Agilent Technologies 4339B - Page 267

4339B
Procedure
5.
Remove the
A1 board
assembly.
a.
Disconnect the
following cable
assemblies from
the A1
board.
i.
Four
cable assemblies
form the
front panel
ii.
The cable
assembly from
the transformer
iii.
Two cable
assemblies form
the DC-DC
Converter
b.
Disconnect the
four
optical
ber
cables
which
are
connected
to
the
A#
Ammeter
Board
Assembly
c.
Disconnect the
four
optical
ber
cables
form
the
A3
Ammeter
Board
Assembly
Caution
T
o
avoid
damaging
the
optical
ber
cable
by bending
or other
mechanical stress
,
remove
all
the
ber
cables
form
the 4339B
when replacing
either the
A1
board
or
the
A3
board.
d.
Remove
the cable
clamp on
the
shield
case
that
surrounds
the
A3
board.
e.
Remove
the
nut
that fastens
the
Ext
Trigger
connector
on
the
rear
panel.
f.
Remove
the
screw
that
secures
the
A1
board
to
the chassis
side.
g.
Remove
the
four
studs
,
that
secure
the
A1
assembly to
the chassis
,by
rotating the
studs
with
a
at-bladed
screwdriver
.
h.
Remove
the
three
screws that
secure the
A1
assembly
to
the
chassis
i.
Remove
the
A1
assembly
form
the chassis
Figure
B-5
shows
the
location
of
the
sockets in
which
the
pull-up
resistors
(J11)
and
the
switch
with
which
to
select
the
voltage
value
of EXT
DCV2.
T
able
B-3
lists
the
socket
numbers for
each
control
signal
and
comparison
signal.
Handler Interface Installation B-7