Heathkit IG-4505 - Page 11

Page 11
Ge gue4rHKire
In the following steps, install IC’s (integrated
circuits) in the designated sockets. Be careful to
match the pin 1 end of each IC to the index
mark on the circuit board. See Detail 1-2A
(below).
Before you apply downward pressure to an IC,
make sure each IC pin is centered in its proper
socket aperture. Handle iC’s with care, as their
pins bend very easily.
ae) D
Ov Cc aD
NOTE:
To
install
a
14-pin integrated
circuit
One
OM
socket.
Insert
the
socket
pins
into
the
holes.
The
index
mark
on
the
circuit
board
should
still
Vp
4
be
visible
after
it
is
installed.
Solder
the
pins
to
the
foil.
\/ ) 1C4: SN7490N IC (#443-7).
M1 14-pin socket at 1C4. } ) 1C3: SN7490N IC (#443-7).
i)
14-pin
socket
at
1C3.
f
)
1C5:
SN7490N
IC
(#443-7).
‘) 14-pin socket at 1C5 “4 1C6: SN7490N IC (#443-7),
eee
(, |) 14-pin socket at IC6.
(7%) 14-pin socket at (C7.
) 1C7: SN7490N IC (#443-7)
(7) 102: SN7490N IC (#443-7).
() 1C1: SN7474N IC (#443-6).
(, 1 14-pin socket at IC2.
{ .) Check each integrated circuit to
make sure the pin 1 end is nearest
the dot on the circuit board.
}) 14-pin socket at IC1.
PICTORIAL 1-2
NOTCH DOT SMALL
= INDENTATION
en
PIN I PIN 1
Detail 1-2A