wrote in message
ups.com...
Henry Kolesnik wrote:
As of this moment it has run over 26 hours without shutting down.
I've
never seen any evidence that ESR can be an intermittent phenomena.
Can
someone please tell me how intermittent ESR comes about?


The measured ESR of an electrolytic capacitor changes with
temperature.... usually ESR decreases slightly. If the power supply
circuit is just at the threshold of operating correctly then very
slight changes in the ESR of critical capacitors will certainly affect
how the power supply operates and sometimes it can cause a catastrophic
failure of other components. Cold or cracked solder connections can
also cause similar intermittent symptoms.
The repair suggestion replies you have been getting to your original
posting are your FIRST troubleshooting and testing steps; otherwise we
are all guessing here.


Just a guess here, as I may have missed a post or two, but does the unit
shut down "completely" to where nothing can be traced through to see where
it stops? IF not, maybe try that too. I agree with the rest otherwise.

L.