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R-733  -

TRE OPERAZIONI IMPORTANTI PER
INCOMINCIARE

1)  Scollegare l'alimentazione elettrica.
2)  Verificare che la porta sia bloccata in posizione

aperta.

3) Scaricare il condensatore ad alta tensione.

ATTENZIONE AL CONDENSATORE AD ALTA
TENSIONE: PUO ESSERE CARICO
Il condensatore ad alta tensione rimane carico per
circa 60 secondi dopo lo spegnimento del forno.
Occorre quindi spettare 60 secondi prima di
cortocircuitare, utilizzando un cacciavite con
impugnatura isolata, il collegamento del
condensatore ad alta tensione (cioè del conduttore
di collegamento del raddrizzatore ad alta tensione)
sul telaio del forno.

Sharp raccomanda, nei limiti del possibile, che la ricerca
dei guasti avvenga in assenza di alimentazione elettrica.
In alcuni casi tuttavia, può essere necessario alimentare
l'apparecchio dopo aver rimosso la scatola esterna. In
questo caso eseguire i tre controlli sopra citati e quindi
scollegare i connettori dal primario del trasformatore.
Assicurarsi che tali connettori non vengano a contatto
con altri componenti, ne con il telaio del forno (fare uso,
se necessario, di nastro isolante). Al termine
dell'intervento, eseguire nuovamente i tre controlli e
ricollegare i conduttori al primario del trasformatore.

QUATTRO VERIFICHE IMPORTANTI DA NON
DIMENTICARE

1) Ricollegare tutti i conduttori staccati dai vari
componenti durante l'intervento.
2) Rimontare la scatola esterna.
3) Ripristinare l'alimentazione elettrica.
4) Rimettere in funzione il forno. Controllare tutte le
funzioni.

I forni a microonde non devono mai funzionare a vuoto.
Per verificare la presenza di energia da microonde
all'interno di una cavitá, mettere una tazza di acqua fredda
sul piatto rotante del forno, chiudere la porta, regolare la
potenza su HIGH ed impostate il temporizzatore su due
(2) minuti. Trascorsi i due minuti (temporizzatore a zero),
controllare accuratamente che ora l'acqua sia calda. Se
l'acqua è rimasta fredda, eseguire i tre controlli iniziali e
verificare nuovamente i collegamenti del componente in
questione.

Dopo aver portato a termine le operazioni di manutenzione
e rimontato il forno, è necessario controllare la potenza
delle microonde emesse ed eseguire un test per verificare
che non vi sia alcuna dispersione.

I forni a microonde contengono un circuito elettrico in grado di generare tensioni e correnti estremamente
elevate. L’eventuale contatto con i seguenti componenti può causare la folgorazione:

condensatore ad alta tensione; trasformatore ad alta tensione; magnetron; rettificatore alta tensione;
cablaggio ad alta tensione.

I

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.

SERVICING

Summary of Contents for R-733B

Page 1: ... 2 PRODUCT SPECIFICATIONS 5 APPEARANCE VIEW 6 OPERATION SEQUENCE 7 FUNCTION OF IMPORTANT COMPONENTS 8 TEST PROCEDURE 10 TOUCH CONTROL ASSEMBLY 18 COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE 22 TEST DATA AT A GLANCE 26 MICROWAVE MEASUREMENT 27 SCHEMATIC DIAGRAMS 28 PICTORIAL DIAGRAM 30 CONTROL PANEL CIRCUIT 31 PRINTED WIRING BOARD DIAGRAM 32 PARTS LIST 33 EXPLODED VIEW OF OVEN 36 CONTROL PANEL D...

Page 2: ...tään väärin tai jos se kytketään väärin Kaikkien mikroaaltoliitäntöjen sekä syöttö että ulostulopuolella aaltoputkien laippojen ja tiivisteiden tulee olla varmistettuja Mikroaaltouunia ei koskaan saa käyttää ilman kuormaa jossa mikroaaltoenergiaa kuluu Avoimeen aaltoputkeen tai antenniin ei koskaan saa katsoa virran ollessa kytkettynä ADVARSEL MIKRØBOLGESTRÅLING Personell må ikke utsettes for mikr...

