All About Transistors

More information located here https://www.slideshare.net/unsiaquarian/types-of-transistors

First easy this to test is continuity between the pins. There should be NO continuity between any of the pins. This is a quick test to know if it is bad.

The symbol for continuity looks like WiFi bars

If the quick test comes up correct then set your meter to the diode setting. Marked like so typically:

In this example I will be testing a Panasonic C5584. Google your part number on the chip to get the design sheet.

Information I found for this example is here https://elcodis.com/parts/5998483/C5584.html

it is a NPN type transistor and it tells me Pin 1 is the Base, Pin 2 is the Collector, and Pin 3 is the Emitter

Now for the testing:

• Clamp a black probe to the Base pin
• Touch the red probe to the Emitter
  • Note whether the resistance is high or low
• Move the red probe to the Collector
  • The reading should be the same as the Emitter reading
• Clamp the red probe to the Base pin
• Touch the black probe to the Emitter AND Collector
  • Compare the results to your previous reading
    • If the previous readings were both high and the current readings are both low, the transistor is good
    • If the previous redings were both low and the current readings are both high, the transistor is good
    • If both readings with the red probe are not the same, both readings with the black probe are not the same, or the readings don’t change when switching probes then the resistor is bad.

Reference: https://www.wikihow.com/Test-a-Transistor