problem with sbg6580 firmware 3.5.8.4 no connection

My signal is fine, settings look fine, can connect to the modem but not internet. It worked perfectly with no dtops and blazing speeds. A few days ago my conn started dropping intermittantly and then it finally just quit. Havent teeaked anything I shouldn't have, called cox and they told me to replace it. I jusy payed $150 for it, and I loved it before this.