[Adam]

The corroded focus lead in the socket was exactly the problem. It was so corroded there was very little left of the sleeve the pin on the crt goes into. Also all the connections on the left side of the socket (all the blue and green and the focus) were broken right in between where the wire crimps on and the sleeve starts. I tried to solder everything back together, but it didn't hold very well. I eventually cut up a color crt extension cord I had and replaced the socket and wires going to it entirely, this worked.

The intermittent focus and white horiz lines flashing across the screen went away. The intermittent jittery vertical did not. It's very slight (only really noticeable on a still picture) and mostly goes away after the set warms up for a few minutes, so I'm going to leave it for now. I tried cleaning the vert hold/size/lin controls and that didn't fix it. I tried swapping the 6HE5 vert tube, and that didn't either (but the only spare I had tested pretty weak), so I'm going to order another one and try that next.

Despite all the little problems I keep having with this set, it still produces the best picture I've seen on a color roundie, and is easily in the running for best color picture on any set I've had.