fan motor is interrupted or the ventilation openings are blocked, the thermal cut-out will open and line voltage to the high voltage transformer will cut off and operation of the magnetron will be stopped. The defective thermal cut-out must be replaced with a new one.

THERMAL CUT-OUT 150˚C (OVEN)

This thermal cut-out protects the oven against the overheat during grill cooking, oven cooking or dual (combination) cooking. If the temperature rises above 150˚C because the fan motor is interrupted, the air inlet duct is blocked or the ventilation openings are obstructed, the thermal cut-out opens and switches off all the electrical parts. When the cools itself down to the operating temperature of 130˚C, the contacts of the thermal cut-out will close again.

ASYMMETRIC RECTIFIER

The asymmetric rectifier is solid state device that prevents current flow is both directions. And it prevents the temperature rise of the high voltage transformer by blowing the fuseF8A when the high voltage rectifier is shorted.

D2 D1

ASYMMETRIC RECTIFIER

The rated peak reverse voltage of D1 of the asymmetric rectifier is 6 KV. The rated peak reverse voltage of D2 of the asymmetric rectifier is 1.7 KV. D1 and D2 of the asymmetric rectifier or high voltage rectifier are shorted when the each peak reverse voltage goes beyond the each rated peak reverse voltage. (The process of the blowing the fuseF8A.)

1. The high voltage rectifier is shorted by some fault when microwave cooking or dual cooking.

2. The peak reverse voltage of D2 of the rectifier goes beyond the rated peak reverse voltage 1.7 KV in the

HIGH VOLTAGE RECTIFIER

FUNCTION OF IMPORTANT COMPONENTS

voltage doubler circuit.

3. D2 of the rectifier is shorted.

4. The large electric currents flow through the high voltage winding of the high voltage transformer.

5. The large electric currents beyond 8A flow through the primary winding of the high voltage transformer.

6. The fuse F8A blows by the large electric currents.

7. The power supplying to the high voltage transformer is cut off.

NOISE FILTER

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

TURNTABLE MOTOR

The turntable motor rotates the turntable.

FAN MOTOR

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

TOP GRILL HEATING ELEMENT

The grill heating element is provided to brown the food and is located on the top of the oven cavity.

BOTTOM GRILL HEATING ELEMENT

The grill heating element is provided to brown the food and is located at the base of the oven cavity.

When the oven cooking time reaches “0”, the heating elements are de-energized and the oven shuts off. At that time if the cavity air temperature has rised above120˚C, the fan motor remains rotating. Automatically the fan motor will be shut down at low temperature (less than 105˚C).

FIRE SENSING FEATURE

The oven will stop its operation when there is a fire in the oven cavity in microwave cooking condition. LSI measures the voltage across the temperature measurement circuit intermittently within 32-seconds time base since the oven is started in microwave cooking condition. The oven will stop its operation when the difference of the voltage is more than 0.781 volts in microwave cooking condition.

1. Within a 32-seconds base, the thermistor is energized for 2 seconds. At that time, the voltage across the temperature measurement circuit is measured.

2. The oven carries out the procedure above again. If the second voltage is 0.781V higher than first voltage, LSI judges it is a fire in the oven cavity and stop the oven.

3. When LSI judges it is a fire in the oven cavity, LSI will switch off the relays to high voltage transformer and fan motor and LSI stops countring down.

THERMISTOR

Sensing

Voltage

OFF

Sensing the voltage across temperature measurement circuit.

30 32 (sec.)

OVEN COOKING SYSTEM

Food is cooked by the top and bottom heating elements. And the temperature of the oven cavity can be controlled by the thermistor circuit. When the temperature inside the oven cavity reaches the selected temperature, the heating elements are de-energized. When the temperature inside the oven cavity drops below the selected temperature, the heating elements are energized again. In this way, the inside of the oven cavity is maintained at approximately

OPEN JUDGE BY THERMISTOR

1. If the temperature of the thermistor does not rise to more than 40˚C after 4 minutes and 15 seconds from when the oven is started in oven cooking mode, dual cooking mode or grill (top and bottom) cooking mode, the oven is turned off.

2. When the thermistor or the wire harness to the thermistor is opened, the oven is turned off after 4 minutes and 15 seconds because this condition is same as above.

the selected temperature.

TROUBLESHOOTING GUIDE

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

IMPORTANT: If the oven becomes inoperative because of a blown fuse (F8A) in the monitored latch switch - monitor

switch circuit, check the monitored latch switch and monitor switch before replacing the fuse (F8A).

TROUBLESHOOTING GUIDE

CONDITION PROBLEM

Fuse F8A blows when the door is opened. Home fuse blows when power cord is plugged into wall outlet.

OFF

CONDITION

Fuse 15A blows when power cord is plugged into wall outlet. Nothing appears in display when power cord is plugged into wall outlet

and the door is opened and closed. Display does not operate properly when STOP/CLEAR key is touched. Oven lamp does not light when door is opened. (Display operates.)

Oven does not start when the START key is touched. (Display operates.) Oven lamp does not light and turntable motor does not operate. Fan motor does not operate. (Oven lamp lights.) Turntable motor does not operate. (Oven lamp lights.)

COOKING

CONDITION

(COMMON MODE)

Oven or any electrical parts (except fan motor) does not stop when cooking time is 0 or STOP/CLEAR key is touched.

Oven stops after 4 minutes and 15 seconds since START key is touched. (Except Microwave mode)

Display operates properly but all electrical parts do not do not operate. Oven goes into cook cycle but shuts down before end of cooking cycle. After cooking, the temperature of oven cavity is higher than 105ßC but

fan motor does not operate. Oven seems to be operating but little or no heat is produced in oven

MICROWAVE

COOKING

CONDITION

load. (Microwave power control is set at HIGH) Oven does not seem to be operating properly during variable cooking

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

OVEN COOKING

CONDITION

GRILL COOKING

CONDITION

Oven seems to be operating but the temperature in the oven cavity is lower or higher than preset one.

Grill heating element does not operate. Oven goes into cook cycle but shuts down before end of cooking cycle.

DUAL COOKING

CONDITION

Oven seems to be operating but little or no heat is produced in oven load. (Microwave power does not seem to be generated properly)

Top or Bottom Grill heating element does not heat.

TEST PROCEDURE

POSSIBLE CAUSE

AND

DEFECTIVE PARTS

ABC DEEE FGGHH I J K L L MNOOOOOOP

HIGH VOLTAGE TRANSFORMER

MAGNETRON

HIGH VOLTAGE CAPACITOR

H.V. HARNESS

H.V. RECTIFIER ASSEMBLY

MONITOR SWITCH SW3

STOP SWITCH SW2

MONITORED LATCH SWITCH SW1

THERMAL CUT-OUT 150ßC TC2

THERMAL CUT-OUT 125ßC TC1

THERMISTOR

NOISE FILTER

FAN MOTOR

TURNTABLE MOTOR

TOP GRILL HEATING ELEMENT

FUSE F8A

FUSE 15A

TOUCH CONTROL PANEL

TC TRANSFORMER

BOTTOM GRILL HEATING ELEMENT

RELAY RY2

RELAY RY1

KEY UNIT

RELAY RY5

RELAY RY4

RELAY RY3

RELAY RY6

MIS-ADJUSTMENT OF SWITCHES

BLOCKED VENTILATION OPENINGS

OPENED WIRE HARNESS

SHORTED WIRE HARNESS

OVEN LAMP OR SOCKET

POWER SUPPLY CORD

FOIL PATTERN ON P.W.B.

BLOCKED

NO POWER AT WALL OUTLET

HOME FUSE OR BREAKER

COOLING FAN

TEST PROCEDURES

PROCEDURE

LETTER

A MAGNETRON TEST

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

CARRY OUT 3D CHECKS. Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal.

To test for an open circuit filament use an ohmmeter to make a continuity test between the magnetron filament terminals, the meter should show a reading of less than 1 ohm.

To test for short filament to anode condition, connect ohmmeter between one of the filament terminals and the case of the magnetron (ground). This test should be indicated an infinite resistance. If a low or zero resistance reading is obtained then the magnetron should be replaced.

MICROWAVE OUTPUT POWER

The power output of this oven is rated using the method specified by IEC 705. Full details of how to curry out this procedure can be found in the Sharp Technical Training notes which is available from Sharp Parts Centre (part number SERV-LITMW01).

The IEC-705 procedure must be carried out using laboratory-type procedures and equipment.

These requirements make the procedure unsuitable for routine performance checks.

NOTE: The following test method gives an indication of the output power only, it cannot be used to

establish the actual/rated output power. If the true output power is required, then the IEC705 test method must be used.

COMPONENT TEST

Alternative simplified method:

1. Place 2 litres of cold water (between 12°C and 20°C) in a suitable container.

2. Stir the water and measure the temperature in °C. Note temperature as T1.

3. Place the container in the microwave and heat the water for 2 minutes on full power.

4. When the 2 minutes is completed, remove the container and stir the water. Note temperature as T2.

5. Calculate the output power using the following formula: R.F. Power Output = (T2 - T1) x 70.

NOTE: The result from this test should be within the allowance of 2000cc alternative method.

(±10%).

MICROWAVE LEAKAGE TEST

This oven should be tested for microwave leakage on completion of any repair or adjustment, following the procedure described in the Sharp Technical Training notes (part number SERV-LITMW01). The maximum leakage permitted in BS EN 60335-2-25 is 50W/m2 (equivalent to 5W/m2), however it is not normal to detect any significant leakage, therefore, any leakage which is detected should be investigated.

It is essential that only leakage detectors with current calibration traceable to National Physical Laboratories are used.

