@luke007, thank you for the info and the new picture.
Looking at the new picture, it looks like USB port is soldered on the circuit board, right? If that's the case, then I was mistaken initially -- I thought that USB charging port was attached to part 6. I'm also not clear on the wiring. Why are there 4 wires? Can you post one more picture showing the back side of the circuit board where the wires are originating from?
Ya the 4 wires enter the board and are soldered in the back as per picture.