Sharp R-363(IN) User manual

SHARP CORPORATION
SERVICE MANUAL
S06278R363EHW
In interests of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
MICROWAVE OVEN
TABLE OF CONTENTS
Page
CAUTION ............................................................................................................................. INSIDE COVER
GENERAL IMPORTANT INFORMATION .................................................................................................. 1
SERVICING ................................................................................................................................................ 2
CAUTION, MICROWAVE RADIATION, WARNING ................................................................................... 5
PRODUCT SPECIFICATIONS ................................................................................................................... 5
APPEARANCE VIEW ................................................................................................................................. 6
OPERATION SEQUENCE .......................................................................................................................... 7
FUNCTION OF IMPORTANT COMPONENTS .......................................................................................... 8
TEST PROCEDURES .............................................................................................................................. 10
TOUCH CONTROL ASSEMBLY .............................................................................................................. 19
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ..................................................... 23
TEST DATA AT A GLANCE ..................................................................................................................... 27
MICROWAVE MEASUREMENT .............................................................................................................. 28
WIRING DIAGRAMS ................................................................................................................................ 29
SWITCH UNIT CIRCUIT ............................................................................................................................32
PICTORIAL DIAGRAM ..............................................................................................................................33
PRINTED WIRING BOARD OF SWITCH UNIT ........................................................................................34
PARTS LIST ............................................................................................................................................. 35
EXPLODED VIEW OF OVEN ....................................................................................................................38
CONTROL PANEL & DOOR PARTS ........................................................................................................39
MISCELLANEOUS/PACKING AND ACCESSORIES ............................................................................... 40
R
R-363(IN)
MODELS
R-363(IN)
DEFROST
COOK
R-363

1
R-363 -
SERVICE MANUAL
MICROWAVE OVEN
R-363(IN)
GENERAL IMPORTANT INFORMATION
This Manual has been prepared to provide Sharp Corp. Service engineers with Operation and Service
Information.
It is recommended that service engineers carefully study the entire text of this manual, so they will be qualified to
render satisfactory customer service.
WARNING
Note: The parts marked "*" are used in voltage more than 250V. (Parts List)
Anm: Delar märket med "*" har en spänning överstigande 250V.
Huom: Huolto-ohjeeseen merkitty "tähdella" osat joissa jännite on yli 250 V.
Bemerk: Deler som er merket "asterisk" er utsatt for spenninger over 250V til jord.
Bemærk: "Dele mærket med stjerne 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.
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 the parts list may cause undue microwave exposure, by themselves, or when they
are damaged, loosened or removed.
Never operate the Grill with the oven outer cabinet removed. (Because air flow is eliminated, and the excess heat
generated on adjacent components). It can cause permanent damage or a fire.
SHARP CORPORATION
OSAKA, JAPAN

