Router problem!! Plz help!!

Rogers had a call back on the modem that i was previously using so i was given a brand new one. When i connect the ethernet cable directly to the computer it works perfectly but when i connect it to router and the other cable to the computer it does not work. The compter say that the device is connected and that there is an internet connection but i dont get internet on my computer or ps3. I have tried restarting it an all those basic method but nothing is working. Some help would be great, thanks.

If you haven't already done so:

Try pulling the power cable from the modem first, then the router.  Leave the cable out of the modem for a full minute before powering it back up.  When you get all the lights back on steady, then power the router.  You should then have an internet connection through your router, but you may need to restart the PC.  If you still get no connection, you might have to call your ISP and have them clear the host address on the modem (basically, your modem may still be "seeing" the PC and not the router; clearing it will solve this problem), and they may walk you through a few things to get this done on your end as well.

I work for my ISP, and this usually solves the problem.  Good luck.