Testing a bottle cap transistor

Robran68

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Just wondering when testing a transistor like a 2SD870 or C1106 by itself what kind of readings I should get when its bad. When I did a continuity check on a supposedly good one I got a reading of 46 and on a I think bad one was 75. Does this sound right??
 
With those readings, you can assume that both are bad.

Set your meter for diode test.
Place the red lead on the case of the trans.
Place the black lead on the metal chassis.

Roughly 1300 or higher is good, anything less is questionable.
 
The problem with these things....they are not all made the same. Their internals can be quite different. Some are a straight up "standard" transistor. Others (in the case of some HOTs), have internal diodes. Some might have several diodes...maybe a resistor....maybe several transistors....or any combination of stuff.

Example, the 2SD870 is a transistor, a diode, and a resistor in one package. It's hard to test something like this with a meter....without already knowing what results you should see.

Edward
 
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