Electrical Instructions - Philips TFT LCD Colour Monitor Service Manual

25 190B4 LCD
0. General
When carry-out the electrical settings in many cases a video
signal must be applied to the monitor. A computer with¡ G
- ATI VGA 1024 V6-1.04/PH BETA4 interface card
- PGA 1024 (4822 212 30916), Mach 8.
- PGA 1280 (4822 212 30917), Mach 32.
- ATI GPT-1600 (4822 397 10065), Mach 64 (up to 107KHz)
0.1 With normal VGA card¡G
If not using the ATI card during repair or alignment, The
service engineer also can use this service test software
adapting with normal standard VGA adaptor and using
standard VGA mode 640x480, 31.5KHz/60Hz (only) as
signal source.
0.2 AC/DC Measurement¡G
The measurements for AC waveform and DC figure is
based on 1280x1024 64KHz/60Hz resolution mode with test
pattern "32 gray scale".
1. General points
1.1 During the test and measuring, supply a distortion free AC
mains voltage to the apparatus via an isolated transformer
with low internal resistance.
1.2 All measurements mentioned hereafter are carried out at a
normal mains voltage (90-132VAC for USA version,
195-264VAC for EUROPEAN version, or 90-264VAC for the
model with full range power supply, unless otherwise
stated.)
1.3 All voltages are to be measurement or applied with respect
to ground, unless otherwise stated.
Note¡ G don't use heat-sink as ground.
1.4 The test has to be done on a complete set including LCD
panel in a room with temperature of 25+/-5 degree C.
1.5 All values mentioned in these test instruction are only
applicable of a well aligned apparatus, with correct signal.
1.6 The letters symbols (B) and (S) placed behind the test
instruction denotes
(B)¡ G carried out 100% inspection at assembly line
(S)¡ G carried out test by sampling
1.7 The white balance (color temperature), has to be tested in
subdued lighted room.
1.8 Repetitive power on/off cycle are allowed except it should
be avoided within 6 sec.
2. Input signal
2.1 Signal type
Video ¡ G 0.7Vp-p linear, positive polarity
Sync. ¡ G TTL level, separate, positive or negative polarity
Signal source¡ G pattern generator format as attachment.
(table 1 to 14) Reference generator¡ G CHROMA2200 or 2250
2.2 Input signal mode
Pre-set 15 modes

Electrical instructions

Dot rate
(MHz)
25.175
28.322
25.175
30.240
31.500
36.000
40.000
49.500
57.300
65.000
78.750
100
108
108
135
3. AC Adaptor
3.1 Setup the AC I/P at 90VAC, 264VAC
4. Display Adjustment
4.1 Input signals check
In factory mode, use 64 gray level and set the R, G, B sub
gain to 100%.
4.2 Display quality test
Use timing mode as described in 2.2, and use the POPO
(pixel on pixel off) pattern to adjust the clock until no stripe
and adjust the phase until clear picture. Check all
pre-setting 15 modes.
4.3 Check of WHITE-D (B)
Apply a 64KHz/60Hz signal with white pattern, set
brightness control at 100%, and contrast control at 70%.
Adjust the R, G, B sub_gain, for the screen center, the 1931
CIE chromaticity (X, Y) co-ordinates shall be;
Use Minolta CA-110 for color coordinates and luminance
check.
Luminance; >160 Nits (CMO panel) in the center of the
screen.
Factory preset video resolution
H. freq
Mode
(KHz)
31.469 IBM VGA 10h
31.469 IBM VGA 3h
31.469 IBM VGA 12h
35.000 MACINTOSH
37.500 VESA
35.156 VESA
37.879 VESA
46.875 VESA
49.700 MACINTOSH
48.363 VESA
60.023 VESA
68.700 MACINTOSH
71.810 SUN WS
63.981 VESA
79.976 VESA
9300°K
x (center) 0.283 ± 0.005
y (center) 0.297 ± 0.005
V. freq
Resolution
(Hz)
640 x 350 70.087
720 x 400 70.087
640 x 480 59.940
640 x 480 66.667
640 x 480 75.000
800 x 600 56.250
800 x 600 60.317
800 x 600 75.000
832 x 624 75.000
1024 x 768 60.004
1024 x 768 75.029
1152 x 870 75.000
1152 x 900 76.150
1280 x 1024 60.020
1280 x 1024 75.020
6500°K
0.313 ± 0.005
0.329 ± 0.005