Testing transistors

[Karl vd Berg]

It reads "OL". But in the datasheet, there's a diode between C and E.

(red probe on Q lead):

B-C = .609
B-E = .725
E-C = .551
E-C = OL

 

[guest122]

View media item 14311I don't always test transistors. But when I do

 

[avionic]

Your transistors might be OK..

 

[avionic]

View media item 14311I don't always test transistors. But when I do

You link doesn´t work..

 

[audiodummy]

Yes, those internal resistors (especially the 500Ω one) and the embedded diode will throw off the B-E (nominally around 1.2V) and E-C measurements, respectively. And yes this diode-checker test is only a quick go-nogo test, it doesn't test the transistor's main ability: to amplify. (As an aside, there are those cheap multimeters with transistor check function. You still need to do the diode check of the junctions before you can trust these transistor checkers.)

Anyone seen a germanium darlington? Not sure if one exists...