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R-380A

9

TEST PROCEDURES

PROCEDURE

LETTER

COMPONENT TEST

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.

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 heat-

up 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.

Summary of Contents for R-380A

Page 1: ......

Page 2: ...R 380A ...

Page 3: ...d 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...

Page 4: ...icrowave 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 SENSOR INSTANT REHEAT pads SENSOR COOK pad SLOW COOK pad EASY DEFROST pad MEMORY pad MORE LESS pads NUMBER pads POWER LEVEL pad CLOCK pad TIMER pad STOP CLEAR pad IN...

Page 5: ...wice to can cel cooking programme TIMER CLOCK PAD Press to set Timer INSTANT COOK START PAD Press once to cook for 1 minute on HIGH or increase by 1 minute multi ples each time this pad is pressed during cooking Press to start the oven after setting programmes Indicator HELP PAD Press to select auto start informa tion guide on off child lock dem onstration modes or info on pads Press to get cookin...

Page 6: ... 2nd latch switch and stop switch are made open 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 the remaining time 6 MONITOR SWITCH CIRCUIT The monitor switch is mechanically controlled by oven door and monitors the operation of the 1st and 2nd latch switches 6 1 When the oven door is o...

Page 7: ...e D 1 When the open button is pushed the open button pushes up the switch lever and then the switch lever pushes up thethelatchhead Thelatchheadsaremovedupwardand released from latch hook Now the door will open Latch Hook 2nd Latch Switch Monitor Switch Stop Switch Switch Lever Latch Heads Door 1st Latch Switch Figure D 1 Door Open Mechanism 1ST LATCH SWITCH 2ND LATCH SWITCH AND STOP SWITCH 1 When...

Page 8: ... 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 de...

Page 9: ...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...

Page 10: ... set Oven operates properly at HIGH and then the STOP CLEARpadistouchedtheoven stops Oven goes into cook cycle but shutsdownbeforeendofcook ing cycle Oven stops as soon as when the START pad is touched AH sensor does not end during Sensor Cooking condition Oven does not shut off after a cup of water is boiling by sen sor cooking Oven stops at 16 sec after starting TEST PROCEDURE CK Check RE Replac...

Page 11: ...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 ove...

Page 12: ... 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 3 Ω b Secondary winding approx 96 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 HIGH V...

Page 13: ...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 O...

Page 14: ...trical parts or wire harness Check them and replace the defective parts or repair the wire harness 2 If the fuse M8A is blown when the door is opened check the 2nd latch switch monitor switch and monitor resistor If the fuse M8A is blown by incorrect door switching replace the defective switch s and the fuse M8A 3 If the fuse M8A is blown there could be a short in the asymmetric rectifier or there...

Page 15: ...mbly 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 p...

Page 16: ...ION 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 a...

Page 17: ...n off after water is boiling bubbling If the oven does not turn off replace the AH sensor or check the control unit refer to explanation below TESTING METHOD FOR AH SENSOR AND OR CONTROL UNIT To determine if the sensor is defective the simplest method is to replace it with a new replacement sensor 1 Disconnect oven from power supply and remove outer case 2 Discharge the high voltage capacitor 3 Re...

Page 18: ...signal circuit absolute humidity sensor circuit and back light circuit 1 ACL This circuit generates a signal which resets the LSI to the initial state when power is supplied 2 Indicator Circuit This circuit consists of 25 segments and 4 common electrodes using a Liquid Crystal Display 3 Power Source Circuit Thiscircuitgeneratesvoltagesnecessaryinthecontrol unit from the AC line voltage In addition...

Page 19: ...ency Thisisthebasictimingfortimeprocess ing of LSI 25 26 P41 P40 OUT Terminal not used 27 P77 IN Signal coming from touch key When either G12 line on key matrix is touched a corresponding signal out of P20 P27 will be input into P77 When no key is touched the signal is held at H level 28 P76 IN Signal similar to R77 WheneitherG11lineonkeymatrixistouched acorrespondingsignalwillbeinputintoR76 29 P7...

Page 20: ...22 OUT Key strobe signal Signal applied to touch key section A pulse signal is input to P74 P77 terminal while one of G3 line keys on key matrix is touched 47 P21 OUT Key strobe signal Signal applied to touch key section A pulse signal is input to P74 P77 terminal while one of G2 line keys on key matrix is touched 48 P20 OUT Key strobe signal Signal applied to touch key section A pulse signal is i...

Page 21: ...s used to detect the output voltage of the absolute humidity circuit to allow the LSI to control sensor cooking of the unit When the unit is set in the sensor cooking mode 16 seconds clearing cycle occurs than the detector circuit starts to function and the LSI observes the initial voltage available at its AN7 terminal With this voltage given the switches SW1 to SW5 in the LSI are turned on in suc...

