Hi @Twinspapa 

Thanks for reaching out to us. Sorry to reply you late. Forum has been busy recently. 

Please disconnect all devices including modem from your TP-Link router, then reboot router. After that, please try reset again: with router powered on, press and hold the reset button until all LEDs turn on to reset the router to its factory default settings.

If the router is successfully reset and you can access to the router web interface, please follow this article to troubleshoot if there is no internet when connecting Archer A10 to the ISP modem:
https://www.tp-link.com/support/faq/1556/
BTW, please be sure you have internet access when connecting a computer directly to the modem first. 

If router still can't be reset, I am afraid this device has hardware issue. We recommend reaching out to the local tech support, so they can work with you in looking into the issue further or help with the replacement.