How do I fix a network cable unplugged error? (RESOLVED!)

[Ultrasonic]

Hi guys. My friend has cable broadband service with no router in between. All was working fine, when he showed up one day and his WinXP SP2 computer was giving him the "Network cable unplugged" error. I've tried the typical suggested fixes like powering off the cable modem for 30 seconds, changing cables, changing duplex settings, but the problem remains.

All the lights come on the modem, except the Activity light which is off. There are no lights on the back of the NIC.

I even tried connecting my laptop to his cable modem, and the same thing happens for my laptop (even though I have the same service provider and it works fine at my home). I get the network cable unplugged error message. ipconfig states that media is disconnected.

We called the service provider and they say that his modem checks out fine and it must be his computer. But how can that be if my computer does not work, either?

Aside from trying out a USB connection, I can't think of any other steps to take. Do you guys have any suggestions? Thanks in advance.

07/04/08 Update

The modem ethernet port was the culprit. Connected via USB, and everything works great! Thanks a lot for your help, guys. It was very much appreciated!

 

[NickOlsen8390]

if your laptop has a known working nic, and you plug it in to his modem and it doesn't turn on it is most likely the eth port on the modem. Nothing else it could be if you KNOW your nic is good, and it works on another modem/router. And you have swapped cables.
Even if the cable company says its fine. All they see in eth link down i would guess.

 

[Ultrasonic]

That's an interesting point. I guess trying out the USB connection will be the deciding factor. I appreciate the reply, Nick.

 

[antyler]

Sounds like you can rule out a computer problem seeing as how its unlikely that both computer would have the same problem, and since your computer works at home. It sounds like it would probably be the modem. It probably looks fine from the providers end, since their service is getting to it.

Had the port on a modem go out the other day on a clients router. Maybe try jiggling the port around a bit or un plugging it and plugging it back in. You may be able to get intermittent connection, and would probably be able to pin down the problem to that port.

 

[Ultrasonic]

Well the modem has both ethernet and USB connection options, so I'm going to attempt to use the USB connection to see if it's the ethernet port that is causing the problems. I'll try this out on Friday and will update the thread at that time. Thanks for your suggestion, antyler.

 

[jasezero]

I've had similar issues with laptops and the power saving techniques they use. Dell laptops specifically turn off the ethernet port on batteries when not in use. The problem is that they don't detect a network cable 100% of the time so I just set it to always on in the Dell Quickset software.

 

[Lemon law]

Nope, sounds to me like you are getting the run around from the cable co, and when in doubt at tech support, blame someone else and hope it get the problem off their back. 99% probable, the modem is bad, and they lie. Even if the power saving idea is correct, the lap top would not work at his house either.

To be 100% definitive, swap modems temporarily. The cable connecting the modem to the computer could have gone bad. There are crimped connectors at each end and what is crimped can become un crimped when pulled.

 

[Ultrasonic]

The modem ethernet port was the culprit. Connected via USB, and everything works great! Thanks a lot for your help, guys. It was very much appreciated!