SHARP R-350A Service Manual

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Page 1

COOK KG DEF HELP

INTERACTIVE

DISPLAY

1 .

BEVERAGE



2 .

PIE/PIZZA



3 .

PORRIDGE

4 .

CASSEROLES

1 .

STEAK/CHOPS

2 .

ROAST MEAT



3 .

POULTRY



4 .

CHICKEN PIECES

MEAT

VEGETABLES

12345 6789O

POWER LEVELS

CLOCK

STOP/CLEAR

INSTANT COOK/START

SER VICE MANU AL

MICROWAVE OVEN

HELP

REHEAT

DEFROST

SLOW COOK

TIMER

MODEL R-350A

R-350A

S8725R350APHR

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

This is supplemental Service Manual for Model R-350A. This model is quite similar to Base Model R-340A. Use this supplemental manual together with the Base Model Service Manual (Refer No. is S7717R340APHR) for complete operation, service information, etc..

TABLE OF CONTENTS

Page

SERVICING ................................................................................................................. INSIDE FRONT COVER

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

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

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

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

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

OPERATION SEQUENCE ............................................................................................................................... 3

TEST PROCEDURE ........................................................................................................................................ 4

TOUCH CONTROL PANEL .............................................................................................................................. 4

MICROWAVE MEASUREMENT ...................................................................................................................... 7

WIRING DIAGRAM .......................................................................................................................................... 8

CPU UNIT CIRCUIT.......................................................................................................................................... 9

PARTS LIST.................................................................................................................................................... 10

SHARP CORPORATION

Page 2

R-350A

SERVICING

WARNING TO SERVICE PERSONNEL

Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts of the high voltage circuit will result in electrocution. High voltage capacitor, Power 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 high-voltage capacitor (that is, of the connecting lead of the high-voltage rectifier) against the chassis with the use of an insulated screwdriver.

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

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 microwave timer for two (2) minutes. Set the power level to HIGH and push the START button. When the two minutes has elapsed (timer at zero) carefully check that the water is now hot. If the water remains cold carry out 3D checks and reexamine the connections to the component being tested.

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

Page 3

SERVICE MANU AL

MICROWAVE OVEN

R-350A

PRODUCT SPECIFICATIONS

R-350A

GENERAL IMPORTANT INFORMATION

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

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

CAUTION

MICROWAVE RADIATION

DO NOT BECOME EXPOSED TO RADIATION FROM THE MICROWAVE GENERATOR OR OTHER PARTS CONDUCTING MICROWAVE ENERGY.

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

APPEARANCE VIEW

OPERATING SEQUENCE

TEST PROCEDURE

TOUCH CONTROL PANEL ASSEMBLY

MICROWAVE MEASUREMENT

WIRING DIAGRAM

WARNING

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

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

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

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

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

SHARP CORPORATION

PARTS LIST

OSAKA, JAPAN

Page 4

R-350A

PRODUCT SPECIFICATIONS

ITEM DESCRIPTION

Power Requirements 220 Volts

50 Hertz

Single phase, 3 wire earthed Power Consumption 1.5kW Power Output 1000 watts nominal of RF microwave energy (IEC 705)

Operating fequency 2450 MHz Case Dimensions Width 520 mm

Height 302 mm including foot

Depth 403 mm Cooking Cavity Dimensions Width 348 mm

Height 212 mm

Depth 379 mm Turntable diameter 335mm Control Complement Touch Control System

Clock ( 1:00 - 12:59)

Timer (0 - 99 minutes 99 seconds)

Microwave Power for Variable Cooking

Repetition Rate;

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

MEDIUM HIGH .................................................. approx. 70% of Full Power

MEDIUM .............................................................approx. 50% of Full Power

MEDIUM LOW .................................................... approx. 30% of Full Power

LOW ................................................................... approx. 10% of Full Power

HELP pad

REHEAT pad

DEFROST pad

SLOW COOK pad

INFORMATION COOK pads

MORE / LESS pads

NUMBER pads

POWER LEVEL pad

CLOCK pad

TIMER pad

STOP/CLEAR pad

INSTANT COOK/START pad Set Weight Approx. 17 kg

GENERAL INFORMATION

WARNING

THIS APPLIANCE MUST BE EARTHED

IMPOTANT

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

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

Page 5

APPEARANCE VIEW

TOUCH CONTROL PANEL

R-350A

INFORMATION COOK PADS Press to select information Cook mode.

NUMBER PADS Press to enter cooking times, clock time or weight or quantity of food.

   

POWER LEVEL PAD Press to select microwave power setting. If not pressed, HIGH is automatically selected.    

STOP/CLEAR PAD Press to clear during programming. Press once to stop operation of oven during cooking; press twice to cancel cooking programme.

COOK KG DEF HELP

INTERACTIVE

DISPLAY

1 .

BEVERAGE



2 .

PIE/PIZZA



3 . 4 .

1 . 2 .



3 .



4 .

 PORRIDGE CASSEROLES

STEAK/CHOPS ROAST MEAT POULTRY

 CHICKEN PIECES

MEAT



VEGETABLES

HELP

REHEAT

DEFROST

SLOW COOK

12345 6789O

POWER LEVEL

STOP/CLEAR

CLOCK

INSTANT COOK/START

TIMER

Indicator

HELP PAD Press to select information guide on/off, child lock, demonstration or language modes. Press to get cooking information.   SLOW COOK PAD Press to cook slowly and for a longer time.  MORE ( ), LESS ( ) PADS Press to increase/decrease the time in one minute increments during cooking or to alter the doneness for the Information Cook mode.   

CLOCK PAD Press to set Clock. 

TIMER PAD Press to set timer.  I

NSTANT COOK/START PAD Press once to cook for 1 minute at HIGH or increase by 1 minute multiples each time this pad is pressed during cooking.  Press to start oven after setting programmes. 

OPERATION SEQUENCE

OFF CONDITION

Closing the door activates all door interlock switches (1st. latch switch and 2nd. interlock relay control switch). IMPORTANT

When the oven door is closed, the monitor switch contacts (COM-NC) must be open. When the microwave oven is plugged in a wall outlet, rated voltage is supplied to the control unit.

Figure O-1 on page 13

1. The display will show , , and .

2. To set any programmes or set the clock, you must first touch the STOP/CLEAR pad.

3. " : " appears in the display. NOTE: When the oven door is opened, the oven lamp comes on at this time.

Page 6

R-350A

TEST PROCEDURES

PROCEDURE

LETTER

M KEY UNIT TEST

If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is making 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 making 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 3D CHECKS.

