For best results, it is recommended that the purity adjustment be made in the final monitor location. If the monitor will be moved, perform this adjustment with it facing west or east. The monitor must have been operating 15 minutes prior to this procedure. Set the converger assembly on the CRT neck with the center line (of the Purity Adjustment Magnet) over the gap between grids no. 3 & 4. (See Figures 2 & 6) Make certain that the magnetic ring-pairs are in their correct positions before starting procedure. This produces a zero-correction state and helps facilitate adjustments.
Vertical raster position adjustment jumper must be in position "C" (center).
Remove the R-G-B signal from the monitor. Turn the Green Cut off Control (VR404) on the Neck Board fully CW. (See Fig. 3)
Turn the Red and Blue Cut off Controls (VR403 & VR405) fully CCW.
Pull the Deflection Yoke backward so that the Green belt will appear. (See Fig. 4)
Decrease the horizontal width of the raster, if necessary, in order to be able to see the right and left edges of the raster.
2.10 Move the two Purity Magnets with respect to each other in order to center the raster on the screen and the Green belt on the raster horizontally.
2.11 Push the Deflection Yoke forward gradually and fix it at the place where the Green screen becomes uniform throughout.
2.12 Turn the Cut off and Drive Controls and confirm that each color is uniform.
2.13 If the color is not uniform, re-adjust it moving the Purity Magnets slightly.
2.14 Decrease the vertical size of the raster, if necessary, such that the top and bottom raster edges can be seen.
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