NIGHT HAWK EX7700 EXTENDER CANNOT FACTORY RESET,GREEN LIGHT KEEP FLASHING

[THUPHONG]

Dear friends! my extender over 3 month phone support,now it not connect to internet and the both lights keep flashing and I cannot do factory reset,if some one know how to resole problem please help me.I am not so good at computer I try every thing in my knowlege but no luck.thanks

[plemans]

What actual lights are flashing? 

What color? 

Why can't you factory reset? What happens when you push and hold reset for 7-15 seconds? 

[THUPHONG]

green light beside power buton flashing and there white in the front keep flashing all the time even I press reset for 15 second nothing change,thanks

[plemans]

You can try recoving it with tftp or nmrpflash.  

are you on windows? if so, follow this guide

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

just make sure you enable tftp 

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

and here's a 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

and if that doesn't work, you can try using nmrpflash

https://github.com/jclehner/nmrpflash