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R-363 -
GB Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts 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 power to HIGH and set the microwave timer for two (2)
minutes. When the two minutes has elapsed (timer at zero)
carefully check that the water is now hot. If the water remains
cold carry out 3D checks and re-examine 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 a microwave leakage test carried out.
Magnetronovens bevatten circuits die een zeer hoge spanning en stroom kunnen voortbrengen. Contact met
de volgende 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 HOOGSPANNINGSCONDENSATOR
De hoogspanningscondensator blijft nog ongeveer
60 seconden lang opgeladen, nadat de oven is
uitgeschakeld. Wacht 60 seconden voordat u de
verbinding van de hoogspannings-condensator
(m.a.w. de verbindingsdraad van de
hoogspanningsgelijkrichter) met een geïsoleerde
schroevedraaier kortsluit tegen het chassis.
Sharp beveelt ten sterkste aan dat, voor zover
mogelijk, defecten worden opgespoord wanneer de
stekker uit het stopcontact is gehaald. Soms is het
nodig om de stroomtoevoer weer tot stand te
brengen nadat de buitenmantel verwijderd is.
Herhaal dan de bovengenoemde 3 stappen en haal
de electrische draden uit deprimaire zijde vande
vermogenstransformator. Zorg ervoor dat deze draden
geïsoleerd blijven van andere elementen en van het
chassis van de oven. (Gebruik zo nodig isolatieband.)
Wanneer de test is uitgevoerd, herhaalt u de
bovenstaande 3 stappen en verbindt u de electrische
draden weer aan de primaire zijde van de
vermogenstransformator.
VERGEET DE VOLGENDE 4 STAPPEN
NIET
1) Sluit de draden weer aan diezijn losgehaald
voor de test.
2) Plaats de buitenmantel weer om het toestel
heen (kabinet).
3) Stop de stekker weer in het stopcontact.
4) Zet de oven aan. Controleer alle functies.
Magnetronovens mogen niet leeg aangezet worden.
Om te controleren of er microgolf-energie binnen de
oven wordt geproduceerd, plaatst u een mok met koud
water op de draaitafel van de oven, sluit de deur, zet de
oven op HIGH en stelt de klok van de magnetron in op
twee (2) minuten. Wanneer de twee minuten voorbij
zijn (klok staat op nul), controleert u voorzichtig of het
water heet is. Indien het water nog steeds koud is,
herhaalt u de allereerste drie stappen en controleer
nogmaalsde aansluitingennaar degetesteonderdelen.
Wanneer alle reparaties zijn uitgevoerd en de oven weer
in elkaar is gezet, moet de het magnetronvermogen
worden gecontroleerd en moet worden gecontroleerd of
er geen microgolflekkage is.
WARNING TO SERVICE PERSONNEL
SERVICING

