A4000T+a3640

[Jeff]

Not sure exactly.  Check http://pink.myshoesaretootight.com/mirrors/amiga.serveftp.net/A4000_HardwareGuide/a3640ref.html

Basically there are some dma issues with 3.1 and certain boards.  Also, some caps have reversed polarity on 3.1 and should be reversed so they don't leak.

As I recall the if the PAL ic at location U209 is a revision -03 and the A3640 board is labeled 3.1 then this is the latest 3.2 3640.