Back working on the Type 547 and thanks to some pictures provided by Oculus it looks like I found something around C642A/B which are the filter capacitors for the -150V reference.
This is how my C642A/B is wired. And you can clearly see that some Gorilla has been in there by all the melted wires. And seeing that raised my suspicions and it appears I may be right. It's screwed up.
Here is how C642A/B is wired on Oculus' functional Type 547. There is an additional white with possible colored strip going to side of cap that's tied to ground. I can't see what wires are attached to the lug immediately to the left of grounded lug because that heavy white is covering it. But clearly it doesn't match mine.
Oculus, I hate to ask this but I need 2 pieces of additional info. Does the white wire down against the chassis and going to that grounded cap lug have a color stripe on it? And the lug covered by that heavy white wire. What are the colors of the wire(s) going to that lug? I know it's a PITA because you have to flip the 547 back on it's side to see the wiring.
Edit....in studying this more it appears that the difference is those heavy white and yellow wires. They don't appear anywhere on my wiring harness and could be a running change made by Tek and probably unrelated to the PSU issue. But I still need to know the color of the wires under that hidden lug.
2nd edit.....can you give me a clue as to what those white and yellow wires are for?