But they are "practicing" law and Medicine we already know our jobs and I am with Marc on this one I think the problem should have been found in an hour or less.
it doesn't always work like that.
i did control wiring on a 75' tall high bay door, that had it's upper track
extended out on the bottom of a crane door, so the 500 ton bridge crane
could go outside the building into a canopy area.
everything interlocked eleventeen different ways, to prevent the lower
door from being extended out onto the crane door unless the dogs
on the crane door were fully down in the locked position.
the first weekend the customer used the door, they almost dropped the
75' tall high bay doors, by running them out when the crane door was
unlocked.
monday morning, there were attorneys present, and i, and a third party
who was there to keep me honest, went on a wire by wire survey of the
controls to find where i screwed up. it took more than an hour, it took
three days, for a very simple reason.
i had not made any mistakes... at the end of the third day, we were
up in the basket at 75', looking inside a pull box, checking wires, and 20'
away was a limit switch with a 12" whisker, to pick up when the crane
door locks were fully engaged, securing the door.
and a pigeon flew in the door, and landed on the 12" whisker, causing a
false closure. the other guy and i just looked at one another, and i said
i was sure glad he was there, 'cause NOBODY would believe just one of
us coming down with that story, claiming what they saw.
there are now pigeon guards on the limit switches.
troubleshooting successfully requires communication with the customer,
explaining exactly what i am doing, and why the amount of time is
unknown... i usually explain that the problem will be in the LAST place
i look, and if they can tell me where that is right now, we can be done
in 15 minutes.
that explanation seems to work well for me.
randy