Sharp R-5L16 User manual

SERVICE MANUAL
SHARP CORPORATION
R-5L16
TABLE OF CONTENTS Page
CAUTION, MICROWAVE RADIATION....................................................................................................... 1
WARNING....................................................................................................................................................1
PRODUCT SPECIFICATIONS ................................................................................................................... 2
GENERAL IMPORTANT INFORMATION ...................................................................................................2
APPEARANCE VIEW ................................................................................................................................. 3
OPERATION SEQUENCE.......................................................................................................................... 4
FUNCTION OF IMPORTANT COMPONENTS .......................................................................................... 5
SERVICING ................................................................................................................................................ 7
TEST PROCEDURE................................................................................................................................... 9
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE..................................................... 15
MICROWAVE MEASUREMENT .............................................................................................................. 20
TEST DATA AT A GLANCE ..................................................................................................................... 21
WIRING DIAGRAM................................................................................................................................... 22
PICTORIAL DIAGRAM ............................................................................................................................. 23
PARTS LIST ............................................................................................................................................. 24
MICROWAVE OVEN
In interests of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
MODEL R-5L16
S3401R5L16EHW

R-5L16
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.

1
R-5L16
WARNING
Note: Thepartsmarked"*"areusedinvoltagemorethan250V.
(Parts List)
Allthepartsmarked"∆"onthepartslistmaycauseundue
microwave exposure, by themselves, or when they are
damaged, loosened or removed.
Anm: Delar märket med "*" har en spänning överstigande
250V.
Allareservdelarsom ärmärktamed "∆"ireservdelslistan
kanförorsakaomåttingmikrovågsstrålning,antingenisig
själva, eller när de har blivit skadade, lösa eller.
Huom: Huolto-ohjeeseen merkitty "tähdella" osat joissa jännite
on yli 250 V.
Kaikki varaosaluettelossa ∆:lla merkityt osat voivat
aiheuttaa asiaankuulumatonta mikroaaltosäteilyä; joko
sinällään, tai kun ne ovat rikki, löystyneet tai irroitettu.
Bemerk: Deler som er merket "asterisk" er utsatt for spenninger
over 250V til jord.
Alle delene som er merkt med "∆" på del-listen kan
forårsake utstrakt mikrobølgestråling, og denne faren
øker når de er skadet, løsner eller fjernes.
Bemærk: "Delemærketmedstjernebenyttesmedhøjerespænding
end 250 volt.
Alle delene mærket "∆" på delbetegnelsen på medføre
udsættelse for mikrobølger, af sig selv eller når de bliver
beskadigede, løsnede eller fjernet.
SHARP CORPORATION
OSAKA, JAPAN
SERVICE MANUAL
GENERAL INFORMATION
APPEARANCE VIEW
OPERATING SEQUENCE
FUNCTION OF IMPORTANT
COMPONENTS
SERVICING AND
TROUBLESHOOTING CHART
TEST PROCEDURE
COMPONENT
REPLACEMENT AND
ADJUSTMENT PROCEDURE
MICROWAVE MEASUREMENT
TEST DATA AT A GLANCE
WIRING DIAGRAM
PARTS LIST
PRODUCT SPECIFICATIONS
MICROWAVE OVEN
R5L16
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
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.
Servicingand repairwork mustbe carried out only bytrained service
engineers.

2
R-5L16
ITEM DESCRIPTION
Power Requirements 220-230 Volts
50 Hertz
Single phase, 3 wire earthed
Power Consumption 1750 W Approx. 8 A
Power Output 1000 W nominal of RF microwave energy (measured by method of IEC 705)
Operating fequency 2450 MHz
Case Dimensions Width 520 mm
Height 305 mm including foot
Depth 413 mm
Cooking Cavity Dimensions Width 342 mm
Height 193 mm
Depth 368 mm
Turntable diameter 325mm
Control Complement 30 min. Single-speed timer
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
Set Weight (Approx.) Approx. 17.0 kg
PRODUCT DESCRIPTION
SPECIFICATION
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

3
R-5L16
APPEARANCEVIEW
CONTROLPANEL
Turntable
Coupling
Roller Stay
1. Place the roller stay on the floor of
the oven cavity.
2. Then place the turntable on it fitting
to the coupling.
OVEN
Oven lamp
Door hinges
Coupling
Control panel
Door
Oven cavity




Ventilation openings
Outer cabinet
Rear cabinet
Power supply cord
Spacer
Waveguide cover
Door seals and sealing surfaces
Door lock opening
Safety door latches
Oven lamp access cover
5
10
20 15
25
30
START BUTTON
MICROWAVE POWER
CONTROL
TIMER (0 - 30 mim)
DOOR OPEN BUTTON

