I'm getting a decent bit of arcing from what appears to be one end of the HV diode after replacing the old one. Actually, there wasn't an "original" when I got it, just an NTE518 soldered in-line and sorta covered with heat shrink tubing (monitor was DOA, blown F102). I replaced this with an SK3108 (NTE505) and globbed on the silcone. After a day of drying, I re-assembled and fired it up. Monitor "works" but as I said before, it's arcing inside the HV cage.
Should I just add more silcone or is this a sign of another issue?
Should I just add more silcone or is this a sign of another issue?