Suitable leakage detectors: CELTEC A100

APOLLO X1

TEST PROCEDURES

PROCEDURE

LETTER

B HIGH VOLTAGE TRANSFORMER TEST

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

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

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

a. Primary winding ................................... approximately 2 Ω

b. Secondary winding ............................ approximately 99 Ω

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

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

C HIGH VOLTAGE RECTIFIER TEST

CARRY OUT 3D CHECKS. Isolate the high voltage rectifier assembly from the HV circuit. The high voltage rectifier can be tested using an ohmmeter set to its highest range. Connect the ohmmeter across the terminal B+C of the high voltage rectifier and note the reading obtained. Reverse the meter leads and note this second reading. The normal resistance is infinite in one direction and more than 100 kΩ in the other direction.

CARRY OUT 4R CHECKS.

COMPONENT TEST

D2 D1

ASYMMETRIC RECTIFIER TEST

CARRY OUT 3D CHECKS.

Isolate the high voltage rectifier assembly from the HV circuit. The asymmetric rectifier can be tested using an ohmmeter set to its highest range across the terminals A+B of the asymmetric rectifier and note the reading obtained. Reverse the meter leads and note this second reading. If an open circuit is indicated in both directions then the asymmetric rectifier is good. If the asymmetric rectifier is shorted in either direction, then the asymmetric rectifier is probably faulty and must be replaced with high voltage rectifier. When the asymmetric rectifier is defective, check whether magnetron, high voltage rectifier, high voltage wire or filament winding of the high voltage transformer is shorted.

CARRY OUT 4R CHECKS.

NOTE:

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

D HIGH VOLTAGE CAPACITOR TEST

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

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

resistance range.

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

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

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

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

ASYMMETRIC RECTIFIER

HIGH VOLTAGE RECTIFIER

CARRY OUT 4R CHECKS.

TEST PROCEDURES

PROCEDURE

LETTER

E SWITCH TEST

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

Plunger Operation COM to NO COM to NC

Released Open circuit Short circuit Depressed Short circuit Open circuit

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

F THERMISTOR TEST

CARRY OUT 3D CHECKS. Disconnect theconnector B from CPU unit. Measure the resistance of the thermistor with an ohmmeter. Connect the ohmmeter leads to Pin No's C1 and C3 of the thermistor harness.

If the meter does not indiicate above resistance, replace the thermistor. CARRY OUT 4R CHECKS.

COMPONENT TEST

Table: Terminal Connection of Switch

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

Room Temperature Resistance

20˚C - 30˚C Approximately 359.9 kΩ - 152 kΩ

G THERMAL CUT-OUT TEST

CARRY OUT 3D CHECKS.

Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make a continuity test across the two terminals as described below.

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

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

(˚C) (˚C) is approx. 20˚C.) Thermal cut-out 125˚C Thermal cut-out 150˚C

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

restricted ventilation, cooling fan failure. An open circuit thermal cut-out (OVEN) indicates that the oven cavity has overheated, this may be due

to no load operation.

CARRY OUT 4R CHECKS.

H MOTOR WINDING TEST

CARRY OUT 3D CHECKS.

Table: Thermal Cut-out Test

This is not resetable Above 125˚C Closed circuit Below 130˚C. Above 150˚C Closed circuit

Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two terminals as described in the table below.

Table: Resistance of Motor

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

If incorrect readings are obtained, replace the motor.

CARRY OUT 4R CHECKS.

TEST PROCEDURES

PROCEDURE

LETTER

I NOISE FILTER TEST

COMPONENT TEST

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

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

MEASURING POINTS INDICATION OF OHMMETER

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

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

J BLOWN FUSE 15A

CARRY OUT 3D CHECKS.

If the fuse15A is blown, there is a shorts or grounds in electrical parts or wire harness. Check them and replace the defective parts or repair the wire harness.

CARRY OUT 4R CHECKS.

CAUTION: Only replace fuse

4R CHECKS.

15A

F8A

L (min) Cx ± 20% Cy ± 20% R1 R2

1.0mH 0.22µF 4700pF 10 MΩ 680kΩ

with the correct value replacement.

WHT

RED

K BLOWN FUSE F8A

CARRY OUT 3D CHECKS.

1. If the fuse F8A is blown when the door is opened, check the monitored latch switch and monitor switch.

2. If the fuseF8A is blown by incorrect door switching replace the defective switch(es) and the fuse F8A.

3. If the fuse F8A is blown, there could be shorts in the asymmetric rectifier or there is a ground in wire harness. A short in the asymmetric rectifier may be occurred due to short or ground in H.V. rectifier, magnetron, high voltage transformer or H.V. wire. Check them and replace the defective parts or repair the wire harness.

CARRY OUT 4R CHECKS.

CAUTION: Only replace fuse

L GRILL HEATING ELEMENT (TOP) AND BOTTOM HEATING ELEMENTS TEST

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

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

Grill heating element (top) Approximately 61 Ω Bottom heating element Approximately 115 Ω

F8A with the correct value replacement.

Table: Resistance of heating element

Parts name Resistance

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

TEST PROCEDURES

PROCEDURE

LETTER

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

CARRY OUT 4R CHECKS.

M TOUCH CONTROL PANEL ASSEMBLY TEST

The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance can not be performed with only a voltmeter and ohmmeter. In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key Unit, and also the Control unit is divided into two units, CPU unit and Power unit, and troubleshooting by replacement is described according to the symptoms indicated.

1. Key Unit Note : Check key unit ribbon connection before replacement. The following symptoms indicate a defective key unit. Replace the key unit. a) When touching the pads, a certain pad produces no signal at all. b) When touching a number pad, two figures or more are displayed. c) When touching the pads, sometimes a pad produces no signal.

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

2-1 In connection with pads

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

2-2 In connection with indicators

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

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

a) Buzzer does not sound or continues to sound. b) Clock does not operate properly. c) Cooking is not possible. d) Proper temperature measurement is not obtained.

COMPONENT TEST

N KEY UNIT TEST

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

CARRY OUT 4R CHECKS.

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

10 sec. 1 min. 10 min.

AUTO

COOK

g • oz

MICROWAVE

POWER LEVEL

GRILL

OVEN ( ˚C )

DUAL GRILL

CRISPY CRUMB FOODS

PIZZA

G12 G11 G10 G 9

CHICKEN PTNS

AUTO

FRESH VEG.

MORE LESS

DEFROST

MIXED GRILL

BAKED POTATOES

START

AUTO MINUTE

Kg / Lb

OVEN CHIPS

AUTO START

CLOCK

STOP/

CLEAR

BREAKFAST

Kg • Lb

TIMER

TEST PROCEDURES

PROCEDURE

LETTER

O RELAY TEST

CARRY OUT 3D CHECKS.

Remove the outer case and check voltage between Pin Nos. 1 and 3 of the 4 pin connector (E) on the control unit with an A.C. voltmeter. The meter should indicate 230 - 240 volts, if not check oven circuit.

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

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

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

RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS

RY1 Approx. 18.0V D.C. Oven lamp / Turntable motor RY2 Approx. 18.0V D.C. High voltage transformer RY3 Approx. 24.0V D.C. Grill (Top) heating element RY4 Approx. 24.0V D.C. Bottom heating element RY5 Approx. 24.0V D.C. Touch control transformer RY6 Approx. 24.0V D.C. Fan motor

COMPONENT TEST

control unit is defective.

CARRY OUT 4R CHECKS.

P PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD

(PWB) IS OPEN

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

CARRY OUT 3D CHECKS.

STEPS OCCURRENCE CAUSE OR CORRECTION

The rated AC voltage is not present between

Pin Nos. 1 and 3 of the 4-pin connector (E). The rated AC voltage is present at primary Low voltage transformer or secondary circuit defective.

side of low voltage transformer. Check and repair.

3 Only pattern at "a" is broken.

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

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

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

Check supply voltage and oven power cord.

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

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

CN - E

VRS1

(J1)

CN - A

RY6

RY4

(J2)

CARRY OUT 4R CHECKS.

POWER

TOUCH CONTROL PANEL ASSEMBLY

OUTLINE OF TOUCH CONTROL PANEL

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

(1) Key Unit (2) Control Unit (The Control unit consists of Power unit

and CPU unit.)

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

Key Unit

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

Control Unit

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

1) LSI

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

2) Power Source Circuit

This circuit generates voltage necessary in the control unit.

Symbol Voltage Application

VC -5.2V LSI(IC1)

3) Synchronizing Signal Circuit

The power source synchronizing signal is available in order to compose a basic standard time in the clock

circuit. It accompanies a very small error because it works on commercial frequency.

4) ACL

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

5) Buzzer Circuit

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

6) Door Sensing Switch (Stop Switch)

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

7) Relay Circuit

To drive the magnetron, grill heating element, bottom heating element, fan motor, turntable motor, touch control transformer and light the oven lamp.

8) Back Light Circuit

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

9) Indicator Circuit

This circuit consists 7-digits, 39-segments and 3-common electrodes using a Liquid Crystal Display.

10) Temperature Measurement Circuit : (OVEN THERMISTOR)

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

DESCRIPTION OF LSI

LSI(IZA965DR)

The I/O signal of the LSI(IZA965DR) are detailed in the following table.

Pin No. Signal I/O Description

1 C1 IN Terminal not used. 2 VL1 IN Power source voltage input terminal.

Standard voltage for LCD.

3 AN7 IN Terminal to change the on timing of the cook relay (RY2). 4-5 AN6-AN5 IN Heating constant compensation terminal. 6 AN4 OUT Terminal not used. 7 AN3 IN Temperature measurement input: OVEN THERMISTOR.

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

DESCRIPTION OF LSI

LSI(IZA965DR)

The I/O signal of the LSI(IZA965DR) are detailed in the following table.

Pin No. Signal I/O Description

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

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

9-10 AN1-AN0 OUT Terminal not used. 11 P57 OUT Timing signal output terminal for temperature measurement(OVEN

THERMISTOR).

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

1.2 sec

0.12 sec

2.4 sec

1.2 sec H: GND

12 P56 OUT Signal to sound buzzer.

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

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

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

THERMISTOR).

