Model : Archer C8

Hardware Version : V1

Firmware Version :

ISP :

Hello,

I've bought my router from amazon in january 2015. I wanted to upgrade the firmware so my router is up to date.
I downloaded the newest firmware, and from the web interface, I've selected to upgrade. Everything seemed fine : the % number grew up... and nothing else. I mean : I cannot connect to the router anymore. Wifi don't work anymore, and even the power led is down. I only have two led awaken : according to the manuel, it's the ethernet and USB.
When I turn it off, nothing happens - just the two leds illuminates et noting else.





What can I do so I recover the router's functions ? Is there anyway to do a factory reset without enter the web interface ?
I've tried to push the reset for 30 seconds, without any success. I fear my router is bricked. :(
If someone could point me in the right direction, I'd appreciate it.