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R-363 -
SERVICING
RECUERDE LA COMPROBACION 3D
1) Desconecte la alimentación.
2) Deje la puerta abierta y calzada.
3) Descargue el condensador de alto voltaje.
ADVERTENCIA SOBRE LA CARGA DEL
CONDENSADOR DE ALTO VOLTAJE
El condensador de alto voltaje permanece cargado unos
60 segundos después de haber apagado el horno. Espere
60 segundos y luego ponga en cortocircuito la conexión
del condensador de alto voltaje (esto es, del conductor de
conexión del rectificador de alto voltaje) al chasis con un
destornillador de mango aislado.
Se recomienda encarecidamente que siempre que sea
posible la localización de fallos se realice con la alimentación
desconectada. Puede ser que en algunos casos sea
necesario conectar la alimentación después de haber
retirado la carcasa exterior. En este caso, realice las
comprobaciones 3D y luego desconecte los conductores
del primario del transformador de alimentación. Asegúrese
de que estos conductores permanezcan aislados de otros
componentes y del chasis del horno. (Use cinta aislante si
es necesario). Cuando termine la prueba efectúe las
comprobaciones 3D y reconecte los conductores al primario
del transformador de alimentación.
RECUERDE LA COMPROBACION 4C
1) Conecte todos los componentes desconectados de
los componentes durante la prueba.
2) Coloque la carcasa exterior (cabina).
3) Conecte la alimentación.
4) Compruebe todas sus funciones despues de poner
en marcha el horno.
Los hornos de microondas no deben funcionar vacíos.
Para comprobar la presencia de energía de microondas
dentro de una cavidad, coloque una taza de agua fría
en el plato giratorio del horno, cierre la puerta y ponga
la potencia en HIGH (alta) y coloque el temporizador
en dos (2) minutos. Cuando transcurran los dos minutos
(temporizador a cero) compruebe cuidadosamente 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 contienen circuitos eléctricos capaces de producir voltajes de alta tensión y descargas
eléctricas. Para evitar el riesgo de electrocución, absténgase de tocar los siguientes componentes: condensador
de alta tensión, transformador de alta tensión, magnetrón, dispositivo del rectificador de alta tensión y arnés de
alta tensión.
E
SV Mikrovågsugnar innehåller kretsar som producerar mycket höga spänningar och strömmar.
Kontakt med följande komponenter kan leda till dödsfall:
Högspänningskondensator, transformator, magnetron, högspännings likriktare, högspännings kablage.
VARNING FÖR LADDNINGEN I
HÖGSPÄNNINGSKONDENSATORN
Högspänningskondensatorn är laddad i 60 sekunder
efter det att ugnen stängts av. Vänta 60 sekunder och
korislut sedan kondensatoms anslutning (dvs
anslutningen till högspänningslikriktaren) till chassiet
med hjälp av en isolerad skruvmejsel.
KOM IHÅG ATT KONTROLLERA 4 STEG
1) Anslut alla ledningar som använts vid testning
2) Sätt tillbaka ytterhöljet.
3) Anslut strömkällan på nytt.
4) Sätt på ugnen. Kontrollera alla funktioner.
Mikrovågsugnarfårinte användastomma. Kontrollera
mikrovågsstrålningen i olika delar av ugnen genom
att placera en kopp med kallt vatten på ugnens tallrik,
stäng dörren, ställ in HIGH och ställ in 2 minuter på
timern. När två minuter har gått (timem visar 0)
kontrollerar du om vattnet är varmt. Om vattnet
fortfarande är kallt utför Du 3 steg kontroller och
kontrolleraranslutningarna tillvarje enskild komponent
på nytt.
När all service är klar och ugnen ihopskruvad skall
ugnens uteffekt och eventuellt mikrovågsläckage
kontrolleras.
KOM IHÅG ATT KONTROLLERA 3 STEG
1) Koppla från strömkällan.
2) Öppna dörren på glänt.
3) Ladda ur högspänningskondensatorn.
Sharp rekommenderar att felsökning sker med
strömmen fränkopplad. Ibland kan det var nödvändigt
att koppla på strömmen efter det att höljet avlägsnats,
utförda3Steg kontrollen och koppla sedanfrånledarna
till transformatorns primärsida. Se till att ledarna är
isoleradefrån andrakomponenter ochchassiet. (Använd
isoleringsband om det behövs). När Du testat färdigt
utför Du 3 Steg kontrollen och ansluter ledningarna till
transformatorns primärsida igen.

4
R-363 -
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
requirethataspecific test be performed.Thesetestsare
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
As part of our policy of continuous improvement, we reserve the
right to alter design and specifications without notice

5
R-363 -
CAUTION
MICROWAVE RADIATION
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
outputmicrowaveconnections,waveguides,flanges
and gaskets must be secured. Never operate the
device without a microwave energy absorbing load
attached. Never look into an open waveguide or
antenna while the device is energized.
WARNING
THIS APPLIANCE MUST BE EARTHED. THE WIRES IN THIS MAINS LEAD ARE COLOURED IN
ACCORDANCE WITH THE FOLLOWING CODE:
GREEN-AND-YELLOW : EARTH BLUE : NEUTRAL BROWN : LIVE
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.
PRODUCT DESCRIPTION
CAUTION/WARNING
SPECIFICATION
Power Requirements 230 Volts 50 Hertz Single phase, 3 wire earthed
Power Consumption 1.35 kW Approx. 6.0 A
Power Output 900W watts nominal of RF microwave energy
(measured by way of IEC 60705) Operating frequency of 2450 MHz
Case Dimensions Width 520mm
Height 305mm including foot
Depth 422mm
Cooking Cavity Dimensions Width 342mm
Height 207mm
Depth 368mm
Turntable diameter 325mm
Control Complement Jog Touch System
Clock (1:00-12:59 or 0:00-23:59)
Timer (0-99 minutes 90 seconds)
Control Complement 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
EXPRESS COOK key
EXPRESS DEFROST key x 3
STOP key
POWER LEVEL key
MINUTE PLUS/START key
ROTARY KNOB
Set Weight Approx. 18.0 kg

