How do you confirm a pin has been damaged and is unable to work as a digital input?
I tried detecting a pushbutton (connecting ground to pin 11 with a pullup resistor enabled) on a fresh Arduino Uno and digitalRead() always registers 0, regardless of the pushbutton state.
To confirm it wasn't my pushbutton's wiring, I tested it on some other pins, and they register the button press perfectly. I then tested pin 11 as an output, and it was able to blink and LED just fine.
The Arduino's pretty new, and I don't remember doing anything with it that would have damaged anything, much less pin 11, but is it fair to say that pin has somehow been damaged? As far as I can tell, everything else on the Arduino works perfectly.