Page 22: ...t twisted 3 Afteraluminiumfoilisremoved becarefulthatabnormal voltage due to static electricity etc is not applied to the input or output terminals 4 Attachconnectors electrolyticcapacitors etc toPWB making sure that all connections are tight 5 Be sure to use specified components where high precision is required E C B E C B Transistor 2SB1238 Transistor KRC243M 1 Precautions for Handling Electroni...

Page 23: ...he 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 Ovenlamp Magnetron Highvoltagetransformer and Oven cavity 3 Sharp edge Bottom plate Oven cavity Waveguide flange Chassis support and other metallic plate 4 Movable parts to prevent a fault Fan blade Fan motor Switch Switch lever O...

Page 24: ...etron to waveguide flange 6 Lift up magnetron with care so that magnetron antenna is not hit by any metal object around antenna 7 Now the magnetron is free Re install 1 Re install the magnetron to waveguide flange with the two 2 screws diagonally as shown in Figure C 1 2 Insertthetwo 2 tabsofthechassissupporttotheoven cavity front plate and back plate 3 Re install the chassis support to oven cavit...

Page 25: ...lamp socket Terminal Wire lead Terminal hole Flate type small screw driver Figure C 5 Oven lamp socket TURNTABLE MOTOR REMOVAL 1 Disconnect oven from power supply 2 Remove turntable and turntable support from oven cavity 3 Lay the oven on it s backside Remove the turntable motor cover by snipping off the material in four corner 4 Where the corners have been snipped off bend corner areasflat Noshar...

Page 26: ...ing to the pictorial diagram Coil Gap Rotor Bracket Stator Groove joint pliers Shaft Axis Stator These are the position where should be pinched with pliers Rotor Shaft Table Center of bracket Side View Rear View POWER SUPPLY CORD REPLACEMENT Removal 1 CARRY OUT 3D CHECKS 2 Disconnect the brown and blue wires of the power supply cord from the noise filter 3 Remove the single 1 screw holding the ear...

Page 27: ...eofupper and lower oven hinges 8 Re install the door stopper to the door assembly Note After any service to the door A Makesurethatdoorsensingswitchandsecondary interlock switch are operating properly Refer to chapter Test Procedures B An approved microwave survey meter should be usedtoassurecompliancewithpropermicrowave radiation emission limitation standards 1ST LATCH SWITCH 2ND LATCH SWITCH STO...

Page 28: ... microwave energy from oven cavity during cook cycle This function does not require that door be air tight moisture condensation tight or light tight 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 Pin Pin Upper oven hinge Lower oven hinge Lower...

Page 29: ...dformicrowaveovensmustbeusedfortesting 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 suc...

Page 30: ... 1 COM THERMAL CUT OUT 125 C OVEN RY 2 2ND LATCH SWITCH MONITOR RESISTOR 0 8 20W EARTH BLU BRN 230 240V 50Hz G Y FUSE M8A N L LINE CROSS CAPACITOR 0 068µ AC250V NOISE SUPPRESSION COIL LINE BYPASS CAPACITOR 0 0022µ AC250V LINE BYPASS CAPACITOR 0 0022µ AC250V POWER TRANSFORMER MAGNETRON H V RECTIFIER ASYMMETRIC RECTIFIER CAPACITOR 1 07µ AC2200V TURNTABLE MOTOR FAN MOTOR OVEN LAMP STOP SWITCH MONITOR...

Page 31: ...ORG BLK RED RED B L K BLK GRY WHT GRY BLK RED THERMAL CUT OUT 125 C OVEN FAN MOTOR RED BLK WHT GRY WHT WHT WHT BLU BRN POWER SUPPLY CORD EARTH NOISE FILTER M8A N L NEUTRAL LIVE GRN GRN BLK ORG WHT GRY OVEN SIDE STOP SWITCH COM NO GRY GRN G Y WHT WHT THERMAL CUT OUT 95 C MG WHT ASYMMETRIC RECTIFIER 2 1 WHT RED 3 MONITOR RESISTOR BLK GRY NOTE Neutral WHT wire must be connected to the terminal with b...

Page 32: ...TE IF NOT SPECIFIED 1 4w 5 IF NOT SPECIFIED 1SS270A TURNTABLE MOTOR OVEN LAMP FAN MOTOR 1 WH 1 R4 27 R5 4 7k R2 680 1 2w R6 3 3k SP1 VRS1 C1 0 1µ 50v C3 0 1µ 50v ZD1 HZ16 1 C4 10µ 35v C5 10µ 35v R3 510 1 2w C2 1000µ 35v R1 2 4k J1 D5 D3 D4 D2 D1 a c d b D6 RY1 D7 D8 RY2 J2 Q2 2SB1238 2SB1238 Q1 D1 D4 11ES1 Q3 KRC243M VR VR VR LD1 LD5 LD1 LD2 LD3 LD4 LD5 A 1 N O COM 2 3 4 ...

