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R-952M  -  13

92

VREF

IN

Connected to GND.

93

AVSS

IN

Connected to VC.

94

COM3

OUT

Terminal not used.

95

COM2

OUT

Connected to LCD (Pin No. 35).

96

COM1

OUT

Connected to LCD (Pin No. 34).

97

COM0

OUT

Connected to LCD (Pin No. 33).

98-99

VL3-VL2

IN

Standard voltage for LCD.

100

C2

IN

Terminal not used.

The I/O signal of the LSI(IZA963DR) are detailed in the following table.

R-952M  -  14

transformer.

4) Re-install the outer case (cabinet).
5) Re-connect the power supply cord after the outer

case is installed.

6) Run the oven and check all functions.

 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 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 equiva-
lent 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 abnor-

mal 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.

Transistor
2SB1238

Transistor
KRC243M

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.

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.

T

herefore, before checking the performance of the touch

control panel,
1) Disconnect the power supply cord, and then remove

outer case.

2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power

transformer.

5) Ensure that these leads remain isolated from other

components and oven chassis by using insulation
tape.

6) After that procedure, re-connect the power supply

cord.

After checking the performance of the touch control

panel,

1) Disconnect the power supply cord.
2) Open the door and block it open.
3) Re-connect the leads to the primary of the power

R-952M  -  15

1. CARRY OUT 3D CHECKS.
2. Remove the control panel assembly referring to

"CONTROL PANEL REMOVAL".

3. Disconnect the all leads from the switches.
4. Remove each one (1) screw holding the upper latch

hook and lower latch hook to the oven cavity.

5. Remove the upper and lower latch hooks from the

oven cavity.

6. Push the monitored latch switch downwards with

pushing the retaining tab.

7. Push the monitor switch or stop switch rightwards with

pushing the retaining tab.

CAUTION: When removing the switch, do not break the

tabs of the latch hooks.

1. CARRY OUT 3D CHECKS
2. Remove five (5) screws holding the upper and lower

oven hinge to the oven cavity.

3. Now, the lower oven hinge is free.
4. Separate the door assembly and upper oven hinge.

Door assembly is now free.

5. Re-install lower oven hinge to the new door assembly.
6. On re-installing new door assembly, secure the upper

and lower oven hinges with the five (5) mounting
screws to the oven cavity. Make sure the door is
parallel with bottom line of the oven face plate and the
latch head pass through the latch holes correctly.

7. CARRY OUT 4R CHECKS

Note: After any service to the door, the approved micro-

wave survey meter should be used to assure in
compliance with proper microwave radiation  stand-
ards. (Refer to Microwave Measurement Proce-
dure.)

RE-INSTALL

DOOR 
ASSEMBLY

SCREWS

SCREWS

UPPER
OVEN HINGE

OUTER CASE
CABINET

LOWER
OVEN HINGE

LATCH
HEADS

1. Insert 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 in figure C-9 to free the
engaging part. The protect sheet may be used so as
not to damage the door panel.

2. Lift up the choke cover, now choke cove is free.

FLAT TYPE
SCREW-DRIVER

PROTECT BY TAPE

CHOKE
COVER

DOOR
PANEL

DOOR

SW3 Monitor
 switch

SW1 Monitored
 latch switch

SW2 Stop switch

Tab

Tab

Tab

R-952M  -  16

Remove the door assembly, refer to items 1 to 4 of “DOOR

REPLACEMENT”.

1. Place the door assembly on a soft cloth with facing up.
2. Remove the choke cover, referring to “CHOKE COVER

REMOVAL”.

3. Remove the eight (8) screws holding the door frame to

the door panel assembly.

4. Release the  door frame from door assembly. Now, the

door frame is free.

5. Remove the two (2) glass stopper holding door glass to

the door frame.

6. Slide the door glass to the up side until stopped by door

frame.

7. Lift up the door glass, now the door glass is free.

1. Remove the choke cover, referring to “CHOKE COVER

REMOVAL”.

2. Release the latch spring from the tabs of the door

panel.

3. Release the latch spring from the latch head.
4. Release the latch head from the door panel.
5. Now, the latch head is free.

 

1)  

isconnect the supply.

2)  

oor opened, and wedged open

3)  

ischarge high voltage capactior

RE-WIRING

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 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.