Thanks ernie ... I'm not getting anything with Wireshark.  The NIC is currently enabled but not configured (as it is set to get IP address automatically - there is no DHCP for it) ... to what ip/subnet would I configure the NIC in order to listen?  or should it be "hearing" something even if unconfigured?  May it also be possible that the device is listening only and not sending any packets unless requested, or should there be something coming through?

If it's the pc's nic, set it to a static ip to be sure. Wireshark sets the nic in to promiscuous mode so it should hear anything. After doing that, reboot the (3rd party) device. you should get something then.

Still not getting anything.  Problem is, I don't know anything about the device.  I followed the network cable to it, and it is just a metal box with tubes attached, seemingly bolted shut with no apparent way to access it ... needless to say, I don't think rebooting it is an option.  Any other ideas?

Very Dr. Who like :-~

So nobody knows anything about it or about the crashed pc? Was the crashed pc connected to the network as well or just to that doomsday ;) device?

Otherwise let's get pragmatic, get a network scanner (http://www.softperfect.com/products/networkscanner/ for example), give the pc a nice address: 1.0.0.1 mask 128.0.0.0 and let it scan (second range 128.0.0.0 mask 128.0.0.0). I hope it doesn't mind the special ranges.......

Ofcourse it might be wise to first try the private ranges.

Well, neither are connected to a network - just the PC directly connected to the doomsday device :).  The only people who know about the device is the third-party who installed it (of course), and they won't be able to help until tomorrow.  I told the bosses that it wouldn't be until tomorrow that they'd have it working, but you know how IT guys like to be the heroes :)

I'll give network scanner a try.  Thanks.

I know :)

But normally the sales guys promise the bosses everything and then the IT guys just make it work (we're still the heroes :)))

Ended up needing a third-party device IP tool to detect it, but I will award points for sharing a tool I didn't know about that would work in many other instances.

Thanks for the points :)

Would you care to tell me what you used to get the ip?

The device is a ProFoss probing instrument and I used an ISIscan (software that works with ProFoss instruments) tool made specifically for discovering ProFoss instruments.  If you want the actual name of the utility, I can get it for you once back to the office, but unless you are using a ProFoss instrument, it probably won't be useful for anything else.

Just googled it, nice stuff (studied chemistry for some years). But you're right, it's not something I came across recently :)
Thanks for the info though :)