General Information - LG STUDIOWORKS 77M Service Manual

GENERAL INFORMATION

All adjustment are thoroughly checked and corrected
when the monitor leaves the factory, but sometimes
several minor adjustment 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.)
- E(E)PROM with each mode data saved.
- 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 CRT 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 CRT magnetized, then press
(DEGAUSSING) on the OSD menu.
ADJUSTMENT PROCEDURE & METHOD
- Install the cable for adjustment such as Figure 1 and 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 C951 + voltage to 160±0.5Vdc with VR901.
2. Adjustment for High-Voltage.
1) Display cross hatch pattern at Mode 4.
2) Adjust FBT Anode voltage to 141± 0.5Vdc with
VR701.
5. Adjustment for Factory Mode (Preset Mode).
1) Display cross hatch pattern at Mode 1.
2) Run alignment program for MB776B on the IBM
compatible PC.
3) COMMAND → START → Y(Yes) command.
4) DIST. ADJ. → TILT command.
5) Adjust tilt as arrow keys to be the best condition.
6) DIST. ADJ. → BALANCE command.
7) Adjust balance of side-pincushion as arrow keys to
be the best condition.
ADJUSTMENT
8) DIST. ADJ. → FOS. ADJ → Mode No. → 1 command.
9) Adjust V-SIZE as arrow keys to 230±2mm.
10) Adjust V-POSITION as arrow keys to center of the
screen.
11) Adjust H-SIZE as arrow keys to 310±2mm.
12) Adjust H-POSITION as arrow keys to center of the
screen.
13) Adjust S-PCC (Side-Pincushion) as arrow keys to
be the best condition.
14) Adjust TRAPEZOID as arrow keys to be the best
condition.
15) Display from Mode 2 to Mode 7 and repeat above
from number 9) to 14).
16) PRESET EXIT → Y(Yes) command.
6. Adjustment for White Balance and Luminance.
1) Set the White Balance Meter.
2) Press the
demagnetization of the CRT.
3) Display color 0,0 pattern at Mode 4.
4) COLOR ADJ. → LUMINANCE command of the
alignment program.
5) Set Brightness and Sub-Brightness to max position.
6) COLOR ADJ. → BIAS ADJ. → COLOR NO. → 1
command of the alignment program.
7) Check whether blue color or not at R-BIAS and G-
BIAS to min position and adjust B-BIAS to
0.3±0.05FL of the raster luminance.
8) Adjust R-BIAS
x=0.281±0.01 and y=0.311±0.01 on the White
Balance Meter with PC arrow keys.
9) Adjust SUB-BRIGHT command to 0.4±0.1FL of the
raster luminance.
10) Display color 15,0 box pattern (70x70mm) at Mode 4.
11) DRIVE ADJ → No 1. command.
12) Set Contrast and Sub-Contrast to max position.
13) Set B-DRIVE to 2/3 150(96 decimal) position at
DRIVE of the alignment program.
14) Adjust R-DRIVE and G-DRIVE command to white
balance x=0.283±0.001 and y=0.298±0.001 on the
White Balance Meter with PC arrow keys.
15) Adjust Sub-Contrast command to 54±2FL(MPR),
46±2FL(TCO) of the raster luminance.
16) Save in COLOR 1.
(DEGAUSSING) on the OSD menu for
and G-BIAS command to