Epson Stylus Photo 750 Service Manual page 38

EPSON Stylus Photo 750
2.2.2.2 Reset Circuit
Reset circuit consists of reset/timer IC(IC8) and peripheral elements.
The reset/timer IC prevents the CPU from running away, which is
caused by the unstable voltage(+5VDC line voltage is less than +4.3V)
in the logic line during the power ON/OFF operation. Also, IC sends the
reset signal to the CPU and gate array when +42VDC line voltage is
less than +35.5V.
IC 8
RTC-9810
+42 VIN
VDD
VBK
GND
Figure 2-5. Reset Circuit
Operating Principles
IC 1
C90A05
/RES
B1
10
29
/VDT
/NMI
3
24
FRST
MRES
2
25
/RST
/RESET
CE
IC 2
SCLK
E05B588
DATA
Operating Principles of Electric Circuit
Revision A
33