Fluke 8021B - Troubleshooting

8021
B
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