2007.03.07 Flow2 stairlift Tab 06: Systematic fault finding
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Systematic fault finding
Distinguish possible causes
You make a distinction in the area of the fault on the basis of the components that can be tested
individually to determine their performance. You adopt a systematic approach. For example, when
you can test an entire sub-system you do not begin by testing the individual components.
The example of the lamp switching
At first, you can make a distinction between two components of the lamp: the power supply, and the
actual lamp. When the correct voltage is applied to the light’s fitting then it can be concluded that the
power supply is in order. So it won’t be necessary to inspect the wiring, the switch, the transformer,
and the wall socket.
Determine the sequence of your work
You have made a note of a number of components that could possibly contribute to the problem. You
will try to eliminate these possible causes; however, you will first need to determine the sequence in
which you are going to carry out the work.
You determine the sequence on the basis of your knowledge of the system, your experience, and the
information you have already collected. Make a note of the possible cause, and determine the
sequence on the basis of:
- the probability that the component is faulty
- the ease with which you can test the appropriate performance of the component.
It is possible that although it is very unlikely that a specific component is faulty you nevertheless
decide to begin by testing the component. You will decide to do so only when the test can be carried
out quickly, and with ease.
The example of the lamp switching
Usually the problem is simply a blown bulb. However, with a halogen light bulb this is not always so
easy to determine. You don't have the right lamp with you for testing it; there are so many different
types and sizes. Nevertheless, in this instance it is easy to test the power supply. So you begin with
this test before you decide to go to the store to buy a new bulb.
Eliminate the causes
You will eliminate the possible causes in the sequence you have just determined.
Diagnostic equipment
You can use the following diagnostic equipment to test the appropriate performance of a component:
- the Flow2 error indication system
- hyperterminal / PDA (training required)
- a multimeter to measure the resistance, voltage and current (AC or DC)
- sliding callipers and a measuring tape
- a digital spirit level
- your ears (a rattle in the system)