No, the OP stated that there were only 3 wires in the box.
Black
White
Ground.
A split would have a red wire.
Sorry, that post was directed at Keebler's post (#22) in which he had an outlet that had one dead and one live receptacle, not towards the OP's dilemma.
And you're right, a split SHOULD have a red wire, however I have seen them done with two black, one white (which I'm pretty sure is not code-compliant but when non-electricians start doing things anything can be found)
Other possibility for one dead receptacle.... if it's an end of run outlet, one of the little tabs connecting the two screws on each side may have broken.

