3com 3CR17451-91 User Manual

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46
C
HAPTER
 4: 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 Unit 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.
The Unit LED will not light if the Switch 3870 is a standalone unit. If the 
Switch 3870 is part of a stack, the Unit ID will be shown.
The Power/Self Test 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. 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 Power/Self Test LED lights yellow for about ten 
seconds after which it starts flashing green.
On powering-up, the Power/Self Test LED remains yellow
This indicates one of the following:
A port has failed and has been automatically disabled. You can verify 
this by checking that the Port Status LED is flashing Green/Yellow 
(fast). This could be due to a loop back failure. If a port fails the Switch 
passes its Power On Self Test and continues to operate normally.
DUA1745-0AAA03.book  Page 46  Friday, April 8, 2005  12:34 PM