USB Short Circuit Breakdown
Here is my experience:

When moving to my new flat, I had no TV / internet the first days. But I had a USB TV receiver as well as a USB UMTS stick. For better signal quality and convenience, I plugged them into an USB hub, taped it all to a window, and used a 3m USB cable. However, both devices together sourced too much current for stable oberation, so I decided to search the wall wart for the hub. I found it, plugged it in, got noise, smell and a bang. It turned out it was not the 6V DC wart, but a 16V AC, 1A one... Finally, the hub, the TV receiver and several USB ports didn't work any more. The ports did not deliver 5V any more. 

It turned out the laptop had special chips from TI for power supply control of the USB ports. They sit on the 5V rail of the laptop and mainly maintain the maximum of 500mA for each port (one IC for two ports). I got some of these chips, soldered them to the  mainboard, and the USB was running again. 

So, if the 5V is missing on your USB port, you may try to identify ICs (or fuses) near the ports, maybe, you find something. If you damaged the data lines, you probably can't recover it.