10 base T Nic problem


Having problem with 10 base T network cards. I can get them to "talk" via the Cat5 connections but not the BNC (coax).

I have used several cards in several computers. I have run the diagnostic/setup programs for each card. They say that they are set for auto detect, eprom OK, board OK but I get continual cable errors when I test them with the coax or terminators connected.

Have checked the coax cable for continuity and shorts, it is OK. Have tried "initiator/responder" tests. They work with the cat5 but not the coax.

My question is, when I run the tests, should I have anything attached to the BNC connector? If so what, a terminator, a "t" connector with a coax connected in a loop to each side or nothing at all?


Ed Barnat
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your problem sceems to be a cabeling problem

So the correct wax to connect all standard cards is this way:
Put a T-connector on every card you want to use (never connect a cable directly), use  tested cables between the cards, on both ends put the approbiate terninator with 50 Ohm (never use more or less then two terminators, never build a loop or a star ar anything else than a bus with exactly two ends)

If you want to test your Nic withouth a cable you must use the t-connector and the terminators on both ends of the terminator.
A initiator test is done with two stations, one is  the initiator the other is the responder.

I know that there are proprietary cards with other rules, but standard ethernet NIC's use this rules.

Best Regards Michael

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edbarnatAuthor Commented:
Thanks Handrich,

That hit the spot. Looks like we not only lost a couple of cards on our small network (6 machines) but developed a couple of intermittent "T" connectors as well! Perhaps the latter caused the former. Either way, your guidance proved invaluable in tracking down the culprits.

Thanks again.

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