A closeup of the connections on the lower PCB. From the top, left to right.... (1) is the green wire connected to the Output hot signal. The blue wire (2) is connecting the grounds. The blue/white wire (3) is connected to the Input hot lead. The short red wire (4) connects the two grounds. On the 9v power jack, the red wire (5) is positive. It's hard to see, but there's a black wire right next to it for the 9v negative.