Arduino Leonardo issue

Hi all, recently I have received a Arduino Leonardo, which seems to have burned off memory or somethingI do not know exactly, is the first time I play an Arduino. The bug is that the plate does not seem to connect to the PC, if I connect, the LEDs light "ON" and "L" and "L" does not blink, showing that at first, if blinking, I've managed to connect to the computer and Blink load. The fault appeared after checking if the input connector was one of an adapter that lay there (16V and 300mA) (was unplugged, but apparently he had some power or I know, because the LEDs are on and off instantly) and then connect it to a 9v adapter and 1A. After that I tried repeatedly connect to PC and I do not detect it, I've tried different cables ... I want to add that "ON" and "L" light when I connect the 9v adapter and 1A but does not load the last sketch I uploaded. Besides also the fact that if I connect a LED to pin 13 and ground "L" goes.

PS: When it seems all pins supply power and connect an LED to ground and any pin (except analog inputs, other lands and pins 4 and 11) and on, if I connect it to pin 13, "L" decreases its luminosity or off, depending on the LED to be connected.

I hope you can help me, Sincerely. Aitor de la Vega.
Sorry for my bad english, I translate this text with the google translator because in the Spanish Forum there aren't so many people for help me. Thanks