Wells-Gardner D9100 service manual

Page 14

7-3.8 Purity and Convergence Adjustment (continued)

Check the purity of the red and blue raster by adjusting the bias controls.

Obtain a white raster, referring to “CRT GRAY SCALE ADJUSTMENT”

Proceed with convergence adjustment.

2.Convergence adjustment:

Change to a crosshatch pattern with a color signal generator.

Adjust the BRIGHTNESS and CONTRAST controls for well defined pattern.

Adjust two tabs of the 4-pole magnets to change the angle between them and superimpose red and blue vertical

lines in the center of the picture screen.

Turn both tabs at the same time keeping their angles constant to superimpose red and blue horizontal lines at the center

of the screen.

Adjust two tabs of 6-pole magnets to superimpose red/blue line with green one. Adjusting the angle affects the vertical

lines and rotating both magnets affects the horizontal line.

Repeat adjustments 3,4 and 5, keeping in mind red, green

and blue movement, because 4-pole magnets and 6-pole magnets interact and make dot movement complex.

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Contents Printed on 02/11/04 Index Safety Precaution Specification Technical Features Timing Chart Description ModeDescription Mode 5, S-VGA Mode 7 VGA Page ② SEL Controls and Adjustments① MODE/EXIT ③ DOWN/UPPage Color Adjust Adjustment Specification Page Page Output MCU PIN Page Vertical section Page Page Troubleshooting No Video No Raster Trouble in Horizontal Size Trouble in Contrast Trouble in Brightness