Service manual

16
R-204(W)
Pin No. Signal I/O Description
8 P20 OUT
Magnetron high-voltage circuit driving signal.
To turn on and off the cook relay (RY2).
The signal holds "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.
9 D5 OUT Digit selection signal.
Signal is input to the anodes of the light-emitting diodes (LD19 - LD24).
10 D4 OUT Digit selection signal.
Signal is input to the anodes of the light-emitting diodes (LD13 - LD18).
11 D3 OUT Digit selection signal.
Signal is input to the anodes of the light-emitting diodes (LD7 - LD12).
12 D2 OUT Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD6, LD12, LD18 and
LD24).
13 D1 OUT Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD5, LD11, LD17 and
LD23).
14 D0 OUT Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD4, LD10, LD16 and
LD22).
15 INT IN Signal coming from encoder.
When the encoder is turned, the contacts of encoder make pulse signals. And
pulse signals are input into INT.
16 CNTR OUT Signal to sound buzzer.
Completion sound.
17 P11 IN Signal coming from encoder.
Signal similar to INT. Pulse signals are input into P11.
18 P10 OUT Oven lamp, turntable motor and fan motor driving signal (Square Waveform
: 50Hz).
To turn on and off shut-off relay (RY1). The
square waveform voltage is delivered to the
relay (RY1) driving circuit and relay(RY2)
control circuit.
19 P03 OUT Digit selection signal.
Signal is input to the anodes of the light-emitting diodes (LD1 - LD6).
20 P02 OUT Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD3, LD9, LD15 and
LD21).
21 P01 OUT Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD2, LD8, LD14 and
LD20).
22 P00 OUT Segment data signal.
Signal is input to the cathodes of the light-emitting diodes (LD1, LD7, LD13 and
LD19).
23 AIN3 IN Signal coming from potentiometer.
By inputting DC voltage corresponding to the power level set by the potentiometer,
this input is converted into the power level by the A/D converter built into the LSI.
24 AIN2 IN Input signal which communicates the door open/close information to LSI.
Door closed; "H" level signal.
Door opened; "L" level signal.
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.
H: GND
L: -5V
2.0 sec
20 msec
During cooking
H
L