Been there, done that...
See the lock and the wires? You need a privilege key, used while in the operator menu, and then the privilege menu pops up.
There ain't no key gonna work, even if you put it in a 3902 board.
I found out the hard way trying to run this old software:
http://media.igt.com/support/psrs/M129_G82.pdfI didn't have a key so I took the lock apart and turn the wheel with long nose pliers.
Whatever software you have for the 3800 board is probably very poor by today's standards. Pick up 4.3 software, very cheap and a keychip will work.