Green Screen Geometry Adjustments; Blue Screen Convergence Procedure - Philips PTV500 series Service Manual

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To prevent customer controls from affecting adjustments,
connect jumpers from the bottom of the following resistors to
ground: R504, R505, R506 and R507 (the top Pin of the
Setup terminal is ground). Also. tie the lower Pin of the
Setup terminal to ground (this is to temporally disable the
Convergence Panel adjustments).
Screen Centering
1. Adjust Centering Tabs to center each color at the center of
the screen (point of string crossing).
Note: Be sure strings are installed correctly or the Skew adjust-
ment will have a major affect on Centering.
Green Screen Geometry Adjustments
1. Cover the Red and Blue CRT Output Lenses with 7 inch
square pieces of cardboard, blocking the light output from
these lenses.
2. Loosen the Yoke clamp on the Green CRT.
3. By rotating the Yoke, visually adjust the vertical Skew.
4. Re-tighten the Yoke clamp.
5. Remove ONLY the lower Setup Pin jumper, enabling the
Convergence Panel controls. Do not remove the other
jumpers at this time (keep Customer Controls disabled).
6. Select the crosshatch pattern.
7. Adjust the Vertical Size (R551) on the Signal/Deflection
Module for approximately 3/4" overscan at the top and bot-
tom of the screen (viewed from the back side of the screen).
8. Adjust the Horizontal Size (R469) on the Signal/Deflection
Module for approximately 3/4" overscan at the left and right
back side of screen.
9. Repeat steps 7 and 8 as needed to produce true squares
(height = width) throughout the crosshatch pattern. Use a
ruler to check these results.
Note: Approximately 3/4" overscan should be maintained.
10. Adjust the Green Controls on the Convergence Panel to
achieve the best possible Green Geometry.
Blue Screen Convergence Procedure
1. Uncover the Blue Output Lens (leave the Red Output Lens
covered).
2. Re-connect the Setup Terminal Jumper (to disable the
Convergence Panel Adjustments).
3. Loosen the Yoke clamp on the Blue CRT.
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