Equipment can malfunction for a variety of reasons. Mechanical contacts and parts can wear out, wires can overheat and burn open or short out, parts can be damaged by impact or abrasion and so on.
Typically, when equipment fails, there is an urgent need to get it ﬁxed and working again. Say, for example, the defective equipment is part of an assembly line. It could bring the entire line to a halt, causing unexpected downtime and costing the company big money for every minute of lost production.
Or say you are at a customer site to repair equipment. The customer may be breathing down your neck, knowing full well how much they are paying you for every minute it takes to troubleshoot the problem and repair their equipment. Either one of these scenarios—and there are more—can put a lot of pressure on you to solve the problem quickly.
So what is “troubleshooting”?
Troubleshooting is the process of analyzing the behavior of a faulty circuit to determine what is wrong with it, and then identifying the defective component(s) and repairing the circuit.
Depending on the type of equipment, troubleshooting can be a very challenging task. Sometimes problems are easily diagnosed and the problem component is easy to see. Other times, the symptoms as well as the faulty component can be very difﬁcult to diagnose. For example, a defective relay with visual signs of burning should be easy to spot, whereas an intermittent problem caused by a high resistance connection can be a challenge to ﬁnd.
What makes an expert troubleshooter?
One trait of expert troubleshooters is that they are able to ﬁnd virtually any fault in a reasonable amount of time. Easy faults, complicated faults—they ﬁnd them all. Another trait is that they typically replace only the components that are defective. They seem to have a knack for ﬁnding out exactly what is wrong, without a lot of trial and error. So what is their secret?
You might think that a person with a very good understanding of how the equipment works should be able to troubleshoot it effectively. But being good at troubleshooting takes more than that.
Expert troubleshooters have a good understanding of the operation of the electrical components that are used in circuits—those they are familiar with, and those they aren’t. They use a system, an approach that allows them to logically and systematically analyze a circuit and determine exactly what’s wrong.
They also understand and effectively use tools such as prints, diagrams and test instruments to identify defective components. Finally, they have had the opportunity to develop and reﬁne their troubleshooting skills.
If you want to troubleshoot like a pro, you will need to develop your skills in each of these areas. Let’s look at them in more detail.
1. Understand how a circuit works
Understanding how a circuit works means understanding the operation of all the components that are used in that circuit, including push buttons, contactors, various types of switches, relays, sensors, motors and so on.
Electrical circuits typically control or operate mechanical systems and components, so you also need to understand how these mechanical aspects of the equipment operate to carry out the work.
You need to be able to determine how the circuit works under normal conditions, and what effect changing one of the circuit inputs has on the circuit operation. For example, what happens to the overall circuit operation when a push button is pressed? Which relays energize? Which lights illuminate? Does the pump start or stop? You also need to be able to determine what effect a faulty component may have on the circuit operation.
2. Use a logical, systematic approach to analyze the circuit’s behavior
This skill is critical, and there are several approaches that troubleshooters use. They may have different steps or processes but they have the following in common: they all approach problems systematically and logically, thus minimizing the number of steps required and avoiding trial and error. One approach used to teach troubleshooting is the “5-Step Approach.” The key steps are:
Most faults provide clues to their cause. There could be visual clues, such as signs of damage or improper operation, but don’t forget to use your other senses—sounds and smells can also provide valuable clues.
Through careful observation and some reasoning, most faults can be identiﬁed to the actual component with very little testing.
- Define the Problem Area
At this stage, apply logic and reasoning to your observations to determine the problem area of the malfunctioning equipment.
- Identify Possible Causes
Once you have the problem area(s) deﬁned, it is necessary to identify all the possible causes of the malfunction.
- Determine the Most Probable Cause
Once you have listed the possible causes, prioritize the items according to likelihood of being the actual cause of the malfunction.
- Test and Repair
Once you have determined the most probable cause, you must test it to prove it whether or not it is the problem.
See Troubleshoot Like an Expert: A Systematic Approach for more details on this approach.
3. Understand how to use tools such as prints, diagrams and test instruments to identify defective component
Let’s ﬁrst look at prints and diagrams. Some of the key things you should be able to determine from these are:
- how the circuit should operate;
- what its features are;
- what voltages you should expect at various points on the circuit;
- where components are physically located; and
- how the components are actually wired together.
Various types of test instruments are available for testing electrical circuits. The ones you choose depend on the type of circuit and its components. A common test instrument that is invaluable to a troubleshooter is a multimeter. A multimeter is capable of measuring voltage and resistance, and some models are capable of additional measurements such as current and capacitance.
You must be able to determine what type of test instrument to use, when and where to use it and how to take readings with it safely.
Troubleshooting, like any skill, requires practice if you are to become proﬁcient. But opportunities to practice can be difﬁcult to find. Depending on your job, you may not have the opportunity to get enough troubleshooting practice. And even if you do, your employer may not want you to practice troubleshooting on equipment they depend on. Until you become reasonably competent, it’s best to practice troubleshooting in a controlled environment.
One option is to build or purchase equipment that can be used for troubleshooting. This equipment is designed so that faults may be applied to it, allowing you to practice your skills in a very realistic environment without affecting the equipment your company is currently using.
Another option, which is gaining more popularity, is the use of computer simulations. These simulations can be extremely realistic and allow you to practice your troubleshooting skills in a safe environment. Some other advantages are portability, cost effectiveness and the fact that they can be used in almost any location. Some even include functionality to assess the user’s troubleshooting skill, provide feedback and record their troubleshooting processes.
Review your own skills in each of these areas. Improving any one of them, along with a good dose of practice, will enrich your troubleshooting skills.