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Is this capacitor bad?

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Mar 24, 2014
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Mar 24, 2014
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It's a 4700uf 35v electrolytic AC filter cap. Reads fine on the capacitance meter, but when I check resistance for short/open, it reads as a dead short for about 3 seconds, then slowly raises to about 147k ohms. I know it's supposed to start low and go high, but is it ever supposed to read as a dead short even if only for a few secs?

I thought buying a cap meter would help but from what I've read on the net, bad caps can test good and the only way to know for sure is with an ESR meter. Any advice?
Thanks!
 

davenn

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Sep 5, 2009
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its a large value cap it will take time to charge up

will try one here and post soon
u using a digital or analog meter ?

Dave
 

davenn

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I got roughly similar results on a 6800uF 35V

if your one really was short circuit, it wouldnt have tested ok on a capacitance meter :)

Dave
 

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Mar 24, 2014
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Thanks for the replies,
I tested it with an analog and digital meter. I'm thinking the cap is good. Now I have to figure out what else could be making this receiver hum. It's a constant hum across all channels that is not affected by the volume knob.
 
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