Fluke 8506A Instruction Manual page 141

8506A
error conditions.
If this
situation
does
occur, the following
procedure can
be
used
to override latching
errors:
1.
With power
on, enable Calibration
mode
by
sliding the rear panel Calibration Switch
to on.
2.
Push
the
A
VG
button.
The
display should read
"Err.
oF FT
indicating latching errors are
now
disabled.
(If
a latching error exists
when
this
procedure
is
performed, the display
will
instead
indicate
an error message.
In this case,
press
any function button
to clear the error
message.)
Pressing
AVG
in
Calibration
mode
does not
enable the
Average mode;
the
Average
mode
is
mutually
exclusive with
Calibration mode.
3.
To
reenable latching errors,
push
the
AVG
button
again,
If
no latching error conditions
exist at
this
time, the display
responds with
"Err. on", and the multimeter
assumes the
normal
Calibration
mode
configuration.
If
a
latching error condition does
exist,
the error
is
identified
in
the display
and must he corrected
before the
multimeter assumes
the
normal
Calibration
mode
configuration.
4. if
Calibration
mode
is
no
longer required, slide
the rear panel Calibration
Switch
to
off.
Latching
errors are
automatically reenabled
whenever
the Calibration
Switch
is
cycled
on
or
off.
CAUTION
Disabling latching
errors
overrides protection
circuitry
between
the multimeter's
pcfos.
Since
latching errors
may
also identify
an
overvoltage
condition (as with Error
4),
discretion
must be
used
to
avoid damaging
the multimeter.
Do
not
disable latching
errors
during normal
operation
or
calibration.
4-110.
A
procedure
for isolating faulty
modules
is
contained
in
Table
4-19.
It is
important
that the theory of
operation given
m
Secton
3
be read before attempting
to
troubleshoot
the
UU'T.
The module
isolation
procedure
involves
making
observation of the
UUT
behavior, then
removing
or replacing
modules
to establish cause-effect
relationships.
Do
not
remove
or replace
modules with
the
power
on.
Follow
the
procedure
step-by-step
all
the
way
through to assure that the
fault
is
isolated to
the correct
module.
Faults
in
some
modules
may
cause apparent
faults in
other
modules.
WARNING
A
HAZARDOUS COMMON
MODE
VOLTAGE
MAY APPEAR ON
THE
OUTPUT
CON-
NECTOR
OF THE
BIT SERIAL
REMOTE
INTERFACE (OPTION
-06) IF
THE BUS
INTERCONNECT MONITOR BOARD
IS
INSTALLED AS A REPLACEMENT FOR THE
ISOLATOR. TO AVOID
THIS
SHOCK
HAZARD, REMOVE
THE
BIT
SERIAL
REMOTE
INTERFACE BEFORE
INSTALLING
THE BUS INTERCONNECT MONITOR
BOARD.
4-111.
Symptom
analysis troubleshooting
is
provided
for
standard modules
in this
section. Possible
failures are
listed
in
order of probability. Troubleshooting
information
for
optional
modules
is
contained
in
Section
6,
The
following
tables
and
figures provide
troubleshooting procedures
for standard modules:
1 .
Controller
-
Table
4-20
2.
Front Panel
-
Table 4-21
3.
DC
Signal
Conditioner
-
Table 4-22
4.
Active
Filter
-
Table 4-23
5.
A/D
Converter
-
Table 4-24
6.
Power
Supply
- Figure 4-13
7.
Thermal True-R
MS
Converter
Module
-Table
4-25
a.
RMS
Sensor Troubleshooting and
Replacement
-
Table
4-26
b.
Thermal True-R
MS
Converter Typical Test
V
oltages -
Table 4-27
c.
Thermal True-R
MS
Converter Attenuator
Logic
-
Table 4-28
4-112.
Static
discharge can
damage
components
contained
in
the
UUT. The
following precautions should
be observed during troubleshooting,
repair, or
module
replacement.
1.
Never
connect
or disconnect
modules
or
components
without
first
pushing
the
UUT
Power
switch to
OFF.
2.
Perform
all
repairs at a
static-free
work
station.
3.
Minimize
handling of ICs and
pcb's;
do
not
handle
them by
their
connectors.
4.
Keep
repair parts
in their original
containers
until
ready
for use.
5.
Use
static
ground
straps to discharge
repair
personnel.
6.
Use conductive
foam
or
anti-static containers
to store
replacement or removed
ICs
and
pcb's
7.
Remove
all
plastic, vinyl,
and styrofoam
products
from
the
work
area.
8.
Do
not
slide static-sensitive
devices over any
surface.
9.
Use
only
anti-static
type solder removal
tools.
10.
Use grounded
tip
soldering
irons.
4-27