Star Tech Journal

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··>. . .STAA*TECH.Joumal •
Taito Chase HQ
Low Power Fix:
Proper Circuit
Chilling Techniques
Lee Morris
Southgate Amusements
San Antonio, Texas
James Beck
Greater Southern Distributing
Atlanta, Georgia
SYMPTOM
PROBLEM
White screen.
I've got a Combatri'bes that fails after 10 minutes
of warm-up. I'm having trouble bringing it back
to life with Circuit Chilling spray. What is the
correct method for pinning down heat-related
board problems?
PROBLEM
The major problem with Chase HQ power con-
nections is the small wires used and the con-
nector block mounted on the back of the slide-
out panel. The problem is that the ground pins
are burnt.
CAUTION
A medium gauge multistrand wire needs to be
run to replace the inadequate ground system.I
disagree with soldering wires directly to the
board. This should always be avoided.
Should you douse a section of the board or just
spray one component at a time and for how long.
How long should you wait for it to take effect? Is
re-powering up always required?
SOLUTION
Every troubleshooting job is different but there
are a few guidelines that you can use to effec-
tively isolate heat/warm-up problems.
SOLUTION
Run #20 wire from the +5v and ground to the
black edge connector on the Pcb. This is direct
from the power supply.
If it's a problem that causes a kemal failure (the
If the pads on the Pcb are destroyed, buy some
If it is a video problem, it shouldn't be a problem
if the board isn't reset, BUTyou should wait until
the system changes screens back to the one the
problem is most noticeable on before going on.
self-sticking copper sheets. Use an exacto knife
to cut strips that wrap over the edge connector to
both sides of the Pcb. After sticking the copper
over the damaged area, lightly solder the ends to
the traces.
SUPPLIER
We use E-Z Circuit copper sheets from Bishop
Graphics Inc., Westlake Village, CA 91359, part
no: EZ7253.
ADDITIONAL SYMPTOMS
The low voltage problem can cause: Erratic
Steering, Lockups, Ram Failures and many
other costly and annoying problems.
NOTE
Chase HQ has an edge connector on the top
board and a molex pin connector on the bottom
board. Check both for discoloration from poor
grounding systems.
thing just crashes/Pcb lockup) then powering
down and up again after the spray is best.
As for which area to try first, or how to do the
cooling, if it is an intermittent problem freeze an
entire 1/ 4 of the board at a time, and keep it cool
until you are confident the problem no longer
exists, then narrow it down by cooling one chip
after another. I use a good 'ol hair dryer to keep
things hot while I'm cooling specific parts. A little
paper card will keep overspray off nearby ICs.
The best tools you have available when looking
for heat related problems are right at the end of
your hands, your fingers. They can tell the
difference between normally operating parts and
overheating parts VERY effectively. Most bad
parts run hot (internally shorted), and the first
time you burn your finger on a bad part you'll
know how you found it!