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R-21FBSTM/R-22FBSTM - 17

LSI(IXA216DRZZ)
The I/O signal 

of the LS

I(IXA216DRZZ) are detailed in the following table.

       42

  P71

OUT   Fan motor driving signal

  To turn on and off the fan motor relay RY4.
  “L” level during cooking.
  “H” level otherwise.

       43

  P72

OUT   Magnetron high-voltage circuit driving signal.

  To turn on and off the cook relay (RY2). In
  100% POWER operation, the signals hold
  "L"level during microwave cooking and "H"
  level while not cooking. In other cooking
  modes (70%, 50%, 30%, 10%) the signal
  turns to "H"level and "L" level in repetition
  according to the power level.

       44

 AVDD

 IN

  A/D converter power source voltage.
  The power source voltage to drive the A/D converter in the LSI. Connected to
  GND.

    45-48     ANI5-ANI2

 IN

  Terminal to change model and cooking input according to the Model.
  By using the A/D converter contained in the LSI, DC voltage in accordance
  with the Model in operation is applied to set up its cooking constant. And DC
  voltage is dependent on the Model.

       49

  ANI1

 IN

  To input signal which communicates the door open/close information to LSI.
  Door close "H" level signal (0V). Door open "L" level signal (-5V).

       50

  ANI0

 IN

  Connected to VSS.

       51

  AVSS

 IN

  A/D converter power source voltage.
  The power source voltage to drive the A/D converter in the LSI.

       52

   P11

OUT    Terminal not used.

       53

   P10

OUT    Terminal not used.

       54

   P33

OUT    Terminal not used.

       55

  INTP2

 IN

  Signal coming from encoder.
  When encoder is turned, the contacts of encoder make pluse signals. And pulse
  signals are input into INTP2.

       56          INTP1          IN        Signal synchronized with commercial power source frequency.

  This is the basic timing for time processing of LSI.

       57          INTP0          IN         Signal coming from encoder.

  Signal similar to INTP2. Pulse signals are input into INTP0.

    58-59        P26-P25

OUT     Terminal not used.

       60            P24

OUT   Tact switch strobe signal.

  Signal applied to tact switch section. A pulse signal is input to P50 or P51
   terminal while the tact switch SW3 or SW4 is touched.

       61

   P23

OUT   Tact switch strobe signal.

  Signal applied to tact switch section. A pulse signal is input to P51 terminal while
  the tact switch SW2 is touched.

       62

   P22

OUT   Tact switch strobe signal.

  Signal applied to tact switch section. A pulse signal is input to P51 terminal while
  the tact switch SW1 is touched.

       63

BZO90

OUT   Signal to sound buzzer (2.0 kHz).

  A: key touch sound.
  B: Completion sound.

       64

   P20

OUT   Terminal not used

H : GND

L 

(During cooking)

ON

OFF

ON/OFF time ratio in Mi-
cro cooking
(a. 32second time base)

MICRO

ON

OFF

COOK

100%

32sec.

0sec.

70%

24sec.

8sec.

50%

18sec.

14sec.

30%

12sec.

20sec.

10%

6sec.

26sec.

A

B

0.1 sec.

2.0 sec.

H : GND

L : -5V

H : GND

L : -5V

R-21FBSTM/R-22FBSTM - 18

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 all 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.

6) Run the oven and check all functions.

A.  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.

B.  On some models, the power supply cord between the

touch control panel and the oven  is long enough that they
may be separated from each other. For those models, it
is possible to check and repair the controls of the touch
control panel while keeping it apart from the oven; in this
case you must short both ends of the door sensing switch
(on PWB) of the touch control panel with a jumper, which
activates an operational state that is equivalent to the
oven door being closed.

from an external power source:
Disconnect the touch control panel completely from the
oven, and short both ends of the door sensing switch (on
PWB) of the touch control panel, which activates 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.

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

4. Other Precautions
1) Before turning on the power source of the control unit,

remove the aluminium foil applied for preventing static
electricity.

2) Connect the connectors 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.

