On Thu, 3 Dec 2015 17:16:03 -0800 (PST), trader_4
wrote:

On Thursday, December 3, 2015 at 7:47:53 PM UTC-5, wrote:
On Thu, 03 Dec 2015 14:08:34 -0700, Don Y
wrote:

No, that's the lazy approach. That's the way auto mechanics start swapping
things (charging you for each "new replacement" -- even if it didn't FIX
the problem) out until they stumble on the "solution".

Since you are not paying for things you try that is not really a good
analogy but without the right test equipment, eliminating things in
the path is probably the only real way to go.


I always start on the path of trying to fully diagnose the problem
instead of swapping parts. But anyone who has worked on cars has sure
had many times where they wished they had the dealers stock of parts
to try swapping something that is easily swappable to see if it fixes it.


When I was fixing things for a living, my first question on a support
call was asking the guy who was working on it "Can you draw a circle
around the problem"? (in an acre of computer room floor, that may not
be as simple as it sounds)

Until you know for sure what box is failing, you really have to back
up and reassess.

It was surprising how many times that just getting your head put of
the box, turned a light on and got you on the right track.
Isolating the problem does not mean simply throwing parts at it. You
should learn something at each step.

In Don's situation,. I would start with a configuration that doesn't
fail and keep adding stuff until you break it.
Drag a known good space heater or heat gun out to the end of that
extension cord and try that, bearing in mind, the fault could be on
the neutral and that will not fail without a load.