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5-15

No microwave
oscillation.

No continuity.

Continuity.

Abnormal or burn
out.

Defective monitor
resistor.

Replace.

Malfunction of the
power control
switch.

Replace the power
control switch.

Check the
power control
switch(cooking
state).

Check the
monitor resistor.

Abnormal

Defective AC
relay.

Replace.

Normal

Check the AC
relay.

Abnormal

Open the
secondary winding
of the high voltage
transformer of
faulty insulation of
filament winding.

Replace .

Check H.V.
transformer.

Abnormal

Shorted H.V. diode

Replace .

Check H.V.
diode.

Abnormal

Faulty capacitor.

Replace .

Check H.V.
capacitor.

Abnormal

Faulty magnetron.

Replace .

Magnetron

¥ When you replace the magnetron, measure for

microwave energy leakage before the outer case is
installed and after all necessary components are
replaced or adjusted.

Special care should be taken in measuring the

following parts. (Circled area of below Fig.)

- Around the magnetron
- The waveguide

¥ After all components, including the outer case, are fully

assembled, measure for microwave energy leakage
around the door viewing window, the exhaust opening,
and air inlet openings.

¥ Microwave energy leakage must not exceed the values

prescribed below.

NOTE: Leakage with the outer case removedless than

5 mW/cm.sq. Leakage for a fully assembled
oven (Before the latch switch (primary) is
interrupted) with the door in a slightly opened
position-less than 2 mW/cm.sq.

¥ Do not  exceed meter full scale deflection.
¥ The test probe must be removed no faster than  

1 inch/sec (2.5 cm/sec) along the shaded area,
otherwise a false reading may result.

¥ The test probe must be held with the grip portion of the

handle.

A false reading may result if the operator's hand is

between the handle and the probe.

¥ When testing near a corner of the door, keep the probe

perpendicular to the surface making sure the probe
horizontally along the oven surface, this may possibly
cause probe damage.

¥ After adjustment and repair of any microwave energy

interruption or microwave energy blocking device,
record the measured values for future reference. Also
enter the information on the service invoice.

¥ The microwave energy leakage should not be more

than 4 mW/cm.sq. after determining that all parts are in
good condition, functioning properly and genuine
replacement parts which are listed in this manual have
been used.

¥ At least once a year, have the electromagnetic energy

leakage monitor checked for calibration by its
manufacturer.

5-2

¥ Microwave power output measurement is made with

the microwave oven supplied at its rated voltage and
operated at its maximum microwave power setting with
a load of (1000±5) g of potable water.

¥ The water is contained in a cylindrical borosilicate glass

vessel having a maximum material thickness of 3 mm
and an outside diameter of approximately 190mm.

¥ The oven and the empty vessel are at ambient

temperature prior to the start of the test.

¥ The initial temperature (T1) of the water is (10±2)¡C It

is measured immediately before the water is added to
the vessel. After addition of the water to the vessel,
the load is immediately placed on the center of the
turntable which is in the lowest position and the
microwave power switched on.

¥ The time T for the temperature of the water to rise by a

value 

Æ T of (10±2)¡K is measured, where T is the time

in seconds and ÆT is the temperature rise.   The initial
and final water temperatures are selected so that the
maximum difference between the final water
temperature and the ambient temperature is 5¡K.

¥ The microwave power output P in watts is calculated

from the following formula :

4187 x (ÆT)

T

is measured while the microwave generator is

operating at full power. Magnetron filament heat-up
time is not included. (about 3 sec)

¥ The  water is stirred to equalize temperature throughout

the vessel, prior to measuring the final water
temperature.

¥ Stirring devices and measuring instruments are

selected in order to minimize addition or removal of
heat.

1) Disconnect the power supply cord from the outlet.

2) Remove the screws from the rear and along side

edges of the case.

The outer case must be moved backward to be lifted

off.

1) Remove the outer case.
2) Disconnect two terminals, and remove one screw of

the earth terminal.

(refer to page 2-1)

1) Disconnect the leadwire from the Timer motor
2) Remove the screws for securing the control panel.
3) Lift control panel ASSÕY from the oven by the tab

unhooked.

5-3

WATER LOAD

TURNTABLE

P =

1) Open the door.
2) Remove the choke cover cap very carefully with a

flat-blade screwdriver.

3) Lift up and push the door.

NOTE:
1. After replacing the door, be sure to check that the

primary switch, monitor switch, and secondary switch
operate normally.

2. After replacing the door, check for microwave energy

leakage with a survey meter. Microwave energy must
be below the limit of 5 mW/cm. (with a 275 ml water
load)

3. When mounting the door assembly to the oven

assembly, be sure to adjust the door assembly parallel
to the chassis. Also adjust so the door has no play
between the inner door surface and oven frame
assembly. If the door assembly is not mounted
properly, microwaves may leak from the clearance
between the door and the oven.

1) Discharge the high voltage capacitor.
2) Disconnect the leadwire from magnetron, high voltage

transformer, and capacitor.

3) Remove the screw holding the high voltage

transformer to the baseplate.

1) Discharge the high voltage capacitor.
2) Disconnect the leadwire from fan motor, noise filter

and high voltage capacitor.

3) Remove the two screws holding the the suction guide

ASSÕY to the oven cavity and remove the high voltage
diode earth screw.

4) Remove the screw of the capacitor bracket.
5) Remove the two screws holding the fan motor ASSÕY

to the suction guide ASSÕY.

1) Discharge the high voltage capacitor.
2) Disconnect the leadwire from fan motor, noise filter

and high voltage capacitor.

3) Remove the screw holding the suction guide ASSÕY to

the oven cavity and remove the high voltage diode
earth screw.

4) Remove the screw holding the high voltage capacitor

bracket.

5-4

Door seal plate

Remove choke cover cap

Remove door

H.V.
Transformer

H.V.
Diode

H.V.
Capacitor

Suction
Guide

Fan Motor ASS'Y