Mega 2560 Says It's "ATMega 16u2 DFU"

[ewb55]

I have purchased eight Arduino Mega 2560 units from you (along with hundreds of dollars worth of other items). When attached to a PC, seven of them nicely identify themselves as “Arduino Mega 2560 R3” and have worked well. However, one of them identifies itself as “ATMega 16u2 DFU”, despite looking much like the other seven and coming in the same sort of box. I cannot find a driver for it. How do I get it to become a Mega 2560?

[adafruit]

thats unusual, what happens if you press the reset button?
if you unplug/replug it from USB does it always come up the same?

[ewb55]

Pressing the reset button doesn't change anything. I've tried that many times. Unplugging and re-plugging it into the PC doesn't change anything. Trying it on another computer doesn't change this, either.

[adafruit]

OK thanks for testing, not sure what happened to zap the serial adapter chip but we can replace the entire mega and that should work fine. email support@adafruit with a link to this thread asking for a new Mega. We dont need the old one back.

If you feel up to it, you can try to repair the old mega if you'd like by following this tutorial http://arduino.cc/en/Hacking/DFUProgramming8U2 = but we dont have any tutorials on how to do it other than that link