6
R-363 -
DEFROST
COOK
R-363
1. Place the roller stay on the coupling.
2. Then place the turntable on it.
AUTO-TOUCH CONTROL PANEL
OVEN
APPEARANCE VIEW
1. Display Window
2. Symbols and Indicators
3. EXPRESS COOK
4. EXPRESS DEFROST
5. +1min/START button
6. STOP button
7. COOKING MODE button
8. TIMER/WEIGHT/POWER knob
3
5
2
1
5
1. Door
2. Door hinges
3. Oven lamp
4. Waveguide cover
5. Contol panel
6. Coupling
7. Door latches
8. Oven cavity
9. Door seals and sealing surfaces
10. Safety door latches
11. Door handle
12. Ventilation openings
13. Outer case
14. Rear back plate
15. Power supply cord
4
6
7
8
TURNTABLE
ROLLER STAY
COUPLING

7
R-363 -
OFF CONDITION
Closing the door activates all door interlock switches
(monitored latch switch and stop 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
(230V 50Hz), the line voltage is supplied to the point
A1+A3 in the control unit.
Figure O-1 on page 29
1. The display flashes "88:88”.
2. To set any programmes or set the clock, you must first
touch the STOP 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 ROTARY knob and
start the oven by touching START button.
Function sequence Figure O-2 on page 29
CONDITION
DURING DOOR OPEN
SWITCH CONTACT COOKING (NO COOKING)
Monitored latch switch COM-NO Closed Open
Monitor switch COM-NC Open Closed
COM-NO Closed Open
Stop switch COM-NO Closed Open
The circuits to the power transformer, fan motor and
turntable motor are cut off when the primary 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 SW2 is mechanically controlled by
oven door, and monitors the operation of the
monitored latch switch SW1
6-1 When the oven door is open during or after the
cycle of cooking program, the monitored latch and
stop switches SW1 + SW3 must open their contacts
first. After that the contacts (COM - NC) of the
monitor switch SW2 can be closed.
6-2 When the oven door is closed, the contacts
(COM - NC) of the monitor switch SW2 must be
opened. After that contacts of the monitored latch
and stop switches SW1 + SW3 are closed.
6-3 When 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 contact which is coupled with the
current-limiting relay RY2. 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. 3 seconds are needed
for heating up the magnetron filament.
CONNECTED COMPONENTS RELAY
Oven lamp, Fan motor, Turntable motor RY1
Power transformer RY2
1. The line 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 single 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.
OPERATING SEQUENCE
32 sec. ON
24 sec. ON
18 sec. ON
12 sec. ON
6 sec. ON
8 sec. OFF
14 sec. OFF
20 sec. OFF
26 sec. OFF
HIGH
MEDIUM
HIGH
MEDIUM
MEDIUM
LOW
LOW
Approx. 70% = 630Watts
Approx. 50% = 450Watts
Approx. 30% = 270Watts
Approx. 10% = 90Watts
Approx100% = 900Watts

