IzzyStradlin:
The chip is still working I'm sure because the "on" green light is still on, and when I run the blink sketch the inbuilt LED does flash. But I cannot get any output from either the 3.3V, 5V, or any of the digital pins.
Since the LED used by the Blink sketch is connected to Pin 13, perhaps it is your measuring device that has failed. It should se Pin 13 switching from 0V to 5V as the LED blinks.