Agilent Technologies 4395A Service Manual

FIND
OUT WHY
THE F
AN
IS
NOT
ROT
A
TING
If the
fan is
not
rotating,
the
problem
ma
y
b
e
in
the
A40
pre-regulator, the
A50 DC-DC
Con
v
erter
or
the
fan.
1.
Check
the
Line
V
oltage,
Selector
Switch
Setting,
and
Fuse
Chec
k
the
main
p
o
w
er
line
cord,
line
fuse,
and
actual
line v
oltage to
see that
they are
all
correct.
Figure
7-4
sho
ws
how
to remo
ve
the line
fuse,
using
a
small
at-bladed
screwdriv
er
to
pry o
the fuse
holder.
F
or
more
information
ab
out
the
line
cord
and
line
fuse,
see
the
Power
R
e
quir
ements
in
App
endix
C.
Figure 7-4.
Remo
ving
Line
Fuse
2.
Check
the
A50
SHUTDO
WN
LED
When
the
fan
stops,
the
A50
SHUTDO
WN
LED
is
o.
The
fan
generates
a
F
AN
LOCK
signal. The
signal is
fed in
to the
F
AN
LOCK
SENSE
circuit
in
the
A50
DC-DC
con
v
erter.
If
the
F
AN
stops,
the F
AN LOCK
signal is
missing. Then
the F
AN LOCK
SENSE circuit
activ
ates
the
A50
sh
utdo
wn
circuitry
,
resulting
the
SHUTDOWN
LED
turned
o.
Perform the follo
wing pro cedure to c
heck the A50 SHUTDO
WN LED on.
a. Remo
ve the analyzer's top co
v
er and shield plate.
b. T
urn the analyzer po
wer on.
c. Look at the A50 SHUTDO
WN LED. The LED lo cation is sho
wn in Figure 7-2 .
If the SHUTDO
WN LED is on, replace the A50 DC-DC Con
verter.
If the SHUTDOWN LED is o, continue with the TROUBLESHOOT THE FAN AND
THE A50 DC-DC Converter in this chapter.
7-6 Power Supply Troubleshooting

Agilent Technologies 4395A Specifications

General

Brand	Agilent Technologies
Model	4395A
Category	Measuring Instruments
Language	English