I found a seller of 4464s on eBay in a France and ordered two. I popped one of the ones that came from China and put one in, and now the #Fixteen works! So now I have two "Minus 4"s!
That means I have a spare 4464 in case one of the others break down later.
Uh oh, that is not good. The second unit gives me a black screen with the expansion installed. I pushed in the RAM chips and got some junk on the screen instead.
Moving the jumper to 16K makes it boot up again, so at least I didn't kill the TED chip (I *did* bend its legs slightly on extraction, so I was worried).
So, are the RAM chips on the Fixteen bad, or the assembly? I have no clue. I'll lend it in, but turned off. At least the other one works fine.
Peter Krefting