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15

Microwave ovens contain circuitry capable of producing very high voltage and current, contact with following parts
may result in severe, possibly fatal, electric shock.
(Example)
High Voltage Capacitor, High Voltage Transformer, Magnetron, High Voltage Rectifier Assembly,  High Voltage
Harness, High Voltage fuse etc..

To prevent an electric shock, take the following
manners.
1. Before wiring,

1) Disconnect the power supply.
2) Open the door and wedge the door open.
3) Discharge the high voltage capacitor and wait for

60 seconds.

2. Don't let the wire leads touch to the following parts;

1) High voltage parts:

Magnetron, High voltage transformer, High volt-
age capacitor, High voltage rectifier assembly
and High voltage fuse.

2) Hot parts:

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 is 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 generat-

ing 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.

Oven lamp, Magnetron, High voltage transformer
and Oven cavity.

3) Sharp edge:

Oven cavity, Waveguide flange, other metallic plate.

4) Movable parts (to prevent a fault)

Fan blade, Fan motor, Switch, Turntable motor
and Timer motor.

3. Do not catch the wire leads in the outer case cabinet.
4. Insert the positive lock connector certainly until its pin

is locked. And make sure that the wire leads should
not  come off even if the wire leads is pulled.

5. To prevent an error function, connect the wire leads

correctly, referring to the Pictorial Diagram.

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

To To remove the outer case, procedure as follows.
1. Disconnect the power supply cord.
2. Open the oven door and block it open.
3. Remove the two (2) screws along the right side of the

outer case.

4. Remove the remaining five (5) screws from the rear of

the outer case.

5. Slide the entire outer case back out about 1 inch (3 cm)

to free it from retaining clips on the cavity face plate.

6. Lift entire outer case from the unit.

7. Discharge the H. V. capacitor before curring out any

further work.

8. Do not operate the oven with the  outer case removed.
NOTE: Step 1, 2 and 7 form the basis of the 3D checks.

CAUTION:1. DISCONNECT OVEN FROM POWER

SUPPLY BEFORE REMOVING OUTER
CASE.

2. DISCHARGE THE HIGH VOLTAGE CA-

PACITOR BEFORE TOUCHING ANY
OVEN COMPONENTS OR WIRING.

16

1. CARRY OUT 3D CHECKS.
2. Disconnect the wire leads from magnetron.
3. Remove the three (3) screws holding the magnetron to

the waveguide.

4. Remove the magnetron from waveguide.

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

®

 connector.

3. Pull down on the positive lock

®

 connector.

CAUTION: WHEN CONNECTING THE POSITIVE

LOCK

®

 CONNECTORS TO THE TERMI-

NALS, INSTALL THE POSITIVE LOCK

®

 SO

THAT THE LEVER FACES YOU

5. Now, the magnetron is free.

CAUTION: WHEN REPLACING THE MAGNETRON,

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

To remove the components, proceed as follows.
1. CARRY OUT 3D CHECKS.
2. Remove one (1) screw holding capacitor holder to rear

cabinet.

3. Disconnect the H.V. wire of the H.V. rectifier assembly

from the magnetron.

4. Disconnect the filament lead of the high voltage trans-

former from the H.V. capacitor.

5. Remove one (1) screw holding ground side terminal of

high voltage rectifier assembly, and remove capacitor
holder.

6. Disconnect all the leads and terminals of high voltage

rectifier assembly from high voltage capacitor.

7. Now the H.V. rectifier assembly and H.V. capacitor

should be free.

CAUTION: WHEN REPLACING HIGH VOLTAGE REC-

TIFIER ASSEMBLY, ENSURE THAT THE
CATHODE (GROUND) CONNECTION IS
SECURELY FIXED TO THE CAPACITOR
HOLDER WITH A GROUNDING SCREW.

CAUTION: DO NOT REPLACE ONLY HIGH VOLT-

AGE RECTIFIER. WHEN REPLACING IT,
REPLACE HIGH VOLTAGE RECTIFIER
ASSEMBLY.

1. CARRY OUT 3D CHECKS.
2. Disconnect the wire leads (main wire harness) from

high voltage transformer.

3. Disconnect the lead from magnetron filament.
4. Disconnect the leads of the high voltage transformer

from high voltage capacitor.

5. Remove the two (2) screws holding the transformer to

bottom plate from the upper side.

6. Remove the remaining two (2) screws from the bottom.
7. Remove the transformer.
8. Now the high voltage transformer is free.

Re-install
1. Rest transformer on the bottom plate with its primary

terminals toward the oven face plate.

2. Secure transformer with four (4) screws to the bottom

plate.

3. Re-connect wire leads (primary and high voltage) and

filament leads to the high voltage transformer, magn-
etron and high voltage capacitor, referring to "Pictorial
Diagram".

4. Re-install outer case and check that the oven is oper-

ating properly.

1. CARRY OUT 3D CHECKS.
2. Disconnect the leads from the control unit and the timer

motor.

3. Remove the one (1) screw holding the control panel to

the front plate of the oven cavity.

