Sharp R-3A56(W) Manuel utilisateur

A-3A56(W)

R-3A56(B)

SHARP.

SERVICE

MANUAL

MICROWAVE

OVEN

MODELS

R-3A56(W)

R-3A56(B)

R-3A56

In

interests

of

user-safety

the

oven

should

be

restored

to

its

original

condition

and

only

parts

identical

to

those

specified

should

be

used.

TABLE

OF

CONTENTS

Page

CAUTION,

MICROWAVE

RADIATION

GENERAL

IMPORTANT

INFORMATION,

WARNING

PRODUCT

SPECIFICATIONS

APPEARANCE

VIEW

OPERATION

SEQUENCE

FUNCTION

OF

IMPORTANT

COMPONENTS

SERVICING

TEST

PROCEDURE

TOUCH

CONTROL

ASSEMBLY?

cccic.t.ccists

locas

da

caaciaciccceqcug

colette

denvevevensetesdtanacedluardaieevebestsvgerbvoauenceusuaers

7

COMPONENT

REPLACEMENT

AND

ADJUSTMENT

PROCEDURE

.0000..

ee

eeseeeeeeseneseeeseeeeteeneeeeeaeaeen

2

MICROWAVE

MEASUREMENT

....0......ccccecscccsscssssessssasceecseeecsaeesseseeaeeeeesesdeceeeseaueseaeseaeseeeessecaneeseaeeeees

-

TEST

DATAAT:

A

GLANCE

iicsiiscccsecetiscwterssstusscsevsosevstarversertibecdvecesisusracacepeasduclasasndaasnbdasiedaddaednert

ofimeersen

-

WIRING:

DIAGRAM

ci.

cis.

ccei.

onteates

sleseesgidscevandiihanadsvents

oseusvacoucededede

cutpa

sunceviiisdesced

GewsdeeavaeVediwedandassdhastactudsTaaiy

.

30

PICTORIAL

DIAGRAM

5.150200

sSasvesezdisiasheiue

dosdiusecastasacasaecoats

Saceydsnscedents

sgeveuct

suuusvaeaasebadaaceustsecasacasaddapeadenesin

-

31

CONTROE

PANEL:

GIRCUUID:

i

screed

ccistesniccucctceSccuseeesgesscedecesatd

osat

tuakbeupccspensygtoundads

cvuadcvesuudyandeacenucned

tee

oa

.

32

PRINTED

WIRING

DIAGRAM

3...

nec.

ccs

cccaescececcceti

eceaiecnsatuteancteasasseveuceaweswedecentensencusicuved

dvlesuteaanaedueevevedn

-

33

PARTS

EIST

vncisvcccesevssessccsennancvtssatvctevesssadataobetisveresbevesveecacedseaedecutesdtctacesuepiucveleadvansdeusastcenedtduasuvestdeteeercnia

-

34

PACKING

AND

ACCESSORIES

.0......cccccccssesssssesceescseeseceesseeeeneeeteeeeeeesaesesueeanessanesassessesesseseeseneasenaeseessar

-

39

SHARP

CORPORATION

R-3A56(W)

R-3A56(B)

CAUTION

MICROWAVE

RADIATION

Personnel

should

not

be

exposed

to

the

mircowave

energy

which

may

radiate

from

the

magnetron

or

other

microwave

generating

devices

if it

is

improperly

used

or

connected.

All

input

and

output

micro-

wave

connections,

waveguides,

flanges

and

gaskets

must

be

secured.

Never

operate

the

device

with-

out

a

microwave

energy

absorbing

load

attached.

Never

look

into

an

open

waveguide

or

antenna

while

the

device

is

energised.

VARNING

MIKROVAGSSTRALING

Personal

far

inte

utsattas

for

mikrovagsenergi

som

kan

utstrala

fran

magnetronen

eller

andre

mikrovagsalstrande

anordningar

om

dessa

4r

felanslutna

eller

anvands

pa

fel

satt.

Alla

in-och

utgangsanslutningar

for

mikrovagor,

vagledare,

flansar

och

packningar

maste

vara

fast

anslutna.

Mikrovagsgeneratorn

far

inte

arbeta

utan

att

absorberande

belastning

ar

ansluten.

Titta

aldrig

ini

en

dppen

vagledare

eller

antenn

nar

mikrovagsgeneratorn

ar

pakopplad

eller

laddad.

=

VAROITUS

MIKROAALTOSATEILYA

Kayttaja

ei

saa

joutua

alttiiksi

mikroaaltoenergialle,

jota

voi

sateilla

magnetronista

tai

muusta

mikroaaltoja

kehittavasta

laitteesta,

jos

sita

kaytetaan

vaarin

tai

jos

se

kytketaan

vaarin.

