October 1997
STAR* TECH JOURNAL
Enzo's
Tech
Tips
"Hey Enzo, I can't find the self-test button on this Captain Fantastic!"
Douglas 'Enzo' Mccallum • Shiawassee Technical Services • Lansing, Ml
SILICONE
THE WONDER
BREAKOFFS
Many times in doing repairs we
come across components that
have cracked their solder and
come free from the PC board, or
sometimes they have broken off
their lead right at the board.
As Mr. Messana noted in his
Rowe Changer article in the May
issue of Star Tech journa~ often
these broken-off parts are the
larger heavier ones.
SANDIES
Common examples include big
five and ten watt rectangular re-
sistors, which we usually call
"sand blocks," and things like
TO-220 transistors and voltage
regulators, especially those wear-
ing heat sinks on their tabs. Any-
thing that isn't tiny but is sup-
ported by its own leads is a can-
didate for this type of failure.
Goop
mechanical stress off the connec-
tions and the heat from the com-
ponent is also kept off the board.
N
ot only can
silicone help
prevent
failures, but it can
even allow parts to
continue to function,
instead of leaving
the equipment
down waiting for a
replacement part.
Sounds like wonder
goop to me!
Goop
MOUNTING
ENTER mE
Inspecting many video monitors
reveals power resistors mounted
with a clamp to the chassis and
wires to the PC board. This solu-
tion does two things, it takes the
It isn't always convenient to
mount everything to a chassis
wall so we need other strategies.
Enter Silicone. It really is the
wonder goop. Silicone sealer,
aquarium sealer, silicone caulk,
it goes by many names. It comes
in small squeeze tubes like tooth-
paste, and in larger tubes for use
in caulking guns.
BUY CHEAP
We use it a lot, so we buy the
larger tubes. I buy whatever
brand is on sale, usually three or
four dollars a tube tops. You want
the stuff that is 100% silicone,
though it may or may not say
caulk on the label.
TYPES
There are many kinds of caulk,
some even containing silicone,
but the 100% is the only one to
use. Don't pay extra for a lengthy
guarantee or other claim. If I
were using it to seal my windows,
I might be concerned, but the
cheap stuff I buy has never let me
down just sticking things together
indoors. A caulking gun can be
had cheap, in fact I even see them
at the dollar store.
CLEAR, WHITE, BROWN?
Doesn't matter. What does mat-
ter is keeping it fresh. Make sure