8
R-363 -
Figure D-1. Door Open Mechanism
MONITORED LATCH SWITCH SW1
STOP SWITCH SW3
1. When the oven door is closed, the contacts (COM - NO)
must be closed.
2. When the oven door is opened, the contacts (COM - NO)
must be opened.
MONITOR SWITCH SW2
1. When the oven door is closed, the contacts (COM - NC)
must be opened and the contacts (COM - NO) must be
closed.
2. When the oven door is opened, the contacts (COM - NC)
must be closed and the contacts (COM - NO) must be
closed.
3. If the oven door is opened and the contacts (COM - NO)
of the monitored latch switch SW1 fail to open, the fuse F1
F8Ablowssimultaneouslywithclosing the contacts (COM
- NC) of the monitor switch SW2.
CAUTION: BEFOREREPLACINGABLOWNFUSE F1 F8A,
TEST THE MONITORED LATCH SWITCH SW1
AND MONITOR SWITCH SW2 FOR PROPER
OPERATION. (REFER TO CHAPTER ”TEST
PROCEDURE”.)
FUNCTION OF IMPORTANT COMPONENTS
FUSE F1 F8A 250V
1. If the wire harness or electrical components are short-
circuited, this fuse blows to prevent an electric shock or
fire hazard.
2. The fuse also blows when monitored latch switch SW1
remains closed with the oven door open and when the
monitor switch SW2 closes.
3. The fuse blows when the asymmetric rectifier, H.V.
rectifier, H.V. wire harness, H.V. capacitor, magnetron
or secondary winding of power transformer is shorted.
THERMAL CUT-OUT 125°C TC1 (MG)
The thermal cut-out protects the magnetron against
overheat. If this temperature goes up higher than 125°C
because the fan motor is interrupted or the ventilation
openings are blocked, the thermal cut-out TC1 will open
and line voltages to the power transformer T will be cut off
and the operation of the magnetron MG will be stopped. The
defective thermal cut-out TC1 must be replaced with new
one.
THERMAL CUT-OUT 125°C TC2 (OVEN)
The thermal cut-out located on the top of the oven cavity is
designed to prevent damage to the oven if the food in the
oven catches fire due to over heating caused by improper
setting of cook time or failure of control unit. Under normal
operation, the oven thermal cut-out remains closed. How-
ever, 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 TC2 must be replaced with new one.
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 chan-
nelled through the oven cavity to remove steam and va-
pours given off from the heating foods. It is then exhausted
through the exhausting vents at the rear of the oven cavity.
NOISE FILTER
The noise filter prevents the radio frequency interference
that might flow back in the power circuit.
Latch Hooks
Stop Switch
SW3
Monitor Switch
SW2
Monitored Latch
Switch SW1
DOOR OPEN MECHANISM
The door can be opened by puiiing the door handle. When
the door handle is pulled, the latch head is moved upward,
and released from the latch hook now the door can be
opened.

9
R-363 -
D2 D1
ASYMMETRIC
RECTIFIER HIGH VOLTAGE RECTIFIER
The rated peak reverse voltage of D1 of the asymmetric
rectifier is 6 KV. The rated peak reverse voltage of D2 of the
asymmetric rectifier is 1.7 KV. D1 and D2 of the asymmetric
rectifier or high voltage rectifier are shorted when the each
peak reverse voltage goes beyond the each rated peak
reverse voltage.
(The process of blowing the fuse F1)
1. The high voltage rectifier is shorted by any causes when
microwave cooking.
2. The peak reverse voltage of D2 of the rectifier goes
beyond the rated peak reverse voltage 1.7 KV in the
voltage doubler circuit.
3. D2 of the rectifier is shorted.
4. The large electric currents flow through the high voltage
winding of the power transformer.
5. The large electric currents beyond 10A flow through the
primary winding of the power transformer.
6. The fuse F1 blows by the large electric currents.
7. The power supply to the power transformer is cut off.
FUNCTION OF IMPORTANT COMPONENTS
ASYMMETRIC RECTIFIER
The asymmetric rectifier is a solid state device that prevents
current flow in both directions. It prevents the temperature
rise of the power transformer by blowing the special fuse F1
when the high voltage rectifier is shorted.