4
R-5L16
OFF CONDITION
1. Whenthetimerknobisat"•",theovenisOFFcondition.
2. Closing the oven door activates the primary latch switch
SW1,the 2nd latchswitch SW2, and the3rd latch switch
SW3.
IMPORTANT:
When the oven door is closed, the contactsCOM-NC of the
monitor switch SW5 must be open.
Figure O-1 on page 22
3. When the microwave oven is plugged in a wall outlet
(220-230V, 50Hz), the noise filter is energized.
4. When the oven door is opened, the oven lamp lights.
MICROWAVE COOKING CONDITION
HIGH COOKING
When the door is closed, the contacts COM-NO of the
primary latch, 2nd latch and 3rd latch switches SW1 + SW2
+ SW3 are activated.
Whenthemicrowavepowercontrolissetto“HIGH”position
and cooking time is selected by turning the timer and push
the start button, the following operations occur: (Figure 0-2)
1.Thecontactsofthetimermotorandvariswitchareclosed.
2. The contacts (COM-NO) of the cook switch are closed.
3. Then following components are energized.
Oven lamp High voltage transformer
Timer motor Fan motor .
Turntable motor Magnetron
Surge relay RY2 Relay RY1
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. on the filament winding, and
approximately2000voltsA.C.onthesecondarywinding.
4. The3.3voltsfilamentwindingvoltageheatsthemagnetron
filamentandthe2000voltssecondarywinding voltageis
sent to a voltage doubler circuit, where it is doubled to a
negative voltage of approximately DC 4000 volts.
5. The 2450MHz microwave energy produced in the
magnetron generates a wave length of 12.24 cm. This
energy is changed through the waveguide (transport
channel)intotheovencavity, wherethefoodisplacedto
be cooked.
6. Upon completion of the selected cooking time, the timer
bell rings, and contacts of the timer are open, then the
activated components as item 2 are de-energized.
7. When the door is opened during a cooking cycle, the
switches come to the following positions.
OPERATION SEQUENCE
8. MONITOR SWITCH CIRCUIT
The monitor switch SW5 is mechanically controlled by the
oven door and monitors the operation of the relay RY1.
8-1.When the ovendoor isopenedduring oraftera cooking
cycle, the primary latch switch SW1 and the 3rd latch
switch SW3 must open their contacts (COM-NO) first.
After that the contacts (COM-NC) of the monitor switch
SW3canbe closedandthe2nd latchswitchSW2 must
openits contacts (COM-NO). Andthen the cookswitch
SW4 must open its contacts (COM-NO).
8-2. When the oven door is closed, the contacts (COM-NC)
of the monitor switch SW5 must be opened.
8-3. When the oven door is opened and the contacts of the
relay RY1 remain closed, the fuse F6.3A F1 will blow,
because the contacts (COM-NC) of the monitor switch
SW5areclosedandashortcircuitiscausedthroughthe
relayRY1,themonitorresistor R1monitorswitchSW5,
and the fuse F6.3A F1
MEDIUM HIGH, MEDIUM, MEDIUM LOW, LOW
COOKING
When the microwave oven is preset for variable cooking
power, the 220-230 volts A.C. power is supplied to the high
voltage transformer intermittently within a 26.4-second time
base through the vari switch. The following levels of micro-
wave power are given.
Condition
Switch Contact Durning Oven Door
Cooking Open(No cooking)
primary latch Switch COM-NO Closed Opened
COM-NC Opened Closed
2nd latch switch COM-NO Closed Opened
Monitor Switch COM-NC Opened Closed
3rd latch switch COM-NO Closed Opened
Note: TheON/OFFtimeratiodoesnotexactlycorrespond
to the percentage of microwave power, because
approx. 3 seconds are needed for heating up the
magnetron filament.
26.4 sec. ON
20.4 sec. ON
14.5 sec. ON
8.6 sec. ON
4.4 sec. ON
6 sec. OFF
11.9 sec. OFF
17.8 sec. OFF
22 sec. OFF
HIGH
MEDIUM HIGH
MEDIUM
MEDIUM LOW
LOW
Approx. 70%
Approx. 50%
Approx. 30%
Approx. 10%
SETTING

5
R-5L16
FUNCTION OF IMPORTANT COMPONENTS
DOOR OPEN MECHANISM
Thedoorcanbeopenedbypushingthedooropenbuttonon
thecontrol panel.When thedoor openbutton ispushed, 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.
CAUTION: BEFORE REPLACING A BLOWN FUSE F1
F6.3A TEST THE RELAY RY1, MONITOR
SWITCH
SW3 AND MONITOR RESISTOR R1
FOR PROPER OPERATION. (REFER TO
CHAPTER “TEST PROCEDURE.)
MONITOR RESISTOR Rl 4.3Ω20W
The monitor resistor prevents the fuse F1 F6.3A bursting
when the fuse F1 F6.3A blows due to the operation of the
monitor switch.
TIMER MOTOR (WITH VARI-SWITCH) TM
Timer contacts
1.When thetimer isat “•“position, thecontacts ofthe timer
TM are opened.
2. When the timer is turned clockwise from “•” position, the
contacts of the timer TM are closed.
Vari-contacts (COM-NO):
The vari-contacts are operated by the cam roller. If the
variable cooking control is set at MEDIUM HIGH, MEDIUM,
MEDIUM LOW or LOW cooking position, the line voltage is
suppliedto thehigh voltagetransformer intermittentlywithin
a 26.4 seconds time base. The following chart shows the
vari-contacts (COM—NO) operation in the various modes.
Figure D-1. Door Open Mechanism
PRIMARY LATCH SWITCH SW1
1. When the oven door is closed, the contacts (COM-NO)
must be closed and the contacts (COM-NC) must be
opened.
2. When the oven door is opened, the contacts (COM-NO)
must be opened and the contacts (COM-NC) must be
closed.
2ND LATCH SWITCH SW2 AND 3RD LATCH
SWITCH SW3
1. When the oven door is closed, the contacts (COM-NO)
must be closed.
2. When the oven door is opened, (COM-NO) must be
opened.
COOK SWITCH SW4
1. When the oven door is closed and the start button is
pushed, the contacts (COM-NO) must be closed.
2. When the oven door is opened, (COM-NO) must be
opened.
MONITOR SWITCH SW5
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 of the relay
RY1failtoopen,thefuseF1F6.3Ablows simultaneously
withclosingthecontacts(COM-NC)ofthemonitorswitch
SW5
SETTING
26.4 sec. ON
20.4 sec. ON
14.5 sec. ON
8.6 sec. ON
4.4 sec. ON
6 sec. OFF
11.9 sec. OFF
17.8 sec. OFF
22 sec. OFF
HIGH
MEDIUM HIGH
MEDIUM
MEDIUM LOW
LOW
Approx. 70%
Approx. 50%
Approx. 30%
Approx. 10%
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.
FUSE Fl F6.3A 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 the relay RY1 remains closed
with the oven door open and when the monitor switch
SW5 closes.
SPECIAL FUSE F2
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 blows when the asymmetric rectifier, H.V.
rectifier,H.V.wireharness,H.V.capacitor,magnetronor
secondarywindingofhighvoltagetransformerisshorted.
LATCH
HEADS
LATCH HOOK
PRIMARY
LATCH SWITCH
MONITOR
SWITCH
3RD. LATCH 
SWITCH
OPEN LEVER
DOOR OPEN BUTTON
2ND. LATCH
SWITCH

