PERFORMANCE
VERIFICATION PROCEDURE
4-3
^/2
. LCD test
While In the SERVICE menu, press the SCOPE softkey to enter the
SCOPE section of the
Performance
Verification Procedure.
Now a (dark) test pattern
is displayed. This pattern consists of a circle placed
In
a square, and a diagonal line (see figure
4.2).
Observe the
test pattern closely. The lines may not be
Interrupted;
the pattern must be continuous. In this
test
sets the c^splay to a high contrast, resulting
In a
dark
display. If there are defects In the pixel columns of the
Liquid
Crystal Display, they must be clearly visible now
as
Intermissions
In the pattern.
After you have checked
the display, press the upper
select/adjust key
once. Now an oscilloscope screen is
displayed.
Figure
4.2 Test pattern
Press the upper select/adjust key again
to go to step 2. Now the display shows
the same pattern, but with
a
low
contrast (bright screen). This will help you to
locate any failures in
the
pixel
rows of the LCD.
3. Ground level check
Press th e u pper select/adj
u
st key
to
go to step 3. The purpose of this
step is to check the
ground level
position
ddjusiments (OV) for both
traces. The
ScopeMeter display
shows
th© text " Verif
3",
to show
that this is the third
SCOPE
Performance Verificatron
step (see
figure 4.3).
Requirements:
A tOOmV OND B tOOfnV QNO
lOOus/OV Trig:A/
a
r
Ag
1
1
ser'VICE
1
—
Verity
CALIBRATE
S
METER EiU ScopeMeter EXrT
Figure 4.3 Reference set-up
Venfy thal the traces of both channels A and
B are
situated
on the vertical middle of the screen.
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