8
104S CM23 GSIII
Electrical Instructions
0. General:
When carrying out the electrical setting, in many cases a video
signal must be applied to the monitor. A computer with :
- "ATI VGA1024" interface card
- PGA1024 (4822 212 30916)
- PGA1280 (4822 212 30917)
are used as the video signal source. The signal pattern are selected
from the "service test software" package. see user guide 4822 727
19896 (ATI 1024), or 4822 727 20273 (PGA 1280).
0.1 Factory preset timing mode
Resolution H.freq./V.freq.
H. V.
640 x 400 31.5 kHz/70 Hz
-
+
640 x 480 37.5 kHz/75 Hz
-
-
800 x 600 46.9 kHz/75 Hz
+
+
800 x 600 53.7 kHz/85 Hz
+
+
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, 31.5kHz/60Hz (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.
1. B+ Supply voltage (3178), 81 VDC
- Set the brightness front control and the contrast front control to
minimum.
- Set the trimming pot-meters 3178/3540 in the mechanical mid-
position (this is a pre-setting).
- Connect a DC voltmeter between capacitor 2156 joint and ground.
- Switch on the monitor.
- Apply a video signal in the 640 x 480 with 31.5 kHz/60 Hz mode.
- Select the "crosshatch" pattern.
- Adjust trimming pot-meter 3178 until the DC voltmeter reads 81 V
+/- 0.2V.
640 x 480 31.5 kHz/60 Hz
-
-
1024 x 768 48.3 kHz/60 Hz
-
-
2. EHT voltage (3540)
- Connect a dc voltmeter between capacitor 2643 joint and ground.
- Apply a video signal in the 640 x 480 with 31.5 kHz/60 Hz mode.
- Select the "crosshatch" pattern. Adjust trimming pot-meter 3540
until the DC voltmeter reads : 67.5 +/- 0.2V (for PHILIPS CRT),
But 68 V for CPT CRT
3. Monitor the following auxiliary voltages
+12V source across C2158 +12.7V +/- 0.5 VDC
- 12V source across C2162 - 12.7V +/- 0.5 VDC
+8V source across C2172
+8.0V +/- 0.4 VDC
+6V source across C2164
+6.2V +/- 0.3 VDC
-178V source across C2647
-178V +/- 8.0 VDC
+180V source across C2153 +183V +/- 1.5 VDC
+5V source across C2168
+5.0V +/- 0.25VDC
+80V source across C2156 +81.0 V +/- 0.5 VDC
4. General conditions for alignment
Note: Do not use heatsink as ground.
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=450 mG, Z=0
Southern hemisphere : H=0, V=-500 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.
4.5 Adjust brightness controls to center position except for contrast
control which should be set to MAX.
5. To access Factory Mode:
1. When "shift" LED is off, control is at 1st level, and when LED is on,
control is at 2nd level.
2. "Shift" LED will flash 0.1 second at the time when function keys (e.g.
H-Shift, H-Size,...,etc.) are pressed, and it should flash continuously
when adjusting "+" or "-" is at end of range. Releasing "+" or "-" key,
all adjusted values will be stored automatically after 10 seconds.(at
user Mode).
3. Factory preset mode entry, in power on status pressed "H-shift" and
"V-size"simultaneously at 1st level. After 2 seconds the shift led will
flash 3 times then the u-controller will entry factory mode.
( turn off power and then on to return to user mode)
4. "Power down overrule" is only functional in power saving status and
will be reset by switching off power.
5. At factory adjust mode, Press Shift key( shift LED on) then press V-
size, the modified data will be stored in factory preset area on
EEPROM and shift LED will flash two times.
6. At service, please entry Factory mode (pressing H-Shift and V-size
simultaneously) first before using service factory alignment tools or
auto-alignment to perform factory alignment.