Fluke 8600A - Power Supply Checks; Fault Area Isolation

8600A
Figure
4-2
TROUBLESHOOTING
FLOW
CHART
4-38.
Power
Supply
Checks
4-39.
Incorrect
output
voltages
from
the +5
volt,
+15
volt,
or
—15
volt
supplies may
cause
the
unit to
exhibit
various
improper
indications.
Because
of
this the
power
supplies
should be
checked
in the
event
of
any
8600A
malfunction.
Use the
following
procedure
to
check
the
power
supply
output
voltages.
a.
Connect
the test
equipment
multimeter
return
lead
to
the
V-L2
LOW
input
terminal.
b.
Connect
the
high
input lead
to TP12,
the +5 volt
supply.
The
power
supply
voltage
should
be
+4.75V
to
+5.75.
c.
Connect
the
high
input
lead
to TP4,
the
-15
volt
supply.
The
power
supply
voltage
should
be
—15.0+0.5
volts.
d.
Connect the
high input
lead
to
TPS,
the
+15
volt
supply.
The
power
supply
voltage
should
be
+
15.0+0.5
volts.
440.
Fault
Area
Isolation
441.
A
malfunction
in the
8600A may
be isolated
to a
particular
section
of
the
circuitry
by
observing
the
front
panel
display
during
each
mode
of
operation.
The perfor-
mance tests
(par.
4-14) will
exercise
the
8600A in each
function
in
order to
determine
the
functional
operations
of
the
unit
affected
by the
failure.
442.
The
indications
observed
during
the
8600A oper-
ation
in each
of
four
functions
(VDC,
VAC,
Ohms,
and
DC
current)
may
isolate
the
failure
to
a particular
area.
Table
4-9
lists the
fault
area
indicated
by
various
combina-
tions
of proper
or
improper
8600A
operation
in each
of
the
four
functions
exercised
in
the performance
test.
443.
Troubleshooting
information
for the
indicated
fault
area
is presented
in
the
following
paragraphs.
Pro-
ceed to the
troubleshooting
information
for the indicated
failure
area. It should
be kept
in mind
that
some failures
may
cause improper
operation
of
functional
areas other
than
the
one
actually
containing
the problem.
444. INPUT
DIVIDER
445
Problems
in the
Input
Divider
will
generally
give
improper
operation
in
the
DCV
and
OHMS
functions,
leaving
other
functions
unaffected.
There are
exceptions,
however.
For
example
the relay,
K4,
must be
energized
in all
ACV ranges
to
connect
the
output of
the
AC Con-
Table
4-9.
FAULT
AREA
INDICATION
8600A
FUNCTION
8600A OPERATION
-
PROPER
OR
IMPROPER
VDC
IMPROPER
PROPER
PROPER
PROPER
IMPROPER
OHMS
IMPROPER
IMPROPER
PROPER
PROPER
IMPROPER
DCI
PROPER
PROPER
IMPROPER
PROPER
IMPROPER
VAC
PROPER
PROPER
PROPER
IMPROPER
IMPROPER
FAULT
AREA
INDICATED
INPUT
DIVIDER
OHMS
CONVERTER
CURRENT
SHUNT
AC
CONVERTER
A/D
CONVERTER
OR CONTROL
AND
DISPLAY
1/77
4-7