Principles of Troubleshooting
Principles of Troubleshooting
A career in electrical and electronic troubleshooting can be a very financially rewarding and personally satisfying one. The expert troubleshooter has a unique blend of understanding electronic theory, problem-solving techniques, and hands-on skills. Most electronic products and devices contain similar components, such as resistors, capacitors, diodes, transistors, contacts, connectors, and wire. Understanding common faults of these components and how to test them is a prerequisite for the troubleshooter. In this chapter, you will learn basic problem-solving analysis, common circuit faults, various troubleshooting methods, and testing procedures for the most common electrical or electronic components.
Before attempting to service a device, you must first develop an understanding of problem solving and how this concept applies to overall troubleshooting and repair. Think of servicing a device as having three phases: (1) situational analysis, (2) problem solving, and (3) decision making. You must proceed in this logical manner; otherwise mistakes, accidents, and wasted time and expense may result. For example, many troubleshooters, upon the discovery of a blown fuse, just replace the fuse, instead of first determining the source of the problem, perhaps only to have another fuse blow.
Therefore, situational analysis is the first step in servicing a device. It involves critical scrutiny and analysis of a problem situation. It allows the troubleshooter to gain insight into an unacceptable condition. It is defined as simply looking at the overall condition of the device and determining whether a problem even exists.
Begin this step by asking questions and making observations as follows for troubleshooting:
- Discuss the defect with the owner or operator.
- Compare the problem with others from your past experiences.
- Perhaps there is no problem at all, and it is an operating error.
- Identify the existing state of operation with the desired state.
- Make an overall observation of the situation, noting symptoms and relevant changes.
Problem solving is the second phase and is completed when it has been determined through situational analysis that a problem exists that needs further investigation. Problem solving is triggered by a deviation from a standard or a desired state. Examples include a malfunctioning or inoperable device. Troubleshooting is the process of problem solving. It is in this phase that the cause of a problem is identified.
The first step in problem solving is to get organized. Begin by obtaining necessary schematics, manufacturer’s specifications and servicing manuals, and tools and equipment. Do not shortchange this step by jumping in and wasting a lot of time attempting to repair a device, when simply reading the servicing guide could have easily solved the problem. In other words, those who fail to plan plan to fail.
Once you are organized, begin by doing the following for troubleshoot :
- Describe the problem.
- Compare the problem situation with known operating conditions prior to the breakdown.
- Describe all known differences such as the symptoms, noises, and smells noticed when defect occurred.
- Compare the “what is” with the “what is not.” Which components are okay and which are not, and to what degree are the components defective?
- Analyze differences through testing by paying close attention to obscure and indirect relationships. For example, slight tolerance changes in components or physical color changes can signal causation.
Once you have determined the actual cause of a problem, you are ready to proceed to the final phase, called decision making. Decision making is defined as examining various solutions or repair alternatives and selecting the best option. For example, if it is determined that an electric motor is the cause of the problem, there could be several alternatives in deciding how to repair the overall system. The motor could be repaired, it could be replaced by the same model, or an entirely new upgraded model could be substituted depending on the operating conditions of the overall system. The troubleshooter might decide that upgrading the motor is more cost-effective because the likelihood of future premature breakdowns is reduced.
When deciding which alternative to utilize, you must consider all the advantages and disadvantages for each alternative along with contingency planning. Contingency planning takes into account future changes in the overall system, such as expected life, operating conditions, and model changes. For example, it may not be wise to replace the motor with a new one when you suspect the entire system may soon be obsolete and replaced anyway.
Remember to always follow the three phases: situational analysis, problem solving (troubleshooting), and decision making (repair). Following these basic stages and understanding the importance of this sequence are essential to becoming a skilled expert in electronic troubleshooting.