On 4/22/2015 11:23 PM, N_Cook wrote:
On 23/04/2015 03:03, Ivan Vegvary wrote:
Okay, I know that electrolytics are the most likely to fail. However
why do the manufacturers of ESR meters discuss ONLY electrolytics? do
ceramics etc. not have an "equivalent series resistance"? Can they
also be checked?
Thanks for putting up with me and your previous answers.

Ivan Vegvary


The common failure mode of non-electrolytics eg tantalum and MLCC is
they go ohmic , so just DVM-R test picks them up. Tantalum because of
microscopic "plate" separation and shorting across, then MLCC due to
metal migration into microscopic cracks , usually created at soldering ,
especially PbF temps. Incidently for electrolytics , you should check
for capacity with a capacitance meter also, if ESR checks out ok

I'm a time-domain kinda guy.
If you stick a current pulse into a cap and look at the voltage
on a scope, the step gives you a measure of ESR and the exponential
gives you a measure of the capacitance.

If testing in a circuit, you can often find which cap is bad in
a cap/inductor/another cap circuit.