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10

752M -

78

COM1

OUT

Connected to LCD signal C2.

79

COM0

OUT

Connected to LCD signal C1.

80

VL3

IN

Standard voltage for LCD.

The I/O signal of the LSI(IZA954DR) are detailed in the following table.

Before carrying out any work carry out 3D checks

1)

isconnect the supply.

2)

oor opened, and wedged open.

3)

ischarge high voltage capacitor.

Ensure the following:

1.

Wires must not touch:

a)

High voltage parts.
(Magnetron, high voltage transformer, high voltage capacitor and high voltage rectifier assembly)

b)

Parts that become hot.
(Heating elements, oven lamp, oven cavity magnetron and high voltage transformer)

c)

Sharp edges.
(Bottom plates, oven cavity, waveguide flange, chassis support and other metallic parts)

d)

Movable parts.
(Fan blade, any motor, switch, switch lever and open button)

2.

Positive lock connectors are fitted correctly.  Ensure the locking pin is located correctly.

3.

Wires are connected correctly as per pictorial diagram.

4.

No wire leads are trapped by the outer wrap.

MONITOR SWITCH

STOP SWITCH

MONITORED
LATCH SWITCH

Tab

Post

Post

Post

Tab

Tab

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.

11

752M -

10

5

4

12

8

7

9

11

3

2

1

Choke Cover

Door Frame

Putty Knife

6

1. Disconnect the power supply cord.
2. Open the door slightly.
3. Remove the choke cover taking care not to break clips

by inserting an  iron plate (thickness of about 0.5mm)
or flat type screw driver to the gap between the choke
cover and door panel as shown Figure C-4 to free the
engaged parts.

4. Release choke cover  from door panel.
5. Now choke cover is free.

6. Release two (2) pins of door panel from two (2) holes

of upper and lower oven hinges by lifting up.

7.

8. Release door panel from tabs of door frame and

remove door frame by sliding the door panel downward.

9. Now, door panel with inner sealer film is free.
10. Tear inner sealer film from door panel.
11. Now, door panel is free.
12. Slide latch head upward and remove it from door

frame with releasing latch spring from door frame and
latch head.

13. Now, latch head and latch spring are free.
14.

15.

16.

17.

1. Re-install the outer door glass to the door frame with

the glass stopper.

2. Hold the glass stopper with the one (1) screw.
3. Re-install latch spring to the head. Re-install latch

spring to the door frame. Re-install latch head to the
door frame.

4. Re-install door panel to door frame by fitting tabs of

door frame to holes of door panel.

5. Put sealer film on door panel. Refer to “Inner Sealer

Film” and figure C-6, on how to handle the new film.

6. Catch two (2) pins of door panel on two (2) hole of

upper and lower oven hinges.

7. Re-install choke cover  to door panel by pushing.

1. Door latch heads smoothly catch latch hook through

latch holes and that latch head goes through center of
latch hole.

2. Deviation of door alignment from horizontal line of

cavity face plate is to be less than 1.0mm.

3. Door is positioned with its face pressed toward cavity

face plate.

4. Check for microwave leakage around door with an

approved microwave survey meter.  (Refer to
Microwave Measurement Procedure.)

Note:

The door on a microwave oven is designed to
act as an electronic seal preventing the leak-
age of microwave energy from oven cavity
during cook cycle. This function does not re-
quire that door be air-tight, moisture (conden-
sation)-tight or light-tight. Therefore, occasional
appearance of moisture, light or sensing of
gentle warm air movement around oven door
is not abnormal and do not of themselves,
indicate a leakage of microwave energy from
oven cavity.

I

1. Tear away the backing film.
3. Put the pasted side of the inner sealer film on the door

panel.

Pin

Pin

Lower
Oven
Hinge

Lower Oven
Hinge

Upper
Oven
Hinge

Upper Oven
Hinge

Door Panel

Choke Cover

Door film

Finger tab

Backing film

12

752M -

approx. 1M ohm

This unit uses CMOS LSI in the integral part of the
circuits. When handling these parts, the following
precautions 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 electricity
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
containing them in aluminium foil.

2) When soldering, ground the technician as shown in

the figure and use grounded soldering iron and
work table.

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 transformer,
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 insulating
tape. After servicing, be sure to replace the leads to
their original locations.

 On some models, the power supply cord between

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 between

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 terminal
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
assembly.
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 preventing
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.

13

752M -

After any repair, the microwave oven must be checked for microwave leakage to ensure continued safe operation. BS EN
60335-2-25 specifies that the maximum permitted leakage with a load of 275 ml is 50 W/m

2 

(equivalent to 5 mW/cm

2) 

at

a distance of 5 cm from the oven.

The following items are required to carry out this test:-
1.  A low form of 600 ml beaker made from an electrically non-conductive material, such as glass or plastic, with an inside

diameter of approximately 8.5 cm. This must contain 275 

±

 15 ml of water, at an initial temperature of 20 

±

 2˚C.

2. A leakage detector which has been calibrated within the preceding 12 months to a standard whose accuracy  can be

traced to National Physical Laboratory Standards.

Recommended instruments are:

Apollo “XI”
Celtec “A100”

Before commencing the test, check that the leakage detector is functioning and adjusted according to the manufacturer’s
instructions, and any spacers are fitted to ensure that measurement is taken 5cm from the surface of the oven.

1. Place the beaker containing the water load in the oven cavity at the centre of the turntable. The placing of this standard

load in the oven is important, not only to protect the oven, but also to ensure that any leakage it is not disguised by too
large a load absorbing energy.

2. Close the oven door, and with the power level set to FULL, turn the oven ON with the timer set for a few minutes

operation. Should the water begin to boil before the test has been completed, it should be replaced.

3. As shown in the diagram below, move the probe slowly (not faster than 2.5 cm/sec.);-
a) around the edge of the door following the gap
b) across the face of the door
c) across any vents in the oven’s sides, rear or top

Dotted line indicates the path by the leakage detector.

Whilst the maximum leakage permitted in BS60335 2-25 is 50 /W/m 

2

(equivalent to 5 W/cm

2

),it is not normal to detect any

significant leakage, and therefore any detected leakage should be investigated.