Troubleshooting - Fluke 8021B Instruction Manual

8021
4-39.
Use
the
following procedure
to calibrate
the 802
IB:
NOTE
This
procedure assumes an ambient temperature of 23
±2° C
(70 to 77°
F)
and
a relative
humidity of
less
than
80%. The
temperature of
the unit should
be allowed
to stabilize for
at least
30 minutes
before
calibration begins.
1.
Remove
the
top cover from
the 8021
B
using the access procedure given
earlier
in
this
section.
2.
Set the 8021
B
power
switch
to
ON
and
select
the
200
mV DC
range.
3.
Set the
output of
the
DC
Calibrator to
-H
90.0
mV
and connect
it
to the 802 IB
input terminals;
+
to V/ft,
and
- to
COMMON.
4.
Adjust
the
DC CAL
pot
(R5), as
shown
in
Figure 4-1
,
fora display of 190.0 or
190.1.
(Use
a plastic
adjustment
tool
ora
plastic
screw
1
driver for
all
adjustments.)
5.
Disconnect
the
DC
Calibrator
from
the
802 IB
input terminals.
6.
Select the
200
mV
AC
range on
the
802
1
B.
7.
Set the output of
the
AC
Calibrator to 190
mV
at
100 Hz, and connect
it
to the
802IB input terminals; V/fi and
COMMON.
8.
Adjust the
AC
CAL
pot (R9)for
a
display of 190.0 (an occasional flash of ±1
digit
is
acceptable).
9.
Execute
the
performance
test
given earlier to ensure
that
all
fixed range
resistors
and
other non-adjustable
components
are
operating within
their specified
limits.
4-40.
TROUBLESHOOTING
CAUTION
Static
discharge can
damage
MOS
components contained
in the
8021
B.
4-41.
When
troubleshooting
or repairing the 8021 B use the precautions
listed
on
the
Static
Awareness
sheet to prevent
damage from
static discharge.
Never remove,
install or
otherwise connect or disconnect components without
first
setting the 802
1
B
power
switch
to
OFF.
4-42.
A
troubleshooting guide
for the 8021
B
is
given
in
Table
4-6.
To
properly use
the
guide complete
the
performance
test
given
earlier in this section
and note any
discrepancies.
Then
locate
the
heading of
the
procedure
in
question
in the
Test
and
Symptom
column
(Table
4-6).
Under
that
heading
isolate the
symptom
that approximates
the observed malfunction.
Possible causes are
listed
to the right of
the selected
symptom.
Details necessary to
isolate a particular cause
can be
derived
from
the
theory of operation
in
Section 3
and
the
schematic diagram
in
Section
7.
4-10