A3
Interface
Board
Assembly
Replacement
Caution
The
tracking
generator
assemblies
are
static
sensitive
.
P
erform
assembly
procedures
at
static-safe
work
stations
.
Refer
to
Figure
7-1
for
an
example
of
a
static-safe
work
station.
Removal
1.
Remove
the
instrument
cover
as
described
on
page
7-7.
2.
Refer
to
Figure
7-5
to
disconnect
the
following
seven
cable
assemblies
from
the
A3
interface
board
assembly:
1
W1
from
A3J2
2
W2
from
A3J1
3
A4W2
from
A3J3
4
W4
from
A3J4
5
W5
from
A3J5
6
W6
from
A3J6
7
W7
from
A3J3
3.
Remove
the
ve
screws
8
(washers
are
attached
to
the
screws)
from
the
A3
board
assembly
.
4.
Loosen
the
board
assembly
from
the
hook
and
loop
fastener
then
lift
the
board
assembly
from
the
instrument.
Replacement
5.
If
you
are
replacing
the
bottom
shield
or
installing
a
new
board
assembly
,
attach
either
the
hook
or
loop
side
to
the
bottom
shield
so
it
aligns
with
the
fastener
remaining
on
the
chassis
.
6.
Replace
the
top
and
bottom
shields
to
the
A3
board
assembly
,
then
tighten
the
six
screws
9
.
7.
Align
the
A3
board
assembly
in
the
chassis
.
The
hook
and
loop
fasteners
hold
the
board
in
position
temporarily
.
Secure
the
board
assembly
with
the
ve
screws
8
and
washers
tightened
to
six
inch-pounds
.
8.
Reconnect
the
following
seven
cable
assemblies
to
the
A3
interface
board
assembly:
1
W1
to
A3J2
2
W2
to
A3J1
3
A4W2
to
A3J3
4
W4
to
A3J4
5
W5
to
A3J5
6
W6
to
A3J6
7
W7
to
A3J3
7-12
Service
Information
HP
85640A
RF
T
racking
Generator
Operation
and
Service
Manual
Summary of Contents for 85640A
Page 2: ...HP 85640A RF Tracking Generator Operation and Service Manual ABCDE Printed in USA ...
Page 111: ......
Page 169: ......
