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R-671M  -  21

Transistor
2SB1238

Transistor
DTA123ES
DTA143ES
DTD143ES

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.

approx. 1M ohm

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.

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.

 On some models, the power supply cord be-

tween 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.

 On some models, the power supply cord be-

tween 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.

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).

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

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.

R-671M  -  22

1. Disconnect oven from power supply.
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. Visually check the door and cavity face plate for damage

(dents, cracks, signs of arcing etc.).

Carry out any remedial work that is necessary before
operating 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.

Please refer to ‘OVEN PARTS, CABINET PARTS, CONTROL PANEL PARTS, DOOR PARTS’, when carrying out any
of the following removal procedures:

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.

7. Now, the high voltage rectifier and the capacitor should

be free.

CAUTION: WHEN REPLACING HIGH VOLTAGE REC-

TIFIER, ENSURE THAT THE CATHODE
(EARTH) CONNECTION IS SECURELY
FIXED TO THE CAPACITOR HOLDER AND
POWER ANGLE WITH AN EARTHING
SCREW.

To remove the outer case proceed as follows.
1. Disconnect oven from power supply.
2. Open the oven door and wedge it open.
3. Remove the screws from rear and along the side edge

of case.

4. Slide the entire case back about 3 cm to free it from

retaining clips on the cavity face plate.

5. Lift the entire case from the oven.

To remove the components, proceed as follows.
1. CARRY OUT 3D CHECKS.
2. Disconnect all the leads except for the terminal of high

voltage rectifier from the high voltage capacitor.

3. Remove one (1) screw holding capacitor holder and

high voltage rectifier earth terminal to the power angle.

4. Release the capacitor holder from the power angle.
5. Remove the capacitor from the capacitor holder.
6. Remove the terminal of high voltage rectifier from the

high voltage capacitor.

1. CARRY OUT 3D CHECKS.
2. Disconnect the filament leads of high voltage trans-

former from high voltage capacitor and the magnetron.

3. Disconnect the H.V. wire A from the high voltage

transformer.

4. Disconnect the main wire harness from the high volt-

age transformer.

5. Remove the HVT thermal cut-out from the high voltage

transformer.

6. Remove the four (4) screws holding the transformer to

power angle.

7. Remove the transformer.
8. Now the high voltage transformer is free.

1. CARRY OUT 3D CHECKS.
2. Disconnect the H.V. wire B and filament lead of the

transformer from the magnetron.

3. Remove the one (1) screw holding the chassis support

to the magnetron.

4. Remove the one (1) screw holding the chassis support

to the oven cavity front flange.

5. Remove the chassis support from the power angle and

R-671M  -  23

the two tabs.

8. Now the control unit assembly is free.
KEY FIXING FRAME REMOVAL
9. Remove the key fixing frame from the control panel by

releasing the six (6) tabs..

10.Now, the key fixing frame with the key unit is free.
NOTE: 1. Before attaching a new key unit, remove

remaining adhesive on the key fixing frame
surfaces completely with a soft cloth soaked in
alcohol.

2. When attaching the key unit to the key fixing

frame, adjust the lower edge and the right edge
of the key unit to the correct positionof frame.

3. Stick the key unit firmly to the key fixing frame

by rubbing with a soft cloth so not to scratch.

CONTROL UNIT ASSEMBLY REMOVAL
1. CARRY OUT 3D CHECKS.
2. Disconnect the main wire harness, the stop switch

harness, the connector CN-A and the connector CN-B
from the control unit.

3. Disconnect the flat ribbon cable from the connector CN-

G and disconnect the connector CN-D from the control
unit.

4. Remove screw holding Control panel to cavaty face plate

and remove control panel.

5. Remove the six (6) screws holding the control unit to

the control panel.

6. Remove the control unit from the control panel.
7. Remove the small PWB (the light emitting diodes LD6-

LD9 are soldered) from the control panel by releasing

move to the right hand side.
6. Release the tabs of air intake duct from the oven cavity.
7. Move the air intake duct to left.
the antenna.
8. Carefully remove two (2) screws holding magnetron to

waveguide, when removing the screws hold the
magnetron to prevent any damage.

