Sharp R-15AM User manual

R-15AM
SHARP CORPORATION
SERVICE MANUAL
S0314R15AMPH/
COMMERCIAL
MICROWAVE OVEN
MODEL R-15AM
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
SERVICING ................................................................................................................. INSIDE FRONT COVER
CAUTION, MICROWAVE RADIATION ................................................................................. Indside front cover
WARNING .......................................................................................................................................................... 1
SERVICING ...................................................................................................................................................... 2
PRODUCT SPECIFICATIONS ..........................................................................................................................5
GENERAL INFORMATION ................................................................................................................................ 5
APPEARANCE VIEW ....................................................................................................................................... 6
OPERATION SEQUENCE .................................................................................................................................7
FUNCTION OF IMPORTANT COMPONENTS ................................................................................................ 8
TROUBLESHOOTING GUIDE .......................................................................................................................... 9
TEST PROCEDURE ....................................................................................................................................... 10
CONTROL PANEL ASSEMBLY ..................................................................................................................... 15
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE ........................................................... 19
MICROWAVE MEASUREMENT .................................................................................................................... 25
TEST DATA AT A GLANCE ........................................................................................................................... 25
WIRING DIAGRAM ......................................................................................................................................... 26
PICTORIAL DIAGRAM ................................................................................................................................... 27
CPU UNIT CIRCUIT ........................................................................................................................................ 28
PRINTED WIRING BOARD .............................................................................................................................29
PARTS LIST ................................................................................................................................................... 30
1000W/ R-15AM

R-15AM
CAUTION
MICROWAVE RADIATION
Personnel should not be exposed to the microwave energy which may radiate from the
magnetron or other microwave generating devices if it is improperly used or connected.
All input and output microwave connections, waveguides, flanges and gaskets must be
secured.
Never operate the device without a microwave energy absorbing load attached.
Never look into an open waveguide or antenna while the device is energized.
VARNING
MICKROVAGSSTRALING
Personal får inte utsättas för mikrovågsenergi som kan ustrala från magnetronen eller
andre mikrovågsalstrande anordningar om dessa är felanslutna eller används på fel sätt.
Alla in-och utgångsanslutningar för mikrovågor, vagledare, flänsar och packningar måste
vara fast anslutna.
Mikrovågsgeneratorn får inte arbeta utan att absorberande belastning är ansluten. Titta
aldrig in i ën öppen vågledare eller antenn när mikrovågsgeneratorn är påkopplad eller
laddad.
VAROITUS
MIKROAALTOSÄTELYÄ
Käyttäjä ei saa joutua alttiiksi mikroaaltoenergialle, jota voi säteillä magnetronista tai
muusta mikroaaltoja kehittävästä laitteesta, jos sitä käytetään tai jos se kytketään väärin.
Kaikkien mikroaaltoliitäntöjen sekä syöttö-että ulostulopuolella, aaltoputkien laippojen ja
tiivisteiden tulee olla varmistettuja.
Mikroaaltouunnia ei koskaan saa käyttää ilman kuormaa jossa mikroaaltoenergiaa kuluu.
Avoimeen aaltoputkeen tai antenniin ei koskaan saa katsoa virran ollessa kytkettynä.
ADVARSEL
MIKROBØLGESTRÅLING
Personell må ikke utsettes for mikrobølge-energi som kan utståles fra magnetronen eller
andre mikrobølge-generende deler dersom apparatet feilbetjenes eller blir feiltikoplet.
Alle inn-og ut-tilkoplinger i forbindelse med mikrobølge-strålingen, bølgeledere, flenser og
tetningsringer/pakninger må festes ordentlig.
Aldri bruk apparatet med mindre en mikrobålge-absorberende last er plassert i
ovnsrommet.
Aldri se direkte inn i en åpen bølgeleder eller antenne imens apparatet er strømførende.
ADVARSEL
MIKROBØLGEBESTRÄLING
Man bør ikke udsætte sig for mikrobølgebestråling fra magnetronen eller andre
mikrobølgefrembringende anordninger, hvilket kan ske hvis apparatet er forkert tilsluttet
eller bruges forkert. Alle mikrobølgeindgange og-udgange, bølgeledere, flanger og
tætningsstrimler må være forsvarligt udført.
Anvend aldrig ovnen uden en mikrobølgesabsorberende anordning. Se aldrig ind i en
åben bølgeleder eller antenne, mens ovnen er i brug.

