Cable connections and screw mounts seem to be in different places. Supposedly this replacement is from an identical model — an A21e — but this came from a source in the United States, and it’s possible that the design differs between the Japanese and the U.S. models. That would be a shame.
I’m going to keep working on it for a little bit, but take a break so I don’t fall into one of Pirsig‘s gumption traps. And it may be that it just needs a little coaxing to work. I’ll return to the fray when I have a calmer state of mind.
This isn’t very reassuring though. I would have liked to have kept this machine on hand just as a spare, but if this doesn’t fit, I’m more or less stuck between ditching it and picking up an external monitor — neither of which is a particularly enticing thought.