3Com 4500 Getting Started Manual page 17

Unit LED 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 52
LEDs 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 52.
Table 4 LED Behavior
Table 4-1
LED Color
Unit LED
Green
Green flashing
Green flashing 'f' There has been a fan failure.
Green flashing 't' The Switch is over temperature and unit temperature is
PWR LED
Green
Green flashing
Yellow flashing
Red
Off
Mode LED (3CR17571-91 and 3CR17572-91 only)
Speed Green
Duplex Yellow
PoE Red
RPS LED (3CR17571-91 and 3CR17572-91 only)
Green
Yellow
Off
10BASE-T/100-TX Port LEDs
Speed Green
Yellow
Yellow Flashing
Indicates
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.
The Switch has failed POST. The Unit LED flashes the
number of the test that has failed.
critical.
The Switch is powered-up and operating normally.
Self Test (POST) or Software Download is in progress.
One or more ports have failed POST.
The Switch has failed its Power On Self Test.
The Switch is not receiving power or there is a fault with the
Power Supply Unit.
10/100 Port Speed and Activity, 1000 SFP Status and
Activity, or Stack Status and Activity.
10/100 Duplex and Activity, 1000 SFP Duplex and Activity,
or Stack Activity
10/100 Port showing PoE Information
AC and RPS supply connected.
AC failed or not connected. RPS supply is OK.
There is no RPS supply connected.
A high speed (100 Mbps) link is present, blinking off for
every packet received or transmitted.
A low speed (10 Mbps) link is present, blinking off for every
packet received or transmitted.
The port has failed POST.
Switch 4500 — Front View Detail 17