First of all, sorry for my english, it isn't my main language.
My problem is -> I can't upload sketch yo my Arduino Uno R3. Im getting an error:
I didn't pass in loopback test.
My Arduino is turning on normally, and the PC recognizes it normally.
When I try to put my arduino on DFU mode shorting the right pins, nothing happens.
I have other Arduino, that is working perfect, and I tryed to switch their 328p, and the bad board still getting this problem
Help me please