Service manual

21
KB-3401LS
KB-3401LK
KB-3401LW
Pin No. Signal I/O Description
the signals holds “H” level during microwave cook-
ing and “L” level while not cooking. In other cooking
modes (90%, 80%, 70%, 60%, 50%, 40%, 30%,
20%, 10%, 0%) the signal turns to “H” level and “L”
level in repetition according to the power level.
48-52 P04-P00 OUT Used for initial balancing of the bridge circuit (absolute humidity sensor).
53 P57 OUT
Common relays driving signal. (Square Waveform : 60Hz)
To turn on and off the shut-off relays (RY1 and
RY3). The square waveform voltage is delivered
to the relays (RY1 and RY3) driving circuit.
54 P56 IN Signal coming from key unit.
55 TXD1 IN Signal coming from key unit.
56 RXD1 IN Signal coming from key unit.
57 P53 IN To input signal which communicates the oven door open/close information to
LSI.
Door open "H" level signal (+5V). Door close "L" level signal (GND).
58 P52 OUT Signal to sound buzzer.
A: Key touch sound.
B: Completion sound.
C: When the oven stops so that the food can be
checked in Automatic cooking mode.
59 P51 IN Input signal which communicates the drawer door open/ close information to
LSI.
Door opened; “H” level signal(+5V).
Door closed; “L” level signal(0V).
60 INT0 IN Signal to synchronize LSI with commercial power source frequency.
This is the basic timing for all real time processing of LSI.
61 AVSS IN
A/D converter power source voltage.
The power source voltage to drive the A/D converter in the LSI.
62 VREF IN Reference voltage input terminal.
A reference voltage applied to the A/D converter in the LSI. Connected to +5V.
63 AN7 IN
AH sensor input.
This input is an analog input terminal from the AH sensor circuit, and connected to the
A/D converter built into the LSI.
64 AN6 IN Used for initial balancing of the bridge circuit (absolute humidity sensor). This input is
an analog input terminal from the AH sensor circuit, and connected to the A/D converter
built into the LSI.
Microwave cooking mode
Other cooking mode
VARI MODE ON TIME OFF TIME ON TIME OFF TIME
100% power 32 sec. 0 sec. 60sec. 0ec.
90% power 30 sec. 2 sec. 54sec. 6sec.
80% power 26 sec. 6 sec. 48sec. 12sec.
70% power 24 sec. 8 sec. 42sec. 18sec.
60% power 22 sec. 10 sec. 36sec. 24sec.
50% power 18 sec. 14 sec. 30sec. 30sec.
40% power 16 sec. 16 sec. 24sec. 36sec.
30% power 12 sec. 20 sec. 18sec. 42sec.
20% power 8 sec. 24 sec. 12sec. 48sec.
10% power 6 sec. 26 sec. 4sec. 56sec.
0% power 0 sec. 32 sec. 0sec. 60sec.
During cooking
L: GND
H: +5V
16.7 msec.
A
B
C
H: +5V
L: GND
0.1 sec
2.0 sec
1.0 sec
1.0 sec
16.7 msec.
H : +5V
L : GND