I had same issues in the past but with a 3C589 interface. Couldn't get Genesis to open the port. Issue was CardReset/CardPatch.
Just add the following lines as first lines in the Startup-Sequence (or second if you have an ACA)
FailAt 11
C:CardPatch
C:CardReset TICKS 50
...
If you get Genesis to open the port then you can configure SetPrism2Defaults since it's not needed for configuring the interface. It's just for pairing with the WiFi access point.
If it doesn't open again, it's more probable some sort of an hardware error. Either PCMCIA card isn't inserted fully in the socket, either the PCMCIA might have some pins bend from the inside (btw have you tried any other PCMCIA expansion like an CF Reader? Did it work?).
Also are you sure the card works with the Amigas? Any pictures?