Pin No.
Port
Signal name
IN/OUT
H/L
Description
56
P04
SMG
OUT
H
Transport motor gain signal
57
P03
SPPD
IN
H
Paper entry detecting signal
58
P02
KEY2
IN
L
Operation PWB key input signal
59
P01
KEY1
IN
L
Operation PWB key input signal
60
P00
KEY0
IN
L
Operation PWB key input signal
61
P87
OP-DATA
OUT
Serial data output to operation PWB
62
P86
NC
—
—
(NC)
63
P85
OP-CLK
OUT
Data output clock signal to operation PWB
64
P84
OP-LATCH
OUT
Data latch signal to operation PWB
65
P83
UN-DATA
OUT
Serial data output to lower unit PWB
66
P82
NC
—
—
(NC)
67
P81
UN-CLK
OUT
Data output clock signal to lower unit PWB
68
P80
UN-LATCH
OUT
Data latch signal to lower unit PWB
69
Vcc
Vcc
Power (5V)
70
AVcc
AVcc
Analog/Digital convertor reference power voltage
71
V
REF
V
REF
Analog/Digital convertor reference voltage input
72
AV
SS
AV
SS
Analog/Digital convertor ground pin
73
Vss
Vss
Power (GND)
74
P77
ANS
IN
Analog input signal (SPF sensor input)
75
P76
MBT
IN
Analog input signal (Main PWB destination setting)
76
P75
CLV
IN
Analog input signal (Copy lamp control)
77
P74
RTH
IN
Analog input signal (Fusing thermistor)
78
P73
Not used
79
P72
Not used
80
P71
TCSA
IN
Analog input signal (Toner density sensor)
(3) Start/stop control circuit
1 General
The circuit senses ON/OFF state of the power source to control
start/stop of the circuits.
The DC power section supplies power voltages (V
H
=+32V, VB=+24V,
VC=+10V, VD1=5V, VD2=5V).
After the power voltage reaches the specified level, the circuit opera-
tion is started. Before the power voltage falls below the specified
level, the circuit operation is stopped, preventing against malfunc-
tions.
5V2
C134
22000PF
5V2
C106
0.1uF
VCC
1
NC
2
CAP
4
/RESET
5
GND
3
IC113
M51953BL
C135
22000PF
R145
2.4kJ
RESET1
RESET2
RESET
28
CPU
(IC110)
12 – 5
