cannot log into n900 model WNDR4500v3 after factory reset

I have a Netgear N900 model WNDR4500v3 that is just out of warranty. After a power outage the router reset itself and the WiFi works fine with the default WiFi password. However, I am now unable to access the router via my network. When I tried to log onto the router using my previous router password (not the WIFi password), it told me the login info was incorrect. When I tried to recover the password it asked me security questions that I never had answered. So I did a factory reset with the understanding that I could then access it with "admin" as user and "password" as password. Same result. I am unable to access the router with my old username and password or the factory default username and password that is supposed to work after a factory reset. And yes, I held the reset button in with a paper clip for a long time, and the router took a couple minutes to get its brain back. Same result, the WiFi works fine with the default WiFI name and password, but I cannot access the router itself using my old use name and password or with the factory default "admin" and"password" combo.