Okay before attempting something on this magnitutde, you are going to have to gain a better knowledge of electronics. Ohm's law would be a good start.
If you hooked it to the 12v+ line, the hub is garbage. Unless you know how to SMD solder, there is no hope of recovering it.
Voltage doesn't drop with less amperage drop, and vise versa. If a device is designed to run on a given voltge, it is going to pull upto a certain amount of amperage.