INstalled replacement immobilizer; Still won't crank.

[roland3337]

2002 Boxster with a water damaged immobilizer....

I had the damaged immobilizer exchanged for a new unit (work done by these guys). Code was matched, and I was told it would be plug & play.

I reinstalled everything, but it still won't crank. I turn the key and...nothing...

The battery has a full charge, and there are no other obvious problems, and I am wondering: Is there something that I should have done, but didn't do that is a normal part of the procedure for reinstalling a new immobilizer? Or is something else going on?

Thanks, as always...