Epson Stylus Color C60, Service Manual

Page: 58 / 188

EPSON Stylus C50/C60/C61/C62 Revision C
Operating Principles Electrical Circuit Operating Principles 50
2.2.2.5 Reset Circuit
Reset IC (IC2) on the main board monitors the two voltage: +5V for the logic line and
+36V
(Stylus C50)
/ +42V
(Stylus C60)
for the drive line. Reset IC outputs the reset
signal to CPU (IC1) in the following case.
1. When the printer power is turned on and reset IC detects 4.2V on +5V line/29.2V
on +36V line
(Stylus C50)
/ 36.3V on +42V line
(Stylus C60)
, reset signal is
output to perform the initialize operation correctly.
2. When the printer power is turned off and reset IC detects 4.2V on +5V line/29.2V
on +36V line
(Stylus C50) / 36.3V on +42V line (Stylus C60) , reset signal is
output to stop the printer operation safely.
3. When reset IC detects 4.2V on +5V line/36.3V on +42V line with fail during the
printer operation, reset signal is output to stop the printer operation safely.
Unlike the previous products, the timer IC is not built in the reset IC and the Lithium
battery is not mounted on this MAIN board either.
.
Figure 2-24. Reset circuit block diagram
Main line for reset IC has the following function.
„
OUT1: Interrupt signal
„
OUT2: Reset line
„
IN: +36Vline monitoring line (Stylus C50)
+42V line monitoring line (Stylus C60)
„
VCC: +5V line monitoring line
2.2.2.6 EEPROM Control Circuit
When the printer power is turned off, the following information is stored in EEPROM
(IC3) which is nonvolatile memory. And, when the printer power is on, CPU (IC1)
reads the information from EEPROM.
Information stored in EEPROM is listed below.
„
Various ink counter (I/C consumption counter, waste pad counter, etc.)
„
Mechanical setting value (Head ID, Bi-D adjustment, USB ID, etc.)
Refer to 7.1.2 that provides the detailed information stored in EEPROM.
Figure 2-25. EEPROM circuit diagram
EEPROM is connected to CPU with 4 lines and each line has the following function.
„
CS: Chip selection signal
„
CK: Data synchronism clock pulse
„
DI: Data writing line (serial data) at power off.
„
DO: Data reading line (serial data) at power on.
IC2
BH6150F-E2
IC1
E01A24CA
+5V
+36V/
+42V
8
7
6
5
MEWS
VCC
OUT1
OUT2
NC1
IN
NC2
GND
1
2
3
4
38
37
36
MRES
NMI
RESET
EEPROM-93C
(IC3)
E01A24CA
(IC1)
+5V
VCC
NC
ORG
GND
CS
SK
DI
DO
C-P20
C-P21
C-P22
C-P23
42
41
40
39
1
2
3
4
8
7
6
5