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Service Adjustments (Electronic Controls, cont.)
Note: Turn the Receiver ON. Operate the Receiver
for 60 minutes using the first Purity Check field
(white screen) to stabilize the CRT. Fully
degauss the Receiver by using an external
degaussing coil.
Horizontal Center Adjustment
Serviceman DAC Adjustment (D0)
Preparation:
1.
Preset the following controls:)
• Picture . . . . . . . . . . . . . . . . . Max.
• Bright . . . . . . . . . . . . . . . . . . Center.
Procedure:
1.
Apply a monoscope pattern.
2.
Adjust Horizontal center register to center the
monoscope pattern on the CRT.
E-W Pincushion Correction
Serviceman DAC Adjustment (Dc)
Preparation:
1.
Apply a Crosshatch pattern
2.
Normalize the Picture Icon Video adjustments.
3.
Set:
• Brightness . . . . . . . .Center.
• Sharpness . . . . . . . .Center
• Picture . . . . . . . . . . .Max.
Procedure:
1.
Enter Serviceman Mode, select DAC Dc. Adjust for
1st and 3rd vertical lines on E&W sides to be
straight (See Fig. 28)
2.
Select DAC Db and adjust vertical lines so that the
top edge is straight (SeeFig. 29)
Horizontal Width Adjustment
Serviceman DAC Adjustment (Dd)
Preparation:
1.
Apply a monoscope pattern.
2.
Adjust D0 Horizontal Center until picture is
centered.
3.
Verify Horizontal Width is in normal range.
4.
Apply a crosshatch pattern.
5.
Adjust Dc, E-W Pincushion and Db, Corners
Pincushion to obtain outside vertical lines as
straight as possible.
Procedure:
1.
Apply a monoscope pattern.
2.
Adjust Dd, Horizontal Width until distance A = B
(4.50 ± 0.40 aprox.) See Fig. 30.
3.
Adjust Vertical Size to obtain a complete round
pattern.
Figure 30. Horizontal Size Adjustment
Vertical Position, Vertical Size
Serviceman DAC Adjustment (D6, D1)
Preparation:
1.
Apply a monoscope pattern.
Procedure:
1.
Adjust D7 Vertical Position until picture is
centered with the vertical center of the CRT. Use
D6 for fine adjustment.
2.
Adjust D1, for Vertical Size to obtain a round
monoscope pattern; distance C = D. See Fig. 31.
Figure 31. Vertical size adjustment
Min adj.
Max adj.
Correct adj.
Figure 28. E-W Pincushion Adjustment
Min adj.
Correct adj.
Figure 29. Corner Pincushion Adjustment
A
B
C
D