mi arduino uno no conecta con el pc

I have this problem with arduino, I tried to connect a module h bridge suddenly no longer able to charge you programs, it does not connect to the computer, then i check my other arduino and this works well, also i try loading the program blink on arduino that works and change the micro to the arduino that does not work to prove and that does work, i already try the dfu mode but I noticed that the pc had to recognize it and not even detect anything, not even sounds the connection, only power