Marky P wrote:

On Wed, 1 Oct 2008 10:42:53 +0100, "David Looser"
wrote:

"Patrick Turner" wrote in message
...



ESR is measured in other ways, but it seems the OP wanted to know how to
work out the C value without a C meter.

Does it? the OP talked about "testing" a capacitor, not "measuring" it; that
sounds to me more like someone who wanted to know whether a capacitor was
faulty.

Since the OP has remained silent since his first post what he actually
wanted remains a mystery.

David.

Very sorry! I forgot made this post (someone over at alt.digital.tv
remined me). I want to test for faulty caps. It's in a power supply
unit in a 1980's professional multi-track tape recorder

Marky P.

Try just replacing it with another of the right type. If the problem of
noise or silence vanishes, maybe its the cap. Hire a tech to find out
for you? every tech knows what to do about testing a cap for a
fault/leakage and its been discussed many times here and else where.

Reading the circuit should inform you of the Vdc across the cap and hum
voltage, so if there is a lot of hum and Vdc is low, and there are hot
parts, then maybe the circuit powered by the Vdc is drawing too much
Idc. Take the wholeistic approach, or else put up with wrong
diagnosies.

Patrick Turner.