10
R-363 -
TEST PROCEDURES
PROBLEM
Home fuse blows when power cord is plugged
into wall outlet.
Fuse F8A blows when the door is opened.
Special fuse blows when power supply cord is
plugged into wall outlet.
“88:88”does not appear in display when power
cord is plugged into wall outlet.
Display does not operate properly when STOP
pad is touched.
Oven lamp does not light when door is opened.
(Display appears.)
Oven does not start when 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 do not stop when
cooking time is 0 or STOP 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 operate properly during the variable
cooking condition except ”HIGH”cooking condition.
(Oven stops when STOP pad is touched.)
Oven goes into cook cycle but shuts down before
end of cooking cycle.
Oven stops as soon as the START pad is touched.
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
TEST PROCEDURE
CONDITION
OFF
CONDITION
COOKING
CONDITION
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11
R-363 -
TEST PROCEDURES
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12
R-363 -
NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL
WHILE THE OVEN IS IN OPERATION.
PROCEDURE
LETTER COMPONENT TEST
AMAGNETRON TEST
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 (IEC-60705-1988)
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 60705, 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(g) 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 ...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 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 of 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 5K.
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 an 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 + 3”sec. 3 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) K.
5. Stir the water to equalize temperature throughout the vessel.
TEST PROCEDURES

13
R-363 -
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.
Initial temperature ......................................................................................................... T1 = 11°C
Temperature after (47 + 3) = 50 sec. ............................................................................ T2 = 21°C
Temperature difference Cold-Warm............................................................................ ∆T1 = 10°C
Measured output power
The equation is “P = 90 x ∆T”.................................................P = 90 x 10°C = 900 Watts Approx.
JUDGMENT: The measured output power should be at least ±15 % of the rated output power.
CAUTION: 1°C CORRESPONDS TO 90 WATTS. REPEAT MEASUREMENT IF THE POWER IS
INSUFFICIENT.
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 ............ 2 ohms approximately
b. Secondary winding ....... 130 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
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 kΩin the other direction.
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.
BPOWER TRANSFORMER TEST
Heat up for 50 sec.
CHIGH VOLTAGE RECTIFIER ASSEMBLY TEST
1000g
1000g
1000g
T1˚CT2˚C
TEST PROCEDURES
CARRY OUT 4R CHECKS

14
R-363 -
PROCEDURE
LETTER COMPONENT TEST
CARRY OUT 3D CHECKS.
Isolate the high voltage rectifier assembly from the HV circuit. The asymmetric rectifier can be tested
using an ohmmeter set to its highest range. Connect the ohmmeter across the terminals A + B of the
asymmetric rectifier and note the reading obtained. Reverse the meter leads and note this second
reading. If an open circuit is indicated in both directions then the asymmetric rectifier is good. If an
asymmetric rectifier is shorted in either direction, then the asymmetric rectifier is faulty and must be
replaced with the high voltage rectifier. When the asymmetric rectifier is defective, check whether
magnetron, high voltage rectifier, high voltage wire or filament winding of the power transformer is
shorted.
CARRY OUT 4R CHECKS
NOTE: FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER, THE BATTERIES OF
THE MEASURING INSTRUMENT MUST HAVE A VOLTAGE AT LEAST 6 VOLTS, BECAUSE
OTHERWISE AN INFINITE RESISTANCE MIGHT BE SHOWN IN BOTH DIRECTIONS.
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 10 MΩafter
it has been charged.
D. A short-circuited capacitor shows continuity all the time.
E. An open capacitor constantly shows a resistance about 10 MΩbecause of its internal 10 MΩ
resistance.
F. When the internal wire is opened in the high voltage capacitor, the 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 readings are obtained, the high voltage capacitor must be replaced.
CARRY OUT 4R CHECKS
DHIGH VOLTAGE CAPACITOR TEST
ESWITCH 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.
COM; Common terminal
NO; Normally open terminal
NC; Normally close terminal
Table: Terminal Connection of Switch
Plunger Operation COM to NO COM to NC
Released Open circuit Short circuit
Depressed Short circuit Open Circuit
If incorrect readings are obtained, make the necessary switch adjustment or replace the switch.
CARRY OUT 4R CHECKS.
TEST PROCEDURES
AB
C
D2 D1
ASYMMETRIC
RECTIFIER
HIGH VOLTAGE RECTIFIER
ASYMMETRIC RECTIFIER TEST

