Power Supply Checks; Fault Area Isolation - Fluke 8600A Instruction Manual

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