6
R-5L16
THERMAL CUT-OUT 125°C TC1 (MG)
The thermal cut-out protects the magnetron against over-
heat.If thistemperature goes uphigher than125°Cbecause
the fan motor is interrupted, the ventilation openings are
blocked, the thermal cut-out TC1 will open and line voltages
to the high voltage transformer T will be cut off and the
operationofthemagnetronMGwillbestopped.Thedefective
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 foods in the
oven catch fire due to over heating produced by improper
setting of cook time or failure of control unit. Under normal
operation, the oven thermal cut-out remains closed. How-
ever,whenab-normallyhightemperaturesarereachedwithin
the oven cavity, the oven thermal cut-out will open at 125°C,
causingtheoventoshutdown.Thedefectivethermalcut-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.
Thiscoolairisdirectedthroughtheairvanessurroundingthe
magnetron and cools the magnetron. This air is channelled
through the oven cavity to remove steam and vapours given
off from the heating foods. It is then exhausted through the
exhausting air vents at the oven cavity.
NOISE FILTER
Thenoisefilterpreventstheradiofrequencyinterferencethat
might flow back in the power circuit.
SURGE RELAY RY AND SURGE RESISTOR R2
10Ω/20W
1. When the oven is switched on the surge current (peak
current) flows through the surge resistor R2, for approx.
6msec.ThesurgeresistorR2putsdownthesurgecurrent
(peak current).
2.After approx,6msec.the contactsofthe surge relay RY2
close and the line voltage is supplied to the high voltage
transformer T.
3.If thesurge resistorR2 is defective,the homefuse orfuse
F2 may break down when the oven is switched on.
4.IfthecontactsofthesurgerelayRY2remainsopenedafter
6msec.since the ovenis switched on the temperatureof
the surge resistor R2 of may rise high and may damage
theelectricormechanicalpartsaroundthesurgeresistor
R2.
ASYMMETRIC RECTIFIER
Theasymmetric rectifieris a solidstate devicethat prevents
current flow in both directions. And it prevents the tempera-
ture rise of the high voltage transformer by blowing the
special fuse F2 when the high voltage rectifier is shorted.
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
reversevoltage.(TheprocessofblowingthespecialfuseF2)
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 high voltage transformer.
5. The large electric currents beyond 10A flow through the
primary winding of the high voltage transformer.
6. The special fuse F2 blows by the large electric currents.
7.Thepowersupplytothehighvoltagetransformeriscutoff.
AB
C
D2 D1
ASYMMETRIC
RECTIFIER
HIGH VOLTAGE RECTIFIER

7
R-5L16
SERVICING
WARNING TO SERVICE PERSONNEL
Microwaveovenscontaincircuitry capableofproducingvery high voltageandcurrent.Contact withfollowingpartswill
result in electrocution.
High voltage capacitor, High voltage transformer, Magnetron, High voltage rectifier assembly, High voltage harness.
Whenallserviceworkiscompleted,andtheovenisfullyassembled,themicrowavepoweroutputshouldbechecked
and microwave reakage test carried out.
TROUBLESHOOTING GUIDE
When troubleshooting the microwave oven, it is helpfull 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 proce-
dureletterwhichwillbefoundinthe"TestProcedure"section.
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
thepresenceofmicrowaveenergywithinacavity,place
acupofcoldwaterontheoventurntable,close thedoor
andsetthepowerleveltoHIGH.Andsetthemicrowave
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.
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
switchedoff.Waitfor60secondsandthenshort-
circuittheconnectionofthehigh-voltagecapacitor
(thatis,oftheconnectingleadofthehigh-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
theoutercasehasbeenremoved,inthiseventcarryout
3Dchecksand then disconnecttheleads to theprimary
of the power transformer. Ensure that these leads
remain isolated from other components and the oven
chassis. (Use insulation tape if necessary.) When the
testingiscompletedcarryout3D checksandreconnect
the leads to the primary of the power transformer.
IMPORTANT: Iftheovenbecomesinoperativebecauseof
a blown fuse F1 in the relay RY1 - monitor
switch - monitor resisitor circuit, check the
1relay RY1, monitor switch and monitor
resistorbeforereplacingthefuseF1(F6.3A).

