Control Circuit - Epson 2070 - LQ B/W Dot-matrix Printer Service Manual

Operation Principles

2.3 CONTROL CIRCUIT

The control circuit consists of the C186 MAIN board assembly and C165 PNL board This section describes
the major components and explains how the boards work.
2.3.1 Overview of Control Circuit Operation
The printer's control circuit includes a TMP96C041AF CPU that runs at 17.20 MHz, an E05B24YA gate
array, a 1M bit PS-RAM (8-bit bus, less than 100ns) , a 2M bit PROM (8-bit bus, less than 100ns), 4M CG
(Standard Version) or 8M CG (NLSP Version). It oversees control of all the components in the printer. The
following chart shows you a block diagram of the control circuit.
Type B I/F
Parallel I/F
Panel LED
Panel SW
Pow er SW
PSC
PWDN
5 V
G L
P/ S
35V
Unit
G P
Figure 2-30 Control Circuit Block Diagram
2-22
IC 3 ROM
IC2
Gate Array
E05B24YA
IC 8
EEPROM
IC 10
Rest IC
IC 12 IC 11, IC14
CR Drv. PF Drv.
SLA7024M TEA3718SDP
LQ-2070 Servcie Manual
Q1 ~Q24
Head Drv.
IC 5 RAM
IC 1
CPU
TMP96C041AF
C S F
CSF Drv.
Detector
: Data Bus
: Address Bus
Head Temp.
Detector
+35V Voltage
Detector
PE-Rear
Detector
PE-Front
Detector
P-Width
Detector
H o m e
Detector
Release
Lever
Detector
G a p
Lever
Detector
Rev.A