"Micky" wrote in message
...

In ESR cap, what does ESR mean?

Look up equivilent series resistance. In short it is a number that tells of
the quality of the capacitor especially when used in switching and high
frequency circuits.

Most any old capacitor will be ok for filtering out 60 hz in the old power
supplies. When the switchers came out , the capacitors begain to fail .
Checking on a simple capacitor meter will show the value ok, but they fail
under the high speed/frequency high current usage.