9. Remove the magnetron from the waveguide with care so

the magnetron antenna is not hit by any metal object
around the antenna

CAUTION: WHEN REPLACING THE MAGNETRON, BE

SURE THE R.F. GASKET IS IN PLACE AND
THE MAGNETRON MOUNTING SCREWS
ARE TIGHTENED SECURELY.

1. CARRY OUT 3D CHECKS.
2. Disconnect the wire leads from the fan motor.
3. Remove the two (2) screws holding the fan motor to the

power angle.

4. Remove the fan blade from the fan motor shaft accord-

ing to the following procedure.
1) Hold the edge of the rotor of the fan motor by using

a pair of groove joint pliers.

2) Remove the fan blade from the shaft of the fan

motor by pulling and rotating the fan blade with your
hand.

3) Now, the fan blade will be free.

5. Now, the fan motor is free.

1.

Install the fan blade to the fan motor shaft according
to the following procedure.

1)

Hold the centre of the bracket which supports the
shaft of the fan motor on a flat table.

2)

Install the fan blade to the shaft of fan motor by
pushing the fan blade with a small, light weight, ball
peen hammer or rubber mallet.

2.

Install the fan motor to the power angle with the two
(2) screws.

3. Re-connect the wire leads to the fan motor, referring to

the pictorial diagram.

Shaft

Table

Center of 
bracket

Coil

Gap

Rotor

Bracket

Stator

Groove joint pliers

Shaft

Axis

Stator

Rotor

These are the position 
where should be 
pinched with pliers

R-671M  -  24

2. Re-install the turntable motor by locating shaft onto

coupling then fitting it to the oven cavity with (1) one
screw and bending of location tab.

3. Re-connect the wire leads to the turntable motor.
4. Insert the two (2) tabs of the turntable motor cover into

the slits of the power angle as shown in Figure C-1(b).

5. Re-install the turntable motor cover to the power angle

with the screw (LX-CZA030WRE0) as shown in Figure
C-1(b).

1. Disconnect the oven from the power supply.
2. Remove the turntable from the oven cavity.
3. Turn the oven over.
4. Cut the four (4) bridges holding the turntable motor

cover to the base plate with cutting pliers as shown in
Figure C-1(a).

CAUTION: DO NOT DROP THE TURNTABLE MOTOR

COVER INTO THE OVEN AFTER CUTTING
THE BRIDGES. BECAUSE IT WILL DAM-
AGE THE WIRE LEADS OF THE MOTOR
AND IS ALSO DIFFICULT TO REMOVE
FROM THE OVEN.

5. Remove the turntable motor cover from the power

angle.

6. Disconnect the wire leads from the turntable motor.
7. Remove the one (1) screw holding the turntable motor

to the oven cavity.

8. Bend locating tab to allow removal of turntable motor.
9. Remove the turntable motor from the oven cavity

taking care not to drop or lose the turntable motor
coupling.

10.Now, the turntable motor is free.

1. Remove the any sharp edges on the turntable motor

cover and the base plate with the cutting pliers.

Screw; 
LX-CZA030WRE0 

Turntable motor cover

Power angle  

Tabs 

Slits 

Cutting pliers

Bridges

Bridges

Turntable motor 
cover

1. CARRY OUT 3D CHECKS.
2. Disconnect the wire lead from the oven lamp, refer-

ring to "Positive lock

®

 connector removal".

3. Lift up the oven lamp with release.
4. Now, the oven lamp is free.

BULB

LOCK

Terminal

Push

Pull down

1

2

Lever

Positive lock®

connector

1. CARRY OUT 3D CHECKS.
2. Push the lever of positive lock

®

 connector.

3. Pull down on the positive lock

®

 connector.

CAUTION: WHEN YOU (SERVICE ENGNEERS) CON-

NECT THE POSITIVE LOCK

®

 CONNEC-

TORS TO THE TERMINALS, CONNECT
THE POSITIVE LOCK

®

 SO THAT THE LE-

VER FACES YOU (SERVICE ENGNEERS).