for Effective Troubleshooting
By Warren Rhude
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; etc. Equipment may operate in a manner far
different than it was designed to, or not at all.
Typically, when equipment fails there is a sense of urgency to get it fixed
and working again. If the defective equipment is part of an assembly line, the
whole assembly line could be down causing unexpected “time off” and lost
revenue. If you are at a customer site to repair equipment, the customer may
watch you, knowing that they are paying for every minute you spend
troubleshooting and repairing their equipment. Either one of these scenarios –
and there are more, can put a lot of pressure on you to solve the problem
So What is troubleshooting? It is the process of
analyzing the behavior or operation of a faulty circuit to determine what is
wrong with the circuit. It then involves 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 easily
visible. Other times the symptoms as well as the faulty component can be
difficult to diagnose. 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 much more difficult 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. No
trial and error here. So what is their secret?
You might think that a person who has a very good understanding of how the
equipment works, should be able to troubleshoot it effectively. Being a good at
troubleshooting requires more than this.
Expert troubleshooters have a good understanding of the operation of
electrical components that are used in circuits they are familiar with, and even
ones they are not. They use a system or approach that allows them to logically
and systematically analyze a circuit and determine exactly what is 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 the pros you will need to develop your
skills in each of these areas. Let’s look at them in more detail.
- Understand how the circuit works. This consists of
understanding the operation of all the components that are used in the
circuit. This could include such components as: push buttons, contactors,
various types of switches, relays, sensors, motors, etc.
Electrical circuits typically control or operate mechanical systems and
components. 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, etc. You also need to be able to
determine what effect a faulty component may have on the circuit operation.
- Use a logical, systematic approach to analyze the circuit’s
behavior. This is critical. 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 steps and ruling out trial and error. One such
approach used to teach troubleshooting is called the “5 Step Approach”.
A summary of the key steps are:
- Observe Most faults provide clues as to their cause. There could be
visual clues such as signs of damage or improper operation. Don’t
forget to use your other senses; sounds and smells can also provide
valuable clues. Through careful observation and a some reasoning, most
faults can be identified to the actual component with very little
- Define Problem Area At this stage you apply logic and reasoning to
your observations to determine the problem area of the malfunctioning
- Identify Possible Causes Once you have the problem area(s) defined it
is necessary to identify all the possible causes of the malfunction.
- Determine Most Probable Cause Once the list of possible causes has
been made it is necessary to prioritize the items as to the possibility
of them 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 to be the problem or not.
Systematic Approach to Troubleshooting for more details on this
- Understand how to use tools such as prints, diagrams and test
instruments to identify defective components. 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 kind of features the circuit has
- what voltages you should expect at various points on the circuit
- where components are physically located
- how the components are actually wired together
Various types of test instruments are available for testing electrical
circuits. The ones you choose depends on the type of circuit and its
components. A common test instrument which is invaluable to a troubleshooter
is a Multimeter. It is capable of measuring voltage and resistance with some
meters capable of other 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 safely take readings with it.
- Practice! Troubleshooting, like any skill, requires practice to
become proficient. Practice can be difficult to get. Depending on
your job, you may not have the opportunity for 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 is best to practice troubleshooting in a controlled
One option is to build or purchase equipment that can be used for
troubleshooting. This equipment is designed with the ability to apply faults
to it. Here you can practice your skills in a very realistic environment
without affecting equipment in use.
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 can be used in almost
any location. Some even include an assessment function that assesses the
user’s troubleshooting skill, provides feedback, and records their
Review your own skills in each of these areas. Improving any one of them,
along with a good dose of practice, will improve your troubleshooting skills.
About the Author:
Warren Rhude is president of Simutech Multimedia Inc. an e-learning company that develops computer based training simulations for
electrical troubleshooting. Warren has an electrical background and has taught
troubleshooting for several years at a prominent electrical utility.
Multimedia has developed a series of award winning simulations for learning
electrical troubleshooting skills. Click here for more
information on these programs or to download
a free demo.
UP-TIME Publications teaches your maintenance crew engineering and asset
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make better decisions and your plant runs more reliably!
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