[DaveWM]

the one I was thinking of is a 80uf that connects to the red lead of the vert out primary it decouples the strong vert rate pulses out of the vert circuit so they dont get into the B+. IIRC its a two section cap kinda in the middle of the chassis (3rd on from the end). Its prob open (if shorted you would have a lot of big time problems, starting with a smoked sand resistor) so just to a quick bridge there and see if it goes away. the other section of that cap looks a decoupler 2uf for the audio screens. If that fixes it you would want to take the existing cap out of the circuit, just in case it decides to short some time in the future. I would replace the 2uf as well (same can, if the 80uf is gone then the 2uf is prob not too far away) do you have any sound bars in the set (turn the set up loud and see if you see any interference patterns that seem to modulate to the sound).