You posted "I'm getting 15v from brown/white and orange/white then getting green/white and green"
If this is the case, then your not testing the correct wires.
If your 100% sure you've got the right colors, then the ports are no good. You will need to call Neptune, and then they will ask if your using one of their cables, and if not, they will tell you to try one of their cables first before they will confirm that it is indeed the base unit that is bad. (This is what I had to do).
Once they can confirm without a doubt that it is a port issue and not a testing issue, then they will start the process and have you send the unit in for repairs. If it's less than a year old, it's obviously under warranty, if not, then you will have to pay for the repairs.
I never saw more than 12v on my bad ports.