6Installing a Fan-Speed Controller in Cisco 3620 Routers
Required Tools and Equipment
Required Tools and Equipment
To install a fan-speed controller in a Cisco 3620 router, you need the following tools and equipment
(some of which are not included in the fan-speed controller kit):
•Cisco 3620 router
•ESD-preventive wrist strap
•Number 2 Phillips screwdriver
Removing the Cover
This section describes how to remove the cover. You must remove the chassis cover to gain access
to the power supply and fan connectors.
Warning Do not touch the power supply when the power cord is connected. For systems with a power
switch, line voltages are present within the power supply even when the power switch is OFF and the power
cord is connected. For systems without a power switch, line voltages are present within the power supply
when the power cord is connected.
Take the following steps to remove the cover:
Step 1 Turn OFF power to the router and unplug the power cable.
Warning Before opening the chassis, disconnect the telephone-network cables to avoid contact with
telephone-network voltages.
Step 2 Remove all network interface cables from the rear panel.
Step 3 Position the router so the front panel is facing you. Remove the three screws located on
top of the cover near the front edge. (See Figure 1.) Set the screws aside in a safe place.
Step 4 Lift the front edge of the cover until the cover clears the front of the