Weird problems with my xbox

[SwollPatroll]

So 2 days ago I bought homefront, beat it, now I want to play on live. Problem is my xbox won't connect. For some reason my modem doesn't even recognize the xbox being plugged in (I run a long cable from my room to the computer room where the modem is located). Now both computers in the house(also hooked up by cable) can access the internet just fine. The lights for the ports that my computers are using flash just fine, but the light for the port the xbox is using does not flash at all.

Now I've tried everything I can think of including unplugging the modem, wait 30 seconds, then plug it back in and I get nothing. I've tried using the cable from my computer thinking it's a bad cable, still nothing. I've switched all the ports around on the modem thinking maybe I fried one and I still get nothing. I don't know why one day it just stopped working, I played gears of war on live about a month ago and everything was just fine. So any help from I can get is much appreciated, I don't feel like spending a half hour on the phone with xbox tech support but I just might have too.

[Mashpotaters]

Does the light on the Xboxs' modem light up? If not then a possibility could be that the modem on the Xbox is bad. Probably a stupid question, but do you by any chance have a wireless adapter for your xbox you could try?

[SwollPatroll]

Are you talking about a light on the back of the xbox that flashes with internet access like on a computer? In that case no I don't see any light on my xbox. I was wondering the same thing though maybe the actual port on my xbox itself is bad. I've just never heard of that happening. And unfortunately no I don't have a wireless adapter, wish I did though because that would help narrow it down that much further.

[Mashpotaters]

It could happen. You said that the last time you used xbox live was a month ago, so maybe it failed somewhere in between that and you didn't find out till just now. Hopefully you're under warranty, and Microsoft will get that fixed. If that happened to me I would be screwed since I'm past the warranty I bought, and the warranty that comes with the xbox. Over 3 years old and the damn thing has yet to have any problems.

[Gulyus]

Your xbox and modem are not recognizing each other. the internal sim card has died. you need to go into your xbox and router and manually set the IP address on both to the automatic setting; this one piece helped me.

Course, dont forget to power cycle EVERYTHING not just the router. you might need to power cycle the router/ then computer / then modem off then all back on in reverse.

[Amaranth]

Or you could try using a different Ethernet cable. I've had mine crap out before, but everything was fine with a different cable.