File name EPSON LQ-300.PDF

EPSON TERMINAL PRINTER LQ-300 SERVICE MANUAL EPSON NOTICE All rights reserved. Reproduction of any part of this manual in any form whatsoever without SEIKO EPSON's express written permission is forbidden. The contents of this manual are subjects to change without notice. Alleffortshavebeen made toensuretheaccuracy of thecontentsofthis manual. However, should any errors be detected, SEIKO EPSON would greatly appreciate being informed of them. The above notwithstanding SEIKO EPSON can manual or the consequence thereof. assume no responsibility for any errors in this Epson is registered trademark of Seiko Epson Corporation. General Notice: Other product names used herein are foridentication purposes only and maybe trademarks of their respective carnpanies. Copyright @ 1994 by SEIKO EPSON CORPORATION Nagano, Japan -i- 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 DANGER Headings. WARNING Signals a precaution which, if ignored, could result in darnage to equipment. Theprecautionary measures itemized below should alwaysbe observed when performin grepair/ maintenance procedures. DANGER 1. ALWAYS DISCONNECT THE PRODUCT FROM BOTH THE POWER SOURCE AND PERIPHERAL DEVICES PERFORMING ANY MAINTENANCE OR REPAIR PROCEDURE. NO WORK SHOULD BE PERFORMED ON THE UNIT BY PERSONS UNTAMILIARWITH BASIC SAFETY MEASURES AS DICTATED FOR ALL ELECTRONICS TECHNICIANS IN THEIR LINE OF WORK. WHEN PERFORMING TESTING AS DICTATED WITHIN THIS MANUAL, DO NOT CONNECT THE UNITTOA 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. 2. 3. WARNING 1. REPAIRS ON EPSON PRODUCT SHOULD BE PERFORMED ONLY BY AN EPSON CERTIFIED REPAIR TECHNICIAN. MAKE CERTAIN THAT THE SOURCE VOLTAGE IS THE SAME AS THE RATED VOLTAGE, LISTED ON THE SERIAL NUMBER/RATING PLATE. IF THE EPSON PRODUCT HAS A PRIMARY AC RATING DIFFERENT FROM AVAILABLE POWER SOURCE, DO NOT CONNECT IT TO THE POWER SOURCE. ALWAYS VERIFY THAT THE EPSON PRODUCT HAS BEEN DISCONNECTED FROM THE POWER SOURCE BEFORE REMOVING OR REPLACING PRINTED CIRCUIT BOARDS AND/OR INDIVIDUAL CHIPS. IN ORDER TO PROTECT SENSITIVE MICROPROCESSORS AND CIRCUITRY, USE STATIC DISCHARGE EQUIPMENT, SUCH AS ANTI-STATIC WRIST STRAPS, WHEN ACCESSING INTERNAL COMPONENTS. REPLACE MALFUNCTIONING COMPONENTS ONLY WITH THOSE COMPONENTS BY THE MANUFACTURE; INTRODUCTION OF SECOND-SOURCE Ics OR OTHER NONAPPROVED COMPONENTS MAY DAMAGE THE PRODUCT AND VOID ANY APPLICABLE EPSON WARRANTY. 2. 3. 4. 5. - ii - PREFACE This manual describes functions, theory of electrical and mechanical operations, maintenance, and repair of LQ-300. The instructions and procedures included herein are intended for the experi