How to Test NPN & PNP Transistor

Introduction:
        A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is a three-terminal semiconductor device, those pin are labeled collector(C), base(B) and emitter(E). now, i will show how to check transistor using multimeter.


method 1: using multimeter with NPN Transistor

(A)

• First turn ON digital multimeter and select diode mode.
• Connect the test leads to the transistor terminals. Keep test leads connected for a few seconds at like this (A) connection.
• Read the measurement displayed. If the transistor value is within the measurement range, the multimeter will display the transistor value.
• displayed multimeter value is from 0 above 150, the transistor is good.
• displayed multimeter value is 0 or .0L, the transistor is bad.

(B)

• Connect the test leads to the transistor terminals. Keep test leads connected for a few seconds at like this (B) connection.
• Read the measurement displayed. If the transistor value is within the measurement range, the multimeter will display the transistor value.
• displayed multimeter value is from 0 above 150, the transistor is good.
• displayed multimeter value is 0 or .0L, the transistor is bad.

(C)

• Connect the test leads to the transistor terminals. Keep test leads connected for a few seconds at like this (C) connection.
• Read the measurement displayed. If the transistor value is within the measurement range, the multimeter will display the transistor value.
• displayed multimeter value is 1, the transistor is good.

(D)

• Connect the test leads to the transistor terminals. Keep test leads connected for a few seconds at like this (D) connection.
• Read the measurement displayed. If the transistor value is within the measurement range, the multimeter will display the transistor value.
• displayed multimeter value is 1, the transistor is good.

method 2: using multimeter with PNP Transistor

(E)

• Connect the test leads to the transistor terminals. Keep test leads connected for a few seconds at like this (E) connection.
• Read the measurement displayed. If the transistor value is within the measurement range, the multimeter will display the transistor value.
• displayed multimeter value is 1, the transistor is good.

(F)

• Connect the test leads to the transistor terminals. Keep test leads connected for a few seconds at like this (F) connection.
• Read the measurement displayed. If the transistor value is within the measurement range, the multimeter will display the transistor value.
• displayed multimeter value is 1, the transistor is good.

(G)

• Connect the test leads to the transistor terminals. Keep test leads connected for a few seconds at like this (G) connection.
• Read the measurement displayed. If the transistor value is within the measurement range, the multimeter will display the transistor value.
• displayed multimeter value is from 0 above 150, the transistor is good.
• displayed multimeter value is 0 or .0L, the transistor is bad.

(H)

• Connect the test leads to the transistor terminals. Keep test leads connected for a few seconds at like this (H) connection.
• Read the measurement displayed. If the transistor value is within the measurement range, the multimeter will display the transistor value.
• displayed multimeter value is from 0 above 150, the transistor is good.
• displayed multimeter value is 0 or .0L, the transistor is bad.

method 3: using power supply with NPN

• If push button is pressed supply side, the transistor will turn ON and the LED will ON. else button is pressed ground side, the transistor will turn OFF  and the LED will OFF. its working properly, the transistor is good. its not working, the transistor is bad.

method 4: using power supply with PNP

• If push button is pressed supply side, the transistor will turn OFF and the LED will OFF. else button is pressed ground side, the transistor will turn ON  and the LED will ON. its working properly, the transistor is good. its not working, the transistor is bad.