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

14-18 P54-P50 OUT Terminal not used. 19 P47 IN Signal coming from touch key.

When any one of G12 line keys on key matrix is touched, a corresponding signal from P40, P41, P72, P73, P74, P75, P76 and P77 will be input into P47. When no key is touched, the signal is held at "L" level.

20 P46 IN Signal similar to P47.

When any one of G11 line keys on key matrix is touched, a corresponding signal will be input into P46.

21 P45 IN Signal similar to P47.

When any one of G10 line keys on key matrix is touched, a corresponding signal will be input into P45.

22 P44 IN Signal similar to P47.

When any one of G9 line keys on key matrix is touched, a corresponding signal will be input into P44.

23 INT1 OUT Terminal not used. 24 INT0 IN Signal to synchronized LSI with commercial power source frequency(50Hz).

This is basic timing for time processing

H : GND

of LSI.

L (-5V)

20 msec.

25 P41 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G8 line key on matrix is touched.

26 P40 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G7 line key on matrix is touched.

27 P77 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G6 line key on matrix is touched.

28 P76 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G5 line key on matrix is touched.

29 P75 OUT Key strobe signal.

Signal applied to touch-key section. A pulse signal is input to P44 - P47 terminal while one of G4 line key on matrix is touched.

DESCRIPTION OF LSI

LSI(IZA965DR)

The I/O signal of the LSI(IZA965DR) are detailed in the following table.

Pin No. Signal I/O Description

30 P74 OUT Key strobe signal.

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

31 P73 OUT Key strobe signal.

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

32 P72 OUT Key strobe signal.

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

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

To turn on and off shut-off relay (RY1). The square waveform voltage is delivered to the relay (RY1) driving circuit.

34 P70 IN Connected to VC. 35 RESET IN Auto clear terminal.

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

36 P81 OUT Magnetron high-voltage circuit driving signal.

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

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

MICRO ON OFF COOK

100% 32 sec. 0 sec.

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

20 msec.

During cooking

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

MICRO ON OFF COOK

100% 48 sec. 0 sec.

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

37 P80 OUT Grill (TOP) heating element driving signal.

To turn on and off the grill heating element relay (RY3). "L" level during grill cooking, convection cooking or dual cooking, "H" level otherwise. The heater relay turns on and off within a 48 second time base in accordance with the special program in LSI.

Power output ON time OFF time

100 % 48 sec. 0 sec.

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

38 XIN IN Internal clock oscillation frequency input setting.

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

39 XOUT OUT Internal clock oscillation frequency control output.

Output to control oscillation input of XOUT.

40 VSS IN Power source voltage: -5V.

VC voltage of power source circuit input.

41 P27 OUT Bottom heating element driving signal.

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

Power output ON time OFF time

100 % 48 sec. 0 sec.

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

DESCRIPTION OF LSI

LSI(IZA965DR)

The I/O signal of the LSI(IZA965DR) are detailed in the following table.

Pin No. Signal I/O Description

42 P26 OUT Terminal not used. 43 P25 OUT Fan motor driving signal.

To turn on and off the fan motor relay RY6. "L" level during cooking, or for 5 minutes after grill cooking or for a while after oven or dual cooking. "H" level otherwise.

44 P24 OUT Terminal not used. 45 P23 OUT Touch control transformer driving signal.

To turn on and off the shut off relay (RY5). If the oven has not been used for more than 2 minutes, the relay RY5 will be turned off. The relay RY5 will be turned on when the oven door is opened and closed.

46-47 P22-P21 OUT Terminal not used. 48 P20 OUT Terminal not used.

49-50 P17-P16 IN Terminal to change functions according to the model. 51-80 SEG39-SEG10 OUT Segment data signal.

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

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

SEG 0 (90) ....................SEG39 (51) SEG21 (69) ................. SEG19 (19)

SEG 1 (89) ....................SEG38 (50) SEG22 (68) ................. SEG18 (18)

SEG 2 (88) ....................SEG37 (49) SEG23 (67) ................. SEG17 (17)

SEG 3 (87) ....................SEG36 (48) SEG24 (66) ................. SEG16 (16)

SEG 4 (86) ....................SEG35 (47) SEG25 (65) ................. SEG15 (15)

SEG 5 (85) ....................SEG34 (46) SEG26 (64) ................. SEG14 (14)

SEG 6 (84) ....................SEG33 (45) SEG27 (63) ................. SEG13 (13)

SEG 7 (83) ....................SEG32 (44) SEG28 (62) ................. SEG12 (12)

SEG 8 (82) ....................SEG31 (43) SEG29 (61) ................. SEG11 (11)

SEG10 (80) ...................SEG30 (30) SEG30 (60) ................. SEG10 (10)

SEG11 (79) ...................SEG29 (29) SEG31 (59) ...................SEG 9 ( 9)

SEG12 (78) ...................SEG28 (28) SEG32 (58) ...................SEG 8 ( 8)

SEG13 (77) ...................SEG27 (27) SEG33 (57) ...................SEG 7 ( 7)

SEG14 (76) ...................SEG26 (26) SEG34 (56) ...................SEG 6 ( 6)

SEG15 (75) ...................SEG25 (25) SEG35 (55) ...................SEG 5 ( 5)

SEG16 (74) ...................SEG24 (24) SEG36 (54) ...................SEG 4 ( 4)

SEG17 (73) ...................SEG23 (23) SEG37 (53) ...................SEG 3 ( 3)

SEG18 (72) ...................SEG22 (22) SEG38 (52) ...................SEG 2 ( 2)

SEG19 (71) ...................SEG21 (21) SEG39 (51) ...................SEG 1 ( 1)

SEG20 (70) ...................SEG20 (20)

OFF

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

GND

81 SEG9 OUT Terminal not used. 82-90 SEG8-SEG0 OUT Segment data signal.

Connected to LCD. Signal is similar to SEG39. 91 VCC IN Connected to GND. 92 VREF IN Connected to GND. 93 AVSS IN Connected to VC. 94 COM3 OUT Terminal not used.

95 COM2 OUT Common data signal: COM3.

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

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

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

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

SERVICING

1. Precautions for Handling Electronic Components

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

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

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

approx. 1M ohm

2. Shapes of Electronic Components

Transistor KRC243M

Transistor

2SB1238

3. Servicing of Touch Control Panel

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

(1) Servicing the touch control panel with power

supply of the oven : CAUTION:

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

Therefore, before checking the performance of the touch

control panel,

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

2) Open the door and block it open.

3) Discharge high voltage capacitor.

4) Disconnect the leads to the primary of the power

transformer.

5) Ensure that these leads remain isolated from other

components and oven chassis by using insulation tape.

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

cord.

After checking the performance of the touch control

panel,

1) Disconnect the power supply cord.

2) Open the door and block it open.

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

transformer.

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

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

case is installed.

6) Run the oven and check all functions.

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

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

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

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

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

(2) Servicing the touch control panel with power

supply from an external power source:

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

4. Servicing Tools

Tools required to service the touch control panel assembly.

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

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

3) Others: Hand tools

5. Other Precautions

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

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

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

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

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

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

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

before operating the oven.

1. Disconnect oven from power supply.

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

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

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

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

1. Door does not close firmly.

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

3. The door gasket or seal or damaged.

4. The door is bent or warped.

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

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

7. There is visible damage to the oven.

Do not operate the oven:

1. Without the RF gasket (Magnetron).

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

3. If the door is not closed.

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

WARNING FOR WIRING

To prevent an electric shock, take the following precautions.

1. Before wiring,

1) Disconnect the power supply.

2) Open the door and wedge the door open.

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

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

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

2) Hot parts: Top heating element, Bottom heating element,

Oven lamp, Magnetron, High voltage transformer and Oven cavity.

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

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

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

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

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

OUTER CASE REMOVAL

To remove the outer case proceed as follows.

1. Disconnect oven from power supply.

2. Open the oven door and wedge it open.

3. Remove the one (1) screw holding the back plate to the oven cavity rear plate. Remove the back plate

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

5. Remove the air duct assembly

6. Remove the eight (8) screws from rear and along the side edge of case.

7. Slide the entire case back about 3 cm to free it from retaining clips on the cavity face plate.

8. Lift the entire case from the oven.

HIGH VOLTAGE COMPONENTS REMOVAL

(HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY)

To remove the components, proceed as follows.

1. CARRY OUT 3D CHECKS.

2. Disconnect the filament lead of the high voltage trans-

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

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

N.B.; Step 1, 2 and 9 form the basis of the 3D checks.

CAUTION: DISCHARGE HIGH VOLTAGE CAPACI-

TOR BEFORE TOUCHING ANY OVEN COMPONENT OR WIRING.

CAUTION: WHEN THE OUTER CASE CABINET IS

RE-INSTALLED, INSTALL IT BEFORE THE BACK PLATE IS INSTALLED, OR THE OUTER CASE CABINET WILL BE DEFORMED.

former and the high voltage wire A from the high voltage capacitor.

3. Disconnect the high voltage wire B from the magnetron.

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

4. Remove one (1) screw holding earth side terminal of the high voltage rectifier assembly.

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

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

7. Release the capacitor holder from the fan duct.

8. Remove the high voltage capacitor from the capacitor holder.

9. Disconnect the high voltage wire B and the high voltage rectifier assembly from the high voltage capacitor.

HIGH VOLTAGE TRANSFORMER REMOVAL

1. CARRY OUT 3D CHECKS.

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

3. Disconnect the H.V. wire A from the high voltage transformer.

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

MAGNETRON REMOVAL

1. CARRY OUT 3D CHECKS.

2. Disconnect the H.V. wire B and filament lead of the transformer from the magnetron.

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

4. Move the air intake duct to left.

5. Carefully remove four (4) screws holding the magnetron to the waveguide, when removing the screws hold the

10.Disconnect the high voltage rectifier assembly from the high voltage wire B.

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

CAUTION: WHEN REPLACING HIGH VOLTAGE

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

age transformer.

