@adenilsonbrs 

Hi,

May I ask what is the reason you've tried to update the firmware via TFTP?

Can you please tell us the exact name of the firmware file you tried to flash and also tell us the router's full model description that is printed on the label on the underside of the Archer C20? (should say something like "Model: Archer C20(EU)   Ver:5.0")

  @woozlI tried to update because I was having DNS problems not connecting. I was not successful through the router interface (error 2503), so I tried through TFTP. Complete model as shown below of the router: Archer C20 <w> . No country. 

  @adenilsonbrs 

I see two possibilities. Either the firmware flash via TFTP wasn't successful or the firmware file you flashed isn't compatible with your "Archer C20 <w>".

Since the router has become a brick anyway, you might want to try if it's still possible to upload the firmware available for download from the following webpage.

https://www.tp-link.com/br/support/download/archer-c20-w/#Firmware

If the TFTP method doesn't work now, then check if the "webpage firmware recovery" method might still be possible. https://www.tp-link.com/us/support/faq/1482/

If none of these work, then you will probably need to contact your country's local TP-Link support for assistance.

  @woozle This recovery doesn't work, because my router doesn't even show the default gateway. So do not enter the web page. It doesn't even identify the network on the computer.