Epson STYLUS COLOR 580, Service Manual

Page: 45 / 149

EPSON Stylus COLOR 580 Revision A
Operating Principles Electrical Circuit Operating Principles 45
2.2.2 C379MAIN-C Board
The printer mechanism is controlled by C379MAIN-C. On this MAIN board, 3.3V
regulator IC is not mounted and all IC is driven with 5.0 V.
See Figure for the C379MAIN-C board block diagram.
Figure 2-18. Block Diagram for the C379MAIN-C Board
Following shows you the major characteristic of this main board.
o
Timer IC & Lithium battery are not mounted
Unlike the previous products, the Timer IC and the Lithium battery are not
mounted on the Main board. So, this product perform the Power-on cleaning or
Timer cleaning based on the time command which is sent from the printer driver.
As for the detail, refer to the 2.1.7 Ink Sequence.
o
D-RAM
1Mbit D-RAM is mounted on the Main board.
o
One CPU controls the all function on the main board.
2.2.2.1 Main elements
Table 2-8 shows the function of the each main elements on C379MAIN-C.
2.2.2.2 Printhead Driver Circuit
The printhead drive circuit consists of the following two components:
n
Head common driver circuit
(Common driver IC7 & Wave amplifier transistor Q1, Q2)
n
Nozzle selector IC on the printhead driver board.
The common driver (IC7) generates a reference drive waveform according to the
output signals from the CPU (IC1). The reference drive waveform is amplified by the
transistors Q1 and Q2 and then transferred to the nozzle selector IC on the print head
circuit board. Print data is converted to serial data by the CPU and then sent to the
nozzle selector IC on the print head circuit board. Based on the serial data, the nozzle
Table 2-8. Main Elements
IC Location Function
CPU
E01A19NA
IC1
16bit CPU mounted on the MAIN board is driven by
clock frequency 24MHz and controls the printer.
PROM IC3
• Capacity 4MB, Bus= 16 bit
• Program for CPU
RAM IC4 Bus= 16 bit, 1Mbit DRAM
AT93C46 IC5
1kbit EEPROM
• Default value setting
• Parameter backup
LA5623M IC6
Reset IC
• For +5V; reset when +4.2V is detected
• For +42V, reset when +33.2 is detected
E09A17RA IC7
Head drive control HIC
• Generates head common voltage.
LB1845 IC8 CR motor drive IC
LB1845 IC9 PF motor drive IC