5. Remove the two (2) screws and one (1) washer holding the transformer to the base plate.

7. Remove the transformer.

8. Now the high voltage transformer is free.

magnetron to prevent it from falling.

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

CAUTION: WHEN REPLACING THE MAGNETRON,

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

CONTROL PANEL ASSEMBLY REMOVAL

1. CARRY OUT 3D CHECKS.

2. Disconnect the wire leads and the connectors from the control unit.

3. Lift up the control panel assembly and pull it forward. Now the control panel assembly is free.

Key / Jog unit

4. Disconnect the connector CN-G from the CPU unit.

5. Remove the two (2) screws holding the LCD holder to the control panel frame.

6. Remove the four (4) screws holding the power unit to

FAN MOTOR REPLACEMENT

REMOVAL

1. CARRY OUT 3D CHECKS.

2. Remove the one chassis support.

3. Release the noise filter from the tabs of the fan duct.

4. Remove the one to the oven cavity front flange.

5. Remove the chassis support from the oven cavity.

6. Disconnect the wire leads from the fan duct.

7. Remove the to the oven cavity back plate.

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

9. Remove the oven cavity back plate.

10.Remove the fan duct from the oven.

(1) screw

one

(1) screw holding the capacitor holder

one

(1) screw holding the fan duct to the

holding the noise filter to the

holding the chassis support

the control panel frame.

7. Remove the control unit assembly (CPU unit and Power unit) from the control panel frame.

8. Remove the six (6) screws holding the key / jog unit to the control panel frame.

9. Remove the key / jog unit from the control panel frame.

10.Remove the vari knob and the rotary knob from the key / jog unit.

11.Now, the key / jog unit is free.

11.Remove the fan duct from the fan motor shaft according to the following procedure.

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

a pair of groove joint pliers.

CAUTION:

• Make sure that no swarf from the rotor enters the gap between the rotor & startor of the fan motor.

• Avoid touch the coil of the fan motor with the pliers as the coil may become cut or damaged.

• Avoid deforming the bracket whilst using the pliers.

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

3) Now, the fan blade is free.

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

CAUTION:

• Do not reuse the removed fan blade as the fixing hole may be oversize.

12.Remove the two (2) screws and nuts holding the fan motor to the fan duct.

13.Now, the fan motor is free.

INSTALLATION

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

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

1) Hold the centre of the bracket which supports the

shaft of the fan motor on a flat table.

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

the fan blade.

3) Install the fan blade to the shaft of fan motor by

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

CAUTION:

• Do not hit the fan blade when installing because the bracket may be deformed.

• Make sure that the fan blade rotates smoothly after installation.

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

3. Insert the

tabs of

the capacitor holder to the fan duct.

4. Install the fan duct to the oven cavity back plate with the one (1) screw.

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

6. Re-install the chassis support to the oven cavity one (1) screw

7. Install the noise filter to the fan duct and support

with the one (1) screw.

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

with the

the chassis

Coil

Groove joint pliers

Stator

Gap

Bracket

Rotor

Shaft

Axis

Stator

Rotor

Rear view Side view

TURNTABLE MOTOR REPLACEMENT

Removal

1. Disconnect the oven from the power supply.

2. Remove the turntable from the oven cavity.

3. Turn the oven over.

4. Cut the four (4) bridges holding the turntable motor cover to the base plate with cutting pliers as shown in Figure C-1(a).

CAUTION: DO NOT DROP THE TURNTABLE MOTOR

COVER INTO THE OVEN AFTER CUTTING THE BRIDGES. BECAUSE IT WILL DAMAGE THE WIRE LEADS OF THE MOTOR AND IT IS DIFFICULT TO REMOVE IT OUT OF THE OVEN.

5. Remove the turntable motor cover from the base plate.

6. Disconnect the wire leads from the turntable motor.

7. Remove the one (1) screw holding the turntable motor

Cutting pliers

Shaft

These are the position where should be pinched with pliers

Table

Center of bracket

to the turntable motor angle.

8. Remove the turntable motor from the turntable motor angle. Now, the turntable motor is free.

Re-install

1. Remove the any sharp edges on the turntable motor cover and the base plate with the cutting pliers.

2. Re-install turntable motor by locating shaft onto turntable motoor shaft to the turntable motoor angle with the one (1) screw.

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

4. Insert the two (2) tabs of the turntable motor cover into the slits of the base plate as shown in Figure C-1(b).

5. Re-install the turntable motor cover to the base plate with the screw (LX-EZA045WRE0) as shown in Figure C-1(b).

Screw;

Turntable motor cover

Tabs

LX-EZA045WRE0

Bridges

Turntable motor cover

Slits

Base plate

Figure C-1(a). Turntable motor cover removal Figure C-1(b). Turntable motor cover re-install

BULB

LOCK

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

POSITIVE LOCK® CONNECTOR REMOVAL

Terminal

1. CARRY OUT 3D CHECKS.

2. Push the lever of positive lock® connector.

3. Pull down on the positive lock® connector.

CAUTION: WHEN YOU (SERVICE ENGNEERS) CON-

NECT THE POSITIVE LOCK® CONNECTORS TO THE TERMINALS, CONNECT THE POSITIVE LOCK® SO THAT THE LEVER FACES YOU (SERVICE ENGNEERS).

OVEN LAMP SOCKET REMOVAL

1. CARRY OUT 3D CHECKS.

2. Remove the wire leads as Positive lock® connector removal above.

3. Lift up the oven lamp from its retaining clips.

4. Now, the oven lamp is free.

POWER SUPPLY CORD REPLACEMENT

Removal

1. CARRY OUT 3D CHECKS.

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

3. Disconnect the leads of the power supply cord from the noise filter, referring to the Figure C-4(a).

4. Release the power supply cord from the rear cabinet.

5. Now, the power supply cord is free.

Positive lock® connector

Lever

Push

Pull down

Figure C-2. Positive lock®connector

Figure C-3. Oven lamp

Re-install

1. Insert the moulding cord stopper of power supply cord into the square hole of the power angle, referring to the Figure C-4(b).

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

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

Oven cavity back plate

Screw

Green/ Yellow wire

Brown wire

Noise filter

Power supply cord

Blue wire

F 8 A

15 A

WHT

RED

MOULDING CORD STOPPER

POWER SUPPLY CORD

OVEN CAVITY BACK PLATE

SQUARE HOLE

Figure C-4 (a) Replacement of Power Supply Cord Figure C-4(b). Power Supply Cord Replacement

TOP HEATING ELEMENT REMOVAL

1. CARRY OUT 3D CHECKS.

2. Remove the two (2) screws holding the two (2) terminals of the main wire harness to the top heating element.

3. Remove the two (2) screws holding the two (2) grill heater angles to the top of the oven cavity.

4. Remove the two (2) grill heater angles from the oven cavity.

5. Remove the top heating element from the top of the oven cavity.

6. Now the top heating element is free.

BOTTOM HEATING ELEMENT REMOVAL

1. CARRY OUT 3D CHECKS.

2. Remove the turntable motor cover from the base plate, referring to "TURNTABLE MOTOR REPLACEMENT".

3. Disconnect the wire leads from the bottom heating element.

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

4. Remove the two (2) nuts holding the bottom heating element to the oven cavity.

5. Remove the heater cover and the heater packing from

MONITORED LATCH SWITCH, MONITOR SWITCH AND STOP SWITCH REMOVAL

1. CARRY OUT 3D CHECKS.

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

3. Remove the open lever from the oven cavity front plate by removing the control panel assembly.

4. Disconnect the leads from all switches.

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

6. Remove the latch hook.

7. Remove the switch(es) from the latch hook by pushing the retaining tab backwards slightly and turning the switch(es) on the post.

8. Now the switch(es) is free.

MONITOR

If the monitored latch switch, stop switch and monitor switch do not operate properly due to a mis-adjustment, the following adjustment should be made.

1. CARRY OUT 3D CHECKS.

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

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

0.5 mm. The horizontal position of the latch hook should be placed where the monitor switch has activated with the door closed. The vertical position of the latch hook should be placed where the monitored latch switch and stop switch have activated with the door closed.

4. Secure the screws with washers firmly.

5. Make sure of the all switches operation. If the latch head has not pushed the plungers of the monitor switch with door closed, adjust the latch hook position. At that time, the latch head should have pushed the plungers of the monitored latch switch and stop switch. If the latch head has not pushed the plungers of the monitored latch switch and stop switch with door closed, loose two (2) screws holding latch hook to oven cavity front flange and adjust the latch hook position.

ED LATCH SWITCH, STOP SWITCH AND MONITOR SWITCH ADJUSTMENT

the bottom heating element.

6. Remove the bottom heating element from the oven cavity .

(SW2) MONITOR SWITCH

TAB

(SW1) MONITORED

TAB

Figure C-5. Switches

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

2. The stop switch interrupt the circuit before the door can be opened.

3. When the door is opened the contacts (COM-NC) of the monitor switch and monitored latch switch close. And the contacts (COM-NO) of their switches open.

4. When the door is closed the contacts (COM-NC) of the monitor switch and monitored latch switch open. And the contacts (COM-NO) of their switches close.

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

DOOR

LATCH HEADS

LATCH SWITCH

(SW3) STOP SWITCH

LATCH HOOK

(SW2) MONITOR SWITCH

(SW1) MONITORED LATCH SWITCH

After adjustment, make sure of following:

1. In and out play of door remains less than 0.5 mm when latched position. First check latch hook position, pushing and pulling upper position of the door toward the

DOOR REPLACEMENT

REMOVAL

1. Disconnect the oven from the power supply.

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

3. Insert an putty knife (thickness of about 0.5mm) into the

(SW3) STOP SWITCH

OPEN LEVER

Figure C-6 Latch Switches Adjustment

gap between the choke cover and door frame as shown in Figure C-7 to free engaging parts.

