Service manual

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EPSON LQ-300+ Revision C
Operating Principles Electric Circuit Operating Principles 43
2.3.2 C294PSB / C294PSE Board
LQ-300+ generates power supply by 2 types of power supply boards: C294PSB
(100V) and C294PSE (200V). The table below shows the power supply boards input
voltage specifications.
2.3.2.1 Electric Circuit
The power supply board supplies two types of power for control circuit and driving
mechanism. The table below shows output voltage and its use.
NOTE: *: Core voltage of CPU and G/A is 3.3V and it is generated by the
regulator IC on the MAIN board form +5VDC.
Table 2-14. Main ICs and Functions
Elements Location Function
CPU/ASIC IC3
E01A17Axx
CPU
• Outside clock 19.66 MHz/
Inside clock 39.32 MHz
• Various DMA
• A/D converter (3ch)
G/A
• Bit Manipulation Unit (Print Date Conversion)
• I/O control unit
LED output/Reset control report
EEPROM (94C46) report
Energy Saving mode
CS motor detector (option)
• Input buffer control unit
• CR/PF/CS motor unit
• Head control unit
CGROM_ IC6 CG (Font)
PROM IC7
8M / 16Mbit
• Stores firmware
•CG
DRAM IC8
1/2/4M bit switching method, SPJ package 40 pin
• Various buffer, work area
EEPROM IC5
AT93C46, 1kbit, SOP 8pin
• Stores default values and various parameters
RESET IC IC4
M62030FP, 8 pin
•CPU reset
CR Motor Driver IC9 A3972SB
PF Motor Driver IC10 A3972SB
Serial I/F Transceiver IC2 MAX202
Regulator IC IC11
BA033FP
• Generates 3.3V logic voltage
Economy Drive Circuit IC12
TL594CN
• 95V rated voltage circuit
• Detects over voltage (over 150V) and sends OFF
signal to the power supply boards.
Table 2-15. Power Supply Boards Input Voltage Specifications
Circuit Input voltage Fuse specification
C294PSB 99 - 132VAC ULTSC-2.5A-NI
C294PSE 198 - 264VAC HT 1.25A
Table 2-16. Output Voltage and its Use
Output voltage Use
35 V +5%/ -10% Drive
5 V ± 5% Logic Voltage*
Table 2-14. Main ICs and Functions
Elements Location Function