Fried usb port

I made a really dumb mistake. I have a external disk reader with a separate power supply. Accidently put in the plug to the power supply in backwards. When I plugged in the usb there was an instant shut down and the smell of burned electronics. My lap top (Toshiba A305) did start back up and does not seem to have any problems with the exception of the usb port no longer works. Everest reports "no device connected". In my device manager everything in non-plug and play drivers is unknown.
The big question is can I possibly repair this? I have no problem working on a lap top but I don't want to take it apart and end up putting it back together with the problem still there.

 

Not that it matters at this point but I am confused at how you could "Accidently put in the plug to the power supply in backwards". It sounds like you talking about the power cord from the wall to the power supply transformer but there is no polarity to that or it wouldn't allow you to connect it backwards.

As far as the resulting problem, if you smelled something burning, that's not a good sign. It may have only fried the power to the USB port without killing the machine but it probably burned the circuit board. You may be able to trace where the burned section goes but most boards are multi-layered which makes this difficult. If you are able to trace it, you could possibly solder a wire from one point to another and perhaps solder a new USB connector to the board.

 

The Toshiba A305's side USB ports are actually not soldered to the board, and are connected via cable much like the front panel USBs of a desktop. If you are familiar with laptop disassembly, yes, you can repair this problem yourself.

Here's a replacement on eBay: http://tinyurl.com/24dxh3t

 

You really need to find out if the laptop is still supplying 5volts to the port, if you see nothing it's
possible whatever regulates this voltage is dead and possibly any polarized capacitors across the
supply.
If your lucky you have a burned out track as shnerdly has said and if your really lucky it could be the
top or bottom layer of the board.
If you can use a multimeter and your controller chip has survived you should be able to sort it out.

 

This is what can happen when you but cheap made in Japan hardware. Its a external reader that you can hook up to a variety of hard drives (sata, ide,2.5, 3.5 etc.)