Star Tech Journal

S T A R * T E C H
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3) Pin Cutters - Hand-held cutters
with a tip small enough to fit between
the pins of an IC but tough enough to
easily cut the pins.
4) Needle Nose Pliers - A small pair
of pliers specially designed for board
work.
S> Solder - Good quality activated
rosin core.
6> Alcohol - A bottle of rubbing
alcohol.
7) Brush - A hard-bristle tooth brush
will do.
Once you have obtained the above
tools you are ready to begin to change
IC chips. Plug in your soldering iron
and let it get hot.
If possible, I recommend that you
practice on an old PC board before you
try to make an actual repair.
Using your pin cutters, carefully cut
all the pins on the chip at the point
where they meet the chip. The black
box-like part should then be removed
leaving Just the pins in the board.
With your needle nose pliers in one
hand and your soldering iron in the
other, heat the pins near the point
where they meet the board and pull them
out of the board with the pliers. You
Just need to heat them enough so they
are easily removed. Don't pull them out
forcefully as you may cause trace
damage on the board.
Now you should have the chip and its
pins totally removed. The only thing
left is solder in all the holes. The
solder is easily removed by using your
hand-held solder vacuum and your
soldering iron.
With your soldering iron in one hand
and your solder vacuum in the other, .
touch the pad on the board (the hole '
with the solder in it) with your iron
for about two seconds or until the
solder liquifies. At the moment the
solder liquifies, touch it with your
vacuum and push the button to suck it
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all face the same way. Carefully insert
the chip into the holes on the board.
Hold the chip in place with your finger
and turn the board over. Slightly bend
a few pins on either side of the chip
so that it doesn't fall out of the
board.
You are now ready to solder the chip
into the board. This operation must be
done carefully to avoid damaging the
board or the chip. You don't want to
overheat the chip so follow this rule;
never touch the pin with your soldering
iron for more than three seconds. Touch
the tip of your iron at the point where
the pin meets the pad on the board.
Count, one-thousand-one, one-thousand-
two, apply solder, one-thousand-three,
remove soldering iron. When you apply
solder, apply it to the pin and the pad
at the same time. Don't apply it to the
tip of the iron. Do not apply too much
or too little solder. The solder should
liquify instantly and flow through the
hole to the other side.
When deciding Just how much solder to
use, compare your Job to the factory
Job on the same board. Your goal is to
make yours look as good as theirs.
Finally, dip your brush in the
alcohol and clean the solder side of
the board removing any flux or residue
from the board. The solder connections
should shine. The final product should
appear as though the chip was never
changed. If it doesn't, keep practicing
until you get it right!
The routine outlined above may be
used for exchanging other components on
a board (resistors, capacitors,
crystals, etc.), as well as !C's. This
procedure must be done correctly if you
want to be successful in board repair.
Electrical connections are, as you must
know, crucial to the proper operation
of electronic components.
:
This procedure takes some practice 'so
don't feel bad if you mess up at first.
Keep at it until you get it right.
Now, check all the traces to be
certain there are no breaks or cracks.
Dip your brush in the alcohol and clean
the board on both sides. Allow the
alcohol to dry completely. Don't use
too much alcohol on the brush, it will
take that much longer to dry. The board
should look like it never had an IC in
it at this point.
You are now ready to insert the new
IC. Be certain the notch on the chip is
facing in the right direction. Comparte
it with other chips in the row. They
ENNIS
CONVERSION TIPS
By Jim Ennis
Jim Ennis Video Repair
Salisbury, MD
Cosmetics
Tnis month we'll talk more about
cosmetics. Remember, we want this
conversion to look like a new game.
Since we have already discussed control
panel paint and decals last month, that
leaves us with the glass.
There are two options for the front
or monitor glass. The first, of course,
O c t
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is to use the old glass. If it is
glass, not plexi, you can scrape off
the paint, then repaint a black border.
The other way to go is your local
glass dealer, pick a piece of 1/4" or
1/8" plexi that they can cut to the
exact size. All you have to do then is
paint a black border. It is sometimes
advantageous to keep the original
glass. (I kept an Atari DIG DUG glass
once, and a week later a customer had
one vandalized and broke the front
glass. It was nice to have one in stock
for the price of the replacement
plexi.)
A few kits such as Nintendo VS.
series will supply you with a new front
glass.
Now for the top marquee glass. Most
kits supply this in plexi but never in
the right size! I use an inexpensive
plexiglass cutter. Using the old glass,
mark where you want to make your cuts.
Then with a straight edge, scribe the
plexi several times, the deeper the cut
- the easier it is to break (without
cracking) the new glass.
After it is scribed hold it over a
straight edge such as a table edge,
press firmly and it should break
straight on your scribe.
Another method I use is with a Black
& Decker workmate bench. Simply tighten
the plexi on the seam and break it off
at your scribe. Some kits such as
SAVAGE BEES by Memetron, give you a
decal type sticker. In this case, use a
piece of clear plexi and apply the
decal as you would the side decals.
(See last month's S*TJ -Volume 7, #4).
If you are doing a SAVAGE BEES kit,
here is a warning. The edge connector
pinout labels pin 22 and Z as +12
common. This is not a ground! It is
tied directly to +12vdc on the board.!
See you next month with more tips.
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ML•RPHV
You can't win.
You can't break even.
You can't even quit the game.