Sri 302 User manual

A/D Board Capacitor and Ground Wire Installation
302 and 333 Boards
To prevent loss of communications
the installation of a 0.1 uf capacitor
and a grounding wire to the A/D
data system (302 or 333) may be
necessary. To perform this modifi-
cation you will need a 0.1 uf ca-
pacitor, a 1000 ohm 1/2 watt resis-
tor, a length of insulated wire,
shrink wrap (or electrical tape) and
a soldering iron. These parts can
be obtained from SRI Instruments
for little or no charge.
Gain access to the inside of the
GC by removing the six screws
that hold the chassis to the base
plate of the GC. Tilt the GC up on
its side. The A/D board is located
on the far right of the GC.
Remove the 4 hex screws, located
on the outside of the chassis, that
secure the A/D board to the chas-
sis by using a 5/64” allen wrench.
Pull out the board so that you can
work on it.
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A/D Board Capacitor and Ground Wire Installation
302 and 333 Boards
Solder one end of the resistor to
one end of the ground wire. The
wire should be approx. 3 feet long.
Secure
some heat
shrink (or
electrical
tape) over
the connec-
tion.
Solder the resistor directly to the
shell of the USB jack on either the
302 or 333 A/D board.
Run the loose end of the ground
wire down the length of the chas-
sis and then behind the L-shaped
circuit board brackets. Attach the
wire to the
chassis
ground
stud with a
ring termi-
nal.
Page 2
SRI Tech Support 310-214-5092
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A/D Board Capacitor and Ground Wire Installation
302 and 333 Boards
For a 333 A/D Board: Solder the
capacitor to the same terminals on
the back of the A/D board as
shown in the picture to the right.
Trim the capacitor legs short in or-
der to prevent electrical short cir-
cuiting and to make sure the board
will fit back into the chassis. Once
it is soldered in, bend the capacitor
down so that it rests flat on the
board.
For a 302 A/D Board: Solder the
capacitor to the small board at-
tached directly to the shell of the
USB jack as shown in the picture
to the right. Trim the capacitor legs
short in order to prevent electrical
short circuiting and to make sure
the board will fit back into the
chassis. Once it is soldered in,
bend the capacitor down so that it
rests flat on the board.
Gently replace the board back into
its space in the GC chassis and re-
secure it using the 4 hex screws.
Tilt the GC back down and reat-
tach the chassis to the base plate
with the 6 screws.
Page 3
SRI Tech Support 310-214-5092
www.srigc.com