BA11-K low AC output levels

Okay, so, I'm back to working on my /34. I think I made significant progress tonight. What's going on is, I've narrowed it down to low AC levels coming off the transformer. The printset and H7xx modules specify an incoming AC of 20-30v (printset says specifically 28v.) All lines coming off the transformer at P1 are reading a value of 10-15v. So that leaves two possibilities. It's either the transformer, or the AC input box. I'd like to test the levels coming out of the input box, but I wouldn't know where to go, as my understanding of electronics fades fast at this time of the night when I've been up since 07:00. Okay, so maybe I traced it back that far, it got more complicated, and it's late and I'm feeling lazy and hoping someone will throw me a bone here :) in any case, advice is always appreciated. toodles Julian