| Title: | DEChub/HUBwatch/PROBEwatch CONFERENCE |
| Notice: | Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7 |
| Moderator: | NETCAD::COLELLA DT |
| Created: | Wed Nov 13 1991 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 4455 |
| Total number of notes: | 16761 |
DEChub 900
Slot
8 DECbridge 900MX
7 DECrepeater 900TM
6 DECrepeater 900TM
5 DECrepeater 900TM
4 DECrepeater 900TM
3 DECrepeater 900TM
2
1 DECrepeater 900TM
Hello
I have a DEChub 900 configured as above with a problem when trying
to use slot 2. The hub has 4 power supplies. Slots 1 & 2 are connected
to the same ethernet bridge port via hubwatch. If we insert a DECrepeater
900TM in slot 2 the '->' indicator on the repeater stays on solid and no
connections can be made via that repeater. If we put the same repeater in any
other slot it has no problem.
Put a different repeater in slot 2 and it does not work either.
We have also swapped the DEChub 900 backplane with no change
in the problem. With 4 power supplies, we should be set as far as power goes.
We also have another hub next to this one which only has 2 DECrepeater 900TM's
in slots 6 & 7. This hub also has 4 power supplies.
Putting a repeater in slot 2 on this hub and it works.
Wondering if the number of modules has anything to do with it.
Anyone have any ideas?
Is it possible we have a voltage low or on the edge causing it?
Is there anyway to measure voltages on the hub?
Thanks
/Steve
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 1944.1 | NETCAD::HERTZBERG | History: Love it or Leave it! | Mon Jan 30 1995 13:36 | 29 | |
>> ... If we insert a DECrepeater 900TM in slot 2 the '->' indicator
>> on the repeater stays on solid...
This indicates a stuck "carrier" condition on the backplane. The most
likely source is a fault in the way the module in this slot attaches to
the backplane thinwire, since this is the interface to which it
connects by default.
Can you try to disconnect the repeater from the thinwire using
Hubwatch? Does the '->' indicator go off? If yes, that would isolate
the problem.
Because the module works in other slots, this seems to suggest a
problem in the backplane itself. When you said you "replaced the
backplane," what exactly did you mean?
>> Is it possible we have a voltage low or on the edge causing it?
>> Is there anyway to measure voltages on the hub?
No, this isn't likely. Voltages at all slots in the hub are virtually
identical, as we use massive bus bars to deliver power to each slot.
This really sounds like a bad backplane slot, perhaps with a faulty
connection from the slot to the upper backplane board (the one with the
48-pin connectors on it).
Marc
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| 1944.2 | GHOST1::SMALL | Mon Jan 30 1995 18:49 | 17 | ||
Hello
The customer bought the equipment through Anixter. They had sent him
another dechub 900 when he suspected this one as having slot 2 bad.
He installed that replacement one and it exhibited the same symptom
as the original. I guess it's possible to have two hubs bad the same
way? Anyway we stuck a decpeater 90T in that same slot and it appears
to work ok.
They are going to order another dechub 900 to replace some other dechub
90s, so they'll see if Anixter will send them another 900 hub.
I'll let you know the results next week when it comes in.
Thanks
/Steve
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