Quick-test component tester.

Find bad components in-circuit on a crowded circuit card. Build this inexpensive, yet very useful tester in a single evening.

In today's world of electronics, technicians sometimes forget or have never learned the older methods used to troubleshoot components. The result is that they spend way too much time working on a problem that a more experienced technician would quickly locate. Today, as always, time is money, and if you spend too much time on simple problems, you are not making as much money or profit as you could. By saving time you might also be able to reduce the charges to your customer. There are several old-time methods for finding trouble in electronic circuits that still apply to the most modern of electronic marvels.

One such troubleshooting method calls for injecting an AC signal into a component, and then reading the voltage produced across the component and the current flowing through it on an oscilloscope. Many test instruments have been sold that perform this task. The advent of more and more digital, CMOS, mega-transistor logic modules that must be replaced as a …