File name Epson LQ-2550 Technical Manual.pdf

L Q - 2 5 5 0 TECHNICAL MANUAL EPSON 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/maintenance 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 PRODUCT HAS A PRIMARY-AC RATING DIFFERENT FROM THE AVAILABLE POWER SOURCE, DO NOT CONNECT IT TO THE POWER SOURCE. 3. ALWAYS VERIFY THAT THE 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 KP CHIPS AND CIRCUITRY, USE STATIC DISCHARGE EQUIPMENT, SUCH AS ANTI-STATIC WRIST STRAPS, WHEN ACCESSING 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. - ii - REV.-A PREFACE This manual describes functions, theory of electrical and mechanical operations, maintenance, and repair of the LQ-2550. 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 Chapter 3 Chapter 4 Describes the theory of printer operation. Discusses the options Includes a step-by-step guide for product disassembly, assembly, and adjustment. Chapter 5 Chapter 6 Provides Epson-approved techniques for troubleshooting. Describes preventive maintenance techniques and lists lubricants and adhesives required to service the equipment. " The contents of this manual are subject to change without notice. - iv - REV.-A REVISION TABLE REVISION A DATE ISSUED March 31, 1988