Power failure for D800

Hey everyone --

Lately I've been having a problem with my D800 power source.  I almost never run it off of battery power, but over the past few weeks, the cord plugged into the wall hadn't been working all the time.  I'd have to rotate or jimmy it to get the AC power back.  This was working less and less, so I ordered a new power adapter -- while that was shipping, my cord gave out entirely, and the battery died (as batteries are wont to do).  I've got the new power adapter now, but the computer still won't turn on.  I can see that the adapter is getting power, but it's not going through to the computer.

Is there something simple I need to do, like resetting the power system somehow?  Or is this an internal problem that I'll need to have Dell fix?

Thanks,

~~Cassandra