INTRODUCTION
BACKGROUND OF THE STUDY
The impact of engineering age is tremendous and its arrears of application are increasing geometrically. It is believed that the information revolution will radically change the nature and quality of engineering work in the near future.
Some of the most exiting arrear of the information technology includes.
– Office automation and computer publishing
– Just-in-time (J.I.T) production techniques to reduce cost and improve quality.
– Electronic shopping and electronic funds transfer
– Computer controlled commuter train system
– Decision support system (DSS) that facilitate real time control of making under battle field condition typically characterized by uncertainty
– Computer aids to the handicapped including intelligent implants and experts for medical diagnosis.
– Computer aids instruction (CAI) and aided manufacturing.
Due to all these mentioned arrears of computer application and more, computer has now been accepted and used by so many organizations, by individuals for various purposes. It is believed that computer is an agent, which improves productivity, enhances competition.
It is however worthy to not that 75% of all computer application generate documented information. This is why it is said that had copy is the spice of information.
Computer generates printed report for adequate circulation and communication. This underlines the importance of printers in computerized operations and environments.
Considering the increasing number of which malfunction ‘vis a vis’ while the scanty availability of maintenance experts, these is no doubt that may important and urgent reports are either frustrated permanent or produced too late to serve their purpose. It therefore become very imperative to develop this EPSON printer troubleshooting and maintenance expert system which will guide a non-expert through step by step approach to troubleshoot and maintain his EPSON printer.

STATEMENT OF THE PROBLEM
When printers malfunction, it is often difficult tracing the causes of such malfunctions with respect to identified symptoms. Often, some of these faults are so minor that virtually every user is supposed to be able to handle them effectively without having to undergo the rigours of finding maintenance experts. In many occasions, the defects are perfectly eliminated by clearing the edge connectors and resisting the plugs and printer interface cards. Some diagnostic software such as Qapuls could also help in locating the causes of the problem.
However, the need for a reliable maintenance service cannot be over emphasized.
Since it is necessary for effective performance of any printer. Also it is pertinent to observe that there are many other preventive maintenance procedures that can be duly appreciate by the user which could minimize printer failure. This project has been designed and preventive maintenance in a “DO IT YOURSELF FASHION. It as well provides most of the salient information necessary to troubleshoot Epson printers.

PURPOSE OF STUDY
The purpose of this project or study is to give expert knowledge or guide on the rectification of several known faults commonly developed by Epson printer and then develop an expert software system which will give any user the expertise knowledge to rectify the problem of his/her Epson printer.
This project will, therefore, briefly, look at the superficial culture of maintaining and trouble shooting printers with a view providing a number of analytical diagnostic steps that an operator could easily implement to enable him/her forge ahead when his/her printer suddenly develops a fault in the make of a printer job.

AIMS AND OBJECTIVES
The aims and objectives of this project are:-
To assemble a knowledge base that is common to the trouble shooting and maintenance Epson printers of diverse models. To prevent this knowledge in a diagnostic format such that will enable even non-expert identify and rectify minor problems of the printers especially. When the maintenance experts are not handy. To provide a printer maintenance teaching aid on the basis of DO IT YOURSELF. To emphasize the concept of preventive maintenance, especially as it effects fragile electronic of the ink of computer and printers.

SCOPE OR DELIMITATION
Even though there are several types – laser, dot – matrix, inkjet – and makes of printer Epson, OK1, NEC, CITIZEN, IBM, STAR, PANASONIC, etc,. for the purpose of this project, it has been designed to focus on the most commonly found (the Epson dot – matrix printer). This option was chosen with the respect to the fact that this could be regarded as the (economy class) hence need as much guide as possible both in preventive and guide as possible both in preventive and corrective maintenance.
It is worth being mentioned that the project has been designed and mainly flow on the Epson and similar. The area of coverage is not very wide, however, since volume of books and journals are regularly on the issue. Hence this work shall not attempt to be exhaustive.

1.6 LIMITATION
The research work cannot contain all it suppose because of the following reasons or limitations.

TIME FACTOR:– The aim that is given for the research on this study is very limited making it impossible to go further into the research.

UNAVAILABILITY OF THE NEEDED INFORMATION:- Seeing that only a few engineering firms exist in this country, it was difficult for me to get much informant for the work.

