The raster now flickers and it needs to be dark to see it, when you turn the contrast to an extreme you see a faint raster. If you turn the brightness knob the raster glows very bright some but then disappears.

Can I pick the brightness problem and work backwards, checking components, and the actual knob/switch? I forget what it is called, that raises/drops brightness.

How do you track whether enough voltage is getting to the crt?

Fun fact- this Stromberg has a replacement RCA Silverama 21" tube, same as the RCA console that I have. And the flyback has been replaced in the Stromberg.