Epson LQ-870 User manual

LQ-1170
24-PIN DOT MATRIX PRINTERS
TM-LQ8/1170
Back to Contents

LQ-870/1170
SERVICE MANUAL
EPSON
T$$$ Printed on recycled paper.

NOTICE
’ All rights reserved. Reproduction of any part of this manual in any from
whatsoever without SEIKO EPSON’s express written permission is forbidden.
* The contents of this manual are subject to change without notice.
* All efforts have been made to ensure the accuracy of the contents of this manual.
However, should any errors be detected, SEIKO EPSON would greatly appreciate
being informed of them.
* The above notwithstanding SEIKO EPSON can assume no responsibility for any
errors in this manual or the consequences thereof.
© Copyright 1991 by SEIKO EPSON CORPORATION
Nagano, Japan

REV.-A
PRECAUTIONS
Precautionary notations throughout the text are categorized relative to 1) personal injury, and 2) damage
to equipment:
DANGER Signals a precaution which, if ignored, could result in serious or fatal personal
injury. Great caution should be exercised in performing procedures preceded by
a DANGER headings.
WARNING Signals a precaution which, if ignored, could result in damage to equipment.
The precautionary measures itemized below should always be observed when performing repair/main-
tenance procedures.
DANGER
1. ALWAYS DISCONNECT THE PRODUCT FROM BOTH THE POWER SOURCE AND THE
HOST COMPUTER BEFORE PERFORMING ANY MAINTENANCE OR REPAIR
PROCEDURE.
2. NO WORK SHOULD BE PERFORMED ON THE UNIT BY PERSONS UNFAMILIAR WITH
BASIC SAFETY MEASURES AS DICTATED FOR ALL ELECTRONICS TECHNICIANS IN
THEIR LINE OF WORK.
3. WHEN PERFORMING TESTING AS DICTATED WITHIN THIS MANUAL, DO NOT
CONNECT THE UNIT TO A POWER SOURCE UNTIL INSTRUCTED TO DO SO. WHEN
THE POWER SUPPLY CABLE MUST BE CONNECTED, USE EXTREME CAUTION IN
WORKING ON POWER SUPPLY AND OTHER ELECTRONIC COMPONENTS.
WARNING
1. REPAIRS ON EPSON PRODUCT SHOULD BE PERFORMED ONLY BY AN EPSON
CERTIFIED REPAIR TECHNICIAN.
2. MAKE CERTAIN THAT THE SOURCE VOLTAGE IS THE SAME AS THE RATED
VOLTAGE, LISTED ON THE SERIAL NUMBER/RATING PLATE. IF THE EPSON PROD-
UCT HAS A PRIMARY-AC RATING DIFFERENT FROM THE AVAILABLE POWER
SOURCE, DO NOT CONNECT IT TO THE POWER SOURCE.
3. ALWAYS VERIFY THATTHE EPSON PRODUCT HAS BEEN DISCONNECTED FROM THE
POWER SOURCE BEFORE REMOVING OR REPLACING PRINTED CIRCUIT BOARDS
AND/OR INDIVIDUAL CHIPS.
4. IN ORDER TO PROTECT SENSITIVE /JP CHIPS AND CIRCUITRY, USE STATIC
DISCHARGE EQUIPMENT, SUCH AS ANTI-STATIC WRIST STRAPS, WHEN ACCESS-
ING INTERNAL COMPONENTS.
5. REPLACE MALFUNCTIONING COMPONENTS ONLY WITH THOSE COMPONENTS
RECOMMENDED BY THE MANUFACTURER; INTRODUCTION OF SECOND-SOURCE
ICs OR OTHER NONAPPROVED COMPONENTS MAY DAMAGE THE PRODUCT AND
VOID ANY APPLICABLE EPSON WARRANTY.

