jut for the record, the entire purpose of this diagram is to circumvent the usage of the massive internal controller board. if you are going to use that, you might as well just wire +5 volts into the charge jack. much simpler.
also i wired my 3.5" (#2) to 7.4 volts, so as to reduce the load on the 7805. i have mine wired like this:
batteries>PCB>charge jack>switch>screen/power board>controls, console.