Arc in the neck
 

So on the Hitachi in the sig, there was a slight arcing going on in the neck of the CRT, little popping, and the focus as going shot every time.

I tapped it lightly, and it's since stopped..

Erm, something loose?

is that the tv you recently replaced the picture tube on for some type of arcing already....?

No, wrong person. :P

Probably some crud was in the gun.
Many other posibilities if it starts again.

73 Zeno:smoke:

Next time a family member gets on my nerves, I'm gonna tell them they're being a real arc in the neck..

lol

lol.
But yeah, I'd hope there was some sort of impurity which has 'flashed' off, meaning that it's a one-off thing.
If the tube elements' supports have shifted some due to thermal cycling or manufacture defect, then the problem can come back to the point where the tube will be ruined.

I've had nothing but good luck with Japanese CRTs from the '79-'82 timeframe.

Check the CRT socket to make sure some of the Focus voltage isn't leaking across to the other pins.

I'll definitely do that, thanks.. Somehow I missed this post, otherwise I'd have already checked.