G 9

G10

G11

G12

COMPONENT TEST

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

TIMER

INSTANT

COOK

START

4 90

SLOW COOK

CLOCK

VEGETABLES

REHEAT

DEFROST

HELP

POWER

LEVEL

STOP

CLEAR

MEAT

DESCRIPTION OF LSI

LSI(IZA814DR):

The I/O signal of the LSI(IZA814DR) is detailed in the following table.

Pin No. Signal I/O Description

1-2 VL2-VL1 IN Power source voltage input terminal.

Standard voltage for LCD.

3-6 AN7-AN4 IN Terminal to change cooking input according to the Model.

By using the A/D converter contained in the LSI, DC voltage in accordance with the Model in operation is applied to set up its cooking constant.

7 AN3 OUT Key strobe signal.

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

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

Door closed "H" level signal (0V). Door opened "L" level signal (-5V) 9-10 P61-P60 OUT Terminal not used. 11 P57 OUT Terminal not used. 12 P56 OUT Oven lamp, fan motor and turntable motor driving signal.

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

square waveform voltage is delivered to

the RY1 driving circuit and RY2 control

circuit.

20.0 msec.

During cooking

H : GND

L : -5V

13 P55 OUT Terminal not used.

Page 7

Pin No. Signal I/O Description

P-HI

H : GND

L : -5V H : GND

L : -5V

P-70

OFF

OFF OFF

24 sec.

8 sec.

14 P54 OUT Signal to sound buzzer (2.0 kHz).

A: key touch sound. B: Completion sound.

0.12 sec.

2.4 sec.

15 P53 OUT Magnetron high-voltage circuit driving signal.

To turn on and off the cook relay (RY2). The signals holds "L" level during microwave cooking and "H" level while not cooking. In other cooking modes (variable cooking) the signal turns to "H" level and "L" level in repetition according to the power level.

(ON and OFF times for other power level.)

16-18 P52-P50 OUT Terminal not used. 19 P47 IN Signal coming from touch key.

When either G12 line on key matrix is touched, a corresponding signal out of AN3 and P20 - P26 will be input into P47. When no key is touched, the signal is held at "H" level.

20 P46 IN Signal similar to P47.

When either G11 line on key matrix is touched, a corresponding signal will be input into P46.

21 P45 IN Signal similar to P47.

When either G10 line on key matrix is touched, a corresponding signal will be input into P45.

22 P44 IN Signal similar to P47.

When either G9 line on key matrix is touched, a corresponding signal will be input

into P44. 23 P43 OUT Terminal not used. 24 INT0 IN Signal synchronized with commercial power source frequency.

This is the basic timing for time processing

of LSI.

20.0 msec.

R-350A

H : GND

L : -5V H : GND

L : -5V

H : GND

L : -5V

25 P41 OUT Terminal not used. 26 P40 IN Connected to VC. 27 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. 28-29 P71-P70 OUT Terminal not used. 30 XIN OUT Internal clock oscillation frequency input setting.

The internal clock frequency is set by inserting the ceramic filter oscillation circuit

with respect to XIN terminal. 31 XOUT OUT Internal clock oscillation frequency control output.

Output to control oscillation input of XOUT. 32 VSS IN Power source voltage: -5.0V.

VC voltage of power source circuit input. 33 P27 OUT Terminal not used. 34 P26 OUT Key strobe signal.

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

while one of G8 line keys on key matrix is touched. 35 P25 OUT Key strobe signal.

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

while one of G7 line keys on key matrix is touched.

Page 8

R-350A

Pin No. Signal I/O Description

36 P24 OUT Key strobe signal.

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

37 P23 OUT Key strobe signal.

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

38 P22 OUT Key strobe signal.

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

39 P21 OUT Key strobe signal.

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

40 P20 OUT Key strobe signal.

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

while one of G2 line keys on key matrix is touched. 41-44 P17-P14 OUT Terminal not used. 45-47 P13-P11 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.)

P13 (45)......................... S16 (25) SEG 13 (59) ....................S20 (12)

P12 (46)......................... S15 (24) SEG 11 (61) ....................S21 (11)

P11 (47)......................... S14 (23) SEG 10 (62) ....................S22 (10)

SEG 24 (48)................... S13 (22) SEG 9 (63).......................S23 ( 9)

SEG 23 (49)................... S12 (21) SEG 8 (64).......................S24 ( 8)

SEG 22 (50)................... S11 (20) SEG 7 (65).......................S25 ( 7)

SEG 21 (51)................... S10 (19) SEG 6 (66).......................S26 ( 6)

SEG 19 (53)..................... S9 (18) SEG 5 (67)........................S 4 ( 5)

SEG 18 (54)..................... S8 (17) SEG 3 (69)........................S 3 ( 4)

SEG 17 (55)..................... S7 (16) SEG 2 (70)........................S 2 ( 3)

SEG 16 (56)..................... S6 (15) SEG 1 (71)........................S 1 ( 2)

SEG 15 (57)..................... S5 (14) SEG 0 (72)........................S 0 ( 1)

SEG 14 (58)................... S19 (13)

48-51 SEG24-SEG21 OUT Segment data signal.

Signal similar to P13. 52 SEG20 OUT Terminal not used. 53-59 SEG19-SEG13 OUT Segment data signal.

Signal similar to P13. 60 SEG12 OUT Terminal not used. 61-67 SEG11-SEG5 OUT Segment data signal.

Signal similar to P13. 68 SEG4 OUT Terminal not used. 69-72 SEG3-SEG0 OUT Segment data signal.

Signal similar to P13. 73/74 VCC/VREF IN Connected to GND. 75 AVSS IN Connected to VC. 76 COM3 OUT Common data signal: COM3.

Connected to LCD signal C3 (Pin No. 29) 77 COM2 OUT Common data signal: COM2.

Connected to LCD signal C2 (Pin No. 28) 78 COM1 OUT Common data signal: COM1.

Connected to LCD signal C1 (Pin No. 27) 79 COM0 OUT Common data signal: COM0.

Connected to LCD signal C0 (Pin No. 26) 80 VL3 IN Power source voltage input terminal.

Standard voltage for LCD.

Page 9

MICROWAVE MEASUREMENT

R-350A

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

REQUIREMENT

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

PREPARATION FOR TESTING:

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

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

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

2. Place the oven tray into the oven cavity.

3. Place the load of 275 ± 15ml of water initially at 20 ± 5˚C in the centre of the oven tray. The water container should be a low form of 600 ml beaker with inside diameter of approx. 8.5cm and made of an electrically non-conductive material such as glass or plastic. The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any leakage is measured accurately.

4. Close the door and turn the oven ON with the timer set for several minutes. If the water begins to boil before the survey is completed, replace it with 275ml of cool water.

