A4
P
ower
Supply
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.
Note
If
replacing
only
the
power
supply
board
assembly
(not
including
A4W1
and
A4W2),
remove
the
jumpers
between
the
transformer
terminals
marked
1
and
3,
and
2
and
4.
Removal
1.
Remove
the
instrument
cover
as
described
on
page
7-7.
2.
Remove
the
four
screws
1
(two
per
side)
from
the
power
supply
shield.
See
Figure
7-6.
3.
Remove
the
cables
from
the
cable
clips
2
on
the
power
supply
shield.
4.
Remove
the
three
screws
3
connecting
the
power
supply
shield
to
the
chassis
.
Remove
the
shield.
5.
Depress
the
clips
on
the
sides
of
A5W1P1
connector
4
between
A5W1
and
A4W1
to
disconnect
the
cables
.
6.
Remove
the
three
screws
6
from
the
back
panel
and
lower
the
rear
frame
.
7.
Desolder
the
two
wires
7
on
the
ALC
switch,
making
note
of
the
proper
connections
.
Lift
the
switch
out
of
its
slot.
8.
Clip
the
two
cable
ties
8
to
free
A4W2
cable
assembly
and
disconnect
it
from
A3J3
9
.
9.
Remove
the
four
screws
A
and
B
that
secure
the
power
supply
bracket
to
the
chassis
.
Lift
the
power
supply
assembly
out
of
the
instrument.
Replacement
10.
Replace
the
A4
power
supply
in
the
chassis
and
lightly
tighten
three
of
the
four
screws
A
.
11.
Replace
the
grounding
wire
with
the
forth
screw
B
.
Alternately
tighten
all
four
screws
to
7
inch-pounds
.
12.
Resolder
the
two
wires
from
A4W2
to
the
ALC
switch
7
.
The
wires
should
be
connected
between
the
closed
contacts
when
the
ALC
switch
is
set
to
INT
.
13.
Connect
A4W1
to
A5W1
4
.
14.
Replace
the
cable
ties
8
with
A4W2
included.
15.
Replace
the
power
supply
cover
,
loosely
tighten
the
four
side
screws
1
and
the
three
chassis
screws
2
.
Alternately
tighten
all
screws
to
six
inch-pounds
.
16.
Replace
the
cables
into
the
cable
clips
2
.
7-14
Service
Information
HP
85640A
RF
T
racking
Generator
Operation
and
Service
Manual
Содержание 85640A
Страница 2: ...HP 85640A RF Tracking Generator Operation and Service Manual ABCDE Printed in USA ...
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