Cleaning; Battery/Fuse Replacement; Performance Test; Initial Procedure - Fluke 8020A Instruction Manual

4-15. L S I ( ~ 8 ) ACCESS
4-16. Use the follow~ng procedure to remove/replace
the A I D Converter and Display Driver IC, U8.
a . R e m o v e t h e
component/ pcb access procedure.
b. O n the bottom of the pcb locate and remove the
two phillips head screws from the display
assembly.
Lift the display assembly from the pcb to expose
by statlc discharge. Observe the precautlons
I n
or replace U8.
d.
Use a screw driver o r a reasonable substitute t o
rock (by prying up on each end of the IC) the 1C
out of its socket.
e. When installing U8 make sure all pins are lined
up in the socket, and then carefully press
place.
f. When re-installing the LCD Bracket be sure to
line up the flex cable holes with theextensians on
the bracket before tightening the bracket screws.

4-17. Cleaning

CAUTION
Do not use aromatlc hydrocarbons or
used In the Instrument.
CAUTION
D not get the liquid crystal dlsplay wet.
O
Remove the display Assembly before washing
the pcb and do not Install it until the pcb has
been fully drled.
4- 18. Clean the front panel and case with a mild
solution of detergent and water. Clean dust from the
circuit board with low pressure (<20 psi) dry air.
Contaminates can be removed from the circuit board
with demineralized water and a soft brush (remove the
Display assembly before washing, and avoid getting
excessive amounts of water on the switches). Dry with
clean dry air at low pressure, and then bake at 50 t o 60° C
for 24 hours.
p c b a s s e m b l y u s i n g t h e
4-1 9.
ONLY BE PERFORMED AFTER THE TEST
LEADS HAVE BEEN REMOVED FROM THE
INPUT JACKS, AND THE POWER SWITCH IS
SET TO OFF.
Refer t o Section 2 of thls manual for battery and
4-20.
fuse replacement procedure. Use only the recommended

4-21. PERFORMANCE TEST

4-22. The performance test is used to compare the
Section I of this manual. It is recommended for
incoming inspection, periodic maintenance, and to
the test, calibration a n d / o r repair is indicated.

4-23. Initial Procedure

4-24. Each of the individual procedures that comprise
the perfo;mance
into
it
conditions exist.
a. The unit has been allowed to stabilize and will
be tested at an ambient temperature of 23
b.
necessary. replaced.
4-25. Display Test
4-26. The following procedure is used to test the
operation of all display digits and segments.
a. Select the 20 h i 1 range. -1 he d~splay should be
blanked with the exception of the overrange
indicator
decimal point in the center of the display.
b. Connect
and COMMON input terminals.
Set the decade resistor to
display of 10.00
Sequentially increase the resistance in 1 . I I k n
d.
steps and verify the operation of each digit and
e. Disconnect the decade resistor at the input
terminals. and select the 2000
decimal point should not be displayed.
WARNING
test assume that the following
F).
( I )
in the left hand column and a
decade resistor between the
a
3 digits.
range. A