wrote in message ...
Mark Zacharias wrote:
Maybe we could share some "war stories" of cool repairs we have done
in the past.

It's definitely not consumer electronics, but here goes.

I used to work at a company that made flight simulators. My official
job was writing code to make the navigation instruments display
correctly, according to the simulated position of the aircraft, which
frequencies the radios were tuned to, the position of circuit breakers,
etc.

Some of the laws of nature at that particular job included:

1) Techs string wire.

2) Programmers write programs.

3) Techs never make mistakes when stringing wires.

4) No programmer could ever possibly understand the intricacies of
stringing wires. Therefore, any complaints by programmers about the
wiring can usually be disregarded.

5) Any persistent complaints about the wiring can be remedied by telling
the programmers to work around it in the code.

Never being one to obey the laws of nature, I brought in my own meter
and checked things out when the sim didn't seem to work right. My boss
knew that I had something of a clue; I had been giving "how to read a
schematic" lessons to a few of my cow-orkers (in software) who were also
new hires or just wanted to know how. He basically told me that he
didn't mind me doing my own checks as long as I was careful with the sim
hardware, and that I should expect the techs to get mad at me if they
ever saw me doing it.

I couldn't get the right DME indicator to light up in one sim. (It was
a box in the instrument panel with three 7-segment displays and a couple
of buttons. It was supposed to display how far the airplane was from a
particular radio station.) After a few rudimentary checks of my code, I
wrote up a "right DME inop" trouble ticket. The technician wrote back,
"Wiring checks to print, DME sent for repair". Sure enough, there was a
hole in the panel. When it was again filled, I tried again...no joy. I
swapped the left and right indicators - hmm, the problem stayed with the
socket instead of following the indicator. I broke out the wiring
diagram and my own personal multimeter and started chasing around behind
the panel - no wires or pins for power on the right DME socket. (It was
something like a DB25 or DB37, with individual "crimp and poke"
contacts.) I dutifully re-opened the ticket, and the tech dutifully
wrote "wiring checks to print" and closed it again.

About this time, the sim was shipped to the site, even though it was
broken. The standard process was to completely build the sim at the
factory, test it out, ship it to the site, certify it, and put it in
revenue service. For sites that were far away from the factory, this
practice was generally followed, because it was expensive to ship people
to site to finish working on the sim. However, the site that was
closest to the factory (~3 hr drive) was notorious for the following:

Factory: We will have the sim done on $DATE.

Site: No no no! We've already sold time on that sim to customers on
$DATE-30days and we can't reschedule! We *must* have it here
sooner!

Factory: Why did you do that? The sim will not be done on
$DATE-30days. It will be broken and unusable for training.

Site: We don't care.

Factory: If we ship it at that time, it will suck.

Site: We don't care!!! Ship it shipit SHIPIT!!1!

Factory: sigh OK.

(time passes)
Site: Well you got the sim to us on time but it sucks! Everything's
broken and we can't put the customers on it! Fix it fixit
FIXIT!!1!

Factory: sighs deeply, starts phoning rental car agencies and hotels

So I get to the site and the site manager is bugging me about the right
DME indicator. I walk in to the site maintenance shop and tell the
techs there I need some connector pins, the crimper tool, some wire, and
a bench power supply. They are extremely wary of this as they have
experienced "programmers with screwdrivers" before, but they give me the
requested items and follow me into the sim, probably in hopes that my
body will shake and jerk in interesting ways as I electrocute myself.
I put the pins on the wires and put them in the (still vacant) slots on
the right DME connector. Wires run out under the panel to the power
supply, which temporarily gets the co-pilot's seat. Fire up the sim,
hit the power supply, and whaddayaknow - DME love for all. I
disappointed the techs, but the site manager was very happy.

I pointed out the relevant page in the wiring diagram book, so the site
techs could get it wired in correctly. I figured they had a lot more
experience than I did in fixing factory screwups. They were satisfied
with this, and I got to go home.

Matt Roberds



Wow. Lots of times I'm too lazy to read to the end - but this was great!
Loved it!

mz