REV.-A
PREFACE
This manual describes functions, theory of electrical and mechanical
operations, maintenance, and repair of the LO-870/1170.
The instructions and procedures included herein are intended for the
experienced repair technician, and attention should be given to the
precautions on the preceding page. The chapters are organized as follows:
Chapter 1
- Provides a general product overview, lists specifications,
and illustrates the main components of the printer.
Chapter 2 - Describes the theory of printer operation.
Chapter 3 -
Includes a step-by-step guide for product disassembly and
assembly.
Chapter 4 -
Includes a step-by-step guide for adjustment.
Chapter 5 - Provides Epson-approved techniques for troubleshooting.
Chapter 6 -
Describes preventive maintenance techniques and lists
lubricants and adhesives required to service the equipment.
l The contents of this manual are subject to change without notice
- iv -

Revision Level
Revision Date
I
1st printing
I
7/23/91
I
I-----
%ViSC?d
I
10/g/91
I
1~
2ndprhting
I
3/17/92
I

REV.-A
TABLE OF CONTENTS
CHAPTER 1.
CHAPTER 2.
CHAPTER 3.
CHAPTER 4.
CHAPTER 5.
CHAPTER 6.
APPENDIX
GENERAL DESCRIPTION
OPERATION PRINCIPLES
DISASSEMBLY AND ASSEMBLY
ADJUSTMENTS
TROUBLESHOOTING
MAINTENANCE
- vi -

6/4/93
CHAPTER 1
GENERAL DESCRIPTION
1.1 FEATURES .....................................................................
1-1
1.2 SPECIFICATIONS ................................................................
1-3
1.2.1 Hardware Specifications
.........................................................
1-3
1.2.2 Firmware Specifications
.........................................................
1-9
1.3 PARALLEL INTERFACE ...........................................................
1-14
1.4 CONTROL PANEL .............................................................
1-16
1.4.1 Buttons ......................................................................
1-16
1.4.2 Indicator Lights. ..............................................................
1-17
1.5 DIP SWITCHES AND JUMPERS ....................................................
1-18
1.5.1 DIP Switches ................................................................
1-18
1.52 Jumpers ...................................................................
1-19
1.6 OPERATING INSTRUCTIONS ......................................................
1-20
1.6.1 Self Test ...................................................................
1-20
1.6.2 Hexadecimal Dump Function
.....................................................
1-20
1.6.3 Paper-out Detection and Form Override Function
......................................
1-21
1.6.4 Error Conditions ..............................................................
1-21
1.6.5 Buzzer Operation .............................................................
1-21
1.6.6 Printer Initialization ............................................................
1-22
1.6.7 Default Values ...............................................................
1-22
1.6.8 Paper Loading and Ejection .....................................................
1-23
1.6.9 Tear-off Function
.............................................................
1-23
1.6.10 Paper-Thickness Lever Operation
................................................
1-24
1.6.11 Printer Protection for Heavy Duty Printing
...........................................
1-25
1.7 MAIN COMPONENTS ............................................................
1-26
1.7.1 C060 MAIN, C061 MAIN, and C060 MAIN B Board (Main Control Circuit Board) ...............
1-27
1.7.2 C060 PNL Board (Control Panel Circuit Board). .......................................
1-28
1.7.3 C060 PSB Board (Power Supply Circuit Board)
.......................................
1-28
1.7.4 C060 DRV Board (Head Control Circuit Board)
........................................
1-29
1.7.5 M-5D10/5D60 Printer Mechanism .................................................
1-29
1.7.6 Housing ...................................................................
1-30
l-i