Kaikkien

mikroaaltoliitantéjen

seka

sy6ttd-etta

ulostulopuolella,

aaltoputkien

laippojen

ja

tiivisteiden

tulee

olla

varmistettuja.

Mikroaaltouunia

ei

koskaan

saa

kayttaa

ilman

kuormaa

jossa

mikroaaltoenergiaa

kuluu.

Avoimeen

aaltoputkeen

tai

antenniin

ei

koskaan

saa

katsoa

virran

ollessa

kytkettyna.

ADVARSEL

—

MIKROBOLGESTRALING

Personell

ma

ikke

utsettes

for

mikrobglge-energi

som

kan

utstrales

fra

magnetronen

eller

andre

mikrobelge-generende

deler

dersom

apparatet

feilbetjenes

eller

blir

feiltikoplet.

Atle

inn-og

ut-

tilkoplinger

i

forbindelse

med

mikrobalge-stralingen,

belgeledere,

flenser

og

tetningsringer/pakninger

ma

festes

ordentlig.

Aldri

bruk

apparatet

med

mindre

en

mikrobalge-absorberende

last

er

plassert

i

ovnsrommet.

Aldrise

direkte

inn

i

en

Apen

belgeleder

eller

antenne

imens

apparatet

er

stramfgrende.

ADVARSEL

MIKROBOLGEBESTRALING

Man

bor

ikke

udszette

sig

for

mikrobalgebestraling

fra

magnetronen

eller

andre

mikrobglgefrembringende

anordninger,

hvilket

kan

ske

hvis

apparatet

er

forkert

tilsluttet

eller

bruges

forkert.

Alle

mikrobelgeindgange

og-udgange,

baigeledere,

flanger

og

tezetningsstrimler

ma

veere

forsvarligt

udfgrt.

Anvend

aldrig

ovnen

uden

en

mikrobelgeabsorberende

anordning.

Se

aldrig

ind

i

en

Aben

bgigeleder

eller

antenne,

mens

ovnen

er

i

brug.

SERVICE

MANUAL

SHARP

MICROWAVE

OVEN

R-3A56(W)

/

R-3A56(B)

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.

The

parts

marked

"*"

are

used

at

voltage

more

than

250V.

(Parts

List)

Delar

market

med

"*“

har

en

spanning

éverstigande

250V.

Huolto-chjeeseen

merkitty.

"tahdelia"

osat

joissa

jannite

on

yli

250V.

Deler

som

er

merket

“asterisk”

er

utsatt

for

spenninger

over

250V

til

jord.

Dele

mzerket

med

stjerne

benyttes

med

hojere

speending

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.

SHARP

CORPORATION

OSAKA,

JAPAN

R-3A56(W)

R-3A56(B)

|

PRODUCT

SPECIFICATION

GENERAL

INFORMATION

APPEARANCE

VIEW

|

OPERATING

SEQUENCE

|

FUNCTION

OF

IMPORTANT

|

COMPONENTS

ISERVICINGAND

~—

|

TROUBLESHOOTING

CHART

t

TEST

PROCEDURE

“~E

TOUCH

CONTROL

PANEL

ADJUSTMENT

PROCEDURE

MICROWAVE

MEASUREMENT

|

TEST

DATA

AT

A

GLANCE

WIRING

DIAGRAM

PARTS

LIST

R-3A56(W)

R-3A56(B)

PRODUCT

SPECIFICATIONS

SPECIFICATION

ITEM

DESCRIPTION

Power

Requirements

220

-230

Volts

50

Hertz

Single

phase,

3

wire

grounded

Power

Consumption

1.5

kW

Power

Output

Q900W

watts

nominal

of

RF

microwave

energy

(measured

by

way

of

IEC

705)

Operating

frequency

of

2450

MHz

Case

Dimensions

Width

450mm

Height

295mm

including

foot

Depth

360mm

=

Cooking

Cavity

Dimensions

Width

290mm

Height

174mm

Depth

313mm

Tumiabie

diameter

Control

Complement

Touch

Control

System

Clock(1:00-12:59

or

0:00-23:59)

Microwave

Power

for

Variable

Cooking

Repetition

Rate;

Full

power

throughout

the

cooking

time

approx.

70%

of

Full

Power

approx.

50%

of

Full

Power

approx.

30%

of

Full

Power

approx.

