I was watching my Zenith SC 400 this morning when alluva sudden

POP!

During this pop, the screen went blank, then came back. I was waiting with my finger on the kill switch to see if anything else would happen - but nothing.

The last time I had a symptom like this it was on a color set with a HV regulator that was failing internally.

The HV rectifier on this set tested ok, but not great.

Anyone have any ideas? i normally don't experience troubles with HV like this so I'm a little at a loss on how to troubleshoot it since its not acting up in a predictable manner. I hate waiting until a major failure hapens considering I just spent 10+ hours working the bugs out of the set.

That happened with my ctc-10, and the trouble was that the wire wrapped around the flyback to provide filament voltage to the HV rectifier burned a hole through itself and was arcing to the chassis.

Thanks Adam, I'll open up the cage and take a look for arcing again.