3com 4210 PWR 9-Port User Manual

In the rare event of your switch unit experiencing a hardware failure, refer to the 
list of suggested solutions below.

Your switch has a fan monitoring system that will generate fan failure warning 
messages. Fan failure could potentially reduce the lifetime of the switch. The 
monitoring system polls the fan status at periodic intervals while the unit is 
powered up.

If one fan has failed in the switch, a warning message will be generated in the 
following ways:

■

The seven segment display will show a green flashing ‘f’.

■

RMON Trap 

If configured, an RMON trap is generated and sent to the management 
workstation.

■

An indication of a general hardware failure is provided through the Top level 
menu displayed when logging on to the CLI. For more detailed information 
about the failure select the display logbuffer command.

■

An indication of fan failure is provided through the Device Summary table for 
the specific unit. In addition all Summary tables turn red to indicate the fan 
failure.

If a fan failure warning message is generated:

Power off the unit.

Check that the air vents are not obstructed.

Power cycle the unit. To do this, remove and reconnect the AC mains supply. If 
another fan failure warning message is generated using the Command Line 
Interface or the Web interface, return the unit to 3Com.

Power cycle the unit. To do this, remove and reconnect the AC mains supply. 

Check the command line interface (display logbuffer command) to 
determine whether a thermal shutdown has occurred.

If no, return the unit:

If yes, check that:

■

The air vents are not obstructed.

■

The ambient temperatures and environmental conditions meet those specified 
in “Technical Specifications” on page 73.

Power cycle the unit. If a further thermal shutdown occurs, and all environmental 
conditions are satisfactory, return the unit to 3Com.