CTC-53 and those RCA flybacks...

[Whirled One]

A few weeks ago, the high voltage on my CTC-53 started going intermittent shortly after I switched on the TV. The raster would collapse and 'diffuse' into weird color patterns as the HV flashed off and on; I let it run long enough to verify it was a physical/vibration-related intermittent (tapping the side of the cabinet would make it go on/off fairly consistently), but I switched off the set pretty quickly.

Anyway, this is one of those many RCA color TVs where the HV rectifier top cap is pressed directly into a receptacle on the flyback itself, rather than connected with a wire lead. My first guess was to check for a bad connection between the HV rect and the flyback. There was a little carbon in the flyback contact, so I cleaned that out a bit. There's a short metal coil spring in there that I assume helps preserve the contact between the HV rect and the flyback, so I wiped that clean too and spread it out a bit just for good measure. Cleaning the contacts removed most of this translucent paste 'goop' that was covering the contacts (some sort of oxidation preventor or arc preventative or something..?), but I tried to leave as much of that as I could. I pressed on the HV rect panel while bolting it in place to try to make sure it was in nice and firmly. I switched on the set, and everything was fine. I left it on for a while to make sure it got fully warmed up, and it worked flawlessly the whole time, so I figured that was that.

The other day, though, the HV quit again briefly for a second or two, but it came back and was OK after that (I let it continue running for several minutes while watching carefully for further signs of HV failure, but then shut it off though nothing more had happened). So, perhaps the contact is still a bit flakey. Is there some 'trick' to this style of RCA flybacks? Is there something important about that 'goop' that was on the HV contact-- should I re-dress the contact with new 'goop'? What is that stuff anyway?