Page 3: ...rne benyttes med højere spænding end 250 volt 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 A...

Page 4: ...lgende onderdelen kan elektrocutie tot gevolg hebben Hoogspanningscondensator hoogspanningstransformator magnetron hoogspanningsgelijkrichter hoogspannings kabelboom NL VERGEET DE VOLGENDE 3 STAPPEN NIET 1 Haal de stekker uit het stopcontact 2 Open de deur en zorg ervoor dat hij niet dicht kan vallen 3 Ontlaad de hoogspanningscondensator PAS OP VOOR DE ELECTRISCHE LADING VAN DE HOOGSPANNINGSCONDEN...

Page 5: ...amente que el agua se ha calentado Si el agua permaneciese fría efectúe las comprobaciones 3D y vuelva a examinar las conexiones de los componentes que han sido probados Cuando haya terminado la intervención en el equipo y el horno haya sido ensamblado de nuevo completamente deberá comprobar la potencia de salida de microondas y realizar una prueba de fugas de microondas Los hornos de microondas c...

Page 6: ...ettrica 4 Rimettere in funzione il forno Controllare tutte le funzioni I forni a microonde non devono mai funzionare a vuoto Per verificare la presenza di energia da microonde all interno di una cavitá mettere una tazza di acqua fredda sul piatto rotante del forno chiudere la porta regolare la potenza su HIGH ed impostate il temporizzatore su due 2 minuti Trascorsi i due minuti temporizzatore a ze...

Page 7: ...r 325mm Control Complement Jog Touch Control Clock 1 00 12 59 or 0 00 23 59 Timer 90 minutes 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 FUNCTION KEYS AUTO COOK key MODE key STOP key ROTARY knob MINUTE PLUS START key ...

Page 8: ...Key Button 3 Start Button 4 Rotary Knob 5 Door Open Button 3 5 2 1 4 1 Door 2 Door hinges 3 Grill Guide 4 Lamp filter 5 Waveguide cover 6 Contol panel 7 Coupling 8 Door open button 9 Door latches 10 Oven cavity 11 Safety door latches 12 Ventilation openings 13 Outer case 14 Rear back plate 15 Power supply cord KG R 733F COOK DEFROST KG R 733 COOK DEFROST OVEN ...

Page 9: ...en the oven door is opened and the contacts of the monitored latch switch SW1 remain closed the fuse F8A 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 the line voltage is supplied to the power transformer intermittently within a 48 second time base through the relay...

Page 10: ...ital readout start the count down to zero 3 Then the grill heating elements turntable motor oven lamp and fan motor are energized 4 Now the food is grilled by the grill heater 5 Upon completion of the selected cooking time audible signal sounds and contacts of relays are opened then the activated components as item 4 are de energized DUAL COOKING CONDITION In this condition the food is cooked by b...

Page 11: ...MOTOR The fan motor drives a blade which draws in external cool air Thiscoolairisdirectedthroughtheairvanessurrounding the magnetron and cools the magnetron This air is then channeled through the oven cavity to remove steam and vapoursgivenofffromheatingthe food Itisthenexhausted through the exhaust air vents at the rear of the oven cavity NOISE FILTER The noise filter prevents any radio frequency...

Page 12: ...t HIGH Oven goes into cook cycle but shuts down before end of cooking cycle Grill Heating element does not operate Oven seems to be operating but little or no heat is produced in oven load Microwave power does not seem to be generated properly Grill Heating element does not operate POSSIBLE CAUSE AND DEFECTIVE PARTS TEST PROCEDURE CONDITION OFF CONDITION COOKING CONDITION COMMON MICROWAVE COOKING ...

Page 13: ... 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 47 3 50 sec P 90 x T Measuring condition 1 Container The water container must be a cylindrical borosilicate glass vessel having a maximum material thickness of 3 mm...

Page 14: ...ding 13 ohms approximately c Filament winding less than 1 ohm If the reading obtained are not stated above then the power transformer is probably faulty and should be replaced CARRY OUT 4R CHECKS PROCEDURE LETTER COMPONENT TEST HIGH VOLTAGE RECTIFIER TEST CARRY OUT 3D CHECKS Isolate the high voltage rectifier assembly from the HV circuit The high voltage rectifier can be tested using an ohmmeter s...