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

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

mW cm

SHARP

Microwave leakage measurement at 5 cm distance

Page 10

R-350A

SCHEMATIC

NOTE: CONDITION OF OVEN

1.DOOR CLOSED

2.CLOCK APPEARS ON DISPLAY

NOISE FILTER

FUSE

EARTH

M10A

0.068µ/AC250V

LINE CROSS CAPACITOR

BRN

220V 50Hz

G-Y

BLU

NOTE: " " indicates components with potentials above 250V.

THERMAL CUT-OUT 125˚C (OVEN)

LINE BYPASS

CAPACITOR

0.0022µ/AC250V

NOISE SUPPRESSION COIL

LINE BYPASS

CAPACITOR

0.0022µ/AC250V

THERMAL CUT-OUT 95˚C (MG)

COM.

2ND  INTERLOCK RELAY

2ND INTERLOCK RELAY CONTROL SWITCH

1ST. LATCH SWITCH

N.O.

RY-2

CONTROL

UNIT

RY-1

OVEN LAMP

FAN MOTOR

TTM

MONITOR

RESISTOR

0.8/20W

MONITOR SWITCH

TURNTABLE MOTOR

POWER TRANSFORMER

H.V. FUSE

0.75 A

CAPACITOR

1.07µ

AC2200V

MAGNETRON

H.V. RECTIFIER

SCHEMATIC

NOTE: CONDITION OF OVEN

1. DOOR CLOSED

2. COOKING TIME PROGRAMMED

3. START KEY TOUCHED

NOISE FILTER

FUSE

BRN

220V 50Hz

G-Y

BLU

EARTH

M10A

0.068µ/AC250V

LINE CROSS CAPACITOR

NOISE SUPPRESSION COIL

Figure O-1. Oven Schematic-OFF Condition

THERMAL CUT-OUT 125˚C (OVEN)

2ND 

LINE BYPASS

CAPACITOR

0.0022µ/AC250V

LINE BYPASS

CAPACITOR

0.0022µ/AC250V

THERMAL CUT-OUT 95˚C (MG)

COM.

INTERLOCK RELAY

2ND INTERLOCK RELAY CONTROL SWITCH

1ST. LATCH SWITCH

N.O.

RY-1

RY-2

CONTROL

UNIT

OVEN LAMP

TTM

FAN MOTOR

TURNTABLE MOTOR

MONITOR

RESISTOR

0.8/20W

MONITOR SWITCH

POWER TRANSFORMER

H.V. FUSE

0.75 A

CAPACITOR

1.07µ

AC2200V

MAGNETRON

H.V. RECTIFIER

Figure O-2. Oven Schematic-Cooking Condition

Page 11

R-350A

C 3 C 2

HELP

LIQUID CRYSTAL DISPLAY

COOK SENSOR LBS KG DEF



29 28 27 C 1 26 C 0 25 S16 24 S15 23 S14 22 S13 21 S12 20 S11 19 S10 18 S 9 17 S 8 16 S 7 15 S 6 14 S 5 13 S19 12 S20 11 S21

10 S22 9 S23 8 S24 7 S25 6 S26 5S 4 4S 3 3S 2 2S 1 1S 0

SEG7 SEG6 SEG5 SEG4 SEG3 SEG2 SEG1 SEG0 VCC VREF AVSS COM3 COM2 COM1 COM0

SEG8 64

65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80

1VL2

SEG9

SEG10

SEG1161SEG1260SEG1359SEG1458SEG1557SEG1656SEG1755SEG1854SEG1953SEG2052SEG2151SEG2250SEG2349SEG24

IZA814DR

M38223M4

2VL1

3AN7

4AN6

5AN5

6AN4

7AN3

8AN2

9P61

10P60

11P57

12P56

13P55

14P54

47 P11

15P53

16P52

17P51

18P50

R67 15k

HELP

R64 15k

R63 15k

P17

P14

42 P16

43 P15

45 P13

46 P12

19P47

P20

P21

P22

P23

P24

P25

P26

P27 VSS

XOUT XIN P70 P71

RESET P40 P41 VL3

R41 680F

R40 1MF

CF1 4.19MHz

/50v 15P C40

32 31 30 29 28 27 26 25

20P46

21P45

22P44

23P43

INT0

R80 4.7k

15P/50v C41

R62 15k

R61 15k

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

R60 15k

G 8

C60 330pF/50v C61 330pF/50v

C62 330pF/50v

C63 330pF/50v R72 100k R73 100k R74 100k R75 100k

54321

G 9

LEVEL

POWER

09876

G10

STOP

MEAT

CLEAR

REHEATTIMER

DEFROST

VEGETABLES

SLOW

COOK

CLOCK

COOK

INSTANT

G12

G11

START

KEY UNIT

C11 0.1µ/50v

(J17) (J15) (J13) (J11)



R14

Q10

1k R10

 R13

/50v

0.1µ C12

4.7k R11

2SA1037AK

C1 47µ/16v

–

(J16) 4.7k (J14) 4.7k (J12) 4.7k (J10) 4.7k

10k 10k 10k

 R12

UDZ4.3B ZD10

C14

/50v

0.1µ C13

R15 4.7k

Q11

KRA101S



C30

R30 4.7k

Q40

KRA101S

R31 15k

C20 0.1µ/50v



Q20

KRA101S

Q22

KRA105S

D22

MA152WA

: IF NOT SPECIFIED 1SS355

: IF NOT SPECIFIED 0.01µF / 25v

: IF NOT SPECIFIED 1/10W ± 5%

NOTE

R71 15k

R70 15k

R69 15k

R68 15k

Figure S-3. CPU Unit Circuit

C 2

C 1

GND

C 3

C 4

INT

C 5

BUZZER

C 6

RY1

C 7

RY2

C 8

C 9

DOOR

SWITCH

Page 12

R-350A

PARTS LIST

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

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

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

ELECTRIC PARTS

1- 1 QSW-MA110WRE0 1- 2 QSW-MA111WRE0 Monitor switch 1 AK 1- 3 FPWBFA310WRK0 Noise filter 1 AT 1- 4 RTHM-A078WRE0 Thermal cut-out 125˚C. 1 AL 1- 5 QACC-A067WRE0 Power supply cord 1 AT 1- 6 FH-DZA075WRK0 High voltage rectifier assembly 1 AR

1- 7 RC-QZA215WRE0 High voltage capacitor 1 AY

1- 7 RC-QZA182WRE0 High voltage capacitor (Interchangeable) 1 AY

1- 8 RV-MZA197WRE0 Magnetron 1 BN

∆

1- 8 RV-MZA222WRE0 Magnetron (Interchangeable) 1 BN

∆

1- 9 RMOTEA340WRE0 Fan motor 1 AX 1-10 QSOCLA022WRE0 Oven lamp socket 1 AG 1-11 RLMPTA069WRE0 Oven lamp 1 AK 1-12 RMOTDA169WRE0 Turntable motor 1 AW 1-13 RTHM-A079WRE0 Thermal cut-out 95 deg. 1 AL 1-14 RTRN-A530WRE0 Power transformer 1 BR