8
R-5L16
MAGNETRON HIGH VOLTAGE TRANSFORMER RECTIFIER ASSEMBLY H.V. CAPACITOR PRIMARY LATCH SWITCH
2ND LATCH SWITCH MONIOTR SWITCH 3RD LATCH SWITCH COOK SWITCH THERMAL CUT-OUT 125˚C
TIMER MOTOR TIMER CONTACT TIMER VAR. SWITCH SPECIAL FUSE FUSE 6.3A SURGE RELAY RY2
NOISE FILTER SURGE RESISTOR POWER SUPPLY CORD SHORTED WIRE HARNESS OPENED WIRE HARNESS
WALL OUTLET FAN MOTOR OVEN LAMP OR SOCKET TURNTABLE MOTOR MISADJUSTMENT SWITCH RELAY RY1
Homefuseorbreakerblows
whenpowercordisplugged
into wall outlet.
Fuse(F1)F6.3Ablowswhen
the door is opened.
Oven does not operate at
all.
Heat is produced in oven
loadbutovenlampdoesnot
light.
Heat is produced in oven
load but fan motor does not
operate.
Heat is produced in oven
load but timer motor does
not operate.
Heat is produced in oven
load but turn-table motor
does not operate.
Oven stops as soon as the
oven is started.
Ovenseemstobeoperating
but little or no heat is pro-
duced in oven load. (Vari-
ablecookingcontrolissetat
"HIGH" position).
Ovendoesnotoperateprop-
erlyinany other positionex-
cept"HIGH"position.(Oven
operate properly at HIGH).
Oven goes into cook cycle,
but shuts down before end
of cycle.
Homefuseorbreakerblows
when the oven is started
Oven lamp lights but the
other electrical parts do not
operate.
PROBLEM
POSSIBLE CAUSE
AND
DEFECTIVE PARTS
TEST PROCEDURE
COOKING
CONDITION
OFF
CONDITION
CONDITION
ABCDEEEEEFGGGH I JKL M M N

9
R-5L16
COMPONENT TEST
The formula is as follows;
P x t / 4.187 = V x ∆T P (W) = 4.187 x V x ∆T / t
Our condition for water load is as follows:
Room temperature ........... around 20°C Power supply Voltage.......... .Rated voltage
Water load ....... 1000 g Initial temperature...... 10±2°C Heating time.......... 42 sec.
P = 100 x VT
PROCEDURE LETTER
AMAGNETRON TEST
NEVER TOUCH ANY PART IN THE CIRCUIT WITH YOUR HAND OR AN INSULATED TOOL
WHILE THE OVEN IS IN OPERATION.
CARRY OUT 3D CHECK
Isolate the magnetron from high voltage circuit by removing all leads connected to filament terminal.
To test for an open circuit filament use an ohmmeter to make a continuity test between the magnetron
filament terminals, the meter should show a reading of less than 1 ohm.
To test for short filament to anode condition, connect ohmmeter between one of the filament terminals
and the case of the magnetron (ground). This test should be indicated an infinite resistance. If a low or
zero resistance reading is obtained then the magnetron should be replaced.
MICROWAVE OUTPUT POWER (IEC-705-1988)
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 705, i.e. it can be measured by using water load how much it can be absorbed by the water load.
Tomeasurethemicrowaveoutputpowerin the microwaveoven,therelationofcalorieandwattis 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±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. Thegraduation ofthe thermometermust be scaled by 0.1°C atminimum andaccurate 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:Theoperationtimeofthemicrowaveovenis“t+2”sec.2sec.ismagnetronfilamentheat-uptime.
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.
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.
TEST PROCEDURES

10
R-5L16
PROCEDURE LETTER COMPONENT TEST
Initial temperature ......................................................................................................... T1 = 11°C
Temperature after (42 + 3) = 45 sec. ............................................................................ T2 = 21°C
Temperature difference Cold-Warm............................................................................ ∆T1 = 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 at least ±15 % of the rated output power.
CAUTION: 1°C CORRESPONDS TO 100 WATTS. REPEAT MEASUREMENT IF THE POWER IS
INSUFFICIENT.
1000g
1000g
1000g
T1˚C T2˚C
Heat up for 45 sec.
CARRY OUT 3D CHECKS
Disconnecttheleadstotheprimarywinding of thehighvoltagetransformer.Disconnectthefilamentand
secondarywindingconnectionsfromtherest oftheHVcircuitry.Usinganohmmeter, set onalowrange,
it is possible to check the continuity of all three windings. The following readings should be obtained:-
a. Primary winding .....................1.4 Ωapproximately
b. Secondary winding.................82 Ωapproximately
c. Filament winding .................... less than 1 Ω
If the reading obtained are not stated above, then the high voltage transformer is probably faulty and
should be replaced.
CARRY OUT 4R CHECKS
WARNING: High voltages and large currents are present at the secondary winding and
filamentwindingtransformer.Itisverydangeroustoworknearthispartwhen
the oven is on. NEVER make any voltage measurements of the high-voltage
circuits, including the magnetron filament.
BHIGH VOLTAGE TRANSFORMER TEST
CHIGH VOLTAGE RECTIFIER ASSEMBLY TEST
HIGH VOLTAGE RECTIFIER TEST
CARRY OUT 3D CHECKS.
Isolate the high voltage rectifier assembly from the HV circuit. The high voltage rectifier can be tested
using an ohmmeter 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
ASYMMETRIC RECTIFIER TEST
CARRY OUT 3D CHECKS.
AB
C
D2 D1
ASYMMETRIC
RECTIFIER
HIGH VOLTAGE RECTIFIER
TEST PROCEDURES (CONT'D)

