[Stratmando]

I would plug something in top, then bottom of receptacle to verify with a load(or Wiggy)you have voltage.
Its like Water heaters, instead of removing wires from Element for testing, use an Amprobe and a Voltmeter, If you have voltage to Element and NO load, the Element IS open.
More work to open and measure resistance.

[jerro]

Back in the 70's the big thing was splitting the tab on the recept so that the top outlet was controlled by a switch for plugging in floor lamps and the bottom outlet was constant hot. Back then a lot of houses did not have ceiling lights. Most recepts were wired with a black/red/white wire with one color going to a switch. Maybe this will help to determine your situation

[Stratmando]

Like jerro was mentioning the red sometimes will be the switch leg, if they are separate to the panel, this may not be the case.
Switching half a receptacle is still done, sometimes on a 3 way, with other switch near the bed?