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.

the oven:
CAUTION:
THE HIGH VOLTAGE TRANSFORMER OF THE
MICROWAVE OVEN IS STILL LIVE DURING
SERVICING AND  PRESENTS A HAZARD.
Therefore, 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

transformer.

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

case is installed.

approx. 1M ohm

R-21FBSTM/R-22FBSTM - 19

The "Control, Switch, LED, and Relay PWB" of this model employ lead-free solder. This is indicated by the "LF" symbol
printed on the PWB and in the service manual. The suffix letter indicates the alloy type of the solder.
Example:

Indicates lead-free solder of tin, silver and copper.

When repairing a PWB with the "LF" symbol, only lead-free solder should be used. (Using normal tin/lead alloy solder may
result in cold soldered joints and damage to printed patterns.)
As the melting point of lead-free solder is approximately 40˚C higher than tin/lead alloy solder, it is recommend that a
dedicated bit is used, and that the iron temperature is adjusted accordingly.

As the melting point of lead-free solder (Sn-Ag-Cu) is higher and has poorer wettability, (flow), to prevent damage to the
land of the PWB, extreme care should be taken not to leave the bit in contact with the PWB for an extended period of time.
Remove the bit as soon as a good flow is achieved. The high content of tin in lead free solder will cause premature corrosion
of the bit. To reduce wear on the bit, reduce the temperature or turn off the iron when it is not required.
Leaving different types of solder on the bit will cause contamination of the different alloys, which will alter their
characteristics, making good soldering more difficult. It will be necessary to clean and replace bits more often when using
lead-free solder. To reduce bit wear, care should be taken to clean the bit thoroughly after each use.

Sn-Ag-Cu

R-21FBSTM/R-22FBSTM - 20

1. CARRY OUT 3D CHECKS.
2. Make sure that a definite "click" can be heard when the

microwave oven door is unlatched. (Hold the door in a
closed position, then pull the door open slowly.  This
causes the latch heads 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 hinges or latch hook is damaged.
3. The door 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 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.

To remove the components, proceed as follows.

1. CARRY OUT 3D CHECKS
2. Disconnect all the leads and terminal of high voltage

rectifier from high voltage capacitor.

3. Remove one (1) screw holding earth side terminal of high

voltage rectifier, and remove capacitor holder from the
base plate.

4. Remove the capacitor from the capacitor holder.
5. Now the high voltage rectifier and capacitor should be

free.

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

To remove the outer case, proceed as follows.
1. Disconnect oven from power supply.
2. Open door and wedge open.
3. Remove the two screws from the rear intake duct.
4. Slide the rear intake duct up and pull it away from the oven

cavity.

5. Remove the screws from the rear(4), along the side

edges(4 hinge side, 3 control panel side) and from the
 top(2 control panel side).

CAUTION: WHEN REPLACING HIGH VOLTAGE

RECTIFIER  ASSEMBLY, ENSURE THAT THE
CATHODE (EARTH) CONNECTION IS
SECURELY FIXED TO THE CAPACITOR
HOLDER AND BASEPLATE WITH AN
EARTHING SCREW.

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

retaining clips on the cavity face plate.

7. Lift the entire case from the oven.
8. Discharge the H.V capacitor before carrying out any

further work.

9. Do not operate the oven with the outer case removed.

To remove the build in frame assembly, proceed as follows.
1. Remove the four screws securing the frame assembly to

the oven cavity, (two from the top and two from the hinge
side).

2. Remove the two screws securing the frame assembly to

the control panel frame (accessed from the back of the
frame)..

3. Open the oven door fully.
4. Push down the built in frame assembly at the bottom,

where it meets the cavity face.

5. Pull the built in frame assembly away from the cavity face
6. Now the built in frame assembly is free.

TOP SCREWS

C.P SECURING
       SCREWS

HINGE SIDE
     SCREWS

PRESS HERE

CAUTION: DISCHARGE HIGH VOLTAGE CAPACITOR

BEFORE TOUCHING ANY OVEN
COMPONENTS OR WIRING.