11
R-5L16
PROCEDURE
LETTER COMPONENT TEST
Isolate the high voltage rectifier assembly from the HV circuit. The asymmetric can be tested using an
ohmmeter set to its highest range 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 direction then the asymmetric rectifier is good. If an asymmetric rectifier is shorted in either
direction,thentheasymmetricrectifierisprobablyfaultyandmustbereplacedwithhighvoltagerectifier.
Whentheasymmetricrectifierisdefective,checkwhethermagnetron,highvoltagerectifier,highvoltage
wire or filament winding of the high voltage transformer is shorted.
CARRY OUT 4R CHECKS
NOTE: FORMEASUREMENTOFTHERESISTANCEOFTHERECTIFIER,THEBATTERIESOFTHE
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. Continuitycheckmustbecarriedoutwithmeasuringinstrumentwhichissettothehighestresistance
range.
C. Anormalcapacitorshowscontinuityforashorttime(kick) andthenaresistanceofabout10MΩafter
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. Theresistanceacrossalltheterminalsandthechassismustbeinfinitewhenthecapacitoris normal.
If incorrect reading are obtained, the high voltage capacitor must be replaced.
CARRY OUT 4R CHECKS
D HIGH VOLTAGE CAPACITOR TEST
ESWITCH TEST
Isolate the switch to be tested and using an ohmmeter check between the terminals as described in the
following table.
CARRY OUT 3D CHECKS Table: Terminal Connection of Switch
Plunger Operation COM to NO COM to NC
Released O.C. S.C.
Depressed S.C. O.C.
COM; Common terminal, NO; Normally open terminal NC; Normally close terminal
S.C.; Short, O.C.; Open circuit
If incorrect readings are obtained, make the necessary switch 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 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
If incorrect readings are obtained, replace the thermal cut-out.
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.
TEST PROCEDURES (CONT'D)

12
R-5L16
COMPONENT TEST
An open circuit thermal cut-out (OVEN) indicates that the foods in the oven may catch fire, this may be
due to over heating produced by improper setting of the cooking timer or failure of the control panel.
G TIMER MOTOR (WITH VARI-SWITCH) TEST
Disconnecting and checking terminals 1 and 2
Disconnecting and checking terminals 5 and 6
Resistance of motor winding approximately 34.2 kohms
PROCEDURE
LETTER
TEST PROCEDURES (CONT'D)
CARRY OUT 4R CHECKS after any of the above tests.
VARI SWITCH - CONTACTS
Before proceeding with this part of the test, check the relay coil as outlined above.
WARNING: This test requires the oven to be operated with supply connected.
Follow the instruction below carefully.
1. CARRY OUT 3D CHECKS
2. Disconnect the leads to the primary of the high voltage transformer. Make sure that the leads remain
isolated from other oven components and chassis.
3. Disconnect the leads from terminals 3 and 4 of the timer, make sure that these leads remain isolated
from other components and the oven chassis (use insulation tape if necessary). Do not disconnect
leads from terminals 5 and 6.
4. Securely clip the leads of an ohmmeter across terminals 3 and 4 of the timer. (Make sure the meter
can be read easily without being touched during the test.)
5. Close the door of the oven.
6. Connect the supply.
7. Set the TIMER to several minutes.
8. Without touching the meter or any part of the oven make a note of the time which the ohmmeter
indicates Short and Open circuit in each power level as described in the table.
9. Set the MICROWAVE TIMER to 0 (zero).
10. CARRY OUT 3D CHECKS
11. Disconnect ohmmeter lead from terminal 4 of the timer.
12. Reconnect the lead of the panel harness to the terminal 4 of the timer.
13. Disconnect the lead from contact NC of vari switch.
14. Clip the lead of an ohmmeter to contact NC of vari switch.
15. Repeat steps 5, 6, 7, 8, 9 and 10.
But in this time, the ohmmeter must indicate Short and Open circuit reversely against the table.
16. Disconnect ohmmeter leads from terminals 3 of the timer and contacts NC of vari switch.
17. Reconnect the leads to the primary of the high voltage transformer.
CARRY OUT 3D CHECKS before any of the following timer tests.
TIMER SWITCH- CONTACTS
Disconnecttheleadsfromterminalsdescribedatfollowingtable.Connectanohmmeteracrossterminals
described at following table. Advance the timer and check that a short circuit reading is obtained on the
meter. Turn the timer back to the zero (0) position and check that an open circuit reading is obtained on
the meter. If these readings are not obtained then replace the timer.
TIMER - MOTOR
Disconnecttheleadsfromterminalsdescribedatfollowingtable.Connect anohmmeteracrossthetimer
motor winding, terminals are described at following table, and check that a reading of resistance
describedatfollowingtableisindicated.Ifthisreadingisnotobtainedthenthetimerisprobablydefective
and should be replaced. (Also refer to test procedure N.)

13
R-5L16
COMPONENT TEST
PROCEDURE
LETTER
VARI-MODE ON TIME OFF TIME
HIGH 26.4 sec 0 sec.
(approx. 100% power)
MEDIUM HIGH 20.4 sec 6 sec.
(approx. 70% power)
MEDIUM 14.5 sec 11.9 sec.
(approx. 50% power)
MEDIUM LOW 8.6 sec 17.8 sec.
(approx. 30% power)
LOW 4.4 sec 22 sec.
(approx. 10% power)
34
M
Vari switch
12
65
Timermotorwithvariswitch
ON: Meter indicates closed. OFF: Meter indicates open.
Check results: If any of the condition as described in the table are not obtained at step 8, or the ohmmeter
does not indicate reverse conditions against the table, then the timer should be re-placed.
CARRY OUT 4R CHECKS
HBLOWN SPECIAL FUSE F2
CARRY OUT 3D CHECKS
1.IfthespecialfuseF2isblown,therecouldbeshortsorgroundsinelectricalpartsorwireharness.Check
them and replace the defective parts or repair the wire harness.
2. If the special fuseF2 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, high voltage transformer or H.V. wire. Check them and replace the defective
parts or repair the wire harness.
CARRY OUT 4R CHECKS
CAUTION: Only replace special fuse F2 with the correct value replacement
IBLOWN FUSE Fl F6.3A
CARRY OUT 3D CHECKS
1. If the fuse F1 F6.3A is blown when the door is opened, check the relay RY1, monitor switch and
monitor resistor. If the fuse F1 F6.3A is blown by incorrect door switching replace the defective
switch(es) and the fuse F1 F6.3A.
2. IfthefuseF16.3A isblown,there couldbeshorts orgroundin electricalpartsor wireharness.Check
them and replace the defective parts or repair the wire harness.
CARRY OUT 4R CHECKS
CAUTION: Only replace fuse with the correct value replacement.
JSURGE RELAY TEST
CARRY OUT 3D CHECKS
Disconnecttheleadstoterminals1and 2. Connectanohmmeteracrosstheterminals1and2, a reading
ofapproximately15kohmsshould beindicated.Ifthisisnot thecasethentherelaycoil is probablyfaulty
and the relay should be replaced.
CARRY OUT 4R CHECKS
Relay contact test for short circuit:
CARRY OUT 3D CHECKS
Isolate terminals 1 and 2, 4 and 5 of the relay. Using an ohmmeter, check continuity between terminal
4and5.Areadingofinfiniteresistanceshouldbeobtained.Ifthisisnotthecasethentherelayisprobably
faulty and should be replaced.
CARRY OUT 4R CHECKS
COIL
4
2
5
1
TEST PROCEDURES (CONT'D)

