CTC21 Flyback Problem

[mr_rye89]

So I was watching this set this evening and I heard a strange sizzling sound, oh sh!t. I was near the set and was able to shut it down after a few seconds, just as the picture was starting to shrink (tale tale sign of HV failure), and it stank up the room pretty good. I waited for it to cool and took a look in the HV cage and saw this:



HV rectumfryer:



So a nice arc trail in a dirty HV cage and a nasty wart on the fly

What (besides a dirty cage/socket) would cause this? and assuming the fly isn't shorted or open, should I coat it with HV silicone or something to repair the "boil"?

HV rectifier and focus rectifier test ok, my tester can't test the shunt regulator, but it doesn't LOOK shorted