LG Flatron F900B, Service Manual

Page: 13 / 35

ADJUSTMENT
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GENERAL INFORMATION
All adjustment are thoroughly checked and corrected
when the monitor leaves the factory, but sometimes
several adjustments may be required.
Adjustment should be following procedure and after
warming up for a minimum of 30 minutes.
• Alignment appliances and tools.
- IBM compatible PC.
- Programmable Signal Generator.
(eg. VG-819 made by Astrodesign Co.)
- EPROM or EEPROM with saved each mode data.
- Alignment Adaptor and Software.
- Digital Voltmeter.
- White Balance Meter.
- Luminance Meter.
- High-voltage Meter.
AUTOMATIC AND MANUAL DEGAUSSING
The degaussing coil is mounted around the CDT so that
automatic degaussing when turn on the monitor. But a
monitor is moved or faced in a different direction, become
poor color purity cause of CDT magnetized, then press
DEGAUSSING on the OSD menu.
ADJUSTMENT PROCEDURE & METHOD
- Install the cable for adjustment such as Figure 1and run
the alignment program on the DOS for IBM compatible PC.
- Set external Brightness and Contrast volume to max position.
1. Adjustment for B+ Voltage.
1) Display cross hatch pattern at Mode 4.
2) Adjust C905 (+) voltage to 190V ± 0.5V with VR901.
2. Adjustment for High-Voltage.
1) Display cross hatch pattern at Mode 4.
2) Adjust CDT Anode voltage to 27kV ± 0.2kV with
VR801.
3. Adjustment for Horizontal Raster Center.
1) Display cross hatch pattern at Mode 4.
2) Adjust the Back Raster should be center of the
screen with SW801.
4. Adjustment for Factory Mode (Preset Mode).
1) Display cross hatch pattern at Mode All.
2) Run alignment program for F900BJ on the IBM
compatible PC.
3) EEPROM
→
ALL CLEAR
→
Y(Yes) command.
<Caution> Do not run this procedure unless the
EEPROM is changed. All data in EEPROM (mode
data and color data) will be erased.
4) COMMAND
→
PRESET START
→
Y(Yes)
command.
5) DIST. ADJ.
→
FOS. ADJ command.
6) Adjust H-POSITION as arrow keys to center of the
screen.
7) Adjust H-SIZE as arrow keys to 350 ± 2mm.
8) Adjust V-POSITION as arrow keys to center of the
screen.
9) Adjust V-SIZE as arrow keys to 262 ± 2mm.
10) Adjust TRAPEZOID as arrow keys to be the best
condition.
11) Adjust SIDE PINCUSHON as arrow keys to be the
best condition.
12) Adjust TILT as arrow keys to be the best condition.
13) Display cross hatch pattern at Mode 4.
14) DIST. ADJ.
→
BALANCE DATA command.
15) Adjust balance of Pin-Balance as arrow keys to be
the best condition.
16) Adjust parallelogram as arrow keys to be the best
condition.
17) Save of the Mode.
18) Save of the System.
19) Display from Mode 4 and repeat above from
number 6) to 16).
20) COMMAND
→
PRESET EXIT
→
Y (Yes) command.
5. Adjustment for White Balance and Luminance.
1) Set the White Balance Meter.
2) Press the DEGAUSSING on the OSD menu for
demagnetization of the CDT.
3) Display color 0,0 pattern at Mode 4.
4) COMMAND
→
PRESET START
→
Y(Yes)
command.
5) Set Bightness and Contrast to max position.
6) COLOR ADJ.
→
LUMINANCE command of the
alignment program.
7) COLOR ADJ.
→
BIAS ADJ. command of the
alignment program.
8) Check whether blue color or not at R-BIAS and G-
BIAS to min position, Sub-Brightness to 90
(5A(h))position, B-BIAS to 70(46(h))position. If it's
not blue color, the monitor must repair.
9) Adjust Screen control on the FBT to 0.15 ± 0.05FL
of the raster luminance.
10) Adjust R-BIAS and G-BIAS command to x=0.283 ±
0.006 and y=0.298 ± 0.006 on the White Balance
Meter with PC arrow keys.