You can test the OLED with simple power. Bitspower lists the display input as DC 5–12V and under 20mA.
Connect +5–12V to the power pin, connect ground, and the screen should light up. The D pin is mainly for the RGB signal, so the OLED itself does not need a data line just to turn on.
If it does not light up with clean 5–12V power, the controller may be required for full function, but basic power should show something.