10%

of

Full

Power

AUTO

MINUTE

pad

START

pad

POWER

LEVEL

pad

STOP/CLEAR

pad

Time

pads

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

R-3A56(W)

R-3A56(B)

APPEARANCE

VIEW

OVEN

Door

—

Tumtable

Door

hinges

Waveguide

cover

Contol

panel

Door

lock

openings

————

Roller

stay

Oven

cavity

Door

seals

and

sealing

surfaces

|

Safety

door

latches

Ventilation

openings

0.

Outer

case

1.

Power

supply

cord

A

SOON

DARWN

=

Seal

packing

1.

Place

the

roller

stay

on

the

floor

of

the

oven

cavity.

2.

Then

place

the

turntable

on

it

fitting

to

the

coupling.

THE

AUTO-TOUCH

CONTROL

PANEL

More

Indicator

Less

Indicator

Low

Indicator

Med/Low

indicator

Med

indicator

Med/High

indicator

High

indicator

Digital

display

Pieces

indicator

.

Unit

weight

indicator

.

Cook

indicator

.

Snack

keys

.

Potato

keys

.

Instant

action

keys

.

More/Less

keys

.

Time

keys

.

Timer/Hold

key

.

Clock

set

key

.

Power

level

key

.

Stop

key

.

Auto

minute/Start

key

.

Door

open

button

©

ODNAaAPR

WON

>

[Onn

©

a

en

i

N+]

CO

DAN

DAR

WN

=

OC

R-3A56(W)

R-3A56(B)

OPERATING

SEQUENCE

OFF

CONDITION

Closing

the

door

activates

all

door

interlock

switches

(pri-

mary

latch

switch,

2nd

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

pluged

in

a

wall

outlet

(240V

50H2),

the

line

voltage

is

supplied

to

the

point

A3+A5

in

the

control

unit.

Figure

O-1

on

page

30

—

.

The

display

flashes

"88:88".

2.

Toset

any

programmes

or

set

the

clock,

you

must

first

touch

the

STOP

pad.

3.

“88:88”

appears

in

the

display

and

the

time

counts

up

every

minute.

NOTE:

When

the

oven

door

is

opened,

the

oven

lamp

comes

on

at

this

time.

MICROWAVE

COOKING

CONDITION

HIGH

COOKING

Enter

a

desired

cooking

time

with

the

touching

Time

pad

and

start

the

oven

with

touching

START

pad.

Function

sequence

Figure

0-2

on

page

30

CONNECTED

COMPONENTS

RELAY

Oven

famp,

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

voltagedoubling

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

channeled

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.

CONDITION

DURING

DOOR

OPEN

SWITCH

CONTACT

COOKING

=

(NO

COOKING)

Primary

latch

switch

COM-NO

Closed

Open

Monitor

switch

COM-NC

Open

Closed

2nd

latch

switch

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,

2nd

latch

switch

and

stop

switch

are

made

open.

The

oven

jamp

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

(SW3)

is

mechanically

controlled

by

oven

door,

and

monitors

the

operation

of

the

1st

latch

switch

(SW1)

6-1

When

the

oven

door

is

opened

during

or

after

the

cycle

of

cooking

program,

the

primary

latch

switch

(SW1),

and

stop

switch

(SW4)

must

open

their

contacts

first.

After

that

the

contacts

(COM

-

NC)

of

the

monitor

switch

(SW3)

can

be

closed

and

then

contacts

of

the

2nd

latch

switch

(SW2)

can

be

opened.

6-2

When

the

oven

door

is

closed,

the

contacts

(COM

-

NC)

of

the

monitor

switch

(SW3)

must

be

opened

and

contacts

(COM

-

NO)

of

the

2nd

latch

switch

(SW2)

must

be

closed

first.

After

that

the

contacts

of

the

primary

latch

switch

(SW1)

and

stop

switch

(SW4)

are

closed.

6-3

When

the

oven

door

is

opened

and

the

contacts

of

the

primary

latch

switch

(SW1)

remain

closed,

the

fuse

(F)

F7.4A

will

blow,

because

the

monitor

switch

is

closed

and

a

short

circuit

is

caused.

HIGH,

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

32-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

32

sec.

ON

HIGH

24

sec.

ON

8

sec.

OFF

MEDIUM

HIGH

Approx.

70%

=

630

Watts

18

sec.

ON

14

sec.

OFF

‘

MEDIUM

kx

°°»

&

|

Approx.

50%

=

450

Watts

-

12

sec.

ON

20

sec.

OFF

MEDIUM

LOW

Approx.

30%

=

270

Watts

6

sec.

ON

30

sec.

OFF

NOTE:

The

ON/OFF

time

ratio

does

not

exactly

correspond

to

the

percentage

of

microwave

power,

because

approx.

2

seconds

are

needed

for

heating

up

the

magnetron

filament.

