Steve, did you check through your cracked/fixed normal/simul board yet. That thing is "involved" in the dayly life of the citizens of the machine like you know what
I wish I had a clue about how diffrent your machine is from your a2340sx machine, but you can look at the schematics, it may give you some clues. I only have those scans that you've sent me back then and it's kind of hard to use for figuring things out.
Look there in the section where you see P.B/REC. heads and switches. See there leads marked as J, K, M and O, then look down/right (I guess, as I have only pieces of the puzzle here
), find section with "BIAS PC Board", there you'll find J,K,M and O. Those leads are one side of Coils Ks- 502,503, 602, 603 ? (hard to read on my prints).
Again, 3340 may have different desing, I've no idea, but you gotta make sure that all your connections are cool. Also in addition to cracked board and/or bad solder/connection the switches themselves may be sloppy. On my machine they are. If I shake/move the switches knobs up/down I get engage/disengage relays/rec.lamps going on, and I actually did spray-clean the switches.