Cannot connect to routeur

-- please disregard this message : I didn't wait enough to do factory reset. It seems that initiating a factory reset without waiting for 10 seconds only reboots the routeur.

Hello,

Today I've tried connecting to my routeur (I did not use it for a few years) and it didn't work at all.

At first I just plugged 2 RJ45 cables : one for internet, the other for the PC. The computer was unable to connect to the routeur (DHCP failed).

I then restored the factory settings and tried again : same thing, the computer could not find the routeur through DHCP.

I tried forcing an IP (IP : 192.168.1.5, mask : 255.255.255.0, gateway : 192.168.1.1).

By forcing the IP, I was able to connect to the routeur but when I tried login in to 192.168.1.1 with admin/password, it would not let me (bad password - remember I did restored the factory settings, several times actually). The http://routeurlogin.net/ address was not found (404) and I was unable to go on websites (404). One curious thing is, using that connection I was able to log in Skype (and send/receive messages), although websites could not be reached from a browser.

I'm running out of ideas to fix the problem, though I suspect a material issue, so any help would be welcome.