1-15 QFS-CQ001YBE0 Fuse M10A 1 AE 1-16 RR-WZA022WRE0 Monitor resistor 0.8Ω 20w 1 AK 1-17 QFS-IA002WRE0 High voltage fuse 0.75 A 1 AQ

1st. latch switch, 2nd. interlock relay control switch

2AK

CABINET PARTS

2- 1 GCABUA608WRP0 Outer case cabinet 1 BB 2- 2 GDAI-A261WRW0 Bottom plate left 1 AP 2- 3 GDAI-A286WRW0 Bottom plate right 1 AN 2- 4 GLEGPA019WRE0 Foot 2 AD 2- 5 GLEGPA067WRF0 Foot 1 AE

CONTROL PANEL PARTS

3- 1 CPWBFA725WRK0 Power unit 1 BC 3- 1A QCNCMA394DRE0 2-pin connector(CN-A) 1 AD 3- 1B QCNCMA275DRE0 2-pin connector(CN-B) 1 AB 3- 1C QCNCMA422DRE0 9-pin connector(CN-C) 1 AF 3- 1D FW-VZA196DRE0 Lead wire harness (WH-1) 1 AD 3- 1E LHLD-A171WRF0 LED holder 1 AE C1 RC-KZA087DRE0 Capacitor 0.1µF 50V 1 AB C2 VCEAB31EW108M Capacitor 1000µF 25V 1 AE C5 VCEAB31VW106M Capacitor 10µF 35V 1 AA D1-4 VHD11ES1///-1 Diode (11ES1) 4 AB D5-8 VHD1SS270A/-1 Diode (1SS270ATA) 4 AA LD1-5 VHPSLZ381A9-3 Light emitting diode 5 AC Q2 VS2SA933S//-3 Transistor (2SA933) 1 AB Q3 VSKRC243M//-3 Transistor (KRC243M) 1 AB R3 VRD-B12HF751J Resistor 750 ohm 1/2W 1 AA R4 VRD-B12EF270J Resistor 27 ohm 1/4W 1 AA R5 VRD-B12EF472J Resistor 4.7k ohm 1/4W 1 AA R6 VRD-B12EF332J Resistor 3.3k ohm 1/4W 1 AA Jumper 6 VRD-B12EF151J Resistor 150 ohm 1/4W 1 AA RY1 RRLY-A021DRE0 Relay (OJSH112LM-UL) 1 AH RY2 RRLY-A094DRE0 Relay (OMIF-S-112LM) 1 AN SP1 RALM-A014DRE0 Buzzer (PKM22EPT-THAI) 1 AG T1 RTRNPA108DRE0 Transformer 1 AR VRS1 RH-VZA032DRE0 Varistor (10G471K) 1 AE 3- 2 DPWBFB703WRK0 CPU unit 1 BE 3- 3 FPNLCB312WRK0 Control panel frame with key unit 1 BB 3- 3-1 FUNTKA823WRE0 Key unit 1 AX 3- 4 PSHEPA588WRE0 LED sheet 1 AE 3- 5 JBTN-B069WRF0 Open button 1 AF 3- 6 MSPRCA050WRE0 Open button spring 1 AB 3- 7 XEPSD30P08XS0 Screw ; 3mm x 8mm 4 AA

OVEN PARTS

4- 1 LANGQA456WRP0 Noise filter angle 1 AG 4- 2 PCUSGA312WRP0 Cushion 1 AB 4- 3 PHOK-A095WRF0 Latch hook 1 AN

∆

4- 4 LBNDKA099WRW0 Capacitor holder 1 AD 4- 5 NFANJA029WRE0 Fan blade 1 AL 4- 6 PDUC-A652WRP0 Fan duct 1 AU 4- 7 FOVN-A375WRT0 Oven cavity 1 BH

∆

4- 8 LANGFA175WRP0 Chassis support 1 AX

Page 13

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

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

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

4- 9 LANGQA452WRP0 Partition angle 1 AK 4-10 LANGQA454WRP0 MG thermo angle 1 AH 4-11 MLEVPA194WRF0 Switch lever 1 AG 4-12 NCPL-A045WRF0 Coupling 1 AH 4-13 PPACGA084WRF0 TTM packing 1 AF 4-14 PCOVPA275WRE0 Waveguide cover 1 AR 4-15 PCUSGA339WRP0 Cushion 2 AG 4-16 PCUSUA212WRP0 Cushion 1 AB 4-17 PCUSUA235WRP0 Cushion 1 AF 4-18 PCUSUA376WRP0 Cushion 1 AG 4-19 LSTPPA162WRF0 Door stopper 1 AE

DOOR PARTS

5 CDORFA773WRK0 Door assembly 1 BL

∆ ∆

5- 1 FDORFA303WRT0 Door panel 1 BA 5- 2 PSHEPA382WRE0 Sealer film 1 AH 5- 3 GWAKPA505WRR0 Door frame 1 AY

∆

5- 4 HPNL-A673WRR0 Door screen 1 AT 5- 5 GCOVHA370WRF0 Choke cover 1 AM

∆

5- 6 LSTPPA139WRF0 Latch head 1 AF 5- 7 MSPRTA084WRE0 Latch spring 1 AB 5- 8 XCPSD40P08000 Screw : 4mm x 8mm 1 AA 5- 9 XCPSD40P08WN2 Screw : 4mm x 8mm 1 AC

R-350A

MISCELLANEOUS

6- 1 FROLPA079WRK0 Turntable support 1 AQ 6- 2 NTNT-A084WRE0 Turntable tray 1 AR 6- 3 FW-VZB602WRE0 Main wire harness 1 AV 6- 4 PZET-A012WRE0 Terminal insulator 1 AB 6- 5 FW-VZB045WRE0 Switch harness 1 AG 6- 6 LHLDWA011WRE0 Purse lock M 1 AB 6- 7 TCAUHA214WRR0 Caution label 1 AC 6- 8 TINSEA714WRR0 Operation manual 1 AK 6- 9 TSPCNC497WRR0 Rating label 1 AD 6-10 TCADCA640WRR0 Cook book for microwave cooking 1 AX 6-11 TCADCA641WRR0 Cook book in Russian 1 AN

SCREWS,NUTS AND WASHERS

7- 1 XFPSD40P08K00 Screw : 4mm x 8mm 10 AA 7- 2 XFPSD30P06000 Screw : 3mm x 6mm 1 AA 7- 3 XHTSD40P08RV0 Screw : 4mm x 8mm 6 AA 7- 4 XOTSE40P08000 Screw : 4mm x 8mm 1 AA 7- 5 XOTSD40P12RV0 Screw : 4mm x 12mm 13 AA 7- 6 XOTSD40P12000 Screw : 4mm x 12mm 8 AA

HOW TO ORDER REPLACEMENT PARTS

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

1. MODEL NUMBER 2. REF. NO.

3. PART NO. 4. DESCRIPTION

INFORMATION FOR PARTS CHANGE

The outer case cabinet will be changed as follows, and new part will be used for products from serial number 9710xxxxx.

