Why is the CRT taking longer to light up?

[walterbeers]

Don't know if this relates to your set, however, sometimes crts develop an intermittent open cathode, where the picture blacks out, and if you tap the neck of the tube lines of the raster will flash intermittently with the tapping and sometime it cures the problem for a while. Only real cure is to replace the crt. Just don't hit the next of the tube too hard. In color crts the same thing can happen, only usually just one color is involved, R. B or G