R-15AM
1
SERVICE MANUAL
COMMERCIAL
MICROWAVE OVEN
R-15AM
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 THAT CON-
DUCT MICROWAVE ENERGY.
WARNING
Note: The parts marked "*" are used at voltages 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 potential 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.
SHARP CORPORATION
OSAKA, JAPAN
SERVICING
PRODUCT SPECIFICATIONS
GENERAL INFORMATION
APPEARANCE VIEW
OPERATING SEQUENCE
FUNCTION OF IMPORTANT
COMPONENTS
TROUBLESHOOTING GUIDE
AND TEST PROCEDURE
TOUCH CONTROL PANEL
COMPONENT REPLACEMENT
AND ADJUSTMENT PROCEDURE
MICROWAVE MEASUREMENT
TEST DATA AT A GLANCE
WIRING DIAGRAM
PARTS LIST

2
R-15AM
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 sec-
onds 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 case carry out 3D checks and
then disconnect the leads to the primary of the High voltage
transformer. Ensure that these leads remain isolated from
other components and the oven chassis. (Use insulation tape
if necessary.) When the testing is completed carry out 3D
checks and reconnect the leads to the primary of the High
voltage transformer.
SERVICING
WARNING TO SERVICE PERSONNEL
GB Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts will
result in electrocution.
High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier assembly,High voltage fuse, High
voltage harness.
REMEMBER TO CHECK 4R
1) Reconnect all leads removed from components dur-
ing 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 ceramic shelf, close the door
and set the power to HIGH and set the microwave timer
for one (1) minutes and push the start key. 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 com-
ponent being tested.
When all service work is completed, and the oven is fully
assembled, the microwave power output should be
checked and a microwave leakage test should be car-
ried out.
NL 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.
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 de primaire zijde van de
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
nogmaals de aansluitingen naar de geteste onderdelen.
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.

R-15AM
3
ELos 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.
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.
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.
KOM IHÅG ATT KONTROLLERA 3 STEG
1) Koppla från strömkällan.
2) Öppna dörren på glänt.
3) Ladda ur högspänningskondensatorn.
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.
Sharp rekommenderar att felsökning sker med strömmen
fränkopplad. Ibland kan det var nödvändigt att koppla på
strömmen efter det att höljet avlägsnats, utför da 3 Steg
kontrollen och koppla sedan från ledarna till transformatorns
primärsida. Se till att ledarna är isolerade från andra
komponenter och chassiet. (Använd isoleringsband om det
behövs). När Du testat färdigt utför Du 3 Steg kontrollen och
ansluter ledningarna till transformatorns primärsida igen.
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.
Mikrovågsugnar får inte användas tomma. 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 kontrollerar
anslutningarna till varje enskild komponent på nytt.
När all service är klar och ugnen ihopskruvad skall ugnens
uteffekt och eventuellt mikrovågsläckage kontrolleras.

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R-15AM
IIforni 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.
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.

R-15AM
5
GENERAL INFORMATION
WARNING
THIS APPLIANCE MUST BE EARTHED
IMPORTANT
THE WIRES IN THIS MAINS LEAD ARE COLOURED IN ACCORDANCE WITH THE FOLLOWING CODE:
GREEN-AND-YELLOW : EARTH
BLUE : NEUTRAL
BROWN : LIVE
PRODUCT DESCRIPTION
SPECIFICATION
ITEM DESCRIPTION
Power Requirements 230 Volts
50 Hertz
Single phase, 3 wire earthed
Power Comsumption 1.55 KW Approx. 7.0 A
Power Output
1000 W nominal of RF microwave energy (measured by method of IEC 60705)
Operating frequency 2450 MHz
Case Dimensions Width 520 mm
Height 309 mm including foot
Depth 424 mm
Cooking Cavity Dimensions Width 351 mm
Height 211 mm
Depth 372 mm
Control Complement Jog Touch Control System
Timer (0 - 30 minutes)
Microwave Power for Variable Cooking
Repetition Rate;
100P ........................................ Full power throughout the cooking time
70P ............................................................ approx.70% of Full Power
50P ............................................................ approx.50% of Full Power
30P ............................................................ approx. 30% of Full
10P ............................................................ approx.10% of Full Power
+1 min button
MICROWAVE POWER LEVEL button
STOP button
START button
TIMER knob
Set Weight Approx. 18 kg

