How can I tell if an iMac Ethernet card is dead?

December 28, 2005 10:04 AM

How can I tell if an iMac Ethernet card is dead?

I'm trying to get a new broadband connection to work with an old iMac (DV SE Graphite, running Mac OS 9.2.2). The Ethernet card did work, at least for AppleTalk file sharing via crossover, but I haven't used it in a long time. The broadband connection works fine with a PowerBook and PC laptops, but not on the iMac.

I suspect that the card has died, but Apple System Profiler is vague about it. On the 'System Profile' page, under the 'Network overview' section, it says 'Ethernet built-in Link: down'. I'm not sure if this means that the card is working but there's something else wrong with the connection.

I've tried TechTool Lite and PCIprober but they don't tell me anything new. I've also zapped the PRAM but that doesn't make any difference.

Does anyone know of other diagnostic software that could tell me if the Ethernet card is still functioning? Is there anything else I could try to get this working?

posted by Grinder to computers & internet (5 comments total)

Do you have a hub, switch, or router? If you plug it in and get a link light on the hub, you can probably rule out hardware problems. There may also be a status light on the card or on the cable modem. If anything lights a link or status light when you plug in the ethernet cable, ethernet is working, and you've got a software problem.
posted by ulotrichous at 10:25 AM on December 28, 2005

I'm pretty sure there's no Ethernet "card" on an iMac (even an older one) -- all the Ethernet hardware should be right on the motherboard.

'Ethernet built-in Link: down'. I'm not sure if this means that the card is working but there's something else wrong with the connection.

Pretty much. You would typically see the same thing if no Ethernet cable was plugged in at all.

Make sure the Ethernet cable is securely plugged in on both sides, make sure you have the right kind of cable (crossover or non-crossover, whichever is appropriate), and make sure the cable is good. Also, what ulotrichous says about indicator lights on other hardware.
posted by xil at 11:36 AM on December 28, 2005

Some iMacs (and other Apple machines) have problems connecting to certain other devices because of their auto-sensing ethernet hardware. (See the link for possible solutions.)
posted by mbrubeck at 12:06 PM on December 28, 2005

Thanks for the pointers. I don't have a hub/router/etc., so I can't check by using lights, but this connection works fine with other equipment. I've tried a few different cables, including crossover, and none work.

I've found software that disables auto-sensing and I'll try that. Thanks, mbrubeck.
posted by Grinder at 1:25 PM on December 28, 2005

I've tried disabling auto-sensing and that doesn't make any difference.

Under Mac OS 9, should the Ethernet card appear in the 'Devices and Volumes' page of the Apple System Profiler?
(It does in Mac OS 8 on a PowerBook.)

Does anyone have any experience with using USB-to-Ethernet adapters on Macs under Mac OS 9?
posted by Grinder at 3:34 AM on December 29, 2005