4. Now, the control panel assembly is free.

Terminal

Push

Pull down

1

2

Lever

Positive lock®

connector

17

REMOVAL
1. CARRY OUT 3D CHECKS.
2. Remove the magnetron from the waveguide. Refer to

chapter "MAGNETRON REMOVAL"

3. Disconnect the wire leads from the fan motor.
4. Disconnect the wire lead from the disconnect the fan

duct.

5. Remove the three (3) screws holding the fan duct to the

oven cavity.

6. Release the fan motor assembly from the oven cavity.
7. Remove the fan blade from the fan motor shaft accord-

ing to the following procedure.

8. Hold the edge of the rotor of the fan motor by using a

pair of groove joint pliers.

9. Remove the fan blade assembly from the shaft of the

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

10.Now, the fan blade will be free.

1. Disconnect the oven from the power supply.
2. Remove the turntable and turntable support from the

oven cavity.

3. Turn the oven over.
4. Remove the one (1) screw holding the turntable motor

cover to the bottom plate.

5. Now, the turntable motor cover is free.
6. Disconnect the wire leads from the turntable motor.
7. Remove the single (1) screw holding the turntable

motor to the oven cavity.

8. Remove the turntable motor from the oven cavity.
9. Remove the TTM packing from the turntable motor.
10.Now, the turntable motor is free.

1. Re-install the TTM packing.
2. Re-install the turntable motor with theTTM packing

with the single (1) screw.

3. Re-connect the wire leads to the turntable motor.
4. Insert the tab of the turntable motor cover into the hole

of the bottom plate.

5. Re-install the turntable motor cover to the bottom plate

with one (1) screw.

TTM packing

Turntable motor

11.Remove the two (2) screws holding the fan motor to the

fan duct.

12.Now, the fan motor is free.

1. Install the fan motor to the fan duct with the two (2)

screws.

2. Install the fan blade to the fan motor shaft according to

the following procedure.

3. Hold the center of the bracket which supports the shaft

of the fan motor on the flat table.

4. Apply the screw lock tight into the hole (for shaft) of the

fan blade.

5. 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.

6. Install the fan motor assembly to the oven cavity with

three (3) screws.

7. Install the magnetron with three (3) screws.
8. Re-install the wire leads of the fan duct.
9. Connect the wire leads to the magnetron and the fan

motor, referring to the pictorial diagram.

Gap

Rotor

Bracket

Stator

Groove joint pliers

Coil

Shaft

Axis

Stator

Rotor

These are the positions  
that should be pinched 
with pliers.

Shaft

Table

Center of
bracket

18

1. CARRY OUT 3D CHECKS.
2. Disconnect wire leads from the switches.
3. Remove two (2) screws holding latch hook to oven

flange.

4. Remove the switch lever from the oven cavity
5. Remove latch hook assembly from oven flange.
6. Push outward on the two (2) retaining tabs holding

switch in place.

7. Switch is now free.

1. CARRY OUT 3D CHECKS.
2. Remove the single (1) screw holding the green/yellow

wire to the oven cavity.

3. Disconnect the leads of the power supply cord from the

noise filter, referring to the Figure C-3 (a).

4. Release the moulding cord stopper of the power supply

cord from the square hole of the oven cavity back plate,
referring to the Figure C-3 (b).

5. Now, the power supply cord is free.

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).

2. Install the earth wire lead of power supply cord and the

earth angle to the oven cavity 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.

Re-install
1. Re-install each switch in its place. The latch/monitor

switches are in the lower position and the monitored
latch switch is in the upper position.

2. Re-connect wire leads to each switch.

Refer to pictorial diagram.

3. Secure latch hook (with two (2) mounting screws) to

oven flange.

4. Install the switch lever to the oven cavity
5. Make sure that the monitor switch is operating properly

and check continuity of the monitor circuit. Refer to
chapter "Test Procedure" and Adjustment procedure.

Power Supply Cord

Oven Cavity 
Back Plate

Screw

Green/Yelow
Wire

Brown Wire

Fuse

Blue Wire

Noise Filter

Power Supply 
Cord

Oven Cavity 
Back Plate

Square 
Hole

Moulding
Cord Stopper

1. CARRY OUT 3D CHECKS.
If the monitored latch switch, latch switch and monitor
switch do not operate properly due to a misadjustment, the
following adjustment should be made.
2. Loosen the two (2) screws holding latch hook to the

oven cavity front flange.

3. With door closed, adjust latch hook by moving it back

and forth, and up and down. In and out play of the door
allowed by the upper and lower position of the latch
hook should be less than 0.5mm. The vertical position
of the latch hook should be adjusted so that the
monitored latch switch and latch switch are activated
with the door closed. The horizontal position of the
latch hook should be adjusted so that the plunger of the
monitor switch is pressed with the door closed.

4. Secure the screws with washers firmly.
5. Check the operation of all switches. If each switch has

not activated with the door closed, loosen screw and
adjust the latch hook position.

Latch Heads

Latch Hook

Door

Monitored
Latch Switch

Monitor Switch

Switch Lever

Latch Switch