R-3A56(W)

R-3A56(B)

FUNCTION

OF

IMPORTANT

COMPONENTS

DOOR

OPEN

MECHANISM

The

door

can

be

opened

by

pushing

the

door

open

button

on

the

control

panel.

When

the

door

open

button

is

pushed,

the

cook

lever

is

moved

upward,

operating

the

latch

head.

The

latch

head

is

moved

upward,

and

released

from

the

latch

hook.

Now,

the

door

can

be

opened.

DOOR

STOP

SWITCH

LATCH

HOOK

2ND

LATCH

SWITCH

MONITOR

SWITCH

LATCH

HEADS

pamany

LATCH

CH

OPEN

LEVER

DOOR

OPEN

BUTTON

Figure

D-1.

Door

Open

Mechanism

PRIMARY

LATCH

SWITCH

(SW1)

2ND

LATCH

SWITCH

(SW2)

apr

SWITCH

(SW4)

.

When

the

oven

door

is

closed,

the

contacts

(COM

-

NO)

must

be

closed.

2.

When

the

oven

dooris

opened,

the

contacts

(COM

-

NO)

must

be

opened.

MONITOR

SWITCH

(SWS)

1.

When

the

oven

door

is

closed,

the

contacts

(COM

-

NC)

must

be

opened.

2.

When

the

oven

door

is

opened,

the

contacts

(COM

-

NC)

must

be

closed.

3.

If

the

oven

door

is

opened

and

the

contacts

(COM

-

NO)

of

the

primary

latch

switch

(SW1)

fail

to

open,

the

fuse

F7.4A

blows

simultaneously

with

closing

the

contacts

(COM

-

NC)

of

the

monitor

switch

(SW3).

CAUTION:

BEFORE

REPLACING

A

BLOWN

FUSE

(F)

F7.4A

TEST

THE

PRIMARY

LATCH

SWITCH

(SW1),

MONITOR

SWITCH

(SW3)

AND

MONITOR

RESISTOR

FOR

PROPER

OPERATION.

(REFER

TO

CHAPTER

"TEST

PROCEDURE”.)

MONITOR

RESISTOR

0.80hm

20W

The

monitor

resistor

prevents

the

maximum

breaking

ca-

pacity

of

the

F7.4A

fuse

from

being

exceeded

due

to

operation

of

the

monitor

switch

ASYMMETRIC

RECTIFIER

The

asymmetric

rectifier

is

a

solid

state

device

that

prevents

current

flow

in

both

directions.

And

it

prevents

the

tempera-

ture

rise

of

the

power

transformer

by

blowing

the

special

fuse

F7.4A

when

the

high

voltage

rectifier

is

shorted.

ASYMMETRIC

Le

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

F7.4A.)

1.

The

high

voltage

rectifier

is

shorted

by

anycauses

when

microwave

cooking

or

dual

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.

.

D2

of

the

rectifier

is

shorted.

.

The

large

electric

currents

flow

through

the

high

voltage

winding

of

the

power

transformer.

5.

The

large

electric

currents

flow

through

the

primary

winding

of

the

power

transformer.

.

The

fuse

F7.4A

blows

by

the

large

electri

currents.

7.

The

power

supply

to

the

power

transformer

is

cut

off.

mee)

ao

Pagar

F7.4A

The

fuse

F7.4A

blows

when

the

contacts

((OM-

NO)

of

the

primary

latch

switch

(SW1)

remain

cls

ed

with

the

oven

door

open

and

when

the

monitor

switch

(SWS)

closes.

2.

The

fuse

F7.4A

also

blows

when

asymmetric

rectifier,

H.V.

rectifer,

H.V.

wire

harness,

H.\.

capacitor,

magnetron

or

secondary

winding

of

powe

transformer

is

shorted.

3.

If

the

wire

harness

or

electrical

components

are

short-

circuited,

the

fuse

F7.4A

blows

to

prevent

an

electric

shock

or

fire

hazard.

THERMAL

CUT-OUT

145°C

TC1

(MG)

The

thermai

cut-out

protects

the

magnetron

against

ove

r-

heat.

if

this

temperature

goes

up

higher

tha

145°C

be-

cause

the

fan

motor

is

interrupted,

the

ventilaio

n

openings

are

blocked,

the

thermal

cut-out

(TC1)

will

men

and

line

voltages

to

the

power

transformer

will

be

cut

off

and

the

operation

of

the

magnetron

will

be

stopped.

Th

©

defective

thermal

cut-out

(TC1)

must

be

replaced

withnéw

one.

