3com Switch 4500 PWR 50-Port Benutzerhandbuch

The Unit LED is a seven segment display visible on the front of the Switch. 
The Unit LED can be used to indicate the unit number in a fabric, POST 
test ID and software upgrade information. In the unlikely event of a 
hardware fault occurring, the Unit LED may be used to help diagnose the 
problem. For information on using the Unit LED for problem solving, see 
“Solving Problems Indicated by LEDs” on page 64

Table 4 lists LEDs visible on the front of the Switch, and how to read their 
status. For information on using the LEDs for problem solving, see 
“Solving Problems Indicated by LEDs” on page 64.

Table 4   LED Behavior  

Green

Power On Self Test (POST) is in progress. During POST a the 
test ID number appears in the Unit LED (seven segment 
display).

or 

Software download is in progress. During software 
download, a clockwise cycling bar appears in the Unit LED.

Green flashing

The Switch has failed POST. The Unit LED flashes the 
number of the test that has failed.

Green flashing ‘f’ There has been a fan failure.

Green flashing ‘t’ The Switch is over temperature and unit temperature is 

critical.

Green

The Switch is powered-up and operating normally.

Green flashing

Self Test (POST) or Software Download is in progress.

Yellow flashing

One or more ports have failed POST. 

Red

The Switch has failed its Power On Self Test.

Off

The Switch is not receiving power or there is a fault with the 
Power Supply Unit.

Speed Green

10/100 Port Speed and Activity, 1000 SFP Status and 
Activity, or Stack Status and Activity.

Duplex Yellow

10/100 Duplex and Activity, 1000 SFP Duplex and Activity, 
or Stack Activity

PoE

Red

10/100 Port showing PoE Information