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5-18

1. Heater is not

operating.

Abnormal.

Normal.

Normal.

Heater.

Relay3, 5.

Abnormal.

Malfunction the
relay.

Malfunction the
heater.

Replace.  

Wire connection.

No continuity.

Open or loosen.

Replace or
connect tightly.  

Replace.  

2. Under or over

cooking in conv.
mode.

Abnormal.

Normal.

Heater.

Thermistor

Abnormal.

Malfunction the
thermistor.

Malfunction the
heater.

Replace.  

Replace.  

Output is full when

you set lower
power level.

Abnormal.

Disconnect the
wire leads from
relay 2 and check
continuity relay 2.
(Operate the unit)

Defective P.C.B.
assembly.

Replace P.C.B.
assembly.  

NOTE: * Make sure the wore leads correct position.

* When removing the wire leads from parts be sure to grasp the connector not the wires.
* When removing the magnetron, be sure to install the magnetron gasket in the correct position and in

good condition.

• 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 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
190 mm.

• The oven and the empty vessel are at ambient

temperature prior to the start of the test.

• The initial temperature (±1) 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 shelf 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 

∆

T of (10±2)°K is measured, where T is

the time in seconds and 

∆

T 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:

P =

is measured while the microwave generator is
operating at full power. Magnetron filament heat-up
time is not included.

• 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.

WATER LOAD

TURNTABLE

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 PCB SUB ASS’Y.
2) Remove the screws for the earth and securing the

control panel.

3) Lift control panel ASS’Y from the oven by the tab

unhooked.

5-3

4187 X (

∆

T) + 0.55 X (T

2 

- T

0

) X M

T

• T

2

: Temperature after heating

• T

0

: Temperature of bowl

• M: Weight of bowl

1) Open the door.
2) Remove the choke cover 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) Disconnect the leadwire from lamp and MGT

thermostat.

2) Remove the mounting screw to the magnetron.

1) Disconnect the leadwire from the high voltage

transformer and high voltage capacitor.

2) Carefully remove the mounting screws holding the

magnetron and the waveguide.

3) Remove the magnetron ASS’Y until the tube is

clear from the waveguide.

NOTE:
1. When removing the magnetron, make sure its

dome does not hit any adjacent parts, or it may be
damaged.

2. When replacing the magnetron, be sure to install

the magnetron gasket in the correct position and
be sure that the gasket is in good condition.

3. After replacing the magnetron, check for microwave

leakage with a survey meter around the
magnetron. Microwave energy must be below the

limit of 5 mW/cm

2

. (With a 275 ml. water load).

magnetron. To prevent microwave leakage,
tighten the mounting screws properly, making sure
there is no gap between the waveguide and the
magnetron.

5-4

Magnetron

Air Duct