Page 15: ...tor 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 very short time kick and then a resistance of about 10 MΩ 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 inte...

Page 16: ...s may be due to over heating produced by improper setting of the cooking timer or failure of the control panel An open circuit thermal cut out GRILL indicates that the oven cavity has overheated this may be due to no load operation CARRY OUT 3D CHECKS If the fuse F1 F8A is blown when the door is opened check the monitored latch switch and monitor switch If the fuse F1 F8A is blown by incorrect doo...

Page 17: ...NG ELEMENT TEST 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 CARRY OUT 3D CHECKS Before carrying out the following tests make sure the heating element is cool completely 1 Resistance of heating element 2 Insulation resistance Disconnect the ...

Page 18: ...t light up g The figure of all digits flicker h When touching a tact switch the control unit does not respond 4 Other possible problems caused by defective control unit a Buzzer does not sound or continues to sound b Cooking is not possible 1 Disconnect the oven from the power supply 2 Discharge the high voltage capacitor 3 Remove the control unit from the control panel 4 By using an ohmmeter chec...

Page 19: ...OWER terminal of CPU connector CN A 2 The rated AC voltage is present at primary Low voltage transformer or secondary circuit defective side of low voltage transformer Check and repair 3 Only pattern at a is broken Insert jumper wire J1 and solder CARRY OUT 3D CHECKS BEFORE REPAIR 4 Pattern at a and b are broken Insert the coil RCILF2003YAZZ between c and d CARRY OUT 3D CHECKS BEFORE REPAIR NOTE A...

Page 20: ...ol unite Symbol Voltage Application VC 5V 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 Circuit A circuit to generate a signals which resets the LSI to the initial state when power is supplied 5 Buzzer Circuit Th...

Page 21: ...o the Model DC voltage in accordance with the Model in operation is applied to set up its function 16 TEST IN Connected to VC 17 RESET IN Auto clear terminal Signal is input to reset the LSI to the initial state when power is supplied Temporarily set to L level the moment power is supplied at this time the LSI is reset Thereafter set at H level 18 HOLD IN OUT Connected to VDD 19 INT2 IN Signal syn...

Page 22: ...gnal Signal applied to tact switch section A pulse signal is input to R53 terminal while the tact switch SW61 is touched 37 R62 OUT Tact switch strobe signal Signal applied to tact switch section A pulse signal is input to R53 terminal while the tact switch SW62 is touched 38 R63 OUT Tact switch strobe signal Signal applied to tact switch section A pulse signal is input to R53 terminal while the t...

Page 23: ...uded ofthetouchcontrol 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 so 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 e...

Page 24: ...tage rectifier assembly and capacitor should be free CAUTION WHEN REPLACING HIGH VOLTAGE RECTIFIERASSEMBLY ENSURETHATTHE CATHODE EARTH CONNECTION IS SECURELY FIXED TO THE CAPACITOR HOLDER WITH AN EARTHING SCREW POWER TRANSFORMER REMOVAL 1 CARRY OUT 3D CHECKS 2 Disconnect the filament leads of the power transformer from high voltage capacitor and the magnetron 3 Disconnect the H V wire A from the p...

Page 25: ...the one 1 screw holding the fan duct to the oven cavity back plate 7 Release the tabs of the capacitor holder from the fan duct 8 Remove the fan duct from the oven 9 Remove the fan blade assembly from the fan motor 10 Remove the two 2 screws holding the fan motor to the fan duct 11 Now the fan motor is free 1 CARRY OUT 3D CHECKS 2 Disconnect the main harness and stop switch harness from the contro...

Page 26: ...hswitch stopswitchand monitor switch operation If those switches have not activated with the door closed repeat steps 1 4 After adjustment make sure of following 1 In and out play of door remains less than 0 5 mm when latchedposition Firstchecklatchhookposition pushing and pulling the door toward the oven face The results play of the door should be less than 0 5 mm 2 The contacts COM NO of monitor...

