Ethernet not registering when connected.

I have a PS3, and would like to connect to the network. I have tried 2 Cat5 Ethernet cables, and both times when I try to connect to the network to sign up it says there is no cable connected (I checked to make sure they were plugged in securely). What do I do?

Also, I don't know if it matters, but I hae 40gb PS3. Would that in someway affect it? Please help! Thanks!

Actually, that may be the problem: Comcast.

Are you using cable?

Try turning off the PS3, and make sure you have the modem connected to the PS3, then go to the network settings to estrablish your wired connection. I hope that works for you.

Unfortunately, no go. I was also reading up on playstation's website about troubleshooting a wired connection, and it said I couldn't run a modem cable to my computer and an ethernet to the PS3 at the same time. I tried disconnected the modem from the computer and tried just the ethernet, and it still didn't work. It just keeps saying "No Ethernet cable connected." militantducky

Wait so let me get this clear, did you take the ethernet cable off from the PC and connected that to the PS3? Because I definetly know you can use your cable moden with the ethernet cable and hook it up with the PS3.