This
cycling
will
continue
until
the
input
thermistors
warm
up
to
a
point
where
the
sensed
voltage
is
within
tolerance
.
At
this
point
the
fault
indicator
stops
ashing,
the
mainframe
is
operational.
If
the
condition
does
not
go
away
after
several
minutes
,
check
the
input
line
voltage
under
load
or
change
the
ambient
operating
temperature
.
High
output
voltage
and
F
an
voltage
failure
These
two
conditions
will
also
cause
the
the
V
OL
T/TEMP
fault
indicator
to
come
on
and
the
instrument
will
latch
in
a
fault
condition.
The
mainframe
is
in
need
of
internal
repair
or
adjustment.
It
will
shut
down
and
not
attempt
to
restart
until
ac
line
power
is
cycled.
CURRENT
This
circuitry
senses
and
indicates
if
the
load
on
the
mainframe
power
supply
is
too
high.
Upon
sensing
an
over-current
condition,
the
power
supply
is
shut
down
and
latched.
It
will
not
attempt
to
restart
until
ac
line
power
is
cycled.
If
a
CURRENT
fault
indicator
is
on,
check
for
a
faulty
module
before
attempting
to
repair
the
mainframe
.
The
following
steps
will
help
isolate
the
problem.
1.
Turn
the
mainframe
o.
2.
Remove
all
the
modules
from
the
mainframe
.
3.
Cycle
the
power
.
Is
the
CURRENT
indicator
still
on?
NO
Turn
o
the
mainframe
and
one
by
one
replace
the
modules
(cycling
power
each
time)
until
the
faulty
module
is
identied.
Refer
to
the
repair
procedures
in
the
installation
and
verication
manual
for
the
system
master
or
the
service
manual
related
to
the
faulty
module
for
repair
alternatives
.
YES
If
the
CURRENT
indicator
is
still
on
when
all
of
the
modules
have
been
removed
from
the
mainframe
,
the
mainframe
probably
has
an
internal
problem.
Check
to
ensure
that
the
grounding
springs
on
the
50
pin
module
connectors
are
not
shorting
the
40
KHz
to
ground.
Refer
to
the
HP
70001A
Service
Manual
for
additional
troubleshooting
information.
T
roubleshooting
5-3
