3com 4400 (3C17204) User Manual

C

HAPTER

 4: P

ROBLEM

 S

OLVING

If the LEDs on the Switch indicate a problem, refer to the list of suggested 
solutions below.

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.

Either:

■

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.

or

■

A port has failed and has been automatically disabled. You can verify 
this by checking that the Port Status LED is quickly flashing Yellow. If a 
port fails the Switch passes its Power On Self Test and continues to 
operate normally.

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.

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

DUA1720-3AAA07.book  Page 58  Wednesday, March 17, 2004  1:14 PM