HP 3400A Service Manual

Model
3400A
Maintenance
5-29.
Second
Attenuator
Adjustment.
Do
the
following:
a.
Connect
the
test
setup
shown
in
Figure
5-2.
b.
Set
the
-hp-
Model
3400A
RANGE
switch
and
Test
Oscillator
output
attenuator
to
the
.3
volt
position.
c.
Set
the
Test
Oscillator
for
a
400
Hz
output
and
adjust
its
amplitude
for
a
90%
full
scale
reading
on
the
3400A.
d.
Change
the
Test
Oscillator
frequency
to
3
MHz.
e.
Adjust
C303
(10
MHz,
.3
V
ADJUST)
for
a
90%
full
scale
reading on
the
3400A.
f.
Vary
the
oscillator
frequency
between
3
and
10
MHz.
If
the
3400A
reading
goes
above
95%
or
below
85%
of
full
scale,
repeat
step
e
until
optimum
response
is
obtained
between.
5-30.
TROUBLESHOOTING
PROCEDURES
5-31.
This
section
contains
procedures
designed
to
assist
in
the
isolation
of
malfunctions.
These
operations
should
be
undertaken
only
after
it
has
been
established
that
the
difficulty
cannot
be
eliminated
by
the
Adjustment
and
Calibration
Procedures,
Paragraph
5-15.
An
investigation
should
also
be
made
to
ensure
that
the
trouble
is
not
a
result
of
conditions
ex-
ternal
to
the
Model
3400A.
5-32.
Conduct
a
visual
check
of
the
Model
3400A
for
possible
burned
or
loose
components,
loose
connections,
or
any
other
condition
which
might
suggest
a
source
of
trouble.
5-33.
Table
5-5
contains
a
summary
of
known
problems
by
front
panel
symptoms.
5-34.
Table
5-6
contains
procedures
which
may
be
used
as
a
guide
in
isolating
malfunctions.
The
checks
outlined
in
Table
5-6
are
not
designed
to
measure
all
circuit
parameters,
rather
only
to
localize
the
malfunction.
Therefore,
it
is
quite
possible
that
additional
measurements
will
be
required
to
completely
isolate
the
problem.
Amplifier
gain
and
biasing
may
vary
slightly
from
instrument
to
instrument;
therefore,
it
should
not
be
necessary
to
precisely
duplicate
waveforms
or
values
described.
NOTE
Do
not
use
an
extender
board
on
the
Chopper
Amplifier
Board
(A6).
5-35.
Checking
Thermocouples
TC401
and
TC402
5-36.
The
following
procedure
shows
how
to
check
the
thermocouples
in
the
-hp-
Model
3400A
RMS
Voltmeter
for
proper
operation.
NOTE
This
check
will
not
yield
any
information
concerning
thermocou-
ple
operation
for
either
sluggish
or
overshoot/undershoot
response
on
the
3400A
meter.
If
these
symptoms
are
noted,
replace
the
thermocouple.
5-11

HP 3400A Specifications

General

Brand	HP
Model	3400A
Category	Measuring Instruments
Language	English