Welp, yup. I have now tried two different "QI" boards with both old and "QI" power supplies, and also swapped the GROM port posts just to be sure. The problem appears to be the "QI" boards.
I am kind-of bummed as this has been my main non-F18A system and it is beige. Ah, well. It would be interesting to figure out what the problem is.
I tracked this down before when I was cleaning up incorrect values on my copy of the original non-QI schematic. I'm not aware of any other missing signals on a QI's GROM port, except for two:
Pin #4: CRUCLK-
Pin #6: CRUIN
Both lines seemed to retain the same, small resistor values between boards as they terminate at pins 22 (CRUCLK.A-) & 33 (CRUIN) respectively on the console I/O side port.
I wish I could assist tracking it for you as I have most of my non-QI boards weeded out, but alas, I haven't got ahead enough on hobby finances to take the FG99 plunge.
Now, about that problem ...
Unfortunately, I don't have any v2.2 consoles (which I always conflated with QI consoles anyway) to test, so during development I only had the known GROM 0 fact to work with. If QI consoles still don't work, I'd also like to know why.
The CRU lines are not used at all, so that isn't it. It would help to know what exactly doesn't work (menu, selection, image load, image start). OLD CS1, could you send me a short description?
Or if someone wants to get rid of his or her QI console (for €€€), please let me know.