14
R-5L16
TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER
KNOISE FILTER TEST
CARRY OUT 3D CHECKS
Disconnect the leads from the terminals of noise filter.
Using an ohmmeter, check between the terminals as de-
scribed in the following table.
L (min) Cx ±20% Cy ±20%
1.0mH 0.22µF 0.0033µF
If incorrect readings are absorbed, replace the noise filter unit.
CARRY OUT 4R CHECKS
MEASURING POINTS INDICATION OF OHMMETER
Between N and L Open circuit
Between terminal N and WHITE Short circuit
Between terminal L and RED Short circuit
L MONITOR RESISTOR AND SURGE RESISTOR TEST
CARRY OUT 3D CHECKS
Disconnect the leads from the monitor resistor or surge resistor.
Using an ohmmeter and set on a low range.
Check between the terminals of the monitor resistor or surge as described in the following table.
Table: Resistance
Resistor Resistance
Monitor resistor Approx. 4.3Ω
Surge resistor Approx. 10Ω
If incorrect readings are obtained, replace the monitor resistor or surge resistor
CARRY OUT 4R CHECKS
M MOTOR 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.
COMPONENT TEST
Table: Resistance of Motor
Motors Resistance
Fan motor Approximately 186 ohms
Turntable motor Approximately 16 kohms
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS
N RELAY TEST
CARRY OUT 3D CHECKS
Disconnect the leads to terminals A1 and A2. Connect an ohmmeter across the terminals A1 and A2, a
reading of approximately 1.7 kohms should be indicated. If this is not the case then the relay coil is
probably faulty and the relay should be replaced.
CARRY OUT 4R CHECKS
Relay contact test for short circuit:
CARRY OUT 3D CHECKS
L
L
N
LCx Cy RED
WHT
F6.3A
COIL
A1 A2
56
34
12
RELAY
IsolateterminalsA1 andA2,1, 2,5and 6 oftherelay. Usinganohmmeter,
checkcontinuity betweenterminals 1 and2 andbetween terminal5and 6.
A reading of infinite resistance should be obtained. If this is not the case
then the relay is probably faulty and should be replaced.
CARRY OUT 4R CHECKS

15
R-5L16
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
WARNING: Avoidpossibleexposuretomicrowaveenergy.Pleasefollowtheinstructionsbelowbeforeoperating
the oven.
1. CARRY OUT 3D CHECKS.
2. Make sure that a definite” click” can be heard when the
microwave oven door is unlatched. (Hold the door in a
closed position with one hand, then push the door open
button with the other, this causes the latch leads to rise,
it is then possible to hear a “click’ as the door switches
operate.)
3. Visuallycheck thedoor andcavity face platefor damage
(dents, cracks, signs of arcing etc.).
Carry out any remedial work that is necessary before oper-
ating the oven.
Do not operate the oven if any of the following conditions
exist;
1. Door does not close firmly.
2. Door hinge, support or latch hook is damaged.
3. The door gasket or seal or damaged.
4. The door is bent or warped.
5. There are defective parts in the door interlock system.
6. There are defective parts in the microwave generating
and transmission assembly.
7. There is visible damage to the oven.
Do not operate the oven:
1. Without the RF gasket (Magnetron).
2. If the wave guide or oven cavity are not intact.
3. If the door is not closed.
4. If the outer case (cabinet) is not fitted.
Pleasereferto‘OVENPARTS,CABINETPARTS,DOORPARTS’,whencarryingoutanyofthefollowingremovalprocedures:
OUTER CASE REMOVAL
6. Discharge the H.V. capacitor before carrying out any
further work.
7. Do not operate the oven with the outer case removed.
N.B.; Step 1, 2 and 6 form the basis of the 3D checks.
CAUTION: DISCHARGE HIGH VOLTAGE CAPACI-
TOR BEFORE TOUCHING ANY OVEN
COMPONENT OR WIRING.
To remove the outer case proceed as follows.
1. Disconnect oven from power supply.
2. Open the oven door and wedge it open.
3. Removethescrewsfrom rearandalongtheside edge of
case.
4. Slide the entire case back about 3cm to free it from
retaining clips on the cavity face plate.
5. Lift the entire case from the oven.
HIGH VOLTAGE COMPONENTS REMOVAL
(HIGH VOLTAGE CAPACITOR AND HIGH VOLTAGE RECTIFIER ASSEMBLY)
To remove the components, proceed as follows.
1. CARRY OUT 3D CHECKS
2. Disconnect all the leads and terminals of high voltage
rectifier assembly from high voltage capacitor.
3. Removeone(1)screwholdingearthsideterminalofhigh
voltagerectifier assembly,and remove capacitorholder.
4. Remove one (1 ) screw holding capacitor holder to the
oven cavity.
5. Release the capacitor holder from the duct.
6. Remove the capacitor from the capacitor holder.
7. Nowhighvoltagerectifierassemblyandcapacitorshould
be free.
CAUTION: WHEN REPLACING HIGH VOLTAGE
RECTIFIER ASSEMBLY, ENSURE THAT
THE CATHODE (EARTH) CONNECTION
IS SECURELY FIXED TO THE CAPACI-
TOR HOLDER WITH AN EARTHING
SCREW.
HIGH VOLTAGE TRANSFORMER REMOVAL
transformer
4. Remove the two (2) screws and one (1) washer holding
the transformer to base plate.
5. Remove the transformer.
6. Now, the high voltage transformer is free.
1. CARRY OUT 3D CHECKS
2. Disconnect the filament leads of the high voltage
transformer from high voltage capacitor and the
magnetron.
3. Disconnect the H.V. wire A from the high voltage
MAGNETRON REMOVAL
1. CARRY OUT 3D CHECKS
2. RemovetheairseparateductBfromthechassissupport
and the air intake duct.
3. Disconnect the H.V. wire B and filament lead of the
transformer from the magnetron
4. Remove this one (1 ) screw holding the chassis support
5. Removetheone(1)screwholdingthechassissupportto
the oven back plate.
6. Removetheone(1)screwholdingthechassissupportto
the magnetron.
7. Unclipthenoiseunitfromthe fanductandliftthechassis
support.
8. Unclip the air separator duct from the fan duct and
remove the air separator duct to the magnetron.
9. Move the air intake duct to left
10.Remove the air deflector from the magnetron.

