Hook the positive lead from the multimeter to the to the EMITTER (E) of the transistor. Hook the negative meter lead to the BASE (B) of the transistor. For an good NPN transistor, you should see “OL” (Over Limit). If you are testing PNP transistor, the meter should show a voltage drop between 0.45V and 0.9V.4 May 2017
How do you know if a transistor is bad?
A bad transistor can sometimes be detected by its partly burned or distorted appearance, but more often there is no visible indication. One approach to troubleshooting is to substitute a known good component, but that is a costly way to go.14 Feb 2020
How do component testers work?
You put a component in the socket and it will identify — with a push of a button — what the part is, which pin is which, and the value of the part. For example, you can insert a resistor, a capacitor, an inductor, a diode, or a transistor and get a readout of which pin is which.1 Oct 2019