Toshiba blackstripe 19"- Retrace lines and unusable g2 control

[zenith2134]

Hey rectangular Tube & Solid State (lol)

This set qualifies for both, and is from 1980. Other info - Model CA 955, Chassis TAC970. Well, I haven't measured voltages yet, but there are faint white retrace lines on a blank raster, which disappear when the raster lights. Note: This set utilizes an auto picture control, called ABC and a G2 pot on the crt neckboard.

Is this one of those cases where G2 is always set, and cannot be adjusted manually? If so can I increase resistance to one more megaohm or so, in-line with the G2 wire/circuit? The only other things I can think of are to clean the g2 pot, maybe it is really dirty (maybe not) , and check screen voltages. The Focus control works as it should, and I think the tube is in great shape otherwise, all color biasing pots work well, too. Thanks in advance, The tv is nothing special, but has hardly any use and makes a great picture otherwise.