1968 Sylvania D10 color chassis help please!

[nasadowsk]

You need a schematic? I might have one at home, but I can't get there till this weekend.

Of the top of my head, I'd look at:

Insufficient or off frequency drive (really off).
6BK4 driven into hard conduction.

To get the 2nd, you might wanna try popping the suction cup off the CRT, tieing it to a 'safe' spot, THEN pulling the 6BK4's cap. Though I'd imagine that tube lights up/looks weird when it's in full X-Ray mode. I haven't peeked into a color HV box in a while, but ISTR they changed their look depending on loading.

I'd be looking hard at that regulator circuit - esp if there's indication of good sweep.

Is there focus voltage (I think these had a focus diode still)? If there is and it's close, then you've got a regulator issue, IMHO.