4. Release choke cover from door panel.

5. Now choke cover is free.

LOWER OVEN HINGE

UPPER OVEN HINGE

LOWER OVEN HINGE

CHOKE COVER

DOOR PANEL

DOOR SUB ASSEMBLY

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

6. Locate door panel hinge pins into cavity hinge location holes.

7. Re-install choke cover to door panel by clipping into position.

Note: After any service to the door; (A) Make sure that the monitor switch, monitored

latch switch and stop switch are operating prop-

PUTTY KNIFE

CHOKE COVER

DOOR FRAME

Figure C-7. Door Disassembly

6. Lift the door upwards.

7. Now, door sub assembly is free from oven cavity.

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

9. Release door panel from six (6) tabs of door frame by sliding door panel upward.

10.Now, door panel is free.

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

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

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

14.Remove the glass stopper from the door frame.

15.Slide the front door glass leftwards and then slide upwards to release the tabs holding it.

16.Now, the front door glass is free

RE-INSTALL

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

a) Insert the upper edge of the front door glass into the

six (6) tabs of the door frame.

b) Slide the front door glass downwards and insert the

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

c) Slide the front door glass rightwards and insert the

right edge of the front door glass into the one (1) tab of the door frame.

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

a) Re-install the glass stopper to the door frame so

that the two (2) holes of the glass stopper meet the two (2) pins of the door frame.

b) Hold the glass stopper to the door frame with the

two (2) screws.

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

4. Re-install door panel to door frame by fitting six (6) tabs of door frame to six (6) holes of door panel.

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

erly. (Refer to chapter "Test Procedures".).

(B) An approved microwave survey meter should be

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

After any service, make sure of the following :

1. Door latch heads smoothly catch latch hook through latch holes and that latch head goes through centre of latch hole.

2. Deviation of door alignment from horizontal line of cavity face plate is to be less than 1.0mm.

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

4. Check for microwave leakage around door with an approved microwave survey meter. (Refer to Microwave Measurement Procedure.)

Note: The door on a microwave oven is designed to act

as an electronic seal preventing the leakage of microwave energy from oven cavity during cook cycle. This function does not require that door be air-tight, moisture (condensation)-tight or lighttight. Therefore, occasional appearance of moisture, light or sensing of gentle warm air movement around oven door is not abnormal and do not of themselves, indicate a leakage of microwave energy from oven cavity.

Figure C-8. Door Replacement

MICROWAVE MEASUREMENT

After any repair, the microwave oven must be checked for microwave leakage to ensure continued safe operation. BS EN 60335-2-25 specifies that the maximum permitted leakage with a load of 275 ml is 50 W/m2 (equivalent to 5 mW/cm2) at a distance of 5 cm from the oven.

PREPARATION

The following items are required to carry out this test:-

1. A low form of 600 ml beaker made from an electrically non-conductive material, such as glass or plastic, with an inside diameter of approximately 8.5 cm. This must contain 275 ± 15 ml of water, at an initial temperature of 20 ± 2˚C.

2. A leakage detector which has been calibrated within the preceding 12 months to a stand whose accuracy can be traced to National Physical Laboratory Standards.

Recommended instruments are: Apollo "XI"

Celtec "A100"

Before commencing the test, check that the leakage detector is functioning and adjusted according to the manufacturer's instructions, and any spacers are fitted to ensure that measurement is taken 5cm from the surface of the oven.

PROCEDURE

1. Place the beaker containing the water load in the oven cavity at the centre of the turntable. The placing of this standard load in the oven is important, not only to protect the oven, but also to ensure that any leakage it is not disguised by too large a load absorbing energy.

2. Close the oven door, and with the power level set to FULL, turn the oven ON with the timer set for a few minutes operation. Should the water begin to boil before the test has been completed, it should be replaced.

3. As shown in the diagram below, move the probe slowly (not faster than 2.5 cm/sec.);-

a) around the edge of the door following the gap b) across the face of the door c) across any vents in the oven's sides, rear or top

Dotted line indicates the path taken by the leakage detector.

Whilst the maximum leakage permitted in BS EN 60335-2-25 is 50 W/m2 (equivalent to 5 mW/cm2), it is not normal to detect any significant leakage, and therefore any detected leakage should be investigated.

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. PLUGGED IN OVEN.

3. NOTHING APPEARS ON DISPLAY.

LIVENEUTRAL

BRN/15BLU/15

230 - 240V ~ 50Hz

SCHEMATIC

FUSE 15A

10M/ 0.5W

NOISE FILTER

MG. THERMAL CUT-OUT

FUSE F8A

N.O.

COM.

RY1 RY2 RY3 RY4

COM.

N.O.

COM.

N.O.

COM.

N.O.

Note: AC CORD CONNECTION BRN : BROWN BLU : BLUE G-Y : GREEN AND YELLOW STRIPE /15 : SECTIONAL AREA OF 1.5mm2 MIN.

" " Indicates components with potential

above 250 V.

HIGH VOLTAGE

TRANSFORMER

MAGNETRON

4700p/ 250V

G-Y/15

EARTH

0.22µ/250V

680 k/ 0.5W

NOISE SUPPRESSION COIL

T/C TRANSFORMER

OVEN THERMAL CUT-OUT

4700p/ 250V

Figure O-1(a) Oven Schematic-OFF Condition right after the oven is plugged in.

LIVENEUTRAL

EARTH

G-Y/15

SCHEMATIC

FUSE 15A

0.22µ/250V

NOISE FILTER

10M/ 0.5W

680 k/ 0.5W

NOISE SUPPRESSION COIL

MG. THERMAL CUT-OUT

4700p/ 250V

T/C TRANSFORMER

OVEN THERMAL CUT-OUT

4700p/ 250V

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. "ENERGY SAVED MODE" APPEARS ON DISPLAY.

BRN/15BLU/15

230 - 240V ~ 50Hz

Figure O-1(b) Oven Schematic-OFF Condition when the oven door is opened.

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. " . O" APPEARS ON DISPLAY.

NOISE FILTER

E5 E7

RY5

E1 E3

CONTROL UNIT

E5 E7

E1 E3

FUSE F8A

N.O.

COM.

RY1 RY2 RY3 RY4

RY5

CONTROL UNIT

FUSE F8A

RY6

THERMISTOR

(SW1)MONITORED LATCH SWITCH

N.O.

COM.

RY6

(SW1)MONITORED LATCH SWITCH

(SW3)STOP SWITCH

COM.

N.O.

COM.

(SW3)STOP SWITCH

N.O.

FAN MOTOR

OVEN LAMP

NC.

OVEN LAMP

NC.

TOP GRILL HEATING ELEMENT

BOTTOM HEATING ELEMENT

TTM

TURNTABLE MOTOR

(SW2)MONITOR SWITCH

BOTTOM HEATING ELEMENT

TTM

TURNTABLE MOTOR

(SW2)MONITOR SWITCH

CAPACITOR

1.07 µF

AC2100V

NC.

TOP GRILL HEATING ELEMENT

NC.

ASYMMETRIC RECTIFIER

HIGH VOLTAGE

TRANSFORMER

CAPACITOR

1.07 µF

ASYMMETRIC RECTIFIER

AC2100V

H.V. RECTIFIER

MAGNETRON

H.V. RECTIFIER

LIVENEUTRAL

BRN/15BLU/15

230/240V ~ 50Hz

EARTH

G-Y/15

FUSE 15A

0.22µ/250V

10M/ 0.5W

NOISE SUPPRESSION COIL

THERMAL CUT-OUT

4700p/ 250V

680 k/ 0.5W

OVEN THERMAL CUT-OUT

4700p/ 250V

COM.

RY1 RY2 RY3 RY4

E5 E7

T/C TRANSFORMER

E1 E3

CONTROL UNIT

N.O.

RY5

RY6

THERMISTOR

N.O.

COM.

(SW3)STOP SWITCH

(SW1)MONITORED LATCH SWITCH

COM.

N.O.

FAN MOTOR

TTM

OVEN LAMP

NC.

TURNTABLE MOTOR

Figure O-1(c) Oven Schematic-OFF Condition after the oven door is closed.

HIGH VOLTAGE

TRANSFORMER

TOP GRILL HEATING ELEMENT

BOTTOM HEATING ELEMENT

(SW2)MONITOR SWITCH

NC.

ASYMMETRIC RECTIFIER

CAPACITOR

1.07 µF

AC2100V

MAGNETRON

H.V. RECTIFIER

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. COOKING TIME ENTERED.

3. BOTTOM GRILL MODE SELECTED.

230 - 240V ~ 50Hz

G-Y/15

EARTH

0.22µ/250V

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

NOISE SUPPRESSION COIL

680 k/ 0.5W

4700p/ 250V

OVEN

THERMAL

CUT-OUT

T/C TRANSFORMER

4700p/ 250V

BRN/15BLU/15

LIVENEUTRAL

FUSE 15A

10M/ 0.5W

MG.

THERMAL

CUT-OUT

4. STRAT KEY TOUCHED.

NOISE

FILTER

SCHEMATIC

G-Y/15

EARTH

0.22µ/250V

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

NOISE SUPPRESSION COIL

680 k/ 0.5W

4700p/ 250V

OVEN

THERMAL

CUT-OUT

T/C TRANSFORMER

4700p/ 250V

230 - 240V ~ 50Hz

BRN/15BLU/15

LIVENEUTRAL

FUSE 15A

10M/ 0.5W

THERMAL

CUT-OUT

MG.

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. COOKING TIME ENTERED.

NOISE

FILTER

3. STRAT KEY TOUCHED.

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. COOKING TIME ENTERED.

3. TOP GRILL MODE SELECTED.

4. STRAT KEY TOUCHED.

SCHEMATIC

NOISE

FILTER

Figure O-2 Oven Schematic-Microwave cooking Condition

4700p/ 250V

OVEN

THERMAL

CUT-OUT

G-Y/15

EARTH

0.22µ/250V

NOISE SUPPRESSION COIL

680 k/ 0.5W

T/C TRANSFORMER

230 - 240V ~ 50Hz

4700p/ 250V

BRN/15BLU/15

LIVENEUTRAL

FUSE 15A

10M/ 0.5W

MG.