TIMITED RESOURCES: Because of the cost in transportation and other financial demands, it was not possible to get all the information needed for an elaborate work.

1.7 DEFINITION OF TERMS
Artificial intelligence result when machines are made to thick. Artificial intelligence is a general term, which expert systems and robotics lie. The expert system technology has been necessitated by the fact that some human domain experts delay some wonderful skill, which is lost whenever they die thereby leaving the future generation with little or nothing to inherit from their wonderful skill. Hence they need the expert knowledge of a human being in a domain of activity to be stored in the computer such that computer mimic the reasoning of the expert in some way reaching the same decisions or conclusion as the expert himself and effectively replacing him.
Because of the reposition of an expert knowledge in the computer memory to enable it think like the expert.

EXPERT SYSTEM (ES)
The title of this work “expert system on trouble shooting and maintenance of Epson printer” presents a lot of computer words or term or jargon which need detailed explanation or definition for absolute comprehensive of this and topic and the intention of this work. I shall therefore proceed to highlight the meanings of the terms.

WHAT IS EXPERT SYSTEM?
According to Daniel L. Stotink and his friends in a book “computer and applications an introduction to data processing” expert system is also a knowledge based system. It is a complex software (program), designed to imitate the thought processes and decision making patterns of human experts in a given field. The expert system is an off-spring of artificial intelligence (AI) and it is developed using the programming techniques of A1. when the expert knowledge of human being in a domain of activity is stored in the computer. Such that the computer repository of this expert knowledge in some way, reaching the same conclusion as the expect himself and efficiently replacing him, an expert system or knowledge based system results.

KNOWLEDGE – BASED
The repository in a computer of an experts knowledge in a given domain as a knowledge base.

DOMAIN EXPERT
It is not easy to effectively replace the human being with just one expert system rather, a piece meal approach is used in which an expert system is instrumental for a narrow domain to mimic the human being in one activity at a time.

REASONING BY INDUCTION
If in an expert system past conditions and corresponding decisions reached are stored such that where a new condition arises.
The computer tries to march it with one of the previous condition, the approach is known as reasoning by induction.

HEURISTIC
In general, the experience a human being acquires in any are of human endeavour are often in the form of rules of thumb which the human experts falls upon when confronted with a new but related situation. Such rules of thumb are known as heuristic in artificial intelligence terminology.

INFERENCE ENGINE
The knowledge of an expert can be represented as a set of rules that allows the computer to make human like decisions on the subject. In other words, a knowledge – base can actually be in the form of rules and not only in the form of tables of information which can also be used as alternative approach. The computer program written to shift through the set of rules representing human expert knowledge so as to reach a decision on the current situation can be referred to as inference mechanism or inference engine.

TROUBLE – SHOOTING
Trouble – shooting is the ac of detecting and mending faults be it a hardware or software facility. To be good trouble shooter one needed to understand a system better than the average person.

MAINTENANCE
Maintenance is the performance of “prevention or remedial maintenance in order to prevent incipient hardware faults or to correct a hardware fault that has occurred”. We therefore define computer and printer maintenance as the prevention and correction of faults in the system or as knowing fault that has occurred or as knowing fault that has occurred or that fault can occur. And taking steps to ensure that the fault is eliminated.
Definition in this ways two kinds of maintenance can be identified.
i. PREVENTIVE:- Knowing that a fault can occur and taking steps to prevent occurrence.
ii. CORRECTIVE:- When the faults has already occurred and it has to be corrected. Also a definition of exactly what is (fault) or what constitute a fault must be known. In essence, for maintenance to take place a description of the normal fault (its cause) and its remedy must be known. It should be clear that maintenance to take place, a large information based about the fault to be diagnose has to available to service personnel. Also needed would be the tool, both of these items are discussed in this project. When take within the context of computer, maintenance and hardware maintenance. The terms “hardware” in the brain, respectively to the brain while a software fault might be equivalent to mis information.
Knowledge engineer is a specialist who works with experts to capture the knowledge they possess in order to develop a knowledge base for expert system and other knowledge from experts and then builds the knowledge base using an iterative, prototyping process until the expert system is acceptable.