Interchangeability

A. OLD

REF.NO.

2- 1 Outer case cabintet GCABUA608WRP0 1 GCABUA649WRP0 1 A Oct/ '97

NEW B. OLD

↔

DESCRIPTION OLD No.

NEW C. OLD

→

REPLACEMENT PART NO. nterchange- EFFECTIVE

Q'ty

NEW No.

NEW D. OLD NEW

←

Q'ty

ability FROM CODE

Page 14

R-350A

OVEN AND CABINET PARTS

4-17

4-18

1-11

4-9

1-10

1-4

7-2

2-1

7-5

7-3

4-10

1-13

6-7

4-16

7-1

1-8

7-5

7-4

6-9

4-7

4-12

4-14

2-2

7-3

7-6

2-4

2-5

7-6

1-12

7-6

6-5

4-13

1-16

7-1

7-3

7-5

4-11

7-1

7-5

2-4

7-5

4-15

7-5

4-2

4-3

1-14

2-3

7-6

1-1

7-1

4-15

7-6

1-2

6-1

1-9

7-6

1-5

7-3

7-1

1-6

4-4

7-1

1-5

1-17

1-7

4-5

4-6

4-1

4-8

6-2

7-6

1-15

1-3

7-3

7-1

Page 15

R-350A

CONTROL PANEL PARTS

3 - 3

3-3-1

3 - 5

3 - 4

3 - 2

3-1E

3 - 7

3 - 1

3 - 7

4-19

5-4

3 - 6

5-3

DOOR PARTS

5-5

5-9

5-2

5-8

5-1

5-7

5-6

6-3

Actual wire harness may be different from illustration.

MISCELLANEOUS

6-4

Page 16

R-350A

PACKING AND ACCESSORIES

DOOR PROTECTION SHEET SPADPA204WRE0

PRINTING MATTER

6- 2 TURNTABLE TRAY

6- 1 TURNTABLE SUPPORT

TOP PAD ASSEMBLY FPADBA311WRK0

PLASTIC BAG SSAKHA034WRE0

BOTTOM PAD ASSEMBLY FPADBA351WRK0

INTO THE OVEN CAVITY

TRAY PACK SPADFA397WRE0

Not replaceable items.

PACKING CASE SPAKCC931WRE0

SPAKCC940WRE0

'97SHARP CORP. (8K0.120E) Printed in Japan

Page 17

COOK KG DEF HELP

INSTANT ACTION

To adjust quantity - touch pad again

BEVERAGE REHEAT PIE

REHEAT PIZZA

FROZEN VEGETABLES

RICE

1.  SREAK / CHOPS

2.  ROAST MEAT

3.  POUL TRY

4.  CHICKEN PIECES

1 2 3 4 5 6 7 8

POWER LEVEL

STOP/CLEAR

FRESH VEGETABLES

JACKET POTATO

REHEAT PORRIDGE

INSTANT COOK /START

SER VICE MANU AL

MICROWAVE OVEN

MODEL R-340A

DEFROST

 

9



TIMER/CLOCK

R-340A

S7717R340APHR

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

TABLE OF CONTENTS

Page

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

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

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

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

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

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

FUNCTION OF IMPORTANT COMPONENTS ................................................................................................ 5

SERVICING ...................................................................................................................................................... 6

TEST PROCEDURE ........................................................................................................................................ 8

TOUCH CONTROL PANEL ............................................................................................................................ 14

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE........................................................... 18

MICROWAVE MEASUREMENT .................................................................................................................... 24

WIRING DIAGRAM ........................................................................................................................................ 25

PICTORIAL DIAGRAM................................................................................................................................... 26

POWER UNIT CIRCUIT.................................................................................................................................. 27

CPU UNIT CIRCUIT........................................................................................................................................ 28

PRINTED WIRING BOARD ............................................................................................................................ 29

PARTS LIST.................................................................................................................................................... 30

SHARP CORPORATION

Page 18

R-340A

Page 19

SERVICE MANU AL

MICROWAVE OVEN

R-340A

PRODUCT SPECIFICATIONS

R-340A

GENERAL IMPORTANT INFORMATION

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

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

CAUTION

MICROWAVE RADIATION

DO NOT BECOME EXPOSED TO RADIATION FROM THE MICROWAVE GENERATOR OR OTHER PARTS CONDUCTING MICROWAVE ENERGY.

APPEARANCE VIEW

OPERATING SEQUENCE

FUNCTION OF IMPORTANT COMPONENTS

SERVICING AND TROUBLESHOOTING CHART

TEST PROCEDURE

TOUCH CONTROL PANEL ASSEMBLY

WARNING

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

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

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

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

SHARP CORPORATION

COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE

MICROWAVE MEASUREMENT

WIRING DIAGRAM

PARTS LIST

OSAKA, JAPAN

Page 20

R-340A

PRODUCT SPECIFICATIONS

ITEM DESCRIPTION

Power Requirements 220 Volts

50 Hertz

Single phase, 3 wire earthed Power Consumption 1.5kW Power Output 1000 watts nominal of RF microwave energy (IEC 705)

Operating fequency 2450 MHz Case Dimensions Width 520 mm

Height 302 mm including foot

Depth 403 mm Cooking Cavity Dimensions Width 348 mm

Height 212 mm

Depth 379 mm Turntable diameter 335mm Control Complement Touch Control System

Clock ( 1:00 - 12:59)

Timer (0 - 99 minutes 99 seconds)

Microwave Power for Variable Cooking

Repetition Rate;

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

MEDIUM HIGH .................................................. approx. 70% of Full Power

MEDIUM .............................................................approx. 50% of Full Power

MEDIUM LOW .................................................... approx. 30% of Full Power

LOW ................................................................... approx. 10% of Full Power

INSTANT ACTION pads

DEFROST pad

NUMBER pads

POWER LEVEL pad

TIMER / CLOCK pad

STOP/CLEAR pad

INSTANT COOK/START pad Set Weight Approx. 17 kg

GENERAL INFORMATION

WARNING

THIS APPLIANCE MUST BE EARTHED

IMPOTANT

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

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

Page 21

1. Ventilation openings

INSTANT ACTION

To adjust quantity - touch pad again

BEVERAGE REHEAT PIE

REHEAT PORRIDGE

REHEAT PIZZA

FRESH VEGETABLES

FROZEN VEGETABLES

JACKET POTATO

RICE

DEFROST

POWER LEVEL

TIMER/CLOCK

1.  SREAK / CHOPS

2.  ROAST MEAT

3.  POULTRY

4.  CHICKEN PIECES

INSTANT COOK /START

STOP/CLEAR

123



456



9



NUMBER PADS Press to enter cooking times, clock time or weight of food.  