THERMAL

CUT-OUT

E1 E3

CONTROL UNIT

THERMISTOR

(SW1)MONITORED LATCH SWITCH

NC.

(SW2)MONITOR

SWITCH

RECTIFIER

(SW3)STOP SWITCH

OVEN LAMP

TTM

TURNTABLE MOTOR

NC.

ASYMMETRIC

BOTTOM HEATING ELEMENT

TOP GRILL HEATING ELEMENT

CAPACITOR

1.07 µF AC2100V

E5 E7

RY5

RY6

FAN MOTOR

COM.

RY1 RY2 RY3 RY4

COM.

N.O.

COM.

N.O.

COM.

N.O.

HIGH VOLTAGE TRANSFORMER

N.O.

FUSE F8A

E1 E3

CONTROL UNIT

THERMISTOR

(SW1)MONITORED LATCH SWITCH

NC.

(SW2)MONITOR

SWITCH

ASYMMETRIC

RECTIFIER

(SW3)STOP SWITCH

OVEN LAMP

TTM

TURNTABLE MOTOR

BOTTOM HEATING ELEMENT

TOP GRILL HEATING ELEMENT

NC.

CAPACITOR

1.07 µF AC2100V

E5 E7

RY5

RY6

FAN MOTOR

COM.

RY1 RY2 RY3 RY4

N.O.

COM.

N.O.

COM.

N.O.

COM.

N.O.

CONVECTION MOTOR

HIGH VOLTAGE TRANSFORMER

FUSE F8A

E1 E3

CONTROL UNIT

THERMISTOR

(SW1)MONITORED LATCH SWITCH

NC.

(SW2)MONITOR

SWITCH

ASYMMETRIC

RECTIFIER

(SW3)STOP SWITCH

OVEN LAMP

TTM

TURNTABLE MOTOR

BOTTOM HEATING ELEMENT

TOP GRILL HEATING ELEMENT

NC.

CAPACITOR

1.07 µF AC2100V

E5 E7

RY5

RY6

FAN MOTOR

COM.

RY1 RY2 RY3 RY4

N.O.

COM.

N.O.

COM.

N.O.

COM.

N.O.

HIGH VOLTAGE TRANSFORMER

FUSE F8A

H.V. RECTIFIER

MAGNETRON

H.V. RECTIFIER

MAGNETRON

H.V. RECTIFIER

MAGNETRON

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. COOKING TIME ENTERED.

3. TOP & BOTTOM GRILL MODE SELECTED.

4. STRAT KEY TOUCHED.

SCHEMATIC

NOISE FILTER

LIVENEUTRAL

BRN/15BLU/15

230 - 240V ~ 50Hz

G-Y/15

EARTH

FUSE 15A

10M/ 0.5W

0.22µ/250V

NOISE SUPPRESSION COIL

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

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. COOKING TIME ENTERED.

3. OVEN TEMPERATURE SELECTED.

4. STRAT KEY TOUCHED.

SCHEMATIC

MG. THERMAL CUT-OUT

4700p/ 250V

680 k/ 0.5W

OVEN THERMAL CUT-OUT

4700p/ 250V

FUSE F8A

COM.

RY1 RY2 RY3 RY4

E5 E7

T/C TRANSFORMER

E1 E3

CONTROL UNIT

N.O.

RY5

RY6

RY7

THERMISTOR

N.O.

COM.

(SW3)STOP SWITCH

(SW1)MONITORED LATCH SWITCH

COM.

N.O.

FAN MOTOR

TTM

OVEN LAMP

NC.

TOP GRILL HEATING ELEMENT

BOTTOM HEATING ELEMENT

TURNTABLE MOTOR

(SW2)MONITOR SWITCH

NC.

HIGH VOLTAGE

TRANSFORMER

CAPACITOR

1.07 µF

ASYMMETRIC RECTIFIER

MAGNETRON

AC2100V

H.V. RECTIFIER

LIVENEUTRAL

BRN/15BLU/15

230 - 240V ~ 50Hz

EARTH

G-Y/15

FUSE 15A

0.22µ/250V

NOISE FILTER

10M/ 0.5W

680 k/ 0.5W

NOISE SUPPRESSION COIL

FUSE F8A

MG. THERMAL CUT-OUT

COM.

N.O.

COM.

N.O.

COM.

N.O.

COM.

N.O.

RY1 RY2 RY3 RY4

4700p/ 250V

T/C TRANSFORMER

OVEN THERMAL CUT-OUT

4700p/ 250V

E1 E3 E5 E7

RY5

CONTROL UNIT

THERMISTOR

RY6

(SW3)STOP SWITCH

(SW1)MONITORED LATCH SWITCH

FAN MOTOR

OVEN LAMP

NC.

Figure O-4 Oven Schematic-Oven cooking Condition

TOP GRILL HEATING ELEMENT

BOTTOM HEATING ELEMENT

TTM

TURNTABLE MOTOR

(SW2)MONITOR SWITCH

NC.

HIGH VOLTAGE

TRANSFORMER

CAPACITOR

1.07 µF

ASYMMETRIC RECTIFIER

MAGNETRON

AC2100V

H.V. RECTIFIER

SCHEMATIC

NOTE: CONDITION OF OVEN

SCHEMATIC

1. DOOR CLOSED.

2. COOKING TIME ENTERED.

3. DUAL GRILL KEY TOUCHED ONCE.

4. MICROWAVE POWER LEVEL ENTERED.

5. STRAT KEY TOUCHED.

NOISE FILTER

LIVENEUTRAL

BRN/15BLU/15

230 - 240V ~ 50Hz

G-Y/15

EARTH

FUSE15A

0.22µ/250V

10M/ 0.5W

680 k/ 0.5W

NOISE SUPPRESSION COIL

Figure O-5(a) Oven Schematic-Dual cooking Condition (Microwave and Top Grill mode)

NOTE: CONDITION OF OVEN

1. DOOR CLOSED.

2. COOKING TIME ENTERED.

3. DUAL GRILL KEY TOUCHED TWICE.

4. MICROWAVE POWER LEVEL ENTERED.

5. STRAT KEY TOUCHED.

SCHEMATIC

MG. THERMAL CUT-OUT

4700p/ 250V

T/C TRANSFORMER

OVEN THERMAL CUT-OUT

4700p/ 250V

FUSE F8A

E5 E7

E1 E3

N.O.

COM.

RY1 RY2 RY3 RY4

RY5

CONTROL UNIT

THERMISTOR

N.O.

COM.

RY6

(SW1)MONITORED LATCH SWITCH

N.O.

COM.

(SW3)STOP SWITCH

COM.

N.O.

FAN MOTOR

OVEN LAMP

NC.

TOP GRILL HEATING ELEMENT

BOTTOM HEATING ELEMENT

TTM

TURNTABLE MOTOR

(SW2)MONITOR SWITCH

NC.

HIGH VOLTAGE

TRANSFORMER

CAPACITOR

1.07 µF

ASYMMETRIC RECTIFIER

MAGNETRON

AC2100V

H.V. RECTIFIER

LIVENEUTRAL

BRN/15BLU/15

230 - 240V ~ 50Hz

EARTH

G-Y/15

Figure O-5(b) Oven Schematic-Dual cooking Condition (Microwave and Buttom Grill mode)

FUSE 15A

0.22µ/250V

NOISE FILTER

10M/ 0.5W

680 k/ 0.5W

NOISE SUPPRESSION COIL

MG. THERMAL CUT-OUT

4700p/ 250V

T/C TRANSFORMER

OVEN THERMAL CUT-OUT

4700p/ 250V

FUSE F8A

E5 E7

E1 E3

N.O.

COM.

RY1 RY2 RY3 RY4

RY5

CONTROL UNIT

THERMISTOR

N.O.

COM.

RY6

(SW1)MONITORED LATCH SWITCH

N.O.

COM.

(SW3)STOP SWITCH

COM.

N.O.

FAN MOTOR

OVEN LAMP

NC.

TOP GRILL HEATING ELEMENT

BOTTOM HEATING ELEMENT

TTM

TURNTABLE MOTOR

(SW2)MONITOR SWITCH

NC.

HIGH VOLTAGE

TRANSFORMER

CAPACITOR

1.07 µF

ASYMMETRIC RECTIFIER

MAGNETRON

AC2100V

H.V. RECTIFIER

CN-C

BLK 2 1

BLK

CONTROL PANEL

CN-G

112

CN-B

1 2

CN-C

CN-E

SP1

RY6

CN-A

CN-E

7 RED 6 5 ORG 4 3 BRN 2 1 BLU

IC-1

CN-1

WH-1

RY2

RY1

RY3

RY4

CN-B 1 2

RY5

7 WHT 6

CN-A

5 GRY 4 3 YLW 2 1 BRN

T/C TRANSFORMER

THERMISTOR

GRN RED

WHT

BLU

ORG

BRN

BLK

RED ORG

RED

BLK

BLU

ORG

BLK

MONITOR SWITCH

MONITORED LATCH SWITCH

GRN

N.C.

