N_Cook wrote:

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.


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.


** A DMM ohmage test is no use unless the cap is removed from circuit.

So the way you find the bad one is with a bench PSU good for a few amps.

The smoking cap or caps are then the bad ones.


Incidently for electrolytics , you should check
for capacity with a capacitance meter also, if ESR checks out ok


** Absolute ******** !!!!!!!!!!!!!!!!!

If the ESR reading is good then the uFs are ALL there.




..... Phil