[drh4683]

That set on the gallery has NO HV either. Its waiting on a new flyback. The fly is shorted and the damper tube plate glows red hot. Make sure thats not your situation.

Do you have a HV probe? Very important when servicing TV's.

As for the 20LF6, I know exactly what you are describing. The tube is just fine as long as it tests OK. Even NOS 20LF6's have that streaked brown appearance.

If your set has a 20LF6, then its a 72 model 19CC19. Of all the different 4 tube hybrid chassis (theres about 6 or 7 of them), this is the only chassis that used the 20LF6.

That being said, if you have NO voltage at the plate cap of the horiz. output tube, then check pin 5 to ground of the 20LF6. You must have -80 DC volts! If not, or very low, suspect oscillator circuit issues.
Ive enjoyed working on these sets. When you get it working and if the CRT is ok the picture will blow you away.