15
R-363 -
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
FTHERMAL CUT OUT TEST
CARRY OUT 3D CHECKS
Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make a
continuity test across the two terminals as described below.
CARRY OUT 4R CHECKS
Temperature of ”ON”condition (closed circuit) ................................................................................. This is not resetable type
Temperature of ”OFF”condition (open circuit) ..................................................................................................... Above 125°C
Indication of ohmmeter (When room temperature is approx. 20°C.) ................................................................... Closed circuit
An open circuit thermal cut-out (MG) indicates that the magnetron has overheated, this may be due to
restricted ventilation, cooling fan failure or a fault condition within the magnetron or HV circuit.
An open circuit thermal cut-out (OVEN) indicates that the foods in the oven may have caught fire, this
may be due to over heating produced by improper setting of the cooking timer or failure of the control
panel.
If incorrect readings are obtained , replace the thermal cut-out.
GBLOWN SPECIAL FUSE F8A
CARRY OUT 3D CHECKS
Disconnect the leads from the terminals of
the noise filter.
Using an ohmmeter, check between the ter-
minals as described in the following table.
MEASURING POINTS INDICATION OF OHMMETER
Between N and L >100MΩohm
Between terminal N and WHITE Short circuit
Between terminal L and RED Short circuit
.ssp If incorrect readings are obtained, replace the noise filter unit.
CARRY OUT 4R CHECKS
L(min) Cx ±20% Cy ±20%
1mH 0.22µF 0.0033µF
HNOISE FILTER TEST
RED
WHT
L
L
L
F8A
N
Cx Cy
R2
R1
R1 = 10MΩ±5%
R2 = 680KΩ±5%
CARRY OUT 3D CHECKS
1. If the special fuse F1 is blown, there could be shorts or grounds in electrical parts or wire harness.
Check them and replace the defective parts or repair the wire harness.
2. If the special fuse F1 is blown, there could be a short in the asymmetric rectifier or there is a ground
in wire harness. A short in the asymmetric rectifier may have occurred due to short or ground in H.V.
rectifier, magnetron, power transformer or H.V. wire. Check them and replace the defective parts or
repair the wire harness.
3. If the fuse F1 8A is blown when the door is opened, check the primary latch switch, monitor switch
and monitor resistor.
If the fuse F1 8A is blown by incorrect door switching replace the defective switch(s) and the fuse
F1 8A.
CARRY OUT 4R CHECKS
CAUTION: Only replace special fuse F1 with the correct value replacement

16
R-363 -
COMPONENT TEST
JTOUCH 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 Switch
Unit, and troubleshooting by unit replacement is described according to the symptoms indicated.
1. Switch Unit. Note : Check switch unit lead wire harness connection before replacement.
The following symptoms indicate a defective switch unit. Replace the switch unit.
a) When touching the keys, a certain key produces no signal at all.
b) When touching a key, two figures or more are displayed.
c) When touching the keys, sometimes a key produces no signal.
2. Control Unit
The following symptoms indicate a defective control unit. Before replacing the control unit
perform the Switch unit test (Procedure I) to determine if control unit is faulty.
2-1 In connection with keys.
a) When touching the keys, a certain group of keys do not produce a signal.
b) When touching the keys, no keys produce a signal.
2-2 In connection with indicators
a) At a certain digit, all or some dots do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light.
d) The corresponding dots 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 problems 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.
IMOTOR 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.
Table: Resistance of Motor
Motors Resistance
Fan motor Approximately 290Ω
Turntable motor Approximately 14.6kΩ
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS
TEST PROCEDURES
PROCEDURE
LETTER
Do not touch the electrical parts and the printed wiring board to prevent an electric
CAUTION shock. Because the control unit is " TRANSLESS CIRCUIT " and all electrical parts
are used at A.C. line voltage.