POWER LEVEL PAD Press to select microwave power setting. If not pressed, 100% is automatically selected. Press to alter the cooking result for automatic operations.    

STOP/CLEAR PAD Press to clear during programming. Press once to stop operation of oven during cooking; press twice to cancel cooking programme.

DEFROST PAD Press to select the Defrost menu.   

TIMER / CLOCK PAD Press to set Clock, timer, child lock or demonstration mode.  I

NSTANT COOK/START PAD Press to start oven after setting programmes. Press once to cook for 1 minute on HIGH or increase in 1 minute increments each time this pad is pressed during cooking.  

Indicator

NSTANT ACTION PADS Press to cook or reheat 8 popular  manus. 

COOK KG DEF HELP

2. Oven lamp

3. Door hinges

4. Door safety latches

5. See through door

6. Door seals and sealing surfaces

7. Coupling

8. Door open button

9. Touch control panel

10.Digital readout

11.Wave guide cover

12.Power supply cord

13.Rating label

14.Turntable tray

15.Turntable support

R-340A

APPEARANCE VIEW

TOUCH CONTROL PANEL

Page 22

R-340A

HIGH 

32 sec. ON

MEDIUM HIGH Approx. 70%

24 sec. ON 8 sec. OFF

14 sec. OFF

20 sec. OFF

26 sec. OFF

MEDIUM Approx. 50%

18 sec. ON

MEDIUM LOW Approx. 30%

12 sec. ON

LOW Approx. 10%

6 sec. ON

OPERATION SEQUENCE

OFF CONDITION

Closing the door activates all door interlock switches (1st. latch switch and 2nd. interlock relay control switch).

IMPORTANT When the oven door is closed, the monitor switch contacts (COM-NC) must be open. When the microwave oven is plugged in a wall outlet, rated voltage is supplied to the control unit.

Figure O-1 on page 25

1. The display will show flashing "88:88".

2. To set any programmes or set the clock, you must first touch the STOP/CLEAR pad.

3. " : " appears in the display.

NOTE: When the oven door is opened, the oven lamp

comes on at this time.

MICROWAVE COOKING CONDITION

HIGH COOKING

Enter a desired cooking time with the touching NUMBER pad and start the oven with touching START pad.

Function sequence

Figure O-2 on page 25

CONNECTED COMPONENTS RELAY Oven lamp, Fan motor, Turntable motor RY1 Power transformer RY2

1. Rated voltage. is supplied to the primary winding of the power transformer. The voltage is converted to about

3.3 volts A.C. output on the filament winding and high voltage of approximately 2000 volts A.C. on the secondary winding.

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

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

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

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

opened after the cooking cycle has been interrupted, because the relay RY1 stays closed. Shown in the display is the remaining time.

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

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

cycle of a cooking program, the 1st. latch switch and 2nd. interlock relay control switch must open their contacts first. After that the contacts (COM-NC) of the monitor switch can be closed.

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

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

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

1st. latch switch and 2nd. interlock relay remain closed. The fuse M10A will blow, because the monitor switch is closed and a short circuit is caused.

MEDIUM HIGH, MEDIUM, MEDIUM LOW, LOW COOKING

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

SETTING;

NOTE: The ON/OFF time ratio does not exactly correspond

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

CONDITION

DURING DOOR OPEN SWITCH CONTACT COOKING (NO COOKING)

1st. latch switch COM-NO Closed Open 2nd. interlock relay

control switch COM-NO Closed Open Monitor switch COM-NC Open Closed

The circuits to the power transformer, fan motor and turntable motor are cut off when the 1st. latch switch and 2nd. interlock relay control switch are made open. The oven lamp remains on even if the oven door is

Page 23

FUNCTION OF IMPORTANT COMPONENTS

R-340A

DOOR OPEN MECHANISM

The door is opened by pushing the open button on the control panel, refer to the Figure D-1. When the open button is pushed, the open button pushes up the switch lever, and then the switch lever pushes up the the latch head. The latch heads are moved upward and released from latch hook. Now the door will open.

Door

Latch Hook 

Latch Heads

Switch Lever

2nd. Interlock Relay Control Switch

Monitor  Switch

1st. Latch  Switch

Figure D-1. Door Open Mechanism

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

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

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

MONITOR SWITCH

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

2. When the oven door is opened, the contacts (COMNC) must be closed.

3. If the oven door is opened and the contacts (COM-NO) of the 1st. latch switch and 2nd. interlock relay fail to open, the fuse M10A blows simultaneously with closing the contacts (COM-NC) of the monitor switch.

CAUTION: BEFORE REPLACING A BLOWN FUSE

M10A TEST THE 1ST. LATCH SWITCH, 2ND. INTERLOCK RELAY, 2ND. INTERLOCK RELAY CONTROL SWITCH, MONITOR SWITCH AND MONITOR RESISTOR FOR PROPER OPERATION.

HIGH VOLTAGE FUSE 0.75A

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

OVEN THERMAL CUT-OUT

The thermal cut-out, located on the top of the oven cavity, is designed to prevent damage to the oven by fire. If the foods load is overcooked, by either error in cook time or defect in the control unit, the thermal cut-out will open. Under normal operation, the oven thermal cut-out remains closed. However, when abnormally high temperatures are reached within the oven cavity, the oven thermal cut-out will open at 125˚C, causing the oven to shut down. The defective thermal cut-out must be replaced with new one.

MAGNETRON THERMAL CUT-OUT

The thermal cut-out located near the magnetron is designed to prevent damage to the magnetron if an over heated condition develops in the tube due to cooling fan failure, obstructed air guide, dirty or blocked air intake, etc. Under normal operation, the thermal cut-out remains closed. However, when abnormally high temperatures are reached within the magnetron, the thermal cut-out will open at 95˚C causing the oven to shut down, when the magnetron has cooled to 75˚C, the thermal cut-out closes and cook cycle will resume.

TURNTABLE MOTOR

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

FAN MOTOR

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

NOISE FILTER

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

MONITOR RESISTOR R 0.8Ω 20W

The monitor resistor prevents the fuse M10A bursting when the fuse M10A blows due to the operation of the monitor switch.

FUSE M10A

1. The fuse M10A blows when the contacts (COM-NO) of the 1st. latch switch and 2nd. interlock relay remain closed with the oven door open and when the monitor switch closes.

