Put the board on some cardboard or several sheets of paper to insulate it, plug it in.
Get a multimeter, put the black probe on a black wire (should always be ground), then probe the rest of the output pins.
IMHO even if the connector is not standard, it should still be relatively identical to atx.
Red should be 5v - you see the caps in the back rated for 10v so it makes sense.
Orange in atx standard is 3.3v but this power supply doesn't have 3.3v, only 12v.. so those are 12v
You can see those four wires (green, brown, blue and red) going to a separate connector on the sides... I'd bet the red cable is a 5v standby, the green being the power good wire and the brown and blue... no clue.
Measure the brown and blue wires, see if they have any voltage on them.
I would try shorting the green to a ground wire and if that doesn't start spinning fans, I'd try shorting the green and brown (if it doesn't have any voltage on it)