16
R-5L16
11.Carefully remove four (4) screws holding magnetron to
waveguide, when removing the screws hold the
magnetron to prevent it from falling.
12.Removethemagnetronfromthewaveguidewithcareso
the magnetron antenna is not hit by any metal object
around the antenna
13.Remove the magnetron cushion from the magnetron.
CAUTION: WHEN REPLACING THE MAGNETRON,
BESURETHER.F.GASKETISINPLACE
AND THE MAGNETRON MOUNTING
SCREWSARETIGHTENEDSECURELY.
1. CARRY OUT ONE 3D CHECKS.
2. Remove the (1 ) screw holding the noise filter to the
chassis support
3. Release the noise filter from the tabs of the fan duct.
4. Disconnect the wire leads from the fan motor.
5. Removetheone(1)screwholdingthecapacitorholderto
the oven cavity back plate.
FAN MOTOR REMOVAL
6. Release the tabs of the capacitor holder from the fan
duct.
7. Remove the fan duct from the oven.
8. Remove the fan blade assembly from the fan motor.
9. Remove the two (2) screws and two (2) nuts holding the
fan motor to the fan duct.
10.Now, the fan motor is free.
1. CARRY OUT 3D CHECKS
2. Disconnect the main harness from the timer motor and
the cook switch.
3. Removetheone(1)screwholdingthecontrolpaneltothe
oven cavity.
4. Lift up the control panel assembly and pull it forward.
Now, the control panel assembly is free.
CONTROL PANEL REMOVAL
1. Remove the turntable motor, refer to "Turntable Motor
Removal".
2. Pull the coupling out of the hole in the oven cavity.
3. At that time the turntable coupling will be free.
CAUTION: REPLACE THE PACKING AT THE SAME
TIME WHEN REPLACING THE COU-
PLING. BECAUSE THE PACKING MAY
BE INJURED BY PULLING OUT THE
COUPLING.
Figure C-1 Turntable Coupling
OVEN LAMP SOCKET REMOVAL
Figure C-2 Oven lamp socket
Oven lamp
socket
Terminal
Wire lead
Flat type small
screw driver
Terminal hole
TURNTABLE MOTOR REMOVAL
1. Disconnect the oven from power supply.
2. Removetheturntablemotorcoverbysnippingofmaterial
in four corners.
3. Where the corners have been snipped off bend corner
areas flat. No sharp edge must be evident after removal
of TT motor cover.
4. Disconnectthewireleadfromturntablemotorandremove
the 2 screws holding the turntable motor.
5. Turntable is now free.
6. After replacement use the one (1) screw allocated to fit
the TT motor cover.
TURNTABLE COUPLING REMOVAL
1. CARRY OUT 3D CHECKS
2. Pullthewireleadsfromtheovenlampsocketbypushing
theterminalholeoftheovenlampsocketwiththeflattype
small screw driver.
3. Lift up the oven lamp socket.
4. Now, the oven lamp socket is free.
COUPLING
T.T.M.
SUPPORT
ANGLE
PACKING

