monitor question (problem diagnosis)

[charlesmorris at direcway.com]

Semi-OT: I have 13 arcade games in my basement, most non-working when I got them. The video monitors in some of them are mounted "sideways" (long axis of the tube is vertical). These old units (early 1980's) all have the HV generated from the horizontal deflection, naturally. So a thin white line running vertically is actually a loss of *vertical* deflection. 
Just to further confuse things :)
-Charles