Hello:
I have a 3d printer wich runs with an arduino mega 2560, i've changed 1 stepper motor driver, i,ve put it in the wrong way and it fired up, after that, my computer didn't recognize the arduino anymore, but the arduino it's ok, because i'm using the printer with a lcd screen.
The computer will recognize the 2650 again if i push the reset button ?
Thanks.
Pd: sorry for my english.
Juan.
remove everything connected to arduino and try again.