"ethernet not connected"

[Doug Lassiter]

... says my Network prefs on my iMac 10.6.8. But yes, the live cable is most certainly connected. And when I take that same cable and plug it in to my laptop, the laptop recognizes it, and sees an ethernet connection on it. So it's my computer, and not the cable. Long ago, it used to work on this iMac, but I've been just using wifi for the last year. Everything works fine with that wifi link. So what's going on?? What changed?? Why can't I use a wired ethernet connection on my iMac anymore??

I tried rebooting, resetting PRAM, resetting SMC, removing and reinstalling Ethernet in the SysPrefs/Network panel. I turned Configure IPv4 "OFF", and then back to "Using DHCP". But nothing helps. It just keeps saying "Status: Cable Unplugged".

Maybe it has to be my NIC, requiring physical service? How do I tell?

 

[chscag]

You can try running the Apple Hardware Test to see if it flags anything about the ethernet port on your iMac. You didn't tell us the year and model of your iMac but your Snow Leopard original DVD can be used to run the Apple Hardware Test. You might also click on the Apple menu and display "About this Mac", and then display system information to see what it says about the ethernet port.

 

[Doug Lassiter]

That's a good idea. Unfortunately, my optical drive is on the blink. I have to get myself a spare external. Now, I have no trouble getting DVD/CD files, because I'm on a large network, but the AHT on the install disks is an "installable package". That is, it isn't an application I can just slide over to my iMac. No sweat, I figured. I can just get it from https://github.com/upekkha/AppleHardwareTest (my iMac is iMac10,1 Mac-F2268CC8). Now, github unfortunately has TWO packages listed under that Mac version number. I tried both. Downloaded the dmg file, and opened into a disk image. In each, when I then restart while holding "D" down, I just get to a gray screen. No farther. Am I using AHT wrong here?

So what started as one problem has turned into two. Ideas?