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APPEARANCE VIEW
1. Digital Display
2. Indicators
The appropriate indicator will flash or light up,
just above each symbol according to the in-
struction. When an indicator is flashing, press
the suitable button (Having the same symbol)
or do the necessary operation.
Microwave power level
Cooking in progress
3. +1 min button
4. MICROWAVE POWER LEVEL button
5. STOP button
6. START button
7. TIMER knob
OVEN
1. Control panel
2. Door lock openings
3. Oven lamp
4. Ceramic floor (Not removal)
5. Door hinges
6. Door
7. Door open handle
8. Safty door latches
9. Door seals and sealing surfaces
10.Cavity face plate
11.Air ventilation cover and openings
12.Power supply cord
13.Air intake openings
14.Outer case cabinet
ONTROL PANEL
14
11
12
13
8910
213456
7
1
3
7
6
5
4
2

R-15AM
7
OPERATION SEQUENCE
OFF CONDITION
Closing the door activates the 1st. interlock switch SW1
and 2nd. interlock relay control switch SW2.
IMPORTANT:
When the oven door is closed, the contacts COM-NC
of the monitor switch SW3 must be open. When the
microwave oven is plugged in a wall outlet (230V
50Hz), the line voltage is supplied to the control unit
through the noise filter.
Figure O-1 on page 26
1. The display will flash 88:88 .
2. Touch the stop button and the display will show
. .
MICROWAVE COOKING CONDITION
Program desired cooking time by rotating the TIMER knob
clockwise. When the START button is pressed, the follow-
ing operations occur:
Figure O-2 on page 26
RELAY CONNECTED COMPONENTS
RY-1 Oven lamp/Antenna motor/Fan motor
RY-2 ,RY3 High voltage transformer
1. The line voltage is supplied to the primary winding of
the high voltage transformer. The voltage is converted
to about 3.3 volts A.C. output on the filament winding
and high voltage of approximately 2300 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+RY3 go back to their home
position. The circuits to the oven lamp, high voltage
transformer, fan motor and antenna motor are cut off.
5. When the oven door is opened during a cooking cycle,
the switches come to the following condition.
Switch Contact Condition
During Oven Door
Cooking Open(No cooking)
1st. interlock switch COM-NO Closed Opened
2nd. interlock relay
control switch COM-NO Closed Opened
Monitor Switch COM-NC Opened Closed
The circuit to the high voltage transformer, fan motor, oven
lamp and antenna motor are cut off when the 1st. interlock
switch SW1 and 2nd. interlock relay control switch SW2
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 RY-1 stays closed. Shown
in the display is remaining time.
6. MONITOR SWITCH CIRCUIT
The monitor switch is mechanically controlled by the
oven door, and monitors the operation of the 1st.
interlock switch SW1 and the relay RY-2.
6-1. When the oven door is opened during or after the
cycle of a cooking program, the 1st. interlock switch
SW1, and 2nd. interlock relay control switch SW2
must open their contacts first. After that the contacts
(COM-NC) of the monitor switch SW3 can be closed.
6-2. When the oven door is closed, the contacts (COM-
NC) of the monitor switch SW3 must be opened. After
that the contacts of the 1st. interlock switch SW1, and
2nd. interlock relay control switch SW2 are closed.
6-3. When the oven door is opened and the contacts of the
1st. latch switch SW1 and the relay RY-2 remain
closed, the fuse F10A will blow, because the monitor
switch SW3 is closed and a short circuit is caused.
POWER LEVEL 10P TO 90P COOKING
When Variable Cooking Power is programmed, the line
voltage is supplied to the power transformer intermittently
through the contacts of relay (RY-3) which is operated by
the control unit within a 32 second time base. Microwave
power operation is as follows:
VARI-MODE ON TIME OFF TIME
100P (100% power) 32 sec. 0 sec.
70P (approx. 70% power) 24 sec. 8 sec.
50P (approx. 50% power) 18 sec. 14 sec.
30P (approx. 30% power) 12 sec. 20 sec.
10P (approx. 10% power) 6 sec. 26 sec.
Note: The ON/OFF time ratio does not correspond with
the percentage of microwave power, because
approx. 3 seconds are needed for heating of the
magnetron filament.

