JVC DT-V1710CG Service Manual page 64

VERTICAL IMAGE POSITION, IMAGE AMPLITUDE AND IMAGE DISTORTION ADJUSTMENTS (NTSC/PAL UNDERSCAN 16:9 MODE)
Measuring Instruments
Card (Slot)
Test Points
Adjustment Points
Notes:
•
Perform the following adjustments after completing the Reference Mode (NTSL/PAL overscan 4:3 mode) and NTSC/
PAL underscan 4:3 mode adjustments.
•
The corner distortions (W) & (S), parallelogram distortion, trapezoidal distortion and horizontal arc distortion adjustment
data for this adjustment are common to those in the NTSC/PAL overscan 16:9 mode and the NTSC/PAL underscan
16:9 mode adjustments. This adjustment data needs to be adjusted in either mode.
•
The corner distortions (W) & (S), parallelogram distortion, trapezoidal distortion and horizontal arc distortion adjustment
data for this adjustment are common to those in the 480/60i and NTSC signal or 576/50i and PAL signal adjustments.
This adjustment data needs to be adjusted with either signal.
(1) Apply the NTSC mono-scope signal to INPUT C (Terminal
VIDEO1 on the NTSC/PAL Video Input Card).
(2) Press the ASPECT and UNDER SCAN buttons on the front
panel to set the scanning size to underscanning for the 16:9
ratio.
(3) Set the CONTRAST and BRIGHT potentiometers on the
front panel to the center click positions.
(4) Adjust DY05 in the Service Menu to set the vertical position
of the image at the center of the CRT screen.
(5) Adjust DY04 to set the vertical amplitude of the image to
175mm.
(6) Apply the NTSC crosshatch signal to INPUT C.
(7) Adjust CE08 to optimize the trapezoidal distortion (observe
the second vertical lines from the left and right edges as the
reference).
(8) Adjust CE07 to optimize the parallelogram distortion (observe
the second vertical lines from the left and right edges as the
reference).
(9) Adjust CE09 to optimize the horizontal arc distortion.
(10) Adjust DY06 so that the second vertical lines from the left
and right edges are linear.
(11) If there is an extreme corner S-shape distortion, adjust CE06
to optimize it (this adjustment is usually unnecessary).
(12) If there is an extreme corner W-shape distortion, adjust CE05
to optimize it (this adjustment is usually unnecessary).
(13) Apply the NTSC mono-scope signal to INPUT C.
(14) Ensure that the vertical amplitude of the image is 175mm. If
it is not, adjust DY04 again.
(15) Adjust DY05 so that the vertical position of the image comes
at the center of the CRT screen.
(16) Vary the adjustment signal and adjustment data, and re-
perform adjustments in steps 1 to 15 above (see Table 17 ).
Adjustment Adjustment
Step No. Signal
1 NTSC
2 PAL
1-64 (No. 52152)
Signal generator (Mono-scope signal, Crosshatch signal)
NTSC/PAL Video Input Card (Slot 2)
DY** (Vertical Size), DY** (Vertical Position), DY** (Side Pin Distortion), CE** (Corner Distortion
(W)), CE** (Corner Distortion (S)), CE** (Parallelogram Distortion), CE** (Trapezoidal Distortion),
CE** (Horizontal Arc Distortion) [Service Menu]
Vertical Vertical Side Pin
Position size Distortion Distortion (W) Distortion (S)
DY05 DY04
DY11 DY10
90 80
Adjustment Data
Corner Corner
DY06 CE05 CE06
DY12 CE10 CE11
Table 17
Scanning size (100%)
90
80
80 90
Screen size
Make these lines linear.
Parallelogram Trapezoidal
Distortion Distortion
CE07 CE08
CE12 CE13
175mm
Horizontal
Arc Distortion
CE09
CE14