R6400v2 won't connect or reset

[RevRonWorley]

I tried to update my router with the app on my phone and it failed to complete and the router disconnected. The power light is flashing. I powered off and back on a couple of times and pressed the reset and held for 30 seconds but nothing happened. The app and all computers say it is disconnected.

[plemans]

up dating via the app isn't a great choice. The best way to update is over a hardwired connection. 

From the sound of it, you/the app interupted it during the update and probably corrupted the firmware. 

You potentially can fix it by using tftp. 

https://kb.netgear.com/000059634/How-to-upload-firmware-to-a-NETGEAR-router-using-Windows-TFTP

just make sure you enable it in windows. 

https://www.thewindowsclub.com/enable-tftp-windows-10

and here's a walk through video of someone doing it on an extender. works the same on the router. 

https://www.youtube.com/watch?v=R9DLrLQrpaw