I will describe the procedure for restoring the firmware of the Netis WF2419 router via TFTP:
1) Download the latest firmware from the official site
2) We will manually register the IP address on the computer, for example 192.168.1.100
3) Connect the computer to the router through the port LAN4.
4) Turn off the power of the router, press the reset button and hold it on, after 3 seconds, release the reset button. After that, the device will enter the recovery mode.
5) Now there will be actions with TFTP. Earlier I wrote articles about TFTP:
Starting a TFTP server in Windows
Installing and Configuring a TFTP Server in Ubuntu.
Actually, you need to send the file of the previously downloaded firmware to the router (its IP in recovery mode 192.168.1.6).
I use TFTP for example in Windows we specify the address of the client 192.168.1.6, the firmware file and press Put thereby starting transferring the file to the router, you do not need to specify anything else.
We are waiting for the completion of the process for several minutes.
Done, the firmware repair process is complete.