Service manual

EPSON Stylus C82 Revision A
OPERATING PRINCIPLES Electrical Circuit Operating Principles 19
2.2.2 C486 MAIN Board
Table 2-4. C486 MAIN Board Major Components and Primary Functions
IC Location Function
ROM IC1
8 Mbit ROM program for CPU provided with CG table, 3.3V
drive (not DOS compliant)
Transceiver IC3
Transceiver IC for the Centronics I/F response to IEEE1284 and
ECP more, Data transfer by DMA, 3.3V drive
Reset regulator IC4
Formed reset signals shown below.
1. Dropping 42V line to 36.3V, 2. Dropping 5V line to 4.2V
D-RAM IC5
4 Mbit RAM 2-CAS type, 16 bit bus, 5V and 3.3V drive provide
page access functions.
EEPROM IC6 1 kbit capacity for default setting or adjusted value.
Motor Driver IC8
For driving both CR and PF motors, PWM control by program
timer, 5V regulation, 42V drive
Head Driver 1 IC9 For creating trapezoidal waveform, 5V drive
ASIC IC10
CPU (equivalent of H8S/2323), Internal 8Kbit RAM, Internal
MASK ROM, 24MHz, 3.3Vdrive
Head Driver 2 Q2, Q3 Based on IC9 control, trapezoidal waveform creates, 42V drive