help with internet connection

[debo]

can someone please give me some advice on what i can try to get logged on to the internet thru my ps3? ive tried evrything i can think of and had a buddy come over and try to help and no matter what it wont find an ip address. ive been on the phone with sony and comcast my internet provider(broadband) and i went and got a new modem from them because they said that might be the problem. ive got it ran thru a buffalo wireless router and ive tried a wireless connection thru it and a wired connection and neither will work. i really need help im about to beat my head against the wall. ive had the ps3 for 2 years and im just now trying to play online and its really pissing me off because i cant