FortiGate-80C: Manually bring up/bring down an interface?

I have a new FortiGate-80C I' m ready to deploy in place of an older FortiGate-60. When I plug the cables into the WAN1, and WAN2 interfaces, I get no link. The internal interface is connected fine. When I shutdown the 80C and restart with a cable plugged into WAN1 or WAN2, the link comes up for several seconds while the unit starts up and tests, but then the link goes down again. Years ago when I set up the 60 unit, I had to manually ' Bring up' the interface after plugging in the cable. There is no such option in the Web UI, and I can find no reference to a CLI command for this. Is this still required? Am I missing something? Thanks in advance...