3Com 4400, Getting Started Manual

Page: 57 / 86

Solving Hardware Problems 57
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Auto-negotiation settings are the same at both ends.
Auto-negotiation problems will occur with 10BASE-T or 100BASE-T
where auto-negotiation is disabled and incorrect cables are being used
(cross-over or straight)
Auto-negotiation problems will occur with fiber if:
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The Receiver (RX) and Transceiver (TX) cable connectors are
swapped
■
Fibers are broken
■
Auto-negotiation differs at either end (a link appears at the ‘fixed’
end and not at the auto-negotiation end)
The Unit LED is flashing green
The Switch unit physically forms a stack with other Switch 4400 units, but
cannot be managed as part of that stack because one or more units have
not been upgraded to software version 2.0 or later. You must upgrade
each unit in the stack to this software version, which is available on the
CD-ROM that accompanies your Switch.
Port LED Status LED flashing yellow
The Switch has a Power over Ethernet (PoE) error. You must press the LED
Mode button to see which ports are affected and to see whether it is a
fault or a power budget issue. If there is a fault, then the Packet LED of
the affected port will be yellow, if a port exceeds its power limit, then the
Packet LED of the port will flash green. If a port has a PoE POST error then
the Port LED Status LED of the affected port will flash yellow.
Solving Hardware
Problems
In the rare event of your Switch unit experiencing a hardware failure,
refer to the list of suggested solutions below.
An expansion module is installed and the unit will not power up
Ensure that the expansion module is fully seated in the slot and the
connectors are engaged so that the securing screws can be tightened.
A fan failure warning message is received
Your Switch has a fan monitoring system that will generate fan failure
warning messages. Fan failure could potentially reduce the lifetime of the
DUA1720-3AAA05.book Page 57 Friday, March 7, 2003 11:53 AM