Page 27: ... 7 Now door sub assembly is free from oven cavity 8 Remove the four 4 screws holding the door panel to the door frame Figure C 7 Door Disassembly 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 spri...

Page 28: ...re that the monitor switch monitored latch switchandstopswitchareoperatingproperly 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 hole...

Page 29: ...rowave 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 center 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...

Page 30: ...HERMAL CUT OUT 160ß C COM NO COM A1 RY2 NO RY3 A3 RY1 B1 B2 SW3 STOP SW OVEN LAMP FAN MOTOR TURN TABLE MOTOR TTM FM OL SW1 MONITORED LATCH SWITCH NO NO NO 680K 0 5W 0 0047 250V 0 0047 250V A5 MAGNETRON MAG THERMAL CUT OUT 125ß C EARTH BLU 15 BRN 15 230V 50Hz 0 22 250V NOISE SUPPRESSION COIL 10M 0 5W ASYMMETRIC RECTIFIER H V CAPACITOR 1 07 F AC2100V MAGNETRON POWER TRANSFORMER H V RECTIFIER L N F2 ...

Page 31: ...RMAL CUT OUT 160ß C COM NO COM A1 RY2 NO RY3 A3 RY1 B1 B2 SW3 STOP SW OVEN LAMP FAN MOTOR TURN TABLE MOTOR TTM FM OL SW1 MONITORED LATCH SWITCH NO NO NO 680K 0 5W 0 0047 250V 0 0047 250V A5 MAGNETRON MAG THERMAL CUT OUT 125ß C EARTH BLU 15 BRN 15 230V 50Hz 0 22 250V NOISE SUPPRESSION COIL 10M 0 5W ASYMMETRIC RECTIFIER H V CAPACITOR 1 07 F AC2100V POWER TRANSFORMER H V RECTIFIER L N F2 FUSE 15A G Y...

Page 32: ...EN C O LIVE POWER SUPPLY CORD FM FAN MOTOR ASYMMETRIC RECTIFIER MG MAGNETRON T HVT C HV CAPACITOR HV WIRE A HV WIRE B HV RECT NEUTRAL EARTH MON LATCH SW RY 3 NO COM NO COM RY 2 CN A WHT ORG BLK BLU BLU RED BLK RED RED BLU WHT WHT GRN BLK BLU BLU GRY BRN BRN BLU WHT ORG BRN WHT BRN BLK BLU BRN BLU G Y RED WHT RED BRN BRN BLU WHT BRN BLK WHT BLU GRY WHT BLK GRN RED ...

Page 33: ...10 XIN 11 XOUT 12 K00 13 K01 14 K02 15 K03 16 TEST 17 RESET 18 HOLD 19 INT2 SEG 8 50 SEG 7 49 SEG 6 48 SEG 5 47 SEG 4 46 SEG 3 45 SEG 2 44 SEG 1 43 SEG 0 42 R73 41 R72 40 R71 39 R70 38 R63 37 R62 36 R61 35 R60 34 R53 33 R52 A 3 A 1 B 2 B 1 A 5 NO NO COM COM RY1 OJ SH 124LM RY2 VRB18 RY3 VRB18SP IF NOT SPECIFIED 1 4w 5 IF NOT SPECIFIED 1SS270A IF NOT SPECIFIED 0 01µF 16v D23 NOTE R30 15k R10 4 7k W...

Page 34: ...22 Q20 D22 5 1 D20 VRS1 CN A J3 J5 J7 J8 CN B 1 2 R10 R61 R62 R63 R64 R66 R67 R68 C1 S1 WH 1 WH 1 6 4 5 2 5 1 3 3 3 2 2 0 1 12 1 9 1 I C 1 3 J6 J4 J2 ZD1 1 5 9 4 J9 SW63 CR60 Q40 Q3 R30 R40 R20 R22 D21 RY1 GRILL SW50 J11 J1 F ZD20 R3 C30 C50 C51 C5 C6 C4 C1 C2 C21 C20 Q23 Q1 Q21 SP1 C7 R4 R5 B B E E E E E B C3 B S P T1 B SW62 CN G SW61 WH 2 DIP LD4 QKITPA018URE0 SW60 Figure S 3 Printed Wiring Boar...