17
R-5L16
POWER SUPPLY CORD REPLACEMENT
Removal
1. CARRY OUT 3D CHECKS.
2. Remove the single (1) screw holding the green/yellow
wire to the chassis support.
3. Disconnect the leads of the power supply cord from the
noise filter, referring to the Figure C-3 (a).
4. Release the power supply cord from the rear cabinet.
5. Now, the power supply cord is free.
Re-install
1. Insert the moulding cord stopper of power supply cord
into the square hole of the rear cabinet, referring to the
Figure C-3 (b). Installation of Power supply cord.
2. Installtheearthwireleadofpowersupplycordtotherear
cabinet with one (1) screw and tight the screw.
3. Connect the brown and blue wire leads of power supply
cord to the noise filter correctly, referring to the Pictorial
Diagram.
Figure C-3 (a) Replacement of Power Supply Cord
SQUARE HOLE
MOULDING
CORD
STOPPER
OVEN CAVITY
BACK PLATE
POWER SUPPLY
CORD
Figure C-3 (a) Replacement of Power Supply Cord
POWER SUPPLY CORD
OVEN CAVITY
PLATE
BROWN WIRE
BLUE WIRE
NOISE FILTER
CHASSIS SUPPORT
PRIMARY LATCH SWITCH, 2ND LATCH SWITCH, 3RD LATCH SWITCH AND MONITOR SWITCH REMOVAL
1. CARRY OUT 3D CHECKS.
2. Remove the control panel assembly referring to
"CONTROL PANEL REMOVAL”.
3. Disconnect the leads from all switches.
4. Remove the two (2) screws holding the latch hook to the
oven cavity.
5. Remove the latch hook.
6. Push the retaining tab slightly and remove the switch.
PRIMARY LATCH SWITCH, 2ND LATCH SWITCH, 3RD LATCH SWITCH AND MONITOR SWITCH ADJUSTMENT
Iftheprimarylatchswitch,2nd.Iatchswitch,3rdlatchswitch
and monitor switch do not operate properly due to a mis-
adjustment, the following adjustment should be made.
1. CARRY OUT 3D CHECKS
2. Loosen the two (2) screws holding the latch hook to the
oven cavity front flange.
3. Withdoorclosed,adjust thelatchhookbymoving it back
and forward, or up and down. In and out play of the door
allowed by the latch hook should be less than 0.5 mm.
Thehorizontalpositionofthelatchhookshouldbeplaced
where the 2nd, latch switch and the monitor switch have
activated with the door closed.
The vertical position of the latch hook should be placed
wherethe primarylatch switchand 3rd latchswitch have
activated with the door closed.
4. Secure the screws with washers firmly.
5. Make sure of the primary, 2nd latch, 3rd latch switches,
and monitor switch operation. If those switches have not
activated with the door closed, two (2) screws holding
Figure C-4. Switches
TAB
MONITOR
SWITCH
3RD. LATCH 
SWITCH
PRIMARY
LATCH SWITCH
TAB
2ND. LATCH
SWITCH

18
R-5L16
latchhooktooven cavityfrontflangeandadjust the latch
hook position.
After adjustment, make sure of following:
1. In and out play of door remains less than 0.5 mm when
latchedposition.Firstchecklatchhookposition,pushing
and pulling the door toward the oven face. The results
(play of the door) should be less than 0.5mm.
2. The contacts (COM-NO) of primary latch switch and 3rd
latch switch interrupt the circuit before the door can be
opened.
3. The contacts (COM-NC) of the monitor switch close and
the contacts (COM-NO) of the 2nd latch switch open
when the door is opened.
4. Re-install outer case and check for microwave leakage
around the door with an approved micro-wave survey
meter. (Refer to Microwave Measure-ment Procedure.)
DOOR ADJUSTMENT
When removing and/or loosening hinges such as in door
replacement, the following adjustment criteria are taken.
Door is adjusted to meet the following three conditions by
keeping screws of hinge loose.
1. Adjustdoorlatchheadsatapositionwheretheysmoothly
catch the latch hook through the latch holes. Refer to
latch switch adjustments.
2. Deviation of the door alignment from horizontal line of
cavity face plate is to be less than 1.0mm.
3. Thedoorispositionedwithitsfacedepressedtowardthe
cavity face plate.
4. Reinstall outer case and check for microwave leakage
around the door with an approved microwave survey
meter. (Refer to Microwave Measurement Procedure.)
LATCH HEAD REMOVAL
1. Remove door choke, use about 0.5 mm steel plate or
small flat type screw driver.
DOOR REPLACEMENT
1. CARRY OUT 3D CHECKS
2. Removefive(5)screwsholdingtheupperandloweroven
hinge to the oven cavity. The lower oven hinge is now
free.
3. Removedoorassemblywithupperovenhingebypulling
it forward.
4. Separatethedoorassemblyandupperovenhinge.Door
assembly is now free.
5. Re-install upper oven hinge to the new door assembly.
6. On re-installing new door assembly, secure the upper
and lower oven hinges with the five (5) mounting screws
to the oven cavity. Make sure the door is parallel with
bottomlineoftheovenfaceplateandthelatchheadpass
through the latch holes correctly.
7. CARRY OUT 4R CHECKS
Note: Afteranyservicetothedoor,theapprovedmicrowave
surveymetershouldbeusedtoassureincompliance
with proper microwave radiation standards. (Refer
to Microwave Measurement Procedure.)
DOOR REPLACEMENT AND ADJUSTMENT
Remove the door assembly, referring to from item 1 through
item 4 of "DOOR REPLACEMENT”.
1. Place the door assembly on a soft cloth with facing up
2. Remove the choke cover, referring to "CHOKE COVER
REMOVAL".
3. Removethefour(4)screwsholding thedoorframetothe
door panel assembly.
4. Release the door frame from the door panel assembly.
5. Remove the upper and lower door sush by making their
DOOR FRAME AND SCREEN REMOVAL
tabs straight.
6. Gently prise apart the screen from the frame.
7. Peel the tape using steady pressure which will allow the
screen to be separated from the door.
Note: Care is needed when peeling away the tape, as
excessive force may damage the screen. Do not
lever the components apart, as this may cause
damage to the screen print.
Figure C-5 Latch Switches Adjustment
LATCH
HEADS
LATCH HOOK
PRIMARY
LATCH SWITCH
MONITOR
SWITCH
3RD. LATCH 
SWITCH
OPEN LEVER
DOOR OPEN BUTTON
2ND. LATCH
SWITCH