EPSON Stylus PHOTO 950
Revision A
OPERATING PRINCIPLES
Electrical Circuit Operating Principles
49
The following figure shows the structure of the reset circuit.
Figure 2-30. Reset Circuit Block Diagram
+5V line reset circuit
The 5V line is monitored at the VCC port of IC12, and if an abnormal voltage
(4.2V or less) is detected, a reset signal for the 2-in-1 CPU-ASIC is output from
the OUT2 port.
+42V line reset circuit
The 42V line is monitored at the IN port of IC12, and if an abnormal voltage
(36.3V or less) is detected, a reset signal for the 2-in-1 CPU-ASIC is output from
the OUT1 port.
EEPROM CONTROL CIRCUIT
Since EEPROM is nonvolatile memory, it keeps written information if the printer
power is turned off. When the printer is turned ON, CPU (IC6) reads data from
EEPROM (IC13) via the RAM and when the power is turned OFF it stores data to
EEPROM via the RAM.
EEPROM is connected to CPU with 4 lines and each line has the following function.
CE
: Chip selection signal
SK
: Data synchronism clock pulse
DI
: Data writing line (serial data) at power off.
DO
: Data reading line (serial data) at power on.
Figure 2-31. EEPROM Circuit Diagram
NC1
IN
NC2
GND
MAES
VCC
OUT1
OUT2
IC12
8H6150F
C23
0.1U
IC6
CPU-ASIC
2 in 1
E01A28CA
MAES
NMILVL
RESET
C25
0.1U
TP1
+42V
+5V
TP2
VCC
NC
ORG
GND
CS
SK
DI
DO
IC13
EEPROM
C26
0.1U
IC6
CPU-ASIC
2 in 1
E01A28CA
C_P13/IEEEINT
C_P15/INT1_PFDCU
C_P16/INT0_PFDCU
C_P17/0_TMA3
Содержание Stylus Photo 950
Страница 1: ...EPSONStylusPHOTO950 Color Inkjet Printer SEIJ01 015 SERVICE MANUAL ...
Страница 5: ...Revision Status Revision Issued Date Description A April 5 2002 First Release ...
Страница 8: ...C H A P T E R 1 PRODUCTDESCRIPTION ...
Страница 25: ...C H A P T E R 2 OPERATINGPRINCIPLES ...
Страница 53: ...C H A P T E R 3 TROUBLESHOOTING ...
Страница 91: ...C H A P T E R 4 DISASSEMBLYANDASSEMBLY ...
Страница 132: ...C H A P T E R 5 ADJUSTMENT ...
Страница 158: ...C H A P T E R 6 MAINTENANCE ...
Страница 174: ...C H A P T E R 7 APPENDIX ...
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