If
the
Green
LEDs
On
A8
are
not
All
On
The
green
LEDs
along
the
top
edge
of
the
A8
post
regulator
are
normally
on.
Flashing
LEDs
on
A8
indicate
that
the
shutdown
circuitry
on
the
A8
post
regulator
is
protecting
power
supplies
from
overcurrent
conditions
by
repeatedly
shutting
them
down.
This
may
be
caused
by
supply
loading
on
A8
or
on
any
other
assembly
in
the
analyzer
.
Remove
A8,
Maintain
A15W1
Cable
Connection
1.
Switch
o
the
analyzer
.
2.
Remove
A8
from
its
motherboard
connector
,
but
keep
the
A15W1
cable
connected
to
A8.
3.
Remove
the
display
power
cable
W14
(see
Figure
5-5).
4.
Short
A8TP2
(A
GND)
(see
Figure
5-3)
to
chassis
ground
with
a
clip
lead.
5.
Switch
on
the
analyzer
and
observe
the
green
LEDs
on
A8.
If
any
green
LEDs
other
than
+5VD
are
still
o
or
ashing,
continue
with
\Check
the
A8
Fuses
and
V
oltages
."
If
all
LEDs
are
now
on
steadily
except
for
the
+5VD
LED
,
the
A15
preregulator
and
A8
post
regulator
are
working
properly
and
the
trouble
is
excessive
loading
somewhere
after
the
motherboard
connections
at
A8.
Continue
with
\Remove
the
Assemblies
."
Check
the
A8
Fuses
and
V
oltages
Check
the
fuses
along
the
top
edge
of
A8.
If
any
A8
fuse
has
burned
out,
replace
it.
If
it
burns
out
again
when
power
is
applied
to
the
analyzer
,
A8
or
A15
is
faulty
.
Determine
which
assembly
has
failed
as
follows
.
1.
Remove
the
A15W1
cable
at
A8
(see
Figure
5-5).
2.
Measure
the
voltages
at
A15W1P1
(see
Figure
5-6)
with
a
voltmeter
that
has
a
small
probe
.
3.
Compare
the
measured
voltages
with
those
in
T
able
5-2 .
If
the
voltages
are
within
tolerance
,
replace
A8.
If
the
voltages
are
not
within
tolerance
,
replace
A15.
5-14
P
ower
Supply
T
roubleshooting
Summary of Contents for 8752C
Page 22: ...Before Applying Power 15 6 Servicing 15 6 Index Contents 16 ...
Page 38: ......
Page 43: ...Figure 2 1 Measurement Uncertainty Window System Veri cation and Performance Tests 2 5 ...
Page 116: ......
Page 122: ...Figure 3 1 Location of Major Assemblies 3 6 Adjustments and Correction Constants ...
Page 176: ......
Page 192: ...4 16 Start Troubleshooting Here ...
Page 193: ......
Page 195: ...Figure 4 7 HP 8752C Overall Block Diagram 3 of 4 Option 006 4 20 Start Troubleshooting Here ...
Page 197: ......
Page 221: ...5 24 Power Supply Troubleshooting ...
Page 222: ......
Page 271: ...Figure 7 21 A14 Generated Digital Control Signals Source Troubleshooting 7 31 ...
Page 302: ......
Page 366: ......
Page 378: ...Figure 11 4 Typical ED Re ection Test Port 11 12 Error Terms ...
Page 380: ...Figure 11 5 Typical ES Re ection Test Port 11 14 Error Terms ...
Page 382: ...Figure 11 6 Typical ER Re ection Test Port 11 16 Error Terms ...
Page 386: ...Figure 11 9 Typical ET 11 20 Error Terms ...
Page 407: ...Figure 12 5 High Band Operation of the Source Theory of Operation 12 21 ...
Page 410: ...Figure 12 6 Receiver Functional Group standard and Option 003 12 24 Theory of Operation ...
Page 411: ...Figure 12 7 Receiver Functional Group Option 003 and 004 Theory of Operation 12 25 ...
Page 412: ...Figure 12 8 Receiver Functional Group Option 006 12 26 Theory of Operation ...
Page 413: ...Figure 12 9 Receiver Functional Group Option 004 and 006 Theory of Operation 12 27 ...
Page 416: ......
Page 419: ...Figure 13 1 Module Exchange Procedure Replaceable Parts 13 3 ...
Page 423: ...Major Assemblies Replaceable Parts 13 7 ...
Page 425: ...Front Panel Assemblies Replaceable Parts 13 9 ...
Page 427: ...Rear Panel Assemblies Replaceable Parts 13 11 ...
Page 429: ...Cables Top View Replaceable Parts 13 13 ...
Page 431: ...Front Panel Cables and Attaching Hardware Replaceable Parts 13 15 ...
Page 433: ...Rear Panel Cables and Attaching Hardware Replaceable Parts 13 17 ...
Page 435: ...Source and Sampler Parts Standard and Option 003 Replaceable Parts 13 19 ...
Page 437: ...Source and Sampler Parts Option 004 006 Replaceable Parts 13 21 ...
Page 439: ...Source and Sampler Parts Options 004 and 003 004 Replaceable Parts 13 23 ...
Page 441: ...Source and Sampler Parts Option 006 Replaceable Parts 13 25 ...
Page 443: ...Display Bezel Assembly Replaceable Parts 13 27 ...
Page 445: ...Chassis Parts Replaceable Parts 13 29 ...
Page 447: ...Top View of Attaching Hardware and Post Regulator Fuses Replaceable Parts 13 31 ...
Page 449: ...Bottom View of Attaching Hardware Replaceable Parts 13 33 ...
Page 488: ......