playstation 3 internet connection?

[Zero]

can someone help me. i have 2 playstation 3. one in my room and another in a different room with the router and modem box. both playstation 3 were connected directly to the router using the cable. at first both ps3s were working but then the one in my room stop working. i could connect to the Internet using the other ps3 but not this one. but two days ago i restarted the router and modem then i was able to go online again with the ps3. but now that does not work anymore. the other ps3 still connects to the internet though. does anyone know what the problem is. Also when we set up the internet connection to the router we did the same exact options for both ps3 so they both should be able to connect. but why one of them does not