Henry Kolesnik wrote:

The power supply was turned on this morning at 8 am and shut down in less
than 10 minutes. I turned it back on about 9:30 and it is still on, that's
over 4 hours. I'm not that versed on ESR but I have a tester and cm
curious if high ESR can be an intermittent condition and if so what would
the physics of that phenomena be? At this point I'm not willing to do a
shotgun replacement of all the caps. I do keep running the power supply and
the condition is not getting worse. I wish it would fail so I might find
the failed component. The way it is now it's impossible to troubleshoot
without shotgunning.

A dried out cap is not an intermittent problem, but if the supply turns
off when some threshold is reached and that threshold has lowered
because of the cap's high ESR then the actual trigger would be caused by
power line fluctuations, temperature changes, etc.

A cold solder joint would be quite intermittent, but it would show up
with board flexing and other "wiggling" kind of diagnostics.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com