Page 35: ...R1 2 VRS B13AA511J U Resistor 510 ohm 1W 2 AB R3 4 VRD B12EF472J U Resistor 4 7k ohm 1 4W 2 AA R5 VRD B12EF241J U Resistor 240 ohm 1 4W 1 AA R10 VRD B12EF472J U Resistor 4 7k ohm 1 4W 1 AA R20 VRD B12EF102J U Resistor 1 0k ohm 1 4W 1 AA R21 VRD B12EF472J U Resistor 4 7k ohm 1 4W 1 AA Note The parts marked are used in voltage more than 250V The parts marked may cause undue microwave exposure MARK S...

Page 36: ...G018URR0 U Control panel frame R 733 LG F 1 AP 3 4 JBTN L017URF0 U Key button R 733 W 1 AD 3 4 JBTN A100URF0 U Key button R 733 B 1 AD 3 4 JBTN 0011URF0 U Key button R 733 Y W LB LG F 1 AC 3 5 JBTN L013URF0 U Start button R 733 W 1 AD 3 5 JBTN A101URF0 U Start button R 733 B 1 AE 3 5 JBTN 0013URF0 U Start button R 733 Y W LB LG F 1 AE 3 6 JKNBKA018URF0 U Rotary knob R 733 W F 1 AD 3 6 JKNBKA040URF...

Page 37: ...4 NFANJA001URE0 U Fan blade 1 AF 4 5 PDUC A637WRF2 U Fan duct 1 AL 4 6 LANGFA155WRP7 U Chassis support 1 AF 4 7 PPACGA108WRE0 U Packing 1 AC 4 8 PCUSUA365WRP1 U Baseplate cushion 1 AA 4 9 MLEVPA001URF3 U Open lever 1 AE 4 10 NCPL A042WRF1 U Coupling 1 AD 4 11 PCOVPA308WRE1 U Waveguide cover 1 AE 4 12 PFILWA042WRP0 U Lamp filter 1 AB 4 13 PDUC A606WRF1 U Air intake duct 1 AK 4 15 PDUC A514WRP0 U Ai...

Page 38: ...OF OVEN CABINET AND UNIT CHASSIS PARTS 7 4 4 16 2 1 7 9 4 15 7 7 7 9 7 8 7 9 TC1 F1 F2 7 1 1 2 7 7 4 6 7 7 7 7 7 7 1 3 7 2 1 1 C SW2 SW1 SW3 4 2 4 4 4 3 6 2 4 11 4 1 7 5 MG 7 7 7 2 6 13 7 7 4 7 TC2 0L TC3 4 12 TTM 7 1 4 10 2 3 7 7 7 7 7 7 7 7 2 2 7 10 7 6 4 9 7 7 4 13 6 1 4 5 7 3 FM 7 7 7 7 4 18 7 7 6 7 GH 4 17 7 7 X2 X2 x4 x2 1 5 T 4 8 4 20 7 2 1 3 ...

Page 39: ...37 R 733 CONTROL PANEL DOOR PARTS 3 2 3 3 3 6 3 8 3 4 3 11 3 10 3 5 3 7 3 9 3 1E 3 1F 3 1D 3 1 DOOR PARTS CONTROL PANEL PARTS 5 4 5 3 5 2 5 7 5 5 5 6 5 1 5 9 5 8 5 10 5 9 x 2 ...

Page 40: ...ACK LOW RACK COOK BOOK INSTRUCTION BOOK TURNTABLE SUPPORT TRAY PAD PACKING PAD KIT CPADBA146WRK0 POLYETHENE BAG SSAKHA041WRE0 DOOR PROTECTION SHEET SPADPA020WRE0 PACKING CASE SPAKCA369URR0 R 733 W SPAKCA370URR0 R 733 B SPAKCA390URR0 R 733 Y F SPAKCA368URR0 R 733 W F SPAKCA388URR0 R 733 LB F SPAKCA389URR0 R 733 LG F Not Replaceable Items SHARP CORP 2000 Printed in the U K ...

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