ASSEMBLY
PROCEDURES
Proper operation
of
your
kit
depends
on
good
soldering
technique, along with
correct
identification and handling
of
the various parts used during construction.Read this manual
thoroughly before plugging
in
your soldering iron.
SOLDERING TECHNIQUES. The Econoram Board is
solder-masked.
In
case you are not familiar with solder-
masked boards, they are similar
to
standard
PC
boards, but
are screened with a solder-resistant coating. This mask is
screened over the entire board,
except
where there are
solder connections to be made; since solder does not com-
fortably hold to or flow over the resist, the chances ofgetting
a bridge between tight, adjacent traces are decidedly
minimized.
However, soldering a solder-masked board requires a bit
of care. All soldering is performed
on
the solderside of the
board; we recommend keeping all component leads straight
up at all times, not bent over as with some other types
of
boards (see figure 1). When soldering, bring the iron tip
in
at
an
angle, against the board pad and component lead; then
feed
in
a tiny bit
of
solder at opposite ends
of
the lead (see
figure
2)
. This makes a good joint with no excess solder.
NOTE:
Use
of
any type
of
solder other than rosin core solder
invalidates the warranty.
Do
not use any type
of
solderpaste
or corrosive flux under any conditions.
IDENTIFICATION OF PARTS. There are many ICs used
in
this
kit
; each one must be oriented
correctly
for proper
operation. Most ICs have a dot near one corner that indi-
cates pin 1 (see figure
3)
; sometimes this
dot
appears
in
conjunction with a deeply cut notch
or
circle
.Other types in-
dicate the pin 1 end of the
IC
by a deep notch,
or
a notch
within a shallow
circle
(see figure 4).
In
case of doubt, place
the
IC
in
front of you so that any identifying numbers read
from left to right; pin 1 is almost always
in
the
lower
left-hand
corner (figure
5)
.
Additionally, the 6 tantalum capacitors must be
correctly
identified as to the (+ )
and
(-) ends. The (+ ) end is the
rounded end and is also identified with a (+ ) mark
on
the
body (see figure
6)
.
HANDLING OF PARTS. All integrated
circuits
may be
damaged by static
electricity
discharges;however,MOS ICs
-such as the memory ICs included with your
kit
-are most
susceptible to this problem. You can easily accumulate a
static charge
on
your body
in
the thousands-of-Volts range
(say, by walking across a rug
on
a dry day). If you then touch
the pins of
an
IC
, those thousands
of
Volts flow into the
IC
and can damage the internal structure. To prevent this from
happening, leave the ICs
in
their protective foil until needed;
then, before plugging
in
each
IC
, touch the protective foil
with your finger to drain off any residual charge. Also, avoid
wearing clothing that is prone to generating static
electricity
during construction (such
as
sweaters, certain types of
acrylic
fabrics, and so on).
Another caution concerns the mounting of resistors.
These are small, somewhat fragile parts, and excessive
force used while bending the leads may cause damage or
crack
the part. Either use a commercial lead bender (availa-
ble from Godbout's and many other
electronic
vendors),
or
use needlenose pliers to grasp the lead
close
to the body of
the resistor and then bend the lead downward (see figure 7).
lead
component
Figure
1.
Figure
2.
dot
notch
Figure
3.
Figure
4.
(+)end
do
not
bend
leads
over
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pin
1
Figure
5.
(-)
end
~
Figure
6.
pliers
Figure
7.
capacitor
legend
on
board
bend
lead
downward
4
ECONORAM
IV
·
COMPUKIT
PRODUCT
FROM
GODBOUT
ELECTRONICS
·
BOX
2355,
OAKLAND
AIRPORT,
CA
94614
