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1-62 (No. 52152)
HORIZONTAL/VERTICAL IMAGE POSITION, IMAGE AMPLITUDE AND IMAGE DISTORTION ADJUSTMENTS (NTSC/PAL UNDERSCAN 4:3 MODE)
Note:
•
Perform the following adjustments after completing
the Reference Mode (NTSL/PAL overscan 4:3 mode)
adjustments.
(1) Apply the NTSC mono-scope signal to INPUT C (Terminal
VIDEO1 on the NTSC/PAL Video Input Card).
(2) Set the CONTRAST and BRIGHT potentiometers on the
front panel to the center click positions.
(3) Press the UNDER SCAN button on the front panel to set
the scanning size to underscanning.
(4) Adjust
DB04
in the Service Menu to set the vertical position
of the image at the center of the CRT screen.
(5) Adjust
DB02
to set the vertical amplitude of the image to
233mm
.
(6) Apply the NTSC crosshatch signal to INPUT C.
(7) Adjust
DB11
to set the sizes of the rectangles at the center
of the image and those at the left and right ends to be
identical.
(8) Adjust
DB12
to set the sizes of the rectangles at the center
of the image and those at the top and bottom to be identical.
(9) Ensure that the center position is not deviated. If it is, adjust
DB04
again.
(10)Adjust
DB11
,
DB12
and
DB04
repeatedly until the center
position and vertical linearity are optimized.
(11) Adjust
DB09
to optimize the trapezoidal distortion (observe
the second vertical lines from the left and right edges as the
reference).
(12)Adjust
DB08
to optimize the parallelogram distortion
(observe the second vertical lines from the left and right
edges as the reference).
(13)Adjust
DB10
to optimize the horizontal arc distortion.
(14)Adjust
DB05
so that the second vertical lines from the left
and right edges are linear.
(15)If there is an extreme corner S-shape distortion, adjust
DB07
to optimize it (this adjustment is usually unnecessary).
(16)If there is an extreme corner W-shape distortion, adjust
DB06
to optimize it (this adjustment is usually unnecessary).
(17)Apply the NTSC mono-scope signal to INPUT C.
(18)Ensure that the vertical amplitude of the image is
233mm
. If
it is not, adjust
DB02
again.
(19)Adjust
DB03
so that the horizontal position of the image
comes at the center of the CRT screen.
(20)Adjust
DB01
to set the horizontal amplitude of the image to
311mm
.
(21)Vary the adjustment signal and adjustment data, and re-
perform adjustments in steps 1 to 20 above (see Table 15).
Measuring Instruments
Signal generator (Mono-scope signal, Crosshatch signal)
Card (Slot)
NTSC/PAL Video Input Card (Slot 2)
Test Points
Adjustment Points
D*01 (Horizontal Size), D*02 (Vertical Size), D*03 (Horizontal Position), D*04 (Vertical Position),
D*05 (Side Pin Distortion), D*06 (Corner Distortion (W)), D*07 (Corner Distortion (S)), D*08
(Parallelogram Distortion), D*09 (Trapezoidal Distortion), D*10 (Horizontal Arc Distortion), D*11
(Vertical Linearity (S Correction)), D*12
(Vertical Linearity (C Correction)) [Service Menu]
Adjustment
Adjustment
Adjustment
Step No.
signal
Data
1
NTSC
DB
2
PAL
DD
Table 15
90
90
80
80
80
311mm
233mm
90
Make these lines linear.
Scanning size (100%)
Screen size