23
202P4 M25P
Electrical Adjustments
9
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0. General
When carry-out the electrical settings in many cases a video
signal must be applied to the monitor. A computer with :
- ATI GPT-1600 (4822 397 10065), Mach 64 (up to 115kHz)
are used as the video signal source. The signal patterns are
selected from the "service test software" package, see user
guide 4822 727 21046 (GPT-1600).
0.1 This monitor has 36 factory-preset modes as below
.
0.2 With normal VGA card:
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 640 x 480, 31.5 kHz/60 Hz (only) as
signal source.
0.3 AC/DC Measurement:
The measurements for AC waveform and DC figure is based
on 640 x 480 31.5 kHz/60 Hz resolution mode with test
pattern "gray scale".
Power input: 110V AC
1. B+ supply voltage (3157) 230Vdc
- Apply a video signal in the 1024 x 768 with 69 kHz/85Hz
mode.
- Select the "cross-hatch" pattern.
- Set the brightness control and the contrast control to the
minimum position.
- Pre-set trimming potentiometer 3157(B+) and 3698(EHT)
in mid-position.
- Set Vg2 (screen) to fully Counter-clockwise (zero
beamcurrent).
- Connect a dc voltmeter between the joint of capacitor 2154
and ground (common ground).
- Set the B+ trimming potentiometer 3157 so that the reading
on the dc voltmeter is 230 V +/- 0.2 Vdc.
2. High-voltage EHT (3698)
- Apply a video signal in the 1024 x 768 with 68.7 kHz/85Hz
mode.
- Select the "cross-hatch" pattern.
- Set the brightness control and the contrast control to the
minimum position.
- Turn off the power.
- Connect a "high-voltage voltmeter" between the high-
voltage connection of the picture tube and earth.
- Turn on the power.
- Set the EHT trimming potentiometer 3661 so that the "high-
voltage voltmeter" reads 27.0 kV +/- 0.2 kV .
- Turn off the power.
- Remove the "high-voltage voltmeter" from the picture tube.
- Turn on the power again.
4.5 Adjust function controls " " to center position except
for contrast control which should be set to MAX.
- Turn off monitor (don't turn off PC)
- Press " " and " " simultaneously on the front
control panel, then press " ",wait till the OSD menu
with characters " factory mode (below OSD menu)" come
on the screen of monitor.
- If OSD menu disappears on the screen of monitor, press
" " again (anytime), then the OSD menu comes on the
screen again.
- using " " : to select OSD menu.
: to increase or decrease the setting.
- Using " " to confirm the selection.
5. To access factory mode:
3. Monitor the following auxiliary voltages.
4. General conditions for alignment
SOURCE ACROSS C2157 - 13.0V +/- 0.5VDC.
SOURCE ACROSS C2172 + 13.0V +/- 0.5VDC.
SOURCE ACROSS C2156 - 6.4 V+/- 0.2VDC.
SOURCE ACROSS C2152 + 193.0V +/- 1.5VDC.
SOURCE ACROSS C2154 + 79.0 V +/- 0.2VDC.
4.1 During all alignments, supply a distortion free AC mains
voltage to set via an isolating transformer with low internal
impedance.
4.2 Align in pre-warmed condition, at least 30 minutes warm-
up with nominal picture brightness.
4.3 Purity, geometry and subsequent alignments should be
carried out in magnetic cage with correct magnetic field.
Northern hemisphere : H=0, V=430+/-50 mG, Z=0
Southern hemisphere : H=0, V=-520+/-50 mG, Z=0
Equatorial Support : H=0, V=0 mG, Z=0
4.4 All voltages are to be measured or applied with respect to
ground.
Note: Do not use heatsink as ground.
SOURCE ACROSS C2362 + 8.0V +/- 0.5 VDC
SOURCE ACROSS C2143 + 5.0V +/- 0.5 VDC
SOURCE ACROSS C2361 + 12.0V +/- 0.5 VDC
SOURCE ACROSS C2134 + 15.1V +/- 1.0 VDC
SOURCE ACROSS C2137 - 15.4V +/- 1.0 VDC
SOURCE ACROSS D6143 “
+
“ 6.1V +/- 0.5 VDC
SOURCE ACROSS C2131 + 230.0V +/- 1.5 VDC
SOURCE ACROSS C2133 + 82.0V +/- 2.0 VDC
MODEL SELECT
Factory
Mode
Indicator
CM25 PLUS V0.55 20011128
00195
RESOLUTION f h f v RESOLUTION f h f v
640 x 480 31.469 kHz 59.941 Hz 1152 x 870 68.681 kHz 74.979 Hz
720 x 400 31.468 kHz 70.084 Hz 1856 x 1392 124.185KHz 85.000Hz
640 x 480 37.500 KHz 75.000 Hz 1920 x1440 128.520KHz 85.000Hz
640 x 480 37.861 kHz 72.810 Hz 1600 x 1200 75.000 kHz 60.000 Hz
800x600 37.879 kHz 60.317Hz 1280 x1024 79.976 kHz 75.024 Hz
640 x 480 43.269 kHz 85.008 Hz 1600 x 1200 81.250 kHz 65.000 Hz
800 x 600 46.875 kHz 75.000 Hz 1792 x 1344 83.640 kHz 59.999 Hz
800 x 600 48.077 kHz 72.188 Hz 1920 x1440 120.56HKz 80.000Hz
1024 x 768 48.363 kHz 60.004 Hz 1856 x 1392 86.333 kHz 59.995 Hz
832 x 624 49.722 kHz 74.546 Hz 1600 x 1200 87.500 kHz 70.000 Hz
640 x 480 50.628 kHz 100.10 Hz 1920 x 1440 90.000 kHz 60.000 Hz
800 x 600 53.674 kHz 85.061 Hz 1280 x 1024 91.146 kHz 85.024 Hz
1024 x 768 56.476 kHz 70.069 Hz 1600 x 1200 93.750 kHz 75.000 Hz
1792 x 1344 119.935KHz 85.000Hz 1600 x 1200 106.250 kHz 85.000 Hz
1024 x 768 60.023 kHz 75.029 Hz 1792 x 1344 106.270 kHz 74.997 Hz
800 x 600 63.923 kHz 100.00 Hz 1920 x 1440 112.5 kHz 75.000 Hz
1280 x 1024 63.981 kHz 60.020 Hz 2048 x 1536 120.450 kHz 75.000 Hz
1024 x 768 68.677 kHz 84.997 Hz 2048 x 1536 130KHz 80Hz
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