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R-15AM
DOOR OPEN MECHANISM
The door is opened by grasping the door handle, refer to
Figure D-1.
When the door handle is grasped, the handle lever is
pulled. And then the upper and lower latch heads are
moved upward by the handle lever, and they are re-
leased from the latch hook. Now the door will open.
Figure D-1. Door Open Mechanism
1ST. INTERLOCK SWITCH SW1 AND 2ND. IN-
TERLOCK RELAY CONTROL SWITCH SW2
1. When the oven door is closed, the contacts (COM-NO)
of each switch must be closed.
2. When the oven door is opened, the contacts (COM-
NO) of each switch must be opened.
MONITOR SWITCH SW3
1. When the door is closed, the contacts (COM-NC) must
be opened.
2. When the door is opened, the contacts (COM-NC)
must be closed.
3. If the oven door is opened and the contacts (COM-NO)
of the 1st. interlock switch SW1 and the relay RY-2 fail
to open, the fuse F1 F10A blows immediately after
closing the contacts (COM-NC) of the monitor switch
SW3.
CAUTION: BEFORE REPLACING A BLOWN FUSE F1
F10A TEST THE 1ST. INTERLOCK SWITCH
SW1, MONITOR SWITCH SW3 AND RELAY
RY-2 FOR PROPER OPERATION. (REFER
TO CHAPTER “TEST PROCEDURE”).
FUSE F1 F10A 250V
1. If the wire harness or electrical components are short-
circuited, this fuse blows to prevent an electric shock or
fire hazard.
2. This fuse blows when the 1st. interlock switch SW1 and
the relay RY-2 remain closed with the oven door open
and when the contacts (COM-NC) of monitor switch
SW3 closes.
FUNCTION OF IMPORTANT COMPONENTS
HIGH VOLTAGE FUSE F2 0.75A
The high voltage fuse blows when the high voltage rectifier
or the magnetron is shorted.
THERMAL CUT-OUT TC2 145˚C (MAGNETRON)
This thermal cut-out protects the magnetron against over-
heating. If the temperature goes up higher than 145˚C
because the fan motor is interrupted or the ventilation
openings are blocked, the thermal cut-out will open and
line voltages to the high voltage transformer will be cut off
and the operation of the magnetron will be stopped. The
thermal cut-out will not resume.
THERMAL CUT-OUT TC1 125˚C (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 produced by im-
proper setting of the cooking time or failure of control unit.
Under normal operation, the oven thermal cut-out re-
mains closed. However, when abnormally high tempera-
tures are reached to the oven thermal cut-out, it will open
at 125˚C causing the oven to shut down. The thermal cut-
out will not resume.
NOISE FILTER
The noise filter assembly prevents radio frequency inter-
ference that might flow back in the power circuit.
ANTENNA MOTOR AM
The antenna motor rotates the stirrer antenna located on
the bottom of the oven cavity, so that the food on the
ceramic shelf is cooked evenly during cooking. The an-
tenna motor may turn in either direction.
COOLING FAN MOTOR FM
The cooling fan motor drives a blade which draws exter-
nal cool air. This cool air is directed through the air vanes
surrounding the magnetron and cools the magnetron.
This air is channelled through the oven cavity to remove
steam and vapors given off from the heating food. It is
then exhausted through the exhausting air vents at the
oven cavity.
Latch Hook
Latch Switch
Lever A
Latch Switch
Lever B
Latch Switch
Lever C
Latch Head
Latch Head
Handle
Lever
Door
Handle
Latch
Lever
SW1: 1st. Interlock Switch
SW3: Monitor Switch
SW2:
2nd. Interlock Relay
Control Switch

R-15AM
9
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 F1 (F10A) in the 1st. interlock switch SW1 -
monitor switch SW3 - relay RY-2 circuit, check the 1st. interlock switch SW1, monitor switch SW3 and
relay RY-2 before replacing the fuse F1 (F10A).
TEST PROCEDURE
CONDITION PROBLEM
POSSIBLE CASE
AND
DEFECTIVE PARTS
Home fuse or circuit
breaker blows when power
cord is plugged into wall
outlet.
Fuse F1 F10A blows when
power cord is plugged into
wall receptacle.
88:88 does not appear
in display when power
cord is first plugged into
wall outlet.
Oven lamp does not light
when door is opened.
Oven lamp lights but fan
motor and antenna motor
do not operate.
Oven does not go into
cook cycle when START
button is touched.
Oven seems to be
operating but little or no
heat is produced in oven
load. (Food incompletely
cooked or not cooked at
all at end of cook cycle.)
Oven goes into a cook
cycle but extremely uneven
heating is produced in oven
load (food).
Oven does not cook
properly when programmed
for Cooking 50% power
mode. (Operates properly
on Cooking 100% power
mode.)
"EE9" Maximum time is
exceeded.
OFF
CONDITION
COOKING
CONDITION
ERROR MODE
MAGNETRON HIGH VOLTAGE TRANSFORMER H.V. RECTIFIER ASSEMBLY HIGH VOLTAGE CAPACITOR THERMAL CUT-OUT 1ST. INTERLOCK SWITCH FUSE F1 F10A HIGH VOLTAGE FUSE NOISE FILTER TOUCH CONTROL PANEL KEY UNIT EXCEED MAX. HEATING TIME RELAY (RY3) RELAY (RY2) RELAY (RY1) FOIL PATTERN ON P.W.B. LOW VOLTAGE WRONG OPERATION DIRTY OVEN CAVITY MISADJUSTMENT SWITCH SHORTED IN POWER CORD OVEN LAMP OR SOCKET COOLING FAN MOTOR ANTENNA MOTOR
SHORT OR OPENED WIRING
MONITOR SWITCH 2ND. INTERLOCK RELAY CONTROL SWITCH
ABC D E E EF GH I I JK L M M M N CK RE RE RE CK CK CK CK

