Agilent Technologies 4395A Service Manual

A50 Shutdo
wn LED
The
A50 SHUTDO
WN LED
turning o
indicates some
of
A50
p
o
w
er
supply
is
sh
ut
do
wn b
y
the
A50
sh
utdo
wn
circuitry
.
There
are
t
w
o
F
AN conditions,
rotating and
not rotating
when the
SHUTDOWN
LED turns
o.
When the
fan is
rotating, the
shutdo
wn circuit
is
probably
activ
ated
b
y
the
o
v
er
curren
t
condition
on
the
p
o
w
er
lines
in
the
A50
DC-DC
Con
v
ereter.
In
this
condition, though
the A50
p
o
w
er
supplies,
+24
V,
+5
VD, +18
V, +7.8
V, -7.8
V, and
-18
V
are
sh
ut
do
wn,
the
F
an
P
ow
er +24
Vis
still
supplied
to
the
fan.
When
the
fan
is
not
rotating,
the
sh
utdo
wn
circuit
is
probably
activ
ated
b
y
the
F
AN
LOCK
signal
missing.
Note
Once
the
A50
sh
utdo
wn
circuit
is
activ
ated,
the only
wa
yto
reset the
circuit
is
turning
the
analyzer
po
wer
o. W
ait
a
min
ute
after
turning
the
analyzer
o.
Then
turn
it
on.
3.
Check
the
A1
+5
VD
LED
a. Remo
ve
the
analyzer's
b
ottom
co
v
er.
b.
T
urn
the
analyzer
po
wer
on.
c.
Lo
ok
at
the
+5
VD LED.
The +5
VD
LED
lo
cation
on
A1
CPU
is
sho
wn
in
Figure
7-3
.
The
LED
is
normally
on.
If
the
+5
VD
LED
is
o,
con
tin
ue
with
the
FIND
OUT
WHY
THE
A1
+5
VD
LED
IS
NOT
ON
STEADIL
Y
in this
c
hapter.
If
the
+5
VD
LED
is
on,
the
+5
VD
p
o
wer
supply
is
v
eried
with
95%
condence
lev
el.
If
y
ou
w
an
t
to
conrm
the
last
5%
uncertain
t
y
,
p
erform
steps
in
the
next Me
asur
e
the
A1
+5
VD
Voltage
.
Figure 7-3. A1 +5 VD LED Location
7-4 Power Supply Troubleshooting

Agilent Technologies 4395A Specifications

General

Brand	Agilent Technologies
Model	4395A
Category	Measuring Instruments
Language	English