can you log into the configure page ?(normally 192.168.0.1) do you remenber the previous firmware version?and which version you upgrade to?

does the extender work well or lose internet when the signal shows red? the signal light changes colors to indicate the strength of the signal received from your wireless router,locating the idea...

what do you mena by: There is no login/password for the ISP,connect a PC, and you have internet access. if it's true,why you need a modem? just plug the ethernet cable into the router and set dynamic...

have you tried to reset and reconfigure?

in this case you can contact the support to do RMA (repalcement) if it still in warranty

do you mean you can get internet via modem and don't have internet via router ? or just no ping response ?