unable to logon to zyxel ex3501 t0 router

daveywavey

I am unable to logon to the router interface, I just get the error message below.

This site can’t be reached

192.168.1.1 took too long to respond.

I have tried this using several different browsers and numerous devices with the same result. I have checked the default gateway using ipconfig and this is correct (192.168.1.1) I have reset the router several times and tried using different cables too. Any help appreciated.