17
R-363 -
PROCEDURE
LETTER
TEST PROCEDURES
KSWITCH UNIT TEST
If the display fails to clear when the STOP key is de-
pressed, first verify the lead wire harness 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 lead
wire harness that connects the switch unit to the display
unit and make sure the door sensing switch is closed
(either close the door or short the door sensing switch
connector). Use the Switch unit matrix indicated on the
switch unit circuit and place a jumper wire between the pins
that correspond to the STOP key making momentary
contact. If the display unit responds by clearing with a beep
the switch unit is faulty and must be replaced. If the display
unit does not respond, it is a faulty and must be replaced.
If a specific key does not respond, the above method may
be used (after clearing the display unit) to determine if the
display unit or switch unit is at fault.
1
2
3
4
5
6
SW1
SW2
SW3
SW4
SW5
SW6
SW7
CN - C
COMPONENT TEST
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, check the tact switch operation.
5. When the tact switch is not depressed, an ohmmeter should indicate an open circuit. When the tact
switch is depressed, an ohmmeter should indicate a short circuit. If improper operation is indicated,
the tact switch is probably defective and should be checked.
L TACT SWITCH TEST
MRELAY TEST
Remove the outer case and check voltage between Pin No 5 of the 3 pin connector (A) and common
terminal of the relay (RY2) on the control unit with an A.C. voltmeter.
The meter should indicate rated voltage, 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.
DC. voltage indicated............. Defective relay.
DC. voltage not indicated....... Check diode which is connected to the relay coil. If diode is good,
control unit is defective.
RELAY SYMBOL OPERATIONAL VOLTAGE CONNECTED COMPONENTS
RY1 Approx. 18.0V D.C. Oven lamp / Turntable motor / Cooling fan motor
RY2 Approx. 7.0V D.C. High voltage transformer

18
R-363 -
TEST PROCEDURES
To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit on
the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given
below for repair.
Problem: POWER ON, indicator does not light up.
STEPS OCCURRENCE CAUSE OR CORRECTION
1 The rated voltage is not applied between Pin Check supply voltage and oven power cord.
No. 5 of the 3 pin connector (A) and the
common terminal of the relay RY2.
2 Only pattern at "a" is broken. *Insert jumper wire J1 and solder.
3 Pattern at "a" and "b" are broken. *Insert the coil RCILF2003YAZZ between "c" and "d".
NOTE: *At the time of making these repairs,
makeavisual inspection of thevaristor.
Check for burned damage. If any ab-
normal condition is detected, replace
the defective parts.
NPROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN
(J1)
b
c d
a
51
R70
RY2
R1
D71
VRS1
ZD70
RY1
PROCEDURE
LETTER COMPONENT TEST

19
R-363 -
OUTLINE OF TOUCH CONTROL PANEL
TOUCH CONTROL PANEL ASSEMBLY
4) Relay Circuit
To drive the magnetron, fan motor, turntable motor and
light the oven lamp.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audiblesounds(tactswitchtouchsoundandcompletion
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.
7) Door Sensing Switch (Stop Switch)
A switch to "tell" the LSI if the door is open or closed.
8) Encoder
The encoder converts the signal generated by LSI into
the pulse signal, and the pulse signal is returned to the
LSI.
9) Back Light Circuit
A circuit to drive the back light (Light emitting diodes
LED1-LED3)
The touch control section consists of the following units.
(1) Switch Unit
(2) Control Unit
The principal functions of these units and the signals commu-
nicated among them are explained below.
Switch Unit
The switch unit is composed of a matrix, signals generated in
the LSI are sent to the switch unit through R60, R61, R62 and
R63.
When a switch button is touched, a signal is completed
through the switch unit and passed back to the LSI through
R81 and R83 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, synchroniz-
ing 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.
2) Indicator Circuit
This circuit consists of 4-digits, 12-segments and 3-
common electrodes using a Liquid Crystal Display.
3) Power Source Circuit
This circuit generates voltage necessary in the control
unit from the AC line voltage.
Symbol Voltage Application
VC +5V LSI(IC1)