Philips DELLP1230 Service Manual page 17

7. Alignment of Vg2 cut-off point, white tracking
.
7.1External degaussing
7.1.1 Remove ferromagnetic measuring equipment, Iron tablet etc
in the neighbourhood of the apparatus within the half meter.
7.1.2 Positioned in the E - W direction (CRT face east), the monitor
has to be degaussed by using external degaussing coil.
Remark: The external degaussing coil should be a stick type, can't
use ring type for MITSUBISHI NF CRT, and set the electrical current
of purity coils (four Corners and N/S) equal to zero, which means
the output of PWM 4 to 8 of 7204 (61P4K420WT)
equal to 128, or switch off the monitor before external degaussing.
7.1.3 Slowly increase the distance between the picture tube and
degaussing coil, keep the coil in parallel with the screen of CRT
when the distance is more than 2 M, then turn off the degaussing
current.
7.1.4 Pre-check the purity by using " full RED pattern"
Especially
four corners after external degaussing, the user (OSD)
control "adjust purity" can be used to optimize the purity
performance in pure RED, this action can help to
Achieve a correct white tracking a djustment.
7.2
7.2.1
Apply 69KHz/85Hz with full white & 10cm X 10cm white patterns (video as 0.7Vpp)
*Use color analyzer (Minolta CA-100) to adjust cutoff and white uniformity.
Preset (OSD control in the factory mode) following items with initial data (DAC value):
R cut off (BAIS) = 60% , R gain (GAIN) = 70%
G cut off (BAIS) = 60% , G gain (GAIN) = 70% sub contrast (SUB)= 70%
B cut off (BAIS) = 60% , B gain (GAIN) = 70% ABL = 50%
Remark: 100% = 255 steps, 60% = 153 steps, 50% = 128 steps, 70% = 179 steps.
To access factory mode
1.Turn off monitor (do not turn off PC)
2. Press " " and " "simultaneously on the frond control
panel, then press " " ,wait till the OSD menu with characters
DELL P1230 VO.15 20031119(below OSD menu)" come on the
screen of monitor.
D E L L P1 2 3 0 V O . 1 5 2 0 0 3 1 1 1 9
3.If OSD menu disappears on the screen of monitor, press "
again (anytime), then the OSD menu comes on the screen again.
4.Using " ":to select DELL P1230 VO.15 20031119
5.Using" "to access/confirm the selection
6.Bring up the "function adjustment" as shown in Fig.2.2
Press " "button for function selection as shown in Fig.2.2
Press " " button to access/confirm each item selection
(The cursor indicator will be changed from yellow color to red
color
Using " "to increase or decrease the value
FOCUS(H V) VLINBAL USER
RASTER(H V) LIN(H V)SUB
V(OFFSET GAIN) SUB
D CONVERGENCE
EXIT
(For example: 171 is value of "BIAS R")
BIAS R G B: R (red) G(green) B(blue) cut off
GAIN R G B :R (red) G(green) B(blue) gain
V FOCUS: Vertical Focus adjustment
H FOCUS: Horizontal Focus adjustment
VLIN BAL : vertical Linearity Balance
USER Horizontal size range adjustment range
H RASTER: Horizontal raster adjustment
V RASTER: Vertical raster adjustment
H LIN: Horizontal linearity adjustment
V LIN: Vertical linearity adjustment
SUB:" " Zoom range
V OFFSET: Vertical raster center
V GAIN : Vertical size center
SUB : Sub Contrast allowance range
T CORNER: Corner Correction of Top
B CORNER: Corner Correction of BOTTOM
ABL : Auto brightness Limitation
7.2.2 Adjust the cut off of R & B to get 9300K
(X= 0.283 0.006, Y= 0.298 0.006)
and brightness output at reading from 0.06 to 0.07 Ft-L
(may need to readjust the Vg2).
(Apply a signal with 10cm x 10cm white pattern to test set.)*
Keep G cut off with 153
(60%) DAC value during all alignments.
7.2.3 Move the cursor to 9300K R/G/B (GAIN) items.
CPU software will set contrast to maximum when
01379
adjustment OSD cursor stays at GAIN items.
Adjust the gains of R/G/B to get 9300K (x=0.283, y=0.298).
7.2.4 Move the cursor to sub-contrast and adjust the brightness
to 35 0.5 Ft
7.2.5 Switch the input signal to full white pattern. Move the OSD
cursor to ABL and adjust the output brightness to
7.2.6 Repeat 7.2.2, 7.2.5 to get optimal adjustment (white
tracking meet requirement 0.015 with respect to center
value) and return to main menu. After exit, the
OSD will disappear and auto-save the data.
7.2.7 Repeat 7.2.2 to adjust 6500K 'cut off' to meet
(X= 0.313+/- 0.006, Y= 0.329+/- 0.006).
7.2.8 Repeat 7.2.3 to adjust R/G/B 'GAIN' of 6500K to meet
(x= 0.313, y= 0.329) and brightness output
"
to 31+/- 1 Ft-L.
7.2.9 Repeat 7.2.2 to adjust 5500K 'cut off' to meet
(X= 0.332 +/- 0.006, Y= 0.347
7.2.10 Repeat 7.2.3 to adjust R/G/B 'GAIN' of 5500K to meet
7.2.11 Repeat 7.2.2 to adjust sRGB 'cut off' to meet (x=
0.313 +/-0.006, y= 0.329 +/- 0.006).
7.2.12 Repeat 7.2.3 to adjust R/G/B 'GAIN' of sRGB to meet
(x=313, y=329) and brightness output to 27+/-1 Ft-L.
DELL P1230 M25P
NS PURITV
31 0.5 Ft-L
+/- 0.006).
17
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