6/4/93
LIST OF FIGURES
Figure 1-1.
Figure 1-2.
Figure 1-3.
Figure 1-4.
Figure 1-5.
Figure 1-6.
Figure 1-7.
Figure 1-8.
Figure 1-9.
Exterior View of the LQ-870
....................................................
1-2
Pin Configuration
...........................................................
1-3
Printable Area for Single-Sheet Paper
............................................
1-6
Printable Area for Continuous Paper
.............................................
1-6
Character Matrix
...........................................................
1-13
Data Transmission Timing
....................................................
1-14
Control Panel
.............................................................
1-16
Self-Test
................................................................
1-20
Hexadecimal Dump
.........................................................
1-20
Figure 1-10. Paper-Thickness Lever Positions
..............................................
1-24
Figure 1-11. LQ-870/1170 Component Layout ..............................................
1-26
Figure 1-12. C060 MAIN, C061 MAIN, and C060 MAIN B Boards ................................
1-27
Figure 1-13. C060 PNL Board .........................................................
1-28
Figure 1-14. C060 PSB Board .........................................................
1-28
Figure 1-15. C060 DRV Board .........................................................
1-29
Figure 1-16. M-5D10/5D60 Printer Mechanism ..............................................
1-29
Figure 1-17. Housing ................................................................
1-30
LIST OF TABLES
Table 1-1. Optional Interface Cards ....................................................
Table 1-2. Optional Units
1-1
...........................................................
1-2
Table 1-3. Specifications for Single-Sheet Paper
.............................................
1-4
Table 1-4. Specifications for Single-Sheet Multi-Part Forms (Carbonless Duplicating Paper)
..............
1-5
Table 1-5. Specifications for Continuous Paper
..............................................
1-5
Table 1-6. Specifications for Envelopes
....................................................
1-5
Table 1-7. Specifications for Labels
.......................................................
1-5
Table 1-8. Printing (Text Mode) ........................................................
1-10
Table 1-9. Printing (Bit Image Mode) .....................................................
1-11
Table 1-10. Character Matrix and Character Size ............................................
1-12
Table 1-11. Connector Pin Assignments and Signal Functions
..................................
1-14
Table 1-12. DIP Switch Set 1 (SW1) .....................................................
1-18
Table 1-13. DIP Switch Set 2 (SW2) .....................................................
1-18
Table 1-14. International and PC Character Set Selection ......................................
1-19
Table 1-15. Page Length .............................................................
1-19
Table 1-16. Paper-Thickness Lever Positions
...............................................
1-24
Table 1-17. Main Boards and Driver Board ................................................
1-26
l-ii

REV.-A
1.1 FEATURES
The LQ-870/1170 is a small, light-weight, low-cost printer that provides advanced paper
handling and is compatible with The LQ-510/550. The printer’s main features are:
I
0 Use of ESC/P 2 control codes
The printer can print fonts in various point sizes and receive and print raster graphic images.
l Compatibility with LQ and SQ series printers
0 Printing speeds:
300 characters per second (cps) in high-speed draft mode at 10 characters per inch (cpi)
330 cps (draft, 12 cpi)
275 cps (draft, 10 cpi)
1 10 cps (LO, 12 cpi)
92 cps (LO, 10 cpi)
0 Multiple fonts resident in the printer: nine letter quality (LQ) fonts (Roman, Sans Serif, Courier,
Prestige, Script, OCR-B, Script-C, Orator, and Orator-S) and one draft font
0 Clear, easy-to-read printing using standard EPSON fonts
0 Selection of fonts, condensed printing, and the cut-sheet feeder (CSF) bin using control panel buttons
0 Advanced paper handling
Continuous paper:
Three ways to insert continuous paper, using the front, bottom, or rear paper entrance
Auto backout and auto loading when using the front or rear paper entrance
Ability to use continuous paper without removing the cut-sheet feeder
Ability to use the standard tractor in three positions (two push tractor positions and one pull tractor
position)
Single-sheet paper:
Two ways to insert single-sheet paper, using the front or top paper entrance
Auto loading
0 Easy handling of single-sheet paper with the optional cut-sheet feeder
0 Optional tractor that can be used to create a push-pull tractor feeding
0 Optional interface cards
The LQ-870/1170 is equipped with the standard EPSON 8-bit parallel interface. The optional
interface cards ensure compatibility with a wide variety of computers. Table l-l Lists the optional
interface cards, Table 1-2 lists the optional units available for the LO-870/1170, and Figure l-l
shows an exterior view of the LO-870/1170.
Table l-l Optional Interface Cards
Model No. Description
C82305’
Serial interface card (inch screw) l 1
C82306’
Serial interface card (milli screw) l 1
C82307’
32KB serial interface card (inch screw)
C82308’
32KB serial interface card (milli screw)
1-1