3com 5500-EI Quick Setup Guide

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C
HAPTER
 5: P
ROBLEM
 S
OLVING
Solving Problems 
Indicated by LEDs
If the LEDs on the switch indicate a problem, refer to the list of suggested 
solutions below.
The PWR LED does not light
Check that the power cable is firmly connected to the switch and to the 
supply outlet. If the connection is secure and there is still no power, you 
may have a faulty power cord or an internal fault. Firstly, check the power 
cord by:
testing it in another device.
connecting a working power cord to the ‘problem’ device then 
contact your supplier for advice.
On powering-up, the PWR LED lights Red
The switch unit has failed its Power On Self Test (POST) because of an 
internal problem. The fault type will be indicated on the unit LEDs. 
Contact your supplier for advice.
On powering-up, the PWR LED is flashing yellow
A port has failed and has been automatically disabled. You can verify this 
by checking that the Port LED is quickly flashing Yellow. If a port fails, the 
switch passes its Power On Self Test and continues to operate normally.
A Port LED is flashing yellow
The port has failed and has been automatically disabled. The switch 
passes its Power On Self Test and continues to operate normally, even if 
one or more ports are disabled.
A link is connected and yet the Port LED does not light
Check that:
The switch and the device at the other end of the link (or cable) are 
connected securely.
The devices at both ends of the link are powered-up
The quality of cable is satisfactory
Auto-negotiation settings are the same at both ends.