12. Cut-off Adjustment
Purpose: To adjust the beam current of R, G, B, and screen voltage.
Symptom of Misadjustment: White color may be reddish, greenish or bluish.
Test Point | Adj. Point | Mode |
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CH o / p | RF |
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Tape | M. EQ. |
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Pattern | See Reference | ||||
Generator | Notes below. | ||||
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Figure
PATTERN GENERATOR
EXT. INPUT Fig. 2
Note: Screen Control FBT
F.B.T= Fly Back Transformer
Use service remote control unit
1.Degauss the CRT and allow CRT to operate for 20 minutes before starting the alignment.
2.Input the Black Raster Signal from RF Input.
3.Enter the Service mode. (See page
4.Press "VOL p" button on the service remote con- trol unit and select "C/D" mode. (Display changes "C/D," "7F," "LANGUAGE," "ACCESS CODE," "SOUND TYPE," "VIDEO TONE," "FM MODE,"
5.Press the "2" button. The display will momentarily show "CUT OFF G" (G=Green). Adjust the Green Cut off by pressing the "CH o/p" buttons. Proceed to step 6 when the Green Cut off adjustment is done.
6.Press the "3" button. The display will momentarily show "CUT OFF B" (B=Blue). Adjust the Blue cut off by pressing the "CH o/p" buttons. When done with steps 4, 5 and 6 the horizontal line should be pure white if not, then attempt the Cut off adjust- ment again.
13. White Balance Adjustment
Purpose: To mix red, green and blue beams correctly for pure white.
Symptom of Misadjustment: White becomes bluish or reddish.
Test Point | Adj. Point | Mode | Input | |
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Screen | CH o / p | RF | Raster | |
buttons | (APL | |||
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Tape | M. EQ. | Spec. | ||
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Generator, | See below | |||
| Color analyzer |
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| Color Analyzer | Fig. 3 |
Note: Use service remote control unit
1.Operate the unit more than 20 minutes.
2.Face the unit to east. Degauss the CRT using De- gaussing Coil.
3.Input the White Raster (APL 100%).
4.Set the color analyzer to the CHROMA mode and after zero point calibration, bring the optical recep- tor to the center on the tube surface (CRT).
5.Enter the Service mode. Press "VOL p" button on the service remote control unit and select "C/D" mode. (Display changes "C/D," "7F," "LANGUAGE," "AC- CESS CODE," "SOUND TYPE," "VIDEO TONE," "FM MODE,"
6.Press No. 4 button on the service remote control unit for Red adjustment. Press N0. 5 button on the service remote control unit for Blue adjustment.
7.In each color mode, Press "CH o/p" button to adjust the values of color.
8.Adjusting Red and Blue color so that the temperature becomes 9200K (x: 286 / y: 294)±3%.
9.At this time,
10.Turn off and on again to return to normal mode. Re- ceive APL 100% white signal and Check Chroma temperatures become 9200K (x: 286 / y: 294)±3%.
Note: Confirm that Cut Off Adj. is correct after this adjustment, and attempt Cut Off Adj. if needed.
L2401EA |