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8.
Connect
a 2.4K resistor from Pin 6 of the J-Test Connector
to Pin 3 (Red) of the same J-Test Connector
(this forces the
Red cathode to 195Vdc).
9.
Adjust the Red G2 (bottom
row, left) to just barely turn On
the Red CRT.
10.
Now, do the same for the Green Output by connecting
the
same 2.4K resistor from Pin 6 of the J-Test Connector
to Pin
4 (Green).
Then adjust it's G2 Control (bottom row, middle)
while viewing it's CRT.
11.
Finally, the Blue Output
by connecting
the same 2.4K resis-
tor from Pin 6 of the J-Test Connector
to Pin 5 (Blue). Then
adjust
it's G2 Control
(bottom
row, right) while viewing
it's
CRT.
12,
Remove resistor and jumper from the J-Test Connector.
13.
Proceed
to the
Gray
Scale
Tracking,
Sub-Brightness
Adjustment.
Gray Scale Tracking, Sub-Brightness
Adjustment
Procedure
Note:
Gray Scale and Sub-Brightness
must be adjusted
after
replacing
a Signal/Deflection
Module
in the PTV500
Systems.
The following
procedure
assumes
a Gray Scale problem
exists
and G2 (Screen
Controls)
require no further modifications.
Setup
Procedure:
1.
Install the new Signal/Deflection
Module.
2.
Turn the set On and tune to a good air or cable channel.
3.
Picture,
Sharpness,
Brightness
and Tint set to mid-range.
Color set to minimum.
4.
Set the Lo-Lite
Controls
(also
on the Signal/Deflection
Module) to their full counterclockwise
positions.
5.
Set the Hi-Lite
Controls
(On Signal/Deflection
Module)
to
their full clockwise
positions.
6.
Adjust the Sub-Brightness
Control (R776) so that the darkest
part of the picture is just barely lit (raster lines just barely visi-
ble).
7.
Adjust any two (2) Lo-Lite Controls (one to remain fully coun-
terclockwise)
to attain gray in low-light areas of the picture.
8.
Turn down
only the Hi-Lite Control
that is causing
an off-
white condition
in high brightness
white areas of the picture
(if pinkish,
reduce
red; if bluish,
reduce
blue; if greenish,
reduce green).
20
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