An old capacitor on trial

[saturated]

I removed this capacitor from the PS of a Craig 4201 23 channel base station

For some reason it fell under my suspicion and was removed

This was a while back and it's probably innocent

Time to exonerate?

Not having (or the room for) a sencore or tel-ohm mike or Heathkit etc I figured I could do a simple test to check for leakage

You cannot view this attachment.

So far it's holding up at 5V 

You cannot view this attachment.

I'll increase the voltage ⚡ in intervals and see what happens

Or doesn't happen 

[g1]

Since you are often salvaging older stuff, you might want to read up on 're-forming capacitors', which is sometimes done before initially firing up gear that has been sitting a long time.  Some use the dim-bulb tester for similar purpose.

[saturated]

Yes sir thanks well I have some news the jury has spoken

The Oscar capacitor has been acquitted 

He stood up to 30 volts from Paco

You cannot view this attachment.

(I think) you can ignore the millivolts reading on the right it was never steady bouncing all around zero
 

[g1]

Did it's value check out on your capacitance range, or can it measure that high?  Mine can only go up to 400uF, so yours may be like that as well.

A few random notes: 
-always remember to discharge cap, some meters will get fried instantly if you try to measure capacitance of charged cap.
-on meters like this, a high value reading (over-spec) of capacitance means a leaky cap.
-modern caps can be so large that you will now sometimes see values in mF.  That is milli-farads (1mF = 1000uF), don't mistake it for micro!

[saturated]

Yes sir thanks I have not yet checked it's capacitance seems like at the time I was suspicious that it was leaky

Thanks for the heads up about making sure they are discharged

One thing I'm trying to do is be a fundamentalist about this stuff like for instance (of course you know this) even though I have the peak devices I can simply connect a meter in resistance mode and if the capacitor is good then I can sit there and watch the resistance go up 

So fortunately I can test for DC leakage very simply and glad it was only rated for 35V and not 400 V or some crazy capacitor

Then it occurred to me I still need to test to see if it will pass alternating current or signal

One predominantly present theme here is I need to be able to write down or draw these typical bridge rectifier schemes in my sleep and predict/indicate polarity of the terminals of the connected capacitors

Instead of measuring DC on one side of a capacitor and thinking it's bad