Make sure you have the five wires to the DBU in the right sequence. IF you are sure these are right then try resetting the IC.

Before you hit the start button did you see if the DBU lights up with movements to the Left joystick?. Full stick in either direction should make the DBU light up. You configure the system this way, and it is a good test to see if things are OK.

Your wiring seems OK, but make sure the DBU 5 wires are correct. You may have them in reverse.