2. If the wire harness or electrical components are shortcircuited, this fuse M10A blows to prevent an electric shock or fire hazard.

Page 24

R-340A

SERVICING

WARNING TO SERVICE PERSONNEL

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

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.

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

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 M10A in the 1st. latch switch - 2nd. interlock relay - monitor switch

- monitor resistor circuit, check the 1st. latch switch, 2nd. interlock relay control switch, 2nd. interlock relay, monitor switch and monitor resistor before replacing the fuse M10A.

Page 25

CONDITION

OFF CONDITION

TEST PROCEDURE

POSSIBLE CAUSE

AND

DEFECTIVE PARTS

PROBLEM

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

FUSE M10A blows when power supply cord is plugged into wall outlet.

Display does not show anything when power supply cord is plugged into wall outlet.

ABCDEEEGFFH HI LMNO

MAGNETRON

POWER TRANSFORMER

H.V. RECTIFIER ASSEMBLY

HIGH VOLTAGE CAPACITOR

1ST. LATCH SWITCH

MONITOR SWITCH

MONITOR RESISTOR

THERMAL CUT-OUT 95˚C

FAN MOTOR

TURNTABLE MOTOR

FUSE M10A

TOUCH CONTROL PANEL

KEY UNIT

2ND. INTERLOCK RELAY CONTROL SWITCH

THERMAL CUT-OUT 125˚C

RELAY (RY-1, RY-2)

CK = Check / RE = Replace

RE CK CK RE CK CK CK CK CK

FOIL PATTERN ON P.W.B.

POWER SUPPLY CORD

SHORTED WIRE HARNESS

OPENED WIRE HARNESS

OVEN LAMP OR SOCKET

WALL OUTLET

MISADJUSTMENT SWITCH

HOME FUSE OR BREAKER

R-340A

KED VENTILATION

BLOCKED COOLING FAN

BLOC

NOISE FILTER

HIGH VOLTAGE FUSE

ON CONDITION

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

Oven lamp does not light at door opened. (Display appears.)

Oven does not start when the START pad is touched. (Display appears)

Oven lamp does not light (Display appears.)

Fan motor does not operate. (Display appears.)

Turntable motor assembly does not operate. (Display appears.)

Oven or any electrical parts does not stop when cooking time is 0 or STOP/CLEAR pad is touched.

Oven seems to be operating but little or no heat is produced in oven load. (Microwave power level is set at HIGH)

Oven does not seems to be operating properly when oven is set for variable cooking power. (Oven operates properly at HIGH and when the STOP/CLEAR pad is touched the oven stops.)

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

Page 26

R-340A

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

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

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

MICROWAVE OUTPUT POWER (1 Litre water load)

The following test procedure should be carried out with the microwave oven in a fully assembled condition (outer case fitted). Microwave output power from the magnetron can be measured by way of IEC 705, i.e. it can be measured by using water load how much it can be absorbed by the water load. To measure the microwave output power in the microwave oven, the relation of calorie and watt is used. When P(W) heating works for t(second), approximately P x t/4.187 calorie is generated. On the other hand, if the temperature of the water with V(ml) rises ∆T (°C) during this microwave heating period, the calorie of the water is V x ∆T.

COMPONENT TEST

The formula is as follows;

P x t / 4.187 = V x ∆ T P (W) = 4.187 x V x ∆T / t

Our condition for water load is as follows:

Room temperature ......... around 20°C Power supply Voltage........... Rated voltage

Water load........1000 g Initial temperature ........ 10±2°C Heating time.......42 sec.

P = 100 x ∆T

Measuring condition:

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

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

3. Temperature of the water The initial temperature of the water is (10±2)°C.

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

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

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

7. The water load must be (1000±5) g.

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

NOTE: The operation time of the microwave oven is “t + 2” sec. 2 sec. is magnetron filament heat-up time.

Measuring method:

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

2. Add the 1 litre water to the vessel.

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

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

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

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

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

Page 27

TEST PROCEDURES

R-340A

PROCEDURE

LETTER

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

Temperature after (42 + 2) = 44 sec................................................................. T2 = 21°C

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

Measured output power

The equation is “P = 100 x ∆T”............................................P = 100 x 10°C = 1000 Watts

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

CAUTION: 1°C CORRESPONDS TO 100 WATTS REPEAT MEASUREMENT IF THE POWER IS

INSUFFICIENT.

1000g

T1˚C

B POWER TRANSFORMER TEST

1000g

COMPONENT TEST

1000g

T2˚C

Heat up for44 sec.

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

winding of the power 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 power transformer. Disconnect the filament and

secondary winding connections from the rest of the HV circuitry. Using an ohmmeter, set on a low range, it is possible to check the continuity of all three windings. The following readings should be obtained:

a. Primary winding ................... approx. 1.2 Ω

b. Secondary winding............... approx. 86 Ω

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

If the reading obtained are not stated as above, then the power transformer is probably faulty and should be replaced.

CARRY OUT 4R CHECKS.

C HIGH VOLTAGE RECTIFIER ASSEMBLY 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.

HIGH VOLTAGE RECTIFIER

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.

Page 28

R-340A

TEST PROCEDURES

PROCEDURE

LETTER

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.

CARRY OUT

4R CHECKS.

E SWITCH TEST

CARRY OUT

3D CHECKS.

Isolate the switch to be tested and using an ohmmeter check between the terminals as described in the following table.

Table: Terminal Connection of Switch

Plunger Operation COM to NO COM to NC COM; Common terminal

Released Open circuit Short circuit NO; Normally open terminal Depressed Short circuit Open circuit NC; Normally close terminal

COMPONENT TEST

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

F THERMAL CUT-OUT TEST

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

continuity test across the two terminals as described in the table below. CARRY OUT 4R CHECKS.

Temperature of "ON" condition Temperature of "OFF" condition Indication ofohmmeter

Parts Name (closed circuit) (˚C) (open circuit) (˚C) (When room temperature

Thermal cut-out 125˚C This is not resetable type. Above 125˚C Closed circuit. Thermal cut-out 95˚C Below 75˚C Above 95˚C Closed circuit.

If incorrect readings are obtained, replace the thermal cut-out. An open circuit thermal cut-out 95˚C (MG) indicates that the magnetron has overheated, this may be

due to resistricted ventilation, cooling fan failure or a fault condition within the magnetron or HV circuit. An open circuit thermal cut-out 125˚C (OVEN) indicates that the foods in the oven may catch fire,

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

Table: Thermal cut-out Test

is approx. 20˚C)

G MONITOR RESISTOR TEST

CARRY OUT 3D CHECKS. Disconnect the leads from the monitor resist. Using an ohmmeter and set on a low range. Check

between the terminals of the monitor resistor.

