Re: College/Tech Course Work For Pinball Repair

On Sat, 20 Sep 2008 19:12:12 -0700 (PDT), wxforecaster <ebookbinder@xxxxxxxxx> wrote:
Somehow impressed with my diagnosis skills and vast knowledge of the
gameplay, the owner literally offered me a job right there on the
spot. Unfortunately, I can't solder my way out of a paper bag and
while I passed 4 semesters of physics with flying colors, I certainly
can't read a schematic or understand any wiring.

Well, pick one at a time and work on it. Soldering is a skill. It can
be learned, and improved on. Master that, then move on the learning
to read and understand a schematic. Wiring is mostly just following the
wire from one end to the other. Colour codes on the wiring help, as does
reading from the schematic to see where it's supposed to start and where
it's supposed to end.

Which leads me to the following -- I would love to take this gentleman
up on his offer (as a long term goal of sorts). What sort of courses
do you techs suggest a highly motivated, intelligent rookie take in
the aspects of electrical wiring *and* PCB diagnosis, repair,
soldering, etc...

I'm doubting that there's any one course that'll do it. For something
like PCB diagnosis and repair, you need a bit of electrical engineering,
and a bit of computer science. Not a lot, since you're not trying to
design your own, just enough to be able to follow somebody else's
design and figure out what's gone wrong.

Start with something like "The Art of Electronics" by Horowitz and Hill,
maybe, to learn about the components and how they work. Many of the
components used are simple devices. Some are more complex, but from the
diagnosis and repair point of view, you really only care to know that
it's working as expected, or not. On a simple device, like an inverter,
you can "look at" the input signal with a logic probe, and you can look
at the output. If the output is not the inverse of the output, then the
inverter is pretty likely to be bad. It doesn't matter to you how the
inverter works internally, just that it's no longer inverting.

Knowing where to look takes time, familiarity with the system being worked
on, and understanding the schematics. I can pretty easily diagnose and
repair anything made by Zaccaria, because I do a lot of those. I can also
do Bally, Williams, or Gottlieb, but because I'm less familiar with those
systems and their common failures, it takes longer.

Soldering is just a skill. Get a scrap board or two, and practice. You
will screw it up at first, but it's a scrap board so it doesn't matter.
Get some decent tools; a good soldering iron and a good desoldering iron
make this a lot easier than working with crap tools. Remove all parts
from the board (desoldering practice), then reinstall them (soldering
practice). Look at the results. Do they look good? Do it again, until
you can answer "yes".

I wouldn't worry much about wiring. Just follow a wire from one end to
the other. Connectors in the middle are where *most* of the problems
will be. Broken wires are usually obvious.

to repairs 80s-2000s machines. (Yes, I've read Marvin's pages 20 times
over and it's still way over my head). I'd like some hands on formal
learning at a local technical school or university.

Trade or technical school, maybe community college, may have something.
If there's one in your area, go visit them and see what they have to
offer. University level stuff probably won't help for this. To draw a
(probably bad) analogy, I can look out my window and decide if it's
raining or not. I don't need a 4-year degree to do that. Not that the
degree isn't good, it's just overkill.

The biggest problem with the school approach, at least IMHO, is that
you're working on relatively ancient technology here. They're going to
want to teach what's out there now, which isn't the old through-hole,
discreet components stuff that we're working on here. We're on the
trailing edge of technology. Most of this stuff is 1980s designs, some
of which were updated to 1990s, but it's not much beyond that. (I
haven't looked at the new Stern system, it may be current tech, but
unless you're working on a new Stern, that hardly concerns you.)


--
| David Gersic http://www.zaccaria-pinball.com |
| Sysoping - More fun than being beaten with a sledgehammer. |
| Email address is a spam trap. Visit the web site for contact info. |
.

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