Hard reset TP-LINK AC1750 / Archer C8

Factory reset (Hard reset) The Reset button is on the back panel of the router. Press and hold it for more than 5 seconds, release and wait for a couple of minutes while the router resets. Visit http://tplinkwifi.net to create a new login password.
Firmware Firmware link
Default username N/A
Default password You set it at http://tplinkwifi.net
Default IP address 192.168.0.1