Ethernet Stopped Working, Wireless Didn't?

[sampix]

I had been watching TV via Roku and I got up to check something on my iMac. For some reason, it was completely shut off and my wife and kids said they hadn't touched it. I restarted and found the ethernet to be non functioning, but I was still getting a wireless signal to all my devices. I restarted everything, pulled and reinserted all the cables (about the same as looking under the hood of your car when it breaks down and you have no idea why). Still nothing.

I am being told a network cable is not connected, when it is. Could the ethernet (network?) card have gone bad?

Thanks for any information or advice you can give.

 

[sampix]

Just to bump this and add another possibility (I could be wildly off base and it is probably just a coincidence), my iMac turned off by itself and the ethernet stopped working at about the same time Cox doubled the speed of our connection. I understand mechanical things and it made me think of, if your water is shut off at the street, then suddenly turing it back on and having the shock of the pressure damage joints.

Anyone?

 

[tyche]

Is the iMac connected to a switch/router or directly to the cable box? Any other wired devices in your home connected similar to the iMac and do they work?

If you go to the Network from the preferences panel on the iMac does it show an ethernet device and is it green/connected. And take note of the ip address and gateway (router ip). If this shows disconnected, is there a green link light from the cable connecting your iMac to your network switch. No link light could point to a bad cable or a dead ethernet card.

If it's not your iMac then you need to test all the parts downstream. Usually by plugging in devices at the point in the chain and testing connectivity.

 

[gglockner]

This happened recently with my wife's iMac, while I was out of the country on business. When I returned, I swapped a few network cables and everything returned to normal. Bottom line: do some simple tests before you assume the worst.

 

[Thessman]

You can also check with a different cable, and also remove and recreate the ethernet port from the system prefs.

 

[Fishrrman]

Suggestion:

Power down ALL your electronic stuff -- the TV, the Mac, the modem, all routers -- EVERYTHING.

All the way off.

Then, restart everything.

Does this change anything?