Yes, I too saw that once I bothered to look.
So, of course, I accidentally put the RAM in Bank B, assuming it was A. I moved it from B to A, and now the video's back!
Odd design, for sure.
It's probably kind of silly to post about a problem I can't seem to solve when I know better and could probably fix it if I just stared at it awhile.
But I guess I'm not the only one who does this from time to time!
And I admire your extraordinary work with the Mac II-SE/30 ROM SIMM, dougg!
c