Question

What are the different tests that can be carried out to determine if a transistor is good?

Answer 1

To test a transistor, we measure one diode junction (since transistor consists of two diodes connected back to back) by using a multi-meter. one side of the diode should read a very high resistance and on switching the polarity it should read a much lower resistance and vice versa.

The following test can be perform to determine whether the given transistor is of good condition or not:

1. Base to Emitter test

2. Emitter to Base test

3. Collector to Emitter test

4. Emitter to Collector test

5. Base to Collector test

6. Collector to Base test

On performing the above test we should observed that each pair must have one side a very high resistance mostly in the Mega-Ohms range and the other side a much lower resistance of a few hundred thousand ohms. If this is the case for each of the transistors leads then we can conclude that the given transistor is of good condition otherwise it is defective.