Epson Stylus Color 640 Service Manual page 67

EPSON Stylus Color 440/640/740
[C256 Main for Stylus Color 640]
The reset circuit prevents the CPU from running away, which is caused
by the unstable voltage in the logic line during the power ON/OFF
operation. And reset IC(IC9) monitors level of power voltage at the over
loading or malfunction on the circuit and manages the printer to operate
normally, keeping the damage to the printer minimum during the
abnormal situations. On the C256 main board.
Chapter 2 Operating Principles
PST592D
(IC8)
1
Vout
2
NRES
3
Vcc
4
GND
C47
Not mounted
TMP95C061
16
(IC1)
P85
15
30
P84
/RESET
10
/NMI
+42V
M62030
NC8
(IC9)
R10
VCC
2
OUT
IN
NC5
4
R6 GND
Figure 2-21. Reset Circuit for Stylus Color 640
Revision A
+5V
+5V
R1
R138
E05B43
(IC2)
174
/RESET
+5V
8
7
6
5
67