DAEWOO ELECTRONICS 712D, Service Manual

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13
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Standard Adjustment Conditions
1. Power source voltage : AC 100 - 240Vac, 50/60Hz.
2. Aging : Take at least 20 minutes warm-up time.
3. Signals.
Video : Analog 0.7Vpp 75W terminal positive polarity
Synchronizing : TTL Level Negative/Positive Separate
Deflection frequency
Horizontal Frequency : 30KHz - 94KHz
Vertical Frequency : 50Hz - 120Hz
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Pre-Adjustment
1. B+ Adjustment
Adjust 165V dc ± 0.5V dc between P107 and ground at 31.5KHz mode,varying VR151.
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Main Adjustment
1. Setting the Controls
Set the value of items as following.
Contrast : Max. (OSD value up to MAX)
Brightness : Center (Set the OSD value to center)
2. H.size, V.size, H.phase, V.position, Pincushion, Trapezoid
Receive the cross hatch pattern of Factory preset mode.
H.size, V.size, H.phase, V.position, Pincushion, Trapezoid are adjusted at each mode.
In Factory, Auto Alignment was done at each mode. Therefore, Factory preset mode have it’s own
value according to each control.
3. Focus
(a) Set brightness control to center and contrast control to MAX.
(b) Receive all “H” character pattern of 1280x1024 (91KHz).
(c) Adjust the Focus control of FBT to obtain best Focus.
4. Geometric Distortion Adjustment
(a) Receive the cross hatch pattern factory preset mode.
(b) Pincushion, Trapezoid are adjusted the best geometric status
5. White Balance Adjustment
(a) Select 9300°K on the OSD Menu.
(b) Receive a full white pattern of 91KHz mode signal by using the signal generator.
(c) Set the brightness control to maximum and the contrast control to maximum.
(d) Cut off the FBT screen VR.
(e) Receive all the black patterns. The luminance of the screen should be 0.5~0.7 Ft-L by using Screen
VR.
(f) Select the R-BIAS, G-BIAS and B-BIAS on the control menu and adjust the / key to get the
color coordinates in x=0.281 ± 0.015, y=0.311± 0.015.
(g) Receive a full white pattern. Adjust the brightness value to the center.
(h) Select the R-GAIN and B-GAIN and adjust the / key to get the color coordinates in x=0.281 ±
0.015, y=0.311 ± 0.015.
(i) Adjust the sub contrast control to get the screen luminance to 30 Ft/L (a full white pattern over 30
Ft/L)
(j) Check if the x, y coordinates of color analyzer is in x=0.281±0.015, y=0.311±0.015.
If the color coordinates is out of range, adjust the R. G. B BIAS & GAIN to get the coorinates in
x=0.281, y=0.311. Make sure that the coordinates is in the appropriate range.
ALIGNMENT PROCEDURE