COM

BLU

GRY

COM

STOP SWITCH

WHT

GRY

BLU

WHT

YLW

GRY

GRN

RED

WHT

BOTTOM HEATING ELEMENT

TURNTABLE MOTOR

TOP GRILL HEATING ELEMENT

OVEN THERMAL CUT-OUT

WHT

BLU

GRY

WHT

BLK

WHT

BLU

OVEN LAMP

WHT GRY

ORG

BLK

GRY WHT

POWER SUPPLY CORD

EARTH

G—Y

LIVE

RED

BLK

ORG

BRN

BLU

15 A

NOISE FILTER

MG. THERMAL CUT-OUT

BLK

WHT

FAN MOTOR

NEUTRAL

WHT

RED

ORG

F 8 A

HIGH VOLTAGE COMPONENTS

MAGNETRON

H.V.WIRE B

H.V. RECTIFIER

ASYMMETRIC

HIGH VOLTAGE TRANSFORMER

RECTIFIER

H.V.WIRE A

H.V. CAPACITOR

PICTORIAL

Figure S-1. Pictrorial Diagram

POWER UNIT CIRCUIT

AC230 - 240V 50Hz

FAN MOTOR

E 1

E 3 E 5

E 7

A 1

A 3

DOOR OPEN

CONTACT

A 5

A 7

VRS1

(J2)

10G471K

RY5

RY6

(J1)

C 1

–

R5 3.3k

SP1

C4 10µ/35v

R4 510 1w

WH1-4

WH1-3

WH1-6

WH1-9

WH1-10 WH1-5 WH1-11 WH1-8

WH1-7

OVEN THERMISTOR

GND

BUZZER

VR INT POWER

CONTROL

D10 S1NB10

GND

–

C2 1000µ/35v

R3 510 1w

C 3

OVEN LAMP TURNTABLE MOTOR

BOTTOM HEATING ELEMENT

GRILL HEATING ELEMENT

HIGH VOLTAGE TRANSFORMER

STOP SWITCH

N O

COM

N O

COM

N O

COM

N O

COM

B 2

RY1

RY4

RY3

RY2

Q2 2SB1238

R6 130 1w

ZD2

HZ20-1

1.5k

B 1

NOTE 1. NOTE 2.

: IF NOT SPECIFIED, 1/4W ± 5% 15P WIRE HARNESS : IF NOT SPECIFIED, 0.1µF / 50V : IF NOT SPECIFIED, 1SS270A

Q3 KRC243M

WH1-n

WH1-12

WH1-13

WH1-14

–

10µ/35v

WH1-15

WH1-2

WH1-1

STOP SWITCH

Figure S-2. Power Unit Circuit

CPU UNIT CIRCUIT

SEG1 SEG2 SEG3 SEG4 SEG5 SEG6 SEG7 SEG8 SEG9

SEG10 SEG11 SEG12 SEG13 SEG14 SEG15 SEG16 SEG17 SEG18 SEG19 SEG20

nfo

SEG21 SEG22 SEG23 SEG24 SEG25

˚C

SEG26

PCS

SEG27 SEG28

LBS

SEG29 SEG30

COOK SENSOR DEFROST AUTO

LIQUID CRYSTAL DISPLAY

N C N C

N C N C N C N C N C N C N C

COM1 COM2 COM3

SEG31 SEG32 SEG33 SEG34 SEG35 SEG36 SEG37 SEG38 SEG39

51 1

VL3 VL2 C 2

SEG9 SEG8 SEG7 SEG6 SEG5 SEG4 SEG3 SEG2 SEG1 SEG0 VCC VREF AVSS

COM3 COM2 COM1 COM0

SEG10

C 1

SEG11

VL1

SEG12

AN7

SEG13

AN6

SEG14

AN5 5

SEG15

AN4

SEG16

AN3

SEG17

AN2

SEG18

AN1

SEG19

AN0

SEG20

P57

SEG21

P56

SEG22

P55

SEG23

P54

SEG24

P53

SEG25

P52

SEG26

SEG27

SEG28

SEG29

IZA965DR IC-1

P51

P50

P47

P46

SEG30

P45

SEG31

P44

SEG32

INT1

SEG33

INT0

SEG34

P41

SEG35

P40

SEG36

P77

SEG37

P76

SEG38

P75

SEG39

P74

P16 P17 P20 P21 P22 P23 P24 P25 P26 P27 VSS

XIN

P80 P81

P70 P71 P72 P73

XOUT

RESET

R56

R67 15k

TIMER

Kg • Lb

BREAKFAST

R66 15k

GRILL

OVEN ( ˚C )

DUAL GRILL

R65 15k

g • oz

AUTO

COOK

10 sec. 1 min. 10 min.

MICROWAVE

POWER LEVEL

R64 15k

STOP/

CLEAR

CLOCK

OVEN CHIPS

AUTO START

R63 15k

START

BAKED POTATOES

AUTO

DEFROST

Kg / Lb

AUTO MINUTE

LESS

(J16)

(J17) 4.7k

MIXED GRILL

R62 15k

CHICKEN PTNS

R61 15k

R55 4.7k

CF1 4MHz

R60 15k

FRESH VEG.

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

CRISPY CRUMB FOODS

G10 G 9

PIZZA

G12 G11

: IF NOT SPECIFIED, 1/10W ± 5%

: IF NOT SPECIFIED, 1SS355

: IF NOT SPECIFIED, 0.01µF / 50V

LD6LD7LD8LD9LD10

LD1 LD2 LD3 LD4 LD5

R6 620

2SA1037AK

R4 22

15k R14

Q10

2SA1037AK

R10 1k

Q11

DTA143EKA

0.1µ/50v C13

15k R13

–

C11 0.1µ/50v

C10 47µ/16v

R5 4.7k

15k R12

0.1µ/50v C12

R11 4.7k

UDZ4.3B ZD10

C14

R15 4.7k

(J11)

(J14) 4.7k

(J13) 4.7k (J10)

Q40

DTA143EKA

(J15) 4.7k (J12) 4.7k

Q28

DTA143EKA

R71 15k R70 15k R69 15k R68 15k

C60

330p/50v

C61

330p/50v

C62

330p/50v

C63

R72 100k

R73 100k

R74 100k

R75 100k

330p/50v

R82 30kF

C80

Figure S-3. CPU Unit Circuit

C30

R83 15k

R31 15k

R81 0

R30 4.7k

C21

0.1µ/50v

Q23

Q25

DTA143EKA

Q22

DTA123JKA

D22

Q21

DTA123JKA

D23

Q20

DTA123JKA

D30

CN1-3

GND

CN1-10

CN1-6

CN1-5

INT

CN1-9

BUZZER

CN1-11

POWER

CN1-8

FAN

CN1-7

CN1-15

GRILL

OVEN LAMP

TURNTABLE

MOTOR

CN1-13

HEATING

ELEMENT

CN1-12

BOTTOM

HEATING

ELEMENT

CN1-1

CN1-14

STOP SWITCH

HIGH

VOLTAGE

TRANSFORMER

CN1-2

CN1-4

OVEN

THERMISTOR

PRINTED WIRING BOARD

CN - B CN - C

4 5

FA619DR

SHARP

QKITPA026URE0

ZD1

WH1

CN - D

RY8

DIP

SP1

RY9

ROTI

WH2

ZD2

MICRO

RY2

DAMP

OL:TTM

RY1

CN - E

(J1)

RY7

CN - A

RY3 RY4

RY6

(J2)

POWER CONT

D10

VRS1

Figure S-4. Printed Wiring Board of Power Unit

RY5

CH:BH

PARTS LIST

Note: The parts marked "∆" may cause undue microwave exposure. / The parts marked "*" are used in voltage more than 250V. / "§" Mark: Spare parts delivery section

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

ELECTRIC PARTS

1- 1 FPWBFA309WRE2 U Noise filter 1 AT 1- 2 RTRN-A529WRE0 U TC transformer 1 AV 1- 3 QACCBA004URE1 U Power supply cord 1 AT 1- 4 FH-DZA035WRE0 U High voltage rectifier assembly 1 AP

1- 5 RMOTDA227WRE0 U Turntable motor 1 AU 1- 6 QFS-CA025WRE0 U Fuse F8A 1 AC 1- 7 QFS-B0019MRE0 U Fuse 15A 1 AC 1- 8 RC-QZA239WRE0 U High voltage capacitor 1 AR

1- 9 RTHM-A098WRE0 U Thermal cut-out 125˚C off(MG) 1 AH 1-10 RTHM-A099WRE0 U Thermal cut-out 150˚C off 130˚C on (OVEN) 1 AH 1-11 RHET-A225WRE0 U Top grill heating element 1 AR 1-12 RHET-A227WRE0 U Bottom grill heating element 1 AU 1-13 QSW-MA133WRE0 U Monitored latch switch 1 AN 1-14 QSW-MA131WRE0 U Stop switch 1 AK 1-15 QSW-MA133WRE0 U Monitor switch 1 AN 1-16 RMOTEA361WRE0 U Fan motor 1 AT 1-17 RLMPTA066WRE0 U Oven lamp 1 AK 1-18 RTRN-A012URE0 U High voltage transformer 1 BH

1-19 RV-MZA243WRE1 U Magnetron 1 BH

∆*

1-20 FH-HZA075WRE0 U Thermistor 1 AN

CABINET PARTS

2- 1 GCABDA083WRP1 U Back plate 1 AN 2- 2 GLEGPA028WRE0 U Foot 2 AA 2- 3 GCABUA005URP0 U Outer case cabinet [R-772(G)M] 1 AX 2- 3 GCABUA028URP0 U Outer case cabinet [R-772(W)M] 1 AX 2- 4 GDAI-A002URP0 U Base plate 1 AR

