3Com 3C17708-US - Switch 4050 Getting Started Manual page 61

3 Power cycle the unit. To do this, remove and reconnect the AC mains
supply. If the unit has no AC main supply, remove and reconnect the DC
RPS supply.
If another fan failure warning message is generated via the Command
Line Interface or the Web interface, you can replace the fan tray.
4 If the fail trap is for the front fan tray:
a Open the door where the bulge is at the front of the Switch.
b Remove the screws securing the fan tray using a suitable screwdriver
c Gently slide the fan tray from the Switch
If the fail trap is for the rear fan tray:
a Remove the screws securing the fan tray using a suitable screwdriver
b Gently slide the fan tray from the Switch
CAUTION: A fan tray can be temporarily removed and replaced while the
system is running without impacting operations. The system must not be
left with either fan tray removed for more than two minutes or damage
to the product may be caused.
5 Replace the fan tray. If a further fail trap is received, install a replacement
identical fan tray.
6 If a fan fail trap is still received, return the unit.
WARNING: Care must be taken when removing the fan tray as the fan
blades may continue to spin for a short time after removal. Keep fingers
clear.
An SNMP thermal shutdown trap and email is received
1 Power off the unit.
2 Check that the Switch unit is operating with the following:
An expansion module or blanking plate fitted.
A second PSU or blanking plate fitted
3 Check that the air vents are not obstructed.
4 Check that the ambient temperatures and environmental conditions meet
those specified in
5 Check that the front and rear fans have not failed or have been left out
from the Switch.
Appendix C.
Solving Hardware Problems 61