[Goddard11]

I have a dual 1.8 G5 PowerMac, and I'm having issues all of the sudden with my network cards (built-in and PCI slot 4). I go to System Pref's and Network, and Under Network Status it shows nothing but Built in Firewire and Bluetooth, the Ethernets arent even there!. In Network Port configurations it SHOWS both ethernet ports (built in and pci slot 4). I've rebooted, unplugged power after reboot, had it sit for a while, etc. And it still shows the same problem, I've even tried different ethernet devices for it to plug into, different routers, even a MacBook Pro, and still it shows nothing. The only thing I could think of is I recently plugged in an old Studio Display with the old ADC plug, it works fine and everything, but supposedly those are powered by the ADC port.

Does anyone have any idea as to why my Ethernet connections wont show up in network status?

[Waragainstsleep]

Its an odd bug, that I have never gotten to the bottom of. Sometimes it does mean that the ethernet ports have failed, but for two to go would be unlikely (unless they run off the same controller).
Check they are listed in the system profiler, if they aren't you could be in trouble (new logic board is the only way to fix blown ports, though you can always use PCI ones).
If you have another Mac handy, try booting from its HD using firewire. If the ports come back you have a software issue. Archive & install your OS. You could check from another user account too, but if they don't show there it could still be an OS problem. If they do its a bad pref in your user library. Try junking the system prefs preference file in /Users/you/library/preferences/. Its called com.apple.systempreferences.plist

[Goddard11]

I got it working, I suppose it was my network card and my preferences.plist file, after rebooting a few more times, reconnecting the network card, and deleting the plist file, its working perfectly.