Dead 16U2?

Hello everyone!

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

Sounds like it. The 16u2 is pretty fragile electrically.