I have an X910BT and the USB was missing from the unit. There are five pins on the male connector on the board but USB has only 4 wires and the shield wiring. I reconnected four wires according to the picture on the service manual for the radio. However, there are two black ones and I cannot read the schematics well enough to see which goes where. I also see that there are numerous posts telling people to purchase an authentic apple or pioneer wire to solve connectivity issues.

Does anyone here know what the specs are for both pioneer and apple cables? What are the pinouts from the board inside the unit and where do they  go on the 30 pin connector?

I'll answer my own question.

It's not worth fabricating or even buying cheap nonapple cables. Each software update, apple can and will rearrange pinouts depending on new technology or piracy. Anything nonapple is less likely to be considered for pinout rearrangement compatibility. You can find yourself buying more cables every year if you get nonapple products.

Another thing, the fourth black wire or "second ground" goes to the outer metal casing of the usb connector "female". This is used when the radio detects the idevice and converts two pins to data pins. Failure to ground 4th to casing will make the radio reboot.