4
Vertical
geometry for
PAL system
(Key 2)
VPOS50 (04)
HIGH50 (25)
VLIN50 (04)
VSC50 (05)
OSD50 (20)
Input a PAL cross
hatch pattern.
Adjust VPOS50 for vertical position.
Adjust HIGH50 for vertical amplitude.
Adjust VLIN50 for vertical linearity.
Adjust VSC50 for vertical S-correction
Adjust OSD50 for OSD position (normally
use default value).
5
Vertical
geometry for
NTSC system
(Key 3)
VPOS60 (00)
HIGH60 (2E)
VLIN60 (05)
VSC60 (0A)
OSD60 (89)
Input a NTSC
cross hatch
pattern.
Adjust VPOS60 for vertical position.
Adjust HIGH60 for vertical amplitude.
Adjust VLIN60 for vertical linearity.
Adjust VSC60 for vertical S-correction
Adjust OSD60 for OSD position (normally
use default value).
6
Horizontal
geometry for
PAL system
(Key 4)
HPOS50 (0D)
HSIZE50 (2A)
PARA50 (14)
TRAP50 (0E)
CORN50 (0A)
VEHT50 (03)
HEHT50 (02)
Input a PAL cross
hatch pattern with
black and white
background.
Adjust HPOS50 for horizontal position.
Adjust HSIZE50 for horizontal width.
Adjust PARA50, TRAP50 and CORN50
until the vertical line at left and right side
of the picture become straight.
VEHT and HENT is for the picture size
stability when changing the brightness of
the screen. Receive pattern of cross hatch
with black background and then change to
white background, then compare the
vertical and horizontal size between black
and white background. Adjust VEHT and
HEHT until you get the minimum
difference of screen size. After you adjust
VEHT and HEHT, you must re-adjust
vertical and horizontal amplitude.
7
Horizontal
geometry for
NTSC system
(Key 5)
HPOS60 (11)
HSIZE60 (2A)
PARA60 (18)
TRAP60 (0D)
CORN60 (0D)
VEHT60 (03)
HEHT60 (02)
Input a NTSC
cross hatch
pattern with black
and white
background.
Adjust HPOS60 for horizontal position.
Adjust HSIZE60 for horizontal width.
Adjust PARA60, TRAP60 and CORN60
until the vertical line at left and right side
of the picture become straight.
Adjust VEHT and HEHT using same
method of PAL system. Also need re-
adjustment of vertical and horizontal
amplitude.
1
2
Key 6
(Status
adjustment)
RFAGC (25)
PIFAFT (44)
HAFC (00)
S-B-Y (08)
S-R-Y (08)
VOL 05 (48)
VOL 25 (65)
VOL OUT(73)
Receive a 60dB
grey scale + color
bar signal
RFAGC – monitor the voltage at AGC pin
of the tuner. Then increase the setting of
RFAGC until the tuner AGC voltage reach
maximum (about 5V). Then decrease the
RFAGC setting until the AGC voltage just
drop.
Adjust S-B-Y and S-R-Y to get the optimal
color for SECAM system.
Please keep the PIFAFT value after auto
AFT adjustment.
HAFC item must use the default value.
Содержание CT-F687
Страница 1: ...SERVICE MANUAL CTF687 68CM CTV APR03 SERVCTF687 ...
Страница 31: ......
Страница 32: ......