Okay, here we go again. I have been working on this every other night-got to rest in between! I had pretty much decided I would have to swap out the crt but the last couple posts encouraged me to try some more. After more poking & prodding I realized I hadn't used the normal/service switch since the "fireworks" began. With the switch on "service" it was still acting up but there was no more arcing; the flat line would go dim/bright but would not dissappear. I pulled out the schematic, started tracing things out...took some voltage readings & at the screen & drive controls they were normal & unchanging; hmm...you know, nah, it couldn' t be...but just maybe...in trying to fix the color problem I had swapped the video output with a used tube that tested stronger than the old one. I recalled that I had not swapped it back. Folks, I didn't have time last night, but tonight I am going to take that old used Magnavox 12HG7 and I am going to smash it to smithereens so that it can never cause this trouble again
Anyway, with the old tube back in the crt has not acted up the least little bit and I am back to the color problem. It is a little better now after some of the tweaking I have done. Right now when showing a scene Some colors show up and others won't, for instance the background may show up red, a woman's dress may show up blue, but faces, furniture, most other stuff is in pure black & white. Among other things I think I need to refresh my pile of 6GH8's. Its ashame that even a new tube can't be fully trusted.