I have had this Arduino Leonardo R3 since the summer and have used it on countless projects. While working on a physics project yesterday, out of nowhere the code just stopped. I have no clue what happened. There was a capacitor on the breadboard that was receiving 12V from an external battery. I don't know if a resistor bumped or a wire. The chip did not seem to get hot when it happened
The symptoms are:
The Mac OSX Lion cannot pick it up as a COM port anymore. (this is the same computer I have used previous times to load code successfully)
Whenever I supply the board with power (From a 9V into vin/gnd or a usb) it turns on the ON led and stays lit. Then the L Led (pin 13 one) flashes yellow infinitely. I know this is the sample code that runs initially when you buy the arduino.
Is it toast? Did I fry it? 
I have tried resetting it and it doesn't work.