Testing a diode in PCB

[legend killer]

Hello everyone,
I got a PCB from my friend's junk and just as an experiment I would like to see whether the diode in the PCB is working or not. I dont know what is the function of that PCB, just wanna know whether the diode is working or not. Is it possible to test that diode in the PCB or do I have to desolder it. I am having a digital multimeter to check the diode. Any suggestions would be really helpful.
Regards
LK

 

[DerStrom8]

Hi legend killer,

Perhaps this link will help you:

**broken link removed**

 

[JimB]

A lot depends on what other components on the board are connected to the diode.

My own methodology for in circuit testing of diodes is:
1 Test it
2 Does it test like a good diode?
3 Yes - diode is OK
4 No - disconnect one end of the diode, or remove if completely from the board, whichever is easier and test again.

If in doubt, disconnect the diode.

JimB

 

[dr pepper]

The diode test on my meter like most these days does the job for me, if theres something across the diode it might mess up the reading so you'll have to lift one end of it to get a good test, bad diodes are often shorted.

 

[legend killer]

Thank you guys for your valuable feedback.

 

[tvtech]

A lot depends on what other components on the board are connected to the diode.

My own methodology for in circuit testing of diodes is:
1 Test it
2 Does it test like a good diode?
3 Yes - diode is OK
4 No - disconnect one end of the diode, or remove if completely from the board, whichever is easier and test again.

If in doubt, disconnect the diode.

JimB

Or use a YEW or similar Analogue meter. Put a little current through it...and see if it behaves strangely when forward biased...

I have seen this too many times in my life to ignore. That's why my YEW is my trusty repair partner...

Sure, a Digital will find most faults quicker. It's the ones that it does not find that can make a temperamental repair relatively easy...

I am often asked why I use an Analog meter for repairs...my answer...I trust Analog 100%...

Digital for new designs only. Not repairs.

Regards,
tvtech