(12) Cut-off
(a)
lnit
adjustment Signal 3 (VGA480)
ial
settings of the adjustment
VRs
VR704-VR706
BIAS VR
:
Fully counterc
VR707-VR709
SUB BRIGHT VR
:
Fully counterc
SCREEN VR
:
Fully counterc
VR710 SUB BIAS VR
:
Fully counterc
CONTRAST CONTROL
:
Fully counterc
BR
I
GHTNESS CONTROL
:
Fully counterc
(b) Receive an all-black signal.
ockw i se
ockw i se
ockw i se
ockw i se
ockw i se
ockw i se
(c) Short CN-TP
@,a,
@
and
0.
(Use CN-TP- on Adjustment j
ig)
Short SW45 on Adjustment j ig. (TP-B
0
and
0)
(d) Connect a high voltage voltmeter to TP904 and adjust the SCREEN VR
so that the voltage is 470Vdc
±5Vdc(VMA-2(N),(NT),(H)/VMB-2(N),
(NT),
(H)/VMR-2(N),
(H))I
or 665Vdc
±5Vdc(VMA-2(T)/VMB-2(T).
(Use a voltmeter with a maximum voltage capacity of
1.5kV
or greater and an input resistance of
1OOOMn
or greater.)
(e) Turning
VR-71O(SUB
BIAS VR) gradually in the clockwise direction
will cause a signal color to appear
horizontally. Set
the VR so that
the color can be faintly seen.This color is the reference color for
the cut-off
adjustment.Even
if the reference color does not appear,
proceed to step (f).
(f) Turn the BIAS
VRs(on
the VIDEO PWB) for the colors other than the
reference color in the clockwise direction until the colors light
with same brightness as the reference
color.lf
even it the reference
color will not appear VR710 turned fully clockwise, turn VR705
clockwise unitil the green horizontal display appears
faintly.Use
as the reference
color.Next
turn VR704 and VR706 until their
corresponding colors light with the same brightness as the
reference color.
(g)
Open the short SW45 on Adjustment jig. (TP-B between
@
and
0)
NOTE-: White tracking will be best at dark cut-off adjustment settings.
For the best setting,therefore,perform the cut-off adjustment
in as dark a place as possible.
(13) Cut-off Faint Adjustment (Contrast Tracking) signal 13 (VGA480 WINDOW)
(a) Receive the window pattern.
(b) Short SW44
on Adjustment
j
ig. (TP-B
0
and
@)
(c)
Leave CN-TP
0,
@,@I
and
@
short.
(d)
Turn the contrast control fully
clockwise(MAX)
and measure
the color temperature
(Xl,Yl).
(e) Turn the contrast control fully counterclockwise(MIN) and measure the
color temperature
(X2,Y2).Faintly
adjust the BIAS
VRs
of the colors
other than the cut-off reference color so that
(Xl,Yl)=(X2,Y2).
If this adjustment is difficult, try faintly adjusting the
BIAS VR of the reference color.
(f)
Turn the contrast control again fully clockwise(MAX) and measure
the color temperature. If the color temperature has shifted, repeat
the faint adjustment procedure in step (e).
AX=Xl-
x220.
005
AX=Yl-
Y220.
005
.
(g)
Remove the short between CN-TP
@,@,@I
and
0.
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