CONTROL PANEL PARTS

3- 1 DPWBFA095URU0 U Power unit 1 BC 3- 1A QCNCMA412DRE0 U 4-pin connector (CN-A) 1 AD 3- 1B QCNCMA414DRE0 U 2-pin connector (CN-B) 1 AB 3- 1C QCNCMA410DRE0 U 2-pin connector (CN-C) 1 AB 3- 1D QCNCMA230DRE0 U 4-pin connector (CN-E) 1 AC 3- 1E QW-QZA008URE0 U 15pin wire harness (WH-1) 1 AG C1 VCKYD41HF104Z U Capacitor 0.1 uF 50V 1 AC C2 VCEAG31VW108M U Capacitor 1000 uF 35V 1 AE C3 VCKYD41HF104Z U Capacitor 0.1 uF 50V 1 AC C4-5 VCEAG31VW106M U Capacitor 10 uF 35V 2 AB D1-6 VHD1SS270A/-1 U Diode (1SS270A) 6 AA D10 RSRCDA013DRE0 U Diode bridge (S1NB10) 1 AE Q2 VS2SB1238//-3 U Transistor (2SB1238) 1 AD Q3 VSKRC243M//-3 U Transistor (KRC243M) 1 AB R2 VRD-B12EF152J U Resistor 1.5K ohm 1/4W 1 AA R3-4 VRS-B13AA511J U Resistor 510 ohm 1W 2 AB R5 VRD-B12EF332J U Resistor 3.3K ohm 1/4W 1 AA R6 VRS-B13AA131J U Resistor 130 ohm 1W 1 AB RY1 RRLY-A093DRE0 U Relay (VRB18) 1 AM RY2 RRLY-A092DRE0 U Relay (VRB18-SH4) 1 AP RY3-4 RRLY-A076DRE0 U Relay (OMIF-S-124LM) 2 AK RY5-6 RRLY-A080DRE0 U Relay (OJ-SH-124LM) 2 AG SP1 RALM-A014DRE0 U Buzzer (PKM22EPT) 1 AG VRS1 RH-VZA034DRE0 U Varistor (10G471K) 1 AD ZD2 VHEHZ201///-1 U Zener diode (HZ20-1) 1 AB 3- 2 DPWBFB946WRK0 U CPU unit 1 BE 3- 3-1 FUNTKC080URE0 U Key unit [R-772(W)M] 1 AS 3- 3-1 FUNTKC081URE0 U Key unit [R-772(G)M] 1 AS 3- 3-2 HPNLCA030URF0 U Control panel frame [R-772(W)M] 1 AN 3- 3-2 HPNLCG014URF0 U Control panel frame [R-772(G)M] 1 AN 3- 3-3 JBTN-A017URF0 U Open button [R-772(W)M] 1 AE 3- 3-3 JBTN-A061URF0 U Open button [R-772(G)M] 1 AE 3- 3-4 MSPRCA045WRE0 U Open button spring 1 AA 3- 4 LHLD-A007URF0 U LED holder 1 AC 3- 5 PSHEPA647WRE0 U LED sheet 1 AL 3- 6 XEPSD30P10XS0 U Screw : 3mm x 10mm 6 AA

HOW TO ORDER REPLACEMENT PARTS

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

1. MODEL NUMBER 3. PART NO.

2. REF. NO. 4. DESCRIPTION

PARTS LIST

Note: The parts marked "∆" may cause undue microwave exposure. / The parts marked "*" are used in voltage more than 250V. / "§" Mark: Spare parts delivery section

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

OVEN PARTS

∆

4- 1 DOVN-A016URK0 U Oven cavity 1 BK 4- 2 LBNDKA107WRP1 U Capacitor holder 1 AD 4- 3 FDUC-A003URY0 U Air duct assembly 1 AL 4- 4 LANGQA005URP0 U Air separate angle B 1 AC 4- 5 PDUC-A636WRP0 U Air guide duct 1 AN 4- 6 PFILWA001URP0 U Lamp filter 1 AB

∆

4- 7 PHOK-A078WRF5 U Latch hook 1 AH 4- 8 LANGQA014URP0 U Turntable motor angle 1 AE 4- 9 PSKR-A308WRF0 U Rear barrier 1 AH 4-10 FANGTA003URY0 U Turntable motor shaft assembly 1 AK 4-11 PPACGA108WRE0 U Packing 1 AC 4-12 NFANJA001URE0 U Fan blade 1 AF 4-13 PDUC-A637WRF2 U Fan duct 1 AL 4-14 PDUC-A008URP0 U Exhaust duct 1 AK 4-15 GCOVHA001URP0 U Bottom heater cover 1 AL 4-16 LANGFA155WRP7 U Chassis support 1 AF 4-17 PPACGA001URE0 U Heater packing 1 AD 4-18 LANGQA008URP0 U Grill heater angle 2 AD 4-19 MLEVPA001URF3 U Open lever 1 AE 4-20 PSPAGA001WRE0 U Vibration proof cushion 1 AA 4-22 PCOVQA002URP0 U Heater cover 2 AD 4-23 PCOVPA308WRE1 U Waveguide cover 1 AE 4-24 PCUSGA372WRP0 U HVT Cushion 1 AB 4-25 PCUSGA317WRP0 U Absorb cushion A 1 AA

∆

4-26 PCUSUA459WRP0 U Waveguide Cushion 1 AC

∆

4-27 PDUC-A633WRF1 U Air intake duct 1 AK

∆ ∆

DOOR PARTS

5- 1 DDORFA766WRK0 U Door panel assembly 1 BE 5- 2 GWAKPW027URR0 U Door frame [R-772(W)M] 1 AT 5- 2 GWAKPG008URR0 U Door frame [R-772(G)M] 1 AT 5- 3 LSTPPA147WRF1 U Latch head 1 AE

∆

5- 4 LSTPPA003URF0 U Glass stopper 1 AB 5- 5 MSPRTA141WRE0 U Latch spring 1 AA 5- 6 PGLSPA020URR0 U Front door glass 1 AX 5- 7 XEBSD30P06000 U Screw : 3mm x 6mm 6 AA 5- 8 GCOVHA365WRF2 U Choke cover 1 AM

MISCELLANEOUS

6- 1 TCAUHA001WRR1 U Caution label 1 AC

6- 2 FAMI-A095WRK1 U Rack 1 AR

6- 3 LHLDKA008WRF0 U P-clip 1 AA 6- 4 CTNT-A002URK0 U Turntable tray 1 AY 6- 5 FW-VZA031URE0 U Stop switch harness 1 AE 6- 6 QW-QZA014URE0 U High voltage wire A 1 AB 6- 7 QW-QZA210WRE1 U High voltage wire B 1 AD 6- 8 FW-VZA070URE1 U Main harness 1 AX 6-10 TINS-A175URR0 U Operation manual 1 AS 6-11 TINS-A176URR0 U Quick start guide 1 AM

SCREWS,NUTS AND WASHERS

7- 1 XHPSD40P08K00 U Screw: 4mm x 8mm 1 AA 7- 2 XOTSD40P10000 U Screw: 4mm x 10mm 3 AA 7- 3 XWWSD50-06000 U Washer: 5mm x 0.6mm 1 AA 7- 4 XOTSE40P10000 U Screw: 4mm x 12mm [R-772(W)M] 4 AA 7- 4 XOTSF40P10000 U Screw: 4mm x 12mm [R-772(G)M] 4 AA 7- 5 XNEUW40-32000 J M4 Stainless nut 4 AA 7- 6 XHTSD40P08RV0 J Screw: 4mm x 8mm 6 AA 7- 7 LX-EZA045WRE0 J TTM cover screw 1 AA 7- 8 XEBSD30P06000 J Screw: 3mm x 6mm 2 AA 7- 9 XFPSD40P08000 U Screw: 4mm x 8mm 1 AA 7-10 XHPSD40P08000 U Screw: 4mm x 8mm 1 AA 7-11 XFPSD50P10KS0 U Screw: 5mm x 10mm 2 AC 7-12 LX-CZA001URE0 J Screw: 4mm x 12mm 21 AA 7-13 XVPSD30P05K00 J Screw: 3mm x 5mm 2 AA 7-14 XEPSD40P25000 J Screw: 4mm x 25mm 2 AA 7-15 XCTWW40P06000 U Screw: 4mm x 6mm 3 AA

OVEN PARTS

7-8

4-5

7-15

1-12

4-23

6-4

4-21

1-10

7-13

6-1

4-26

7-2

4-1

4-20

7-4

7-12

4-18

4-6

2-3

1-11

7-2

4-11

7-10

4-10

7-9

4-14

4-8

1-5

4-15

4-17

4-22

4-18

7-5

7-12

7-5

7-6

7-13

6-5

1-20

7-12

4-7

7-2

4-19

7-6

1-13

1-14

1-2

4-4

1-15

1-19

1-8

4-2

7-12

7-6

4-25

6-3

7-4

7-12

7-15

7-6

7-12

7-8

7-12

7-6

1-3

4-3

1-3

1-9

1-6

4-12

1-4

7-11

1-17

7-6

2-1

7-12

4-27

4-16

1-7

1-1

7-1

7-14

1-16

4-13

7-3

1-18

7-12

2-2

2-4

4-24

4-20

4-9

7-12

CONTROL PANEL PARTS

6-9

3-3

3-3-2

3-3-1

3-2

3-6

3-4

3-5

3-6

3-1

3-6

3-3-3

DOOR PARTS

5-2

3-3-4

5-6

5-1

5-4

5-7

5-8

5-7

5-3

5-5

MISCELLANEOUS/PACKING AND ACCESSORIES

MISCELLANEOUS

6-6

6-2

Actual wire harness may be different than illustration.

PACKING AND ACCESSORIES

PRINTED MATTER

6-8

6-7

6-5

TOP PAD ASSEMBLY (FPADBA336WRK0)

WRAP COVER R-772(W)M: SSAKHA041WRE0 R-772(G)M: SSAKHA047WRE0

INTO THE OVEN CAVITY

RACK

TURNTABLE TRAY

ACCESSORY HOLDER (SPADPA015URE0)

Not Replaceable Items.

OUTER WRAP COVER (for R-772(G)M) (SPADFA353WRE0)

DOOR PROTECTION SHEET (SPADPA020WRE0)

BOTTOM PAD ASSEMBLY (FPADBA337WRK1)

PACKING CASE R-772(W)M: SPAKCA310URR0 R-772(G)M: SPAKCA336URR0

NOTES

'99 SHARP CORP. (8S1.31E) Printed in U.K.

Sharp R772M-003 Schematic

Specifications and Main Features

Frequently Asked Questions

User Manual