Region : Brazil

Model : TL-MR3420

Hardware Version : V1

Firmware Version : version 3.13 Built 121123 Rel 57630n

ISP :

Hello,
I'm trying to fix my router ....
Some time ago I used the OpenWRT firmware. I went back to using the original firmware from TP-Link ...
Now I'm trying to get back to OpenWRT Firmaware to do some tests.

However, I am unable to access the Firmware Upgrade page in the original firmware of TP-LINK (version 3.13 Built 121123 Rel 57630n). The page does not load, multiple tabs "System Tools" do not load and lock all options.

When this happens, you must reset the router to regain access other network settings etc etc etc..

How should I update the firmware from the original firmware? How can I upgrade the original firmware of TP-Link if the page does not open? Is it possible to do this via TFTP? Or just serial cable?