when you cap a monitor, you have to take into consideration that all adjustments need to be redone on it. that includes white balancing, the brightness adjustments, contrast, the size/positioning.
first adjust your vertical size and horizontal and vertical positioning. make sure there's no foldover or that the center of the picture is super bright like in your picture, otherwise you will burn the CRT.
make sure your flyback Screen G2 isn't cranked. turn the contrast to its center setting, and make sure the brightness is only about 25-33%.
turn all your bias pots to their center positions, or at least set them all at the same position first (if they're too low though, you'll be missing color saturation and the picture quality won't look too good)
turn your red and green drives all the way down, start over. start stepping those back up to where you have a white-ish picture with no obvious tint.
then do your fine-tuning with the bias pots.
put a game signal on the monitor, and adjust your brightness and contrast accordingly. brightness should be turned up just high enough that you don't see any black pixels in the raster, and contrast should only be up high enough to where text/graphics don't have smearing on the edge.
hope this helps.
and I guess the obvious... make sure you capped it properly. make sure there's no solder bridges, and that you have the cap polarities correct. if you've ever capped another monitor before, noting that the cap locations are marked on the negative side, it's easy to fuck up on the K7000 and install them backwards, cause K7000 is marked for positives.