Actually, there are other failure methods. Some caps will test fine for
capacitance and ESR but have high dielectric absorption and/or dc leakage.
These are hard to test for without the proper equipment. Like I (and
others) have said, when in doubt, replace electrolytic caps. They are cheap
and plentiful. You should be able to find the right caps from one of a
number of suppliers, most likely DigiKey or Mouser.

Leonard

"larrymoencurly" wrote in message
om...
"Leonard Caillouet" wrote in message
news:PH4fd.74459$hj.51928@fed1read07...

I find leaky caps that test fine for ESR all the time. If
they are mounted so that you can't see the legs, which most
larger caps are, you have to perform the "smell" test or
remove them to inspect them. The smell test consists of heating
the legs and noting whether you smell bad tuna or not.

When in doubt replace. A few caps is not worth the time to have
to go back into the unit a second time.

Thanks for the information. I wrongly thought that if a capacitor had
low ESR and wasn't shorted that it was OK. That's interesting about
the smell test.

I was going to replace all the caps, but the only ones available
locally are either too fat, mystery brands, or old enough to have been
made at the same time as all those defective Taiwan caps.