3Com 9100 User Manual page 149

C
LEDs
T
ROUBLESHOOTING
If you encounter problems when using the switch, this appendix may be
helpful. If you have a problem not listed here or in the "Release Notes,"
contact your supplier.
Power LED does not light:
Check that the power cable is firmly connected to the device and to the
supply outlet.
On powering-up, the MGMT LED lights yellow:
The device has failed its Power On Self Test (POST) and you should
contact your supplier for advice.
A link is connected, but the Status LED does not light:
Check that
All connections are secure.
Cables are free from damage.
The devices at both ends of the link are powered-up.
Both ends of the Gigabit link are set to the same autonegotiation
state.
Both sides if the Gigabit link must be enabled or disabled. It the two
are different, typically the side with autonegotiation disabled will have
the link LED list, and the side with autonegotiation enabled will not
list. The default configuration for a Gigabit port is autonegotiation
enabled. This can be verified by entering the following command:
show port config