The resistance of monitor resistor is approx. 0.8 ohms.

If incorrect readings are obtained, replace the monitor resistor. CARRY OUT 4R CHECKS.

Page 29

TEST PROCEDURES

WHT

RED

R-340A

PROCEDURE

LETTER

H MOTOR WINDING TEST

CARRY OUT 3D CHECKS. Disconnect the leads from the motor.

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

If incorrect readings are obtained, replace the motor. CARRY OUT 4R CHECKS.

I BLOWN FUSE F M10A

CARRY OUT 3D CHECKS.

1. If the fuse M10A is blown, there could be shorts or ground in electrical parts or wire harness. Check them and replace the defective parts or repair the wire harness.

2. If the fuse M10A is blown when the door is opened, check the 1st. latch switch, 2nd. interlock relay, 2nd. interlock relay control switch, monitor switch and monitor resistor. If the fuse M10A is blown by incorrect door switching replace the defective switch(s) and the fuse M10A.

COMPONENT TEST

Table: Resistance of Motor

Motors Resistance Fan motor Approximately 390 Ω Turntable motor Approximately 16.08 kΩ

CARRY OUT 4R CHECKS. CAUTION: ONLY REPLACE FUSE M8A WITH THE CORRECT VALUE REPLACEMENT.

J NOISE FILTER TEST

CARRY OUT 3D CHECKS. Disconnect the leads from the terminals of the noise filter. Using an ohmmeter, check between the terminals as described in the following table.

MEASURING POINT Between N and L Open circuit

Between terminal N and WHITE Short circuit Between terminal L and RED Short circuit

If incorrect readings are obtained, replace the noise filter unit. CARRY OUT 4R CHECKS.

K HIGH VOLTAGE FUSE TEST

CARRY OUT 3D CHECKS. If the high voltage fuse is blown, there could be a short in the high voltage rectifier or the magnetron.

Check them and replace the defective parts and the high voltage fuse.

INDICATION OF OHMMETER

L (min) Cx ± 20% Cy ± 20% 600µH 0.068µF 0.0022µF

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

MENT.

Page 30

R-340A

TEST PROCEDURES

PROCEDURE

LETTER

L TOUCH CONTROL PANEL ASSEMBLY TEST

The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and ohmmeter. In this service manual, the touch control panel assembly is divided into two units, Control Unit and Key Unit, and also the Control Unit is divided into two units, CPU Unit and Power Unit, and troubleshooting by unit 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 Unit. The following symptoms indicate a defective control unit. Before replacing the control unit, perform the Key unit test (Procedure K) to determine if control unit is faulty.

2-1 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. 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.

COMPONENT TEST

M KEY UNIT TEST

G 9

G10

G11

G12

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

INSTANT

COOK

START

POWER

LEVEL

4 90

DEFROST

TIMER

CLOCK

JACKET

POTATO

REHEAT

PORRIDGE

FRESH

VEGETABLES

RICE

REHEAT

PIE

FROZEN

VEGETABLES

BEVERAGE

REHEAT

PIZZA STOP

CLEAR

Page 31

TEST PROCEDURES

RY2

HVT

(COM)

CN - A

(J1)

R-340A

PROCEDURE

LETTER

N RELAY TEST

Remove the outer case and check voltage between Pin No 3 of the 2-pin connector (A) and the common terminal of the relay RY2 on the power unit with an A.C. voltmeter. The meter should indicate 220 volts, if not check oven circuit.

RY1 and RY2 Relay Test These relays are operated by D.C. voltage. Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation or convection cooking 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. 13.1V D.C. Oven lamp / Turntable motor / Cooling fan motor RY2 APPROX. 11.7V D.C. Power transformer

CARRY OUT 4R CHECKS.

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

(PWB) IS OPEN

COMPONENT TEST

control unit is defective.

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

1 The rated AC voltage is not present between Check supply voltage and oven power cord.

Pin No. 3 of the 2-pin connector (A) and the common terminal of the relay RY2.

2 The rated AC voltage is present to primary Low voltage transformer or secondary circuit defective.

side of low voltage transformer. Check and repair.

3 Only pattern at "a" is broken. *Insert jumper wire J1 and solder. 4 Pattern at "a" and "b" are broken. *Insert the coil RCILF2003YAZZ between "c" and "d".

NOTE: *At the time of making these repairs,

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

CARRY OUT 4R CHECKS.

Page 32

R-340A

TOUCH CONTROL PANEL ASSEMBLY

OUTLINE OF TOUCH CONTROL PANEL

The touch control section consists of the following units. (1) Key Unit

(2) Control Unit (The Control Unit consists of Power Unit

and CPU Unit).

The principal functions of these units and the 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 through P20 - P26 and AN3. 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, ACL circuit, indicator circuit, power source circuit, relay circuit, buzzer circuit, synchronizing signal circuit and back light circuit.

1) ACL

This circuit generates a signal which resets the LSI to the initial state when power is supplied.

3) Power Source Circuit

This circuit generates voltages necessary in the control unit from the AC line voltage. In addition, the synchronizing signal is available in order to compose a basic standard time in the clock circuit.

Symbol Voltage Application

VC -5.1V LSI(IC1)

4) Relay Circuit

A circuit to drive the magnetron, fan motor, turntable motor and light the oven lamp.

5) Buzzer Circuit

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

6) Synchronizing Signal Circuit

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

2) Indicator Circuit

This circuit consists of 25 segments and 4 common

7) Door Sensing Switch

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

electrodes using a Liquid Crystal Display.

8) Back Light Circuit

A circuit to drive the back light (Light emitting diodes LD1 - LD5).

DESCRIPTION OF LSI

LSI(IZA813DR):

The I/O signal of the LSI(IZA813DR) is detailed in the following table.

Pin No. Signal I/O Description

1-2 VL2-VL1 IN Power source voltage input terminal.

Standard voltage for LCD.

3-6 AN7-AN4 IN Terminal to change cooking input according to the Model.

By using the A/D converter contained in the LSI, DC voltage in accordance with the Model in operation is applied to set up its cooking constant.

7 AN3 OUT Key strobe signal.

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

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

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

square waveform voltage is delivered to

the RY1 driving circuit and RY2 control

circuit.

20.0 msec.

During cooking

H : GND

L : -5V

Page 33

Pin No. Signal I/O Description

0.12 sec.

2.4 sec.

H : GND

L : -5V H : GND

L : -5V

P-HI

H : GND

L : -5V H : GND

L : -5V

P-70

OFF

OFF OFF

24 sec.

8 sec.

20.0 msec.

H : GND

L : -5V

13 P55 OUT Terminal not used. 14 P54 OUT Signal to sound buzzer (2.0 kHz).