Well, on the one hand, I learned a lot since yesterday. On the other hand, I'm going to have to learn a whole lot more!
I now think I don't have a power supply problem but rather a start up problem. Prior to posting, I had checked all the resistors and electrolytic caps mentioned and had found them to be OK. I did think an SCR (near the bottom on the attached pdf) was bad, and replaced it. I was testing the powere supply board with it unhooked and removed from the TV. With it back in the TV, when plugged in, I hear a steady whine (deflection?) and every 5-10 seconds the relay clicks. Pushing the power button also causes the relay to click. 0v measuring across the relay. No picture or sound.
On the attached schematic (the other half of the first schematic but as noted, from a different model) I have -30v and 5v supplies from the lower transformer. This TV, only has one secondary from the upper transformer (T862), which I measure as 5v, UNLESS I remove F802, and I then get 115v as apparently I should. So, presumably the problem is downstream of that fuse.
That 115v source is supposed to feed (?) the SCR I replaced, which of course makes me wonder about that?? It also goes to the ''400"s numbered components, and I don't have a schematic for them. I've read about SCRs but am not experienced enough to really understand how this one is being turned on and off. It will not latch in the circuit when tested with my DMM--though it would latch when tested prior to installing it. Not sure if that's significant or not.
Any explanation of how that SCR is supposed to be turned on and off, or where to look further would be greatly appreciated.
Thanks again.