One general tip on locating the area of the board where the bad joints are: Get a wooden Q-tip, or some kind of a nonconductive thing and gently tap around on the board while somebody is watching the TV. That way you can get an idea of where it is.
If you can't find the vertical output IC, which is likely an AN-5521 or LA7838, etc, follow the yellow wire out of the deflection yoke on the neck of the tube. It will go to a plug on the board, and lead you directly to the vertical output. The blue and red wires are the horizontal, and the yellow and (white or black) are the vertical. The vertical output IC will be a single inline IC, mounted on a fairly big heat sink.
Just a general caution: you mention you aren't familiar with NEWER sets, so I assume you're familar with the high voltage, etc etc in general same as old sets. Be careful
Charles