What's Happened with my Arduino?
First, did the Arduino continue to respond and operate after you smelled the burning?

Just because there isn't smoke doesn't mean you didn't kill something on the board.

If your Arduino is not responding, there are two possibilites I can think of:


Your port is not working so simply switch to a different USB port
Somehow your laptop must have sent a large amount of amps/volts to the circuit and burned it out. If you have a multimeter you can use the sound setting to test whether or not wires are burned out, and if your nifty with an iron/heat gun, you can replace the part. Or you could buy a new one. 



If the connection is good, you will hear a small beep. Oh, and these things don't work if there's a resistor in the way.