Nighthawk Nightmare - won't factory re-set (tried the 7 second and 30 second button-press...)

[2911Productions]

Nighthawk Nightmare - won't factory reset

(have repeatedly tried the 7-second and 30-second button press with the paperclip...)

I have the Nighthawk RAX 50 (AX 5400 6-stream router) AX5400 WiFi Router (RAX50) 

I tried to do the firmware update and now it's bricked. Can't access routerlogin.net, it isn't broadcasting any sort of discernable WiFi SSID (its default should be NETGEAR23).

I have downloaded the latest firmware  V1.0.12.120 to a thumb drive.

Is there a button combo to load/update firmware manually using the USB on the back?

I'm afraid it's toast - and not sure what to do next.

Any suggestions?

AX5400 WiFi Router (RAX50) 

[FURRYe38]

https://kb.netgear.com/000059634/How-to-upload-firmware-to-a-NETGEAR-router-using-Windows-TFTP
Need to press the reset button for 30 seconds then release, then it send to PUT the command and upload the FW. 
Make sure you enable tftp: https://www.thewindowsclub.com/enable-tftp-windows-10
Video walk through using a tftp client. Use the built in one for windows 10 though. the video is more of an example of how its done:
https://www.youtube.com/watch?v=R9DLrLQrpaw
I had a problem on a Windows 10 PC where this didn't work to use TFTP, so I switched to a Windows 7 PC and the TFTP worked.
Mac TFTP: https://www.petenetlive.com/KB/Article/0001247

Try nmrpflash:
https://github.com/jclehner/nmrpflash

I recommend loading v.112. There seems to be problems with v.120 currently.