Star Tech Journal

STAR*TEcH
Journal
CID
March 1996
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... continued from page 11
components. Include in that the
connectors that are used to hook it
up, make sure they are not burnt
or worn. If the job looks to be a
little more than you want to do
replace it with a switching power
supply. Although I personally
prefer the linear supply, I have
found that you could send almost
anyone out to replace it. If they
follow it wire for wire they do not
require any electronic skills mak-
ing future service easier.
Switching power supplies in our
business basically come in two
packages. The first is the roughly
6" x 5" x 2" cased model. This is
the preferred one to use as I will
explain shortly. The second is a
computer grade power supply
and is roughly 7" x 6" x 5" and
usually mounted to the back wall
of the cabinet. Although the sec-
ond power supply is generally ca-
pable of more power output it
also has a minimum current rat-
ing. This rating is often 2 - 3
amps. When less than this cur-
rent value is drawn from the
supply it doesn't properly
regulate or may even shut
down. Over the past few years I
have found that most PCBs draw
less than 2 amps and that would
barely make the minimum rating
of the power supply. A solution
to this problem has been to
putload resistors in the cabinet
and their sole purpose is to draw
extra current from the power sup-
ply to keep it from shutting down.
just generating heat which is an
enemy of electronic circuits! This
could raise the temperature in-
side the cabinet considerably and
should be avoided. If you need a
switching power supply try to use
the small ones.
where to put the quarters. Make
sure the marquee lightworks so the
game stands out. If the kit re-
quires a service and/ or test switch
make sure they are installed - this
makes it easier to service in the
future.
The cabinet wiring can be done
one of several ways. A new har-
ness for the game board can be
installed or the existing wiring
could be used. The latter is be-
coming more and more a reality
because most cabinets are wired
for the JAMMA standard. Some
kits come with auxiliary cables
for extra controls and speakers. Use
these and keep wiring neat and
properly dressed. Use lots of
cable ties and clamps to keep
wiring from flopping around.
Avoid splicing wires and if you
do, solder them and use heat
shrink tubing to insulate. Keep
the board wiring away from fluo-
rescent fixtures, AC wiring and
flyback transformers.
Use all the mounting hardware to
secure the logic board(s) to the
cabinet - leaving them loose or
not fully secured allows ICs to
wiggle loose in their sockets and
surface mount chips to break
loose from the board. A couple
of pennies spent now can save
you an expensive repair later.
Speakers are the last part to dis-
cuss. Use a good quality speaker
that can handle the output of the
board. If the board is capable of
stereo output consider taking
advantage of this. The sound
quality is usually much improved
over the standard mono output.
When wiring the speakers, make
sure you keep both speakers in
phase. Wire speaker positive to
game board positive and the
same with negative connections.
Do this for both speakers.
Hims:
Wire in coin door lights, it is alot
nicer when the customer can see
OTHER HELPFUL
Personally I do not feel this is a
sound approach because you are
Finally, staple up a copy of the
dip switch settings if the game has
them, throwing the manual in
doesn't always work because ser-
vice people (including myself!)
are notorious for taking them out
and never returning them.
All in all if you follow these tips
you will wind up with a nicer
looking conversion that will gen-
erate more revenue than if it were
slapped together. It will also re-
quire less service work so that
you have more time to do the
more "important" things.
ONE FINAL NOTE:
If a problem is found with a game
and the manufacturer provides a
fix - DO IT! Even if your game
doesn't exhibit the problem (yet).
It is very difficult to get these
kinds of updates a year or so
down the road. You will see more
and more of this on the software
end of things because the pr0<:. _
gramming is getting more and
more complicated. Good luck!