10
R-15AM
AMAGNETRON TEST
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
CARRY OUT 3D CHECKS.
Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal.
To test for an open circuit filament use an ohmmeter to make a continuity test between the magnetron
filament terminals, the meter should show a reading of less than 1 ohm.
To test for short circuit 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 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 60705, i.e. it is measured by how much power the water load can absorb. 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.
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±1)°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 be 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˚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.
NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL
WHILE THE OVEN IS IN OPERATION.
The formula is as follows;
P x t / 4.187 = V x ∆T+ 0.55 x mc (T2-T0)/4.187 P (W) = 4.187 x V x ∆T / t + 0.55 x mc (T2-T0)/t
Our condition for water load is as follows:
Room temperature (T0) ... around 20°CPower supply Voltage .............. Rated voltage
Water load..................................1000 g Initial temperature (T1) ...................... 10±1°C
Heating time .............................. 42 sec. Mass of container (mc) ......................... 330 g
T2 ............................ Final Temperature P = 100 x ∆T + 0.55 x mc (T2-T0)/42

R-15AM
11
Room temperature ................................................................................................. To = 21˚C
Initial temperature .................................................................................................. T1 = 11°C
Temperature after (42 + 3) = 45 sec ...................................................................... T2 = 21°C
Temperature difference Cold-Warm........................................................................ ∆T = 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 within the range of ±15 % of the rated output
power.
CAUTION: 1°C CORRESPONDS TO 100 WATTS. REPEAT MEASUREMENT IF THE POWER IS
INSUFFICIENT.
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
1000g
1000g
1000g
T1˚C T2˚C
Heat up for 45 sec
BHIGH VOLTAGE TRANSFORMER TEST
WARNING: High voltage and large currents are present at the secondary winding and
filament winding of the high voltage transformer. It is very dangerous to work
near this part when the oven is on. NEVER make any voltage measurements
of the high-voltage circuits, including the magnetron filament.
CHIGH 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 kΩin the other direction.
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, BE-
CAUSE OTHERWISE AN INFINITE RESISTANCE MIGHT BE SHOWN IN BOTH DIREC-
TIONS.
CARRY OUT 3D CHECKS.
Disconnect the leads to the primary winding of the high voltage transformer. Disconnect the filament
and secondary winding connections from the rest of the HV circuitry. Using an ohmmeter, set on a low
range, it is possible to check the continuity of all three windings. The following readings should be
obtained:-
a. Primary winding ................................ approximately 1.3 Ω
b. Secondary winding ............................. approximately 90Ω
c. Filament winding......................................... less than 1 Ω
If the readings obtained are not stated as above, then the high voltage transformer is probably faulty
and should be replaced.
CARRY OUT 4R CHECKS.
BC
HIGH VOLTAGE RECTIFIER
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.

12
R-15AM
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT 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.
If incorrect readings are obtained, make the necessary switch adjustment or replace the switch.
CARRY OUT 4R CHECKS.
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 in the below.
Table: Thermal Cut-out Test
Temperature of "ON" Temperature of "OFF" Indication of ohmmeter
Parts Name condition (closed circuit). condition (open circuit). (When room temperature
(˚C) (˚C) is approx. 20˚C.)
Thermal cut-out TC1125˚C This is not resetable type. Above 125˚C Closed circuit
Thermal cut-out TC2 145˚C This is not resetable type. Above 145˚C Closed circuit
If incorrect readings are obtained, replace the thermal cut-out.
An open circuit thermal cut-out TC2 (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 TC1 (OVEN) indicates that the food in the oven cavity may catch fire,
this may be due to over heating produced by improper setting of the cooking timer or failure of the
control panel.
CARRY OUT 4R CHECKS.
GBLOWN FUSE F1 F10A
CARRY OUT 3D CHECKS.
If the fuse F1 F10A is blown when the door is opened, check the 1st. interlock switch SW1, monitor
switch SW3 and relay RY-2.
If the fuse F1 F10A is blown, there could be a short or ground in electrical parts or wire harness. Check
them and replace the defective parts or repair the wire harness.
CARRY OUT 4R CHECKS.
CAUTION: Only replace fuse F1 F10A with the correct value replacement.
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 MΩbecause 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.
Table: Terminal Connection of Switch
Plunger Operation COM to NO COM to NC
Released Open circuit Short circuit
Depressed Short circuit Open circuit
COM; Common terminal,
NO; Normally open terminal
NC; Normally close terminal