R-3A56(W)

R-3A56(B)

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

foods

in

the

oven

catch

fire

due

to

over

heating

produced

by

unproper

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

channeled

through

the

oven

cavity

to

remove

steam

and

vapours

given

off

from

the

heating

foods.

It

is

then

ex-

hausted

through

the

exhausting

air

vents

at

the

oven

cavity.

NOISE

FILTER

The

noise

filter

prevents

the

radio

frequency

interference

that

might

flow

back

in

the

power

circuit.

R-3A56(W)

R-3A56(B)

SERVICING

WARNING

TO

SERVICE

PERSONNEL

Microwave

ovens

contain

circuitry

capable

of

producing

very

high

voltage

and

current,

contact

with

following

parts:

High

voltage

capacitor,

Power

transformer,

Magnetron,

High

voitage

rectifier

assembly,

High

voltage

harness.

REMEMBER

TO

CHECK

3D

REMEMBER

TO

CHECK

4R

.

1)

Reconnect

all

leads

removed

from

components

1)

Disconnect

the

supply.

during

testing.

2)

Door

opened,

and

wedged

open.

2)

Replace

the

outer

case

(cabinet).

3)

Discharge

high

voltage

capacitor.

3)

Reconnect

the

supply.

WARNING

AGAINST

THE

CHARGE

OF

THE

4)

Run

the

oven.

Check

all

functions.

HIGH-VOLTAGE

CAPACITOR

Microwave

ovens

should

not

be

run

empty.

To

test

for

the

presence

of

microwave

energy

within

a

cavity,

place

a

cup

of

cold

water

on the

oven

turntable,

close

the

door

and

set

the

microwave

timer

for two

(2)

minutes.

Set

the

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

power

level

to

HIGH

and

push

the

START

button.

When

connection

of

the

high-voltage

capacitor

(that

is,

of

the

connecting

lead

of

the

high-voltage

recti-

fier)

against

the

chassis

with

the

use

of

an

insu-

lated

screwdriver.

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.

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

re-

main

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.

When

all

service

work

is

completed,

and

the

oven

is

fully

assembled,

the

microwave

power

output

shouldbe

checked

and

a

microwave

leakage

test

carried

out.

TROUBLESHOOTING

GUIDE

When

troubleshooting

the

microwave

oven,

it

is

helpful

to

IMPORTANT:

If

the

oven

becomes

inoperatve

because

follow

the

Sequence

of

Operation

in

performing

the

checks.

of

a

blown

fuse

F7.4A

in

the

prirmary

latch

Many

of

the

possible

causes

of

trouble

will

require

that

a

switch

-

monitor

switch

-

moritor

resistor

specific

test

be

performed.

These

tests

are

given

a

proce-

circuit,

check

the

primary

lach

switch,

dure

letter

which

will

be

found

in

the

"Test

Procedure”

monitor

switch

and

monitor

resistor

before

section.

replacing

the

fuse

F7.4A.

R-3A56(W)

R-3A56(B)

[esr

proceune

JA]

8]

COE

[EEE]

Flap

[sa

Mi

epluilulel2imi]s|]r]el|nimMielr

AlolvivilrRInilo|tilHluloloitalu

clwl|.]|.trlolnwlo]lels|rininie

N|E

clmM]|.{/i}]e}]erielsia

N

E}R|R]A;Aalilt

M

E/|t|mM{T

E/PirR{|Alols|aler

olola

POSSIBLE

CAUSE

R/TtTlc}lajly}lTr]R{/|wilcel]

7]/rl]

eit

s

AND

Pree

ale

colabale

taal

LI

a

c

L/R]

RIE

DEFECTIVE

PARTS

N|

FI

TIA

wilclu|]*/tle

sS}/1}o]Tt{]s]i]H}]

tr]

Ale]s

M

FIlE{R|cilwli|t

l

R

|

I

O

Oo}

R

H]/1ic¢

0

S

T

R

TI

H

U

T

O

MIA

sic

T

O

R

E|

S

wl

R

R|

Ss

1

E

T

M

Cc

B

H

L

Y

PROBLEM

Home

fuse

blows

when

power

cord

is

plugged

into

wall

outlet.

Fuse

F7.4A

blows

when

power

cord

is

plugged

into

wall

outlet.

“88:88”

dose

not

appear

in

display

when

power

cord

is

plugged

into

wall

outlet.

Display

does

not

operate

properly

when

STOP/CLEAR

pad

is

touched.

OFF

CONDITION

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

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.

COOKING

CONDITION

Oven

stops

as

soon

as

the

START

pad

is

touched.

Sharp R-3A56(W) Manuel utilisateur

Manuels Four à micro-ondes populaires d'autres marques