Simple diode question - Does it have to be removed from the PCB to test it?

Thread Starter

Lumenosity

Joined Mar 1, 2017
469
Seems too many people assume too much especially in electronics.

After spending over an hour watching YouTube videos I could not answer that one basic question.

Can anyone answer that question?

Do Diodes HAVE to be removed from a circuit board (or at least one lead) in order to test them?

Thanks a million!
 

dl324

Joined Mar 30, 2015
11,872
Do Diodes HAVE to be removed from a circuit board (or at least one lead) in order to test them?
It depends. In many cases, you can do simple testing (open, short, diode). It depends on what is connected in parallel with the diode.

I routinely test diodes with a continuity tester that consists of 2 AA batteries and an incandescent bulb. If a diode is open, no light. If it's shorted, bright light. If it's "good", dim light. It's not a definitive test for everything, but it confirms whether it's obviously bad.
 

crutschow

Joined Mar 14, 2008
25,647
You can test the diode in place (circuit must have no power applied).
If it passes the test then the diode is likely okay.
If it doesn't pass then you need to remove one lead to determine if it's actually bad.
 
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