Cannot put UNO R3 in DFU Mode

Hi,

I have an arduino board UNO R3 model and I'm trying put it on DFU mode, but is not working. When I shortcut the pins 5 and 6 of ISP, like showed here: https://www.arduino.cc/en/Hacking/DFUProgramming8U2 the board don't get in DFU, its just return to normal mode, and the COM port is showed on Device Manager.

Any idea of what is happening?

Thanks!!

Plz!! Any one?

Tanks!

For anyone that pass through the same problem, I found out the solution:

I used those two tutorials:

https://www.arduino.cc/en/Tutorial/ArduinoISP

http://www.instructables.com/id/How-to-Restore-the-Arduino-UNO-R3-ATmega16U2-Firmw/?ALLSTEPS

but I made some changes:

First: In programmer board, use 10-13 pins like first tuto; In target board, use ICSP header, like second tuto;

Second: Take out the 10uf capacitor. In my UNO r3 board it's wasn't needed.

That's it. Hope help anyone with the same problem.

PS.: Sorry for my English. I'm using google translator!!