Page 33: ...55 P54 P53 P52 P51 P50 P47 P46 P45 P44 P43 P41 P40 P77 P76 P75 P74 INT0 VL2 VL3 COM0 COM1 COM3 AVSS VREF VCC SEG0 SEG1 SEG2 SEG3 SEG4 SEG5 SEG6 SEG7 SEG8 SEG9 COM2 30 1 51 80 Q20 KRA101S C11 0 1µ 50v C30 C63 330p 50v C62 330p 50v C61 330p 50v C60 330p 50v R75 100k R74 100k R73 100k R72 100k C103 LIQUID CRY STAL DISPLAY C104 IC2 D101 AH SENSOR NOTE IC1 IZA778DR VA GND VC INT BUZZER RY1 RY2 RY3 DOOR...

Page 34: ...0 LD1 LD2 LD3 LD4 LD5 WH 1 SH A GREEN SH B R2 J4 Q2 Q1 C5 T1 6 1 1 3 3 7 4 4 RY1 RY2 HVT DU DU OMIF OMIF AC COM OL FM AC VH XH 1 3 1 3 CN A TTM 1 E E R4 D6 D5 C4 B B 1 1 1 2 2 DIP CN C 9 R5 R1 ZD1 CN B DOOR SW C3 R6 SP1 D7 Q3 J3 J2 J1 6 7 C1 D4 D2 D1 D3 C2 B E R3 D9 D8 VRS1 RY3 LOT NO F 2 3 4 5 1 2 WH 1 ...

Page 35: ...NTROL PANEL PARTS 3 1 CPWBFA741WRK0 Power unit New Zealand only 1 BD 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 VCEAB31VW108M Capacitor 1000µF 35V 1 AF C3 RC KZA087DRE0 Capacitor 0 ...

Page 36: ...e 1 AP 4 22 PCUSUA192WRP0 Cushion 1 AD DOOR PARTS 5 CDORFA761WRK0 Door assembly 1 BL 5 1 FDORFA303WRT0 Door panel 1 BA 5 2 PSHEPA382WRE0 Sealer film 1 AH 5 3 GWAKPA471WRR0 Door frame 1 AZ 5 4 HPNL A662WRE0 Door screen 1 AK 5 5 GCOVHA370WRF0 Choke cover 1 AM 5 6 LSTPPA139WRF0 Latch head 1 AF 5 7 MSPRTA084WRE0 Latch spring 1 AB 5 8 PCUSUA481WRP0 Cushion 1 AB 5 9 PCUSUA452WRP0 Cushion 1 AB 5 10 XCPSD...

Page 37: ... 16 7 3 1 5 7 6 6 2 7 3 1 1 1 1 4 1 1 15 1 1 4 8 1 7 4 4 7 5 7 6 7 1 7 5 6 5 4 3 7 6 6 1 7 1 7 1 1 9 1 5 4 6 1 8 1 4 4 7 4 12 4 14 1 12 7 1 x2 4 13 4 2 4 15 1 14 7 3 1 16 4 15 2 3 4 5 1 3 1 2 1 6 7 1 7 6 7 5 7 6 7 6 2 5 2 4 7 5 2 4 7 3 2 2 4 11 6 11 4 9 4 10 1 13 7 1 7 3 1 11 1 10 6 7 7 6 7 1 7 5 4 17 4 21 4 22 7 2 1 17 ...

Page 38: ... G H A B C D E F G H CONTROL PANEL PARTS MISCELLANEOUS DOOR PARTS 4 20 5 2 5 10 5 5 5 1 5 3 5 6 5 7 5 Actual wire harness may be different from illustration 6 4 6 3 CAPACITOR 5 4 5 8 6 10 5 10 5 9 3 2 3 4 3 3 6 9 3 6 3 5 3 7 3 7 3 7 3 1E 3 1 3 3 1 ...

Page 39: ... SPADPA204WRE0 TOP PAD ASSEMBLY FPADBA311WRK0 PLASTIC BAG SSAKHA034WRE0 Not replaceable items PACKING CASE SPAKCC883WRE0 BOTTOM PAD ASSEMBLY FPADBA351WRK0 6 2 TURNTABLE TRAY PRINTING MATTER 6 1 TURNTABLE SUPPORT TRAY PACK SPADFA397WRE0 INTO THE OVEN CAVITY ...

Page 40: ...R 380A 38 97SHARP CORP 5S0 730E Printed in Australia ...

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