Testing procedures for the 2N4124 NPN transistor.

 

1.     Using the HP 34401 multimeter press the "Cont" button to place the unit in Continuity mode.

2.     Test the Base – Collector forward junction. 

a.     Multimeter Lead configuration.

b.     Positive: Base “center pin”

c.     Negative: Collector “right pin with markings facing up.”

d.     Passing result ~730Ω

3.     Test the Base – Emitter forward junction. 

a.     Multimeter Lead configuration.

b.     Positive: Base “center pin”

c.     Negative: Collector “left pin with markings facing up.”

d.     Passing result ~730Ω  

4.     Test the Base – Collector reverse junction. 

a.     Multimeter Lead configuration.

b.     Negative: Base “center pin”

c.     Positive: Collector “right pin with markings facing up.”

d.     Passing result OPEN

5.     Test the Base – Emitter reverse junction. 

a.     Multimeter Lead configuration.

b.     Negative: Base “center pin”

c.     Positive: Collector “left pin with markings facing up.”

d.     Passing result OPEN

6.     Steps 2-5 must have a passing result to qualify a passing transistor.