Sharp 21F-PA18, Service Manual

Page: 21 / 89

21F-PD250 / 21F-PT220 / 21F-PA18 / 21F-PA18(B)
3 – 18
5. SCREEN, WHITE BALANCE, SUB-BRIGHTNESS & SUB-CONTRAST ADJUSTMENT
No. Adjustment point Adjustment procedure/conditions Waveform and others
SCREEN
ADJUSTMENT
(I
2
C BUS
CONTROL)
1) In window pattern signal condition.
2) Go to service mode, then select V00.
1
2
White
Dark White
WINDOW PATTERN SIGNAL
By pressing R/C key S-Mute (Hex E8), R-D
auto switch to 63, B-D auto switch to 63, R-
C auto switch to 127, G-C auto switch to
127, B-C auto switch to 127, Sub-
brightness V06 auto switch to 127 .
Y-mute & Vertical off, screen will be in
vertical cut-off condition.
3)
Adjust the Screen so that cut-off line ap-
pear in low bright, then judge that whether
the cut-off line appear in Red or Green or
Blue color, in this condition between R-C &
G-C & B-C, fix the data of the color appear
in cut-off line and adj the other two cut-off
data (Note 1) so that cut-off line color be-
come white.
4)
Turn the screen VR of FBT so that cut-off
line just
disappear and use R/C by press-
ing key S-Mute (Hex E8) to disable the Y-
mute & V-cut so that picture appear in nor-
mal mode.
5)
WHITE (HIGH BEAM) ( In Window Pattern
Signal)
First use Minolta Color Analyzer CA100, let
the gun point at
Dark White position (as
drawing attach), Adj V06 until LUMI-
NANCE Y become 5 cd/m2 , then let the
gun point at White position ( as drawing at-
tach), Adj V04 until LUMINANCE Y be-
come: 160 cd/m2 .
Adj the R-D & B-D until the axis of color
temperature become
1)
DARK WHITE (LOW BEAM) (In Window
Pattern Signal)
Let the gun point at
Dark White position, if
the color temperature data shift away from
the data adjusted in
step 1 , adjust R-C, G-
C & B-C but between them, first color
appears in Screen adj item 1)-4 is fixed
,
adj the other two so that to obtain the simi-
lar axis as above.
** Repeat step 1 & 2 to get a regulated
position
2)
R-CUTOFF (R-C) UP
R-CUTOFF (R-C) DOWN
G-CUTOFF (G-C) UP
G-CUTOFF (G-C) DOWN
B-CUTOFF (B-C) UP
B-CUTOFF (B-C) DOWN
R-DRIVE (R-D) UP
R-DRIVE (R-D) DOWN
B-DRIVE (B-D) UP
B-DRIVE (B-D) DOWN RC key "1" (HEX 80)
RC key "4" (HEX 20)
RC key "2" (HEX 40)
RC key "5" (HEX A0)
RC key "3" (HEX C0)
RC key "6" (HEX 60)
RC key "7" (HEX E0)
RC key "Flashback" (HEX E4)
RC key "8" (HEX 10)
RC key "0" (HEX 50)
9.5% IRE
50% IRE
5.5% IRE
Signal using W/B Pattern Generator
SX-1006 (IWATSU) or equivalent.
Window Pattern Signal output level
are as above: *Note :
WHITE
BALANCE ADJ
(to be done
after screen
adj)
(I
2 C BUS
CONTROL)
12300
o
K X : 0.272
Y : 0.275