This is what I suspect is the source of my occasional retrace line problem
http://suzaku.live-evil.org/blanking.jpg
every resistor and cap on the video / color PCB was replaced before I cot the set.
not so with the sweep PCB, it seemed to be OK anyway.
the 100k resistor R70 is on the sweep PCB, far side tied directly to the plate of the vertical output, it is still original. and I suspect it has gone up in value, c31 is a disc on the color PCB, and R71 new 2% carbon film type, so it has to be R70! :P