R-15AM
13
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 219 Ω
Antenna motor Approximately 11 kΩ
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
IMOTOR WINDING TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of noise filter.
Using an ohmmeter, check between the terminals as described
in the following table.
MEASURING POINTS INDICATION OF OHMMETER
Between N and L Approx. 680 kΩ
Between terminal N and WHITE Short circuit
Between terminal L and RED Short circuit
If incorrect readings are absorbed, replace the noise filter unit.
CARRY OUT 4R CHECKS.
HNOISE FILTER TEST
JHIGH VOLTAGE FUSE F2 TEST
CARRY OUT 3D CHECKS.
If the high voltage fuse F2 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 F2.
CARRY OUT 4R CHECKS.
CAUTION: Only replace high voltage fuse with the correct value replacement.
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore,
unlike conventional microwave ovens, proper maintenance can not be performed with only a voltmeter
and ohmmeter.
In this service manual, the touch control panel assembly is in one unit and troubleshooting by unit
replacement is described according to the symptoms indicated.
Control Panel.
The following symptoms indicate a defective control unit.
1. Tact Switch.
The following symptoms indicate a defective tact switch. Replace the tact switch.
a) When touching a tact switch, a certain tact switch produces no signal at all.
b) When touching a tact switch, sometimes a tact switch produces no signal.
2. In connection with tact switches.
a) When touching a tact switch, a certain group of tact switch do not produce a signal.
b) When touching a tact switch, no tact switch produce a signal.
3. Display problems.
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light up.
d) The corresponding segments of all digits do not light up; or they continue to light up.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
KTOUCH CONTROL PANEL ASSEMBLY TEST
F1: FUSE
F10A
NL
DISCHARGE RESISTOR 680 kΩ1/2W
NOISE SUPPRESSION COIL
LINE BYPASS
CAPACITOR
0.0033µF/ AC 250V
DISCHARGE
RESISTOR 10MΩ1/2W
REDWHT
LINE BYPASS
CAPACITOR
0.0033µF/ AC 250V
LINE CROSS CAPACITOR 0.22µF/ AC 250V
NOISE FILTER

14
R-15AM
N PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
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, 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
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
1The rated AC voltage is not present at Check supply voltage and oven power cord.
Power terminal of CPU connector (CN-A).
2The 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)
4Pattern at "a" and "b" are broken. *Insert the coil RCILF2003YAZZ between "c" and "d".
(CARRY OUT 3D CHECKS BEFORE REPAIR)
Remove the outer case and check voltage between Pin No. 1 and Pin No. 3 of the 3 pin connector (A)
on the control unit with an A.C. voltmeter.
The meter should indicate rated voltage, if not check oven circuit.
RY1, RY2 and RY3 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. 24.0V D.C. Oven lamp / Turntable motor / Cooling fan motor
RY2 Approx. 18.0V D.C. High voltage transformer (COM.)
RY3 Approx. 18.0V D.C. High voltage transformer

R-15AM
15
TEST PROCEDURES
PROCEDURE
LETTER COMPONENT TEST
NOTE: *At the time of these repairs, make a
visual inspection of the varistor for
burning damage and examine the
transformer with tester for the pres-
ence of layer short circuit (check pri-
mary coil resistance). f any abnormal
condition is detected, replace the de-
fective parts.
CARRY OUT 4R CHECKS.
RY2
OL / FM
/ TTM
AC
51
D20
VRS1
a
b
d
c
CN - A
D21 RY1
(J1)
T1
4) Reset Circuit
A circuit to generate a signals which resets the LSI to
the initial state when power is supplied.
5) Buzzer Circuit
The buzzer is responsive to signals from the LSI to emit
audible sounds (tact switch touch sound and comple-
tion sound).
6) 2nd. Interlock Relay Control Switch
A switch to "tell" the LSI if the door is open or closed.
7) Relay Circuit
To drive the magnetron, fan motor, antenna motor and
light the oven lamp.
8) Indicator Circuit
This circuit consists of 4-digits, 12-segments and 3-
common electrodes using a Liquid Crystal Display.
9) Encoder
The encoder converts the signal generated by power
source circuit into the pulse signal, and the pulse signal
is returned to the LSI.
10) Back Light Circuit
A circuit to drive the back light (Light emitting diodes
LED1-LED4)
TOUCH CONTROL PANEL ASSEMBLY
OUTLINE OF TOUCH CONTROL PANEL
The touch control section consists of the following units as
shown in the touch control panel circuit.
The principal functions of these units and the signals
communicated among them are explained below.
Tact Switch
Signals R60, R61, R62 and R63 generated in the LSI are
sent to the tact switches.
When a tact switch is touched, a signal is completed
through the tact switch and passed back to the LSI through
R53 to perform the function that was requested.
Control Unit
Control unit consists of LSI, power source circuit, relay
circuit, back light circuit, synchronizing signal circuit, ACL
circuit, buzzer circuit and indicator circuit.
1) LSI
This LSI controls the tact switch strobe signal, relay
driving signal for oven function and indicator signal.
2) Power Source Circuit
This circuit generates voltage necessary in the control
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.

16
R-15AM
Pin No. Signal I/O Description
DESCRIPTION OF LSI
LSI
The I/O signal of the LSI are detailed in the foll owing table.
1-3 SEG21- OUT Terminal not used.
SEG23
4COM1 OUT Common data signal: COM1.
Connected to LCD (Pin No. 1)
5COM2 OUT Common data signal: COM2.
Connected to LCD (Pin No. 2)
6COM3 OUT Common data signal: COM1.
Connected to LCD (Pin No. 3)
7COM4 OUT Terminal not used.
8VLC IN Signal synchronized with commercial power source frequency.
Signal similar to VSS.
9VSS IN Power source voltage: 0V.
VSS voltage of power source circuit input.
10 XIN IN Internal clock oscillation frequency setting input.
The internal clock frequency is set by inserting the ceramic filter oscillation
circuit with respect to XOUT terminal.
11 XOUT OUT Internal clock oscillation frequency control output.
Output to control oscillation input of XIN.
12-15 K00-K03 IN Terminal to change functions according to 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 synchronized with commercial power source frequency.
This is the basic timing for time processing of LSI.
20 R81 IN Signal coming from encoder.
When the encoder is turned, the contacts of encoder make pulse signals. And
pulse signals are input into R81.
21 INT1 IN Signal coming from encoder.
Signal similar to R81. Pulse signals are input into INT1.
22 R83 OUT Terminal not used.
23 R90 IN To input signal which communicates the door open/close information to
LSI.
Door open "L" level signal (0V). Door close "H" level (+5V)
24-25 R91-R92 OUT Terminal not used.
26 VDD IN Connected to GND.
27 R40 OUT Signal to sound buzzer (2.0 kHz).
A: tact switch touch sound.
B: Completion sound.
28 R41 OUT Magnetron high voltage circuit driving signal.
To turn on and off the magnetron high
voltage circuit relay (RY2). "L" level
during cooking, "H" level otherwise.
20.0 msec
H : +5V
L : 0V
A
B
0.1 sec.
2 sec.
H : +5V
L: 0V
H : +5V
L: 0V
ON
OFF
During
cooking
L
GND
H.

R-15AM
17
Pin No. Signal I/O Description
29 R42 OUT Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay (RY3).
In 100% POWER operation, the signals
hold "L" level during microwave cooking
and "H" level while not cooking. In other
cooking modes (70%, 50%, 30%, 10%)
the signal turns to "H" level and "L" level
in repetition according to the power
level.
30 R43 OUT Oven lamp, fan motor and antenna motor driving signal.
To turn on and off shut off relay (RY1). The
square waveform voltage is delivered to
the RY1 driving circuit.
31-33 R50-R52 OUT Terminal not used.
34 R53 IN Signal coming from tact switch.
When either of tact switches SW60-SW63 is touched, a corresponding signal
out of R60, R61, R62 and R63 will be input into R53. When no key is touched,
the signal is held at "H" level.
35 R60 OUT Tact switch strobe signal.
Signal applied to tact switch section. A pulse signal is input to R53 terminal
while the tact switch SW60 is touched.
36 R61 OUT Tact switch strobe signal.
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 tact switch SW63 is touched.
39-42 R70-R73 OUT Terminal not used.
43-54 SEG0 - OUT Segment data signal.
SEG11 Connected to LCD.
The relation between signals are as follows:
LSI signal (Pin No.) LCD segment LSI signal (Pin No.) LCD segment
SEG 0 (43) ............................ S12 SEG 6 (49) ............................ S6
SEG 1 (44) ............................ S11 SEG 7 (50) ............................ S5
SEG 2 (45) ............................ S10 SEG 8 (51) ............................ S4
SEG 3 (46) .............................. S9 SEG 9 (52) ............................ S3
SEG 4 (47) .............................. S8 SEG 10 (53) .......................... S2
SEG 5 (48) .............................. S7 SEG 11 (54) .......................... S1
55-57 SEG12- OUT Terminal not used.
SEG14
58 VDD IN Power source voltage input terminal.
Connected to GND.
59-64 SEG15- OUT Terminal not used.
SEG20
ON/OFF time ratio in Mi-
cro cooking
(a. 32second time base)
MICRO ON OFF
COOK
100% 32sec. 0sec.
70% 24sec. 8sec.
50% 18sec. 14sec.
30% 12sec. 20sec.
10% 6sec. 26sec.
20.0 msec
During cooking
H : +5V
L : 0V

18
R-15AM
1. Precautions for Handling Electronic Components
This unit uses CMOS LSI in the integral part of the
circuits. When handling these parts, the following pre-
cautions should be strictly followed. CMOS LSI have
extremely high impedance at its input and output
terminals. For this reason, it is easily influenced by the
surrounding high voltage power source, static electric-
ity charge in clothes, etc., and sometimes it is not fully
protected by the built-in protection circuit.
In order to protect CMOS LSI.
1) When storing and transporting, thoroughly wrap
them in aluminium foil. Also wrap PW boards con-
taining them in aluminium foil.
2) When soldering, ground the technician as shown in
the figure and use grounded soldering iron and
work table.
2. Shapes of Electronic Components
3. Servicing of Touch Control Panel
We describe the procedures to permit servicing of the
touch control panel of the microwave oven and the
precautions you must take when doing so.
To perform the servicing, power to the touch control
panel is available either from the power line of the oven
itself or from an external power source.
(1) Servicing the touch control panel with power
supply of the oven :
CAUTION:
THE HIGH VOLTAGE TRANSFORMER OF THE
MICROWAVE OVEN IS STILL LIVE DURING
SERVICING AND PRESENTS A HAZARD .
Therefore, when checking the performance of the
touch control panel, put the outer cabinet on the
oven to avoid touching the high voltage trans-
former, or unplug the primary terminal (connector)
of the high voltage transformer to turn it off; the end
of such connector must be insulated with an insulat-
ing tape. After servicing, be sure to replace the
leads to their original locations.
A. On some models, the power supply cord between
the touch control panel and the oven itself is so short
that the two can't be separated.
For those models, check and repair all the controls
(sensor-related ones included) of the touch control
panel while keeping it connected to the oven.
SERVICING
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 ends of the door
sensing switch (on PWB) of the touch control panel
with a jumper, which brings about an operational
state that is equivalent to the oven door being
closed. As for the sensor-related controls of the
touch control panel, checking them is possible if the
dummy resistor(s) with resistance equal to that of
the controls are used.
(2) Servicing the touch control panel with power
supply from an external power source:
Disconnect the touch control panel completely from
the oven proper, and short both ends of the door
sensing switch (on PWB) of the touch control panel,
which brings about an operational state that is
equivalent to the oven door being closed. Connect
an external power source to the power input termi-
nal of the touch control panel, then it is possible to
check and repair the controls of the touch control
panel; it is also possible to check the sensor-related
controls of the touch control panel by using the
dummy resistor(s).
4. Servicing Tools
Tools required to service the touch control panel as-
sembly.
1) Soldering iron: 30W
(It is recommended to use a soldering iron with a
grounding terminal.)
2) Oscilloscope: Single beam, frequency range: DC -
10MHz type or more advanced model.
3) Others: Hand tools
5. Other Precautions
1) Before turning on the power source of the control
unit, remove the aluminium foil applied for prevent-
ing static electricity.
2) Connect the connector of the key unit to the control
unit being sure that the lead wires are not twisted.
3) After aluminium foil is removed, be careful that
abnormal voltage due to static electricity etc. is not
applied to the input or output terminals.
4) Attach connectors, electrolytic capacitors, etc. to
PWB, making sure that all connections are tight.
5) Be sure to use specified components where high
precision is required.
Transistor
2SB1238
Transistor
DTA123ES
KRA101M
KRA223M
KRC243M
approx. 1M ohm
ECB
ECB