For anyone interested, here's another repair writeup. I didn't keep as good
a notes as I should have on this one and the memory (my memory!) is of
little help. If I'm going write these things up I really should do it
straight afterwards! Anyway, the board lives now. It's something I could
never have diagnosed just from chip swapping.
http://www.classic-computers.org.nz/blog/2015-12-05-repairing-an-appleII+-b…
I did learn that it's possible for the machine to boot to BASIC even with
faulty RAM in the first row, something that I didn't think was possible.
Depends on the nature of the fault I guess.
Terry (Tez)