Testing and troubleshooting are the areas of maintenance that require the greatest technical skill.
Testing procedures are referred to as measurements, tests, and checks. The definitions of these terms
often overlap, depending on their use and the results obtained. For example, a power measurement and a
frequency check could constitute a test of the operation of the same radio transmitter.
Troubleshooting is a term which we in the electronics field use daily. But what does it mean?
Troubleshooting is sometimes thought to be the simple repair of a piece of equipment when it fails to
function properly. This, however, is only part of the picture. In addition to repair, you, as a troubleshooter,
must be able to evaluate equipment performance. You evaluate performance by comparing your
knowledge of how the equipment should operate with the way it is actually performing. You must
evaluate equipment both before and after repairs are accomplished.
Equipment performance data, along with other general information for various electronic
equipments, is available to help you in making comparisons. This information is provided in performance
standards books for each piece of equipment. It illustrates what a particular waveform should look like at
a given test point or what amplitude a voltage should be, and so forth. This data aids you in making
intelligent comparisons of current and baseline operating characteristics for the specific equipment
assigned to you for maintenance. ("Baseline" refers to the initial operating conditions of the equipment on
installation or after overhaul when it is operating according to design.)
Remember, maintenance refers to all actions you perform on equipment to retain it in a serviceable
condition or to restore it to proper operation. This involves inspecting, testing, servicing, repairing,
rebuilding, and so forth. Proper maintenance can be performed only by trained personnel who are
thoroughly familiar with the equipment. This familiarity requires a thorough knowledge of the theory of
operation of the equipment.
A logical and systematic approach to troubleshooting is of the utmost importance in your
performance of electronics maintenance. Many hours have been lost because of time-consuming "hit-or-
miss" (often referred to as "easter-egging") methods of troubleshooting.
GENERAL TEST EQUIPMENT INFORMATION
In any maintenance training program, one of your most important tasks is to learn the use of test
equipment in all types of maintenance work. To be effective in maintenance work, you must become
familiar not only with the common types of measuring instruments, but also with the more specialized
equipment. Some examples of common types of typical measuring instruments are the ammeter,
voltmeter, and ohmmeter; examples of specialized test equipment are the spectrum analyzer, dual-trace
oscilloscope, and power and frequency meters.
TEST EQUIPMENT SAFETY PRECAUTIONS
The electrical measuring instruments included in test equipment are delicately constructed and
require certain handling precautions to prevent damage and to ensure accurate readings. In addition, to
prevent injury to personnel, you must observe precautions while using test equipment. You can find a list
of applicable instructions in appendix II of this module.
To prevent damage to electrical measuring instruments, you should observe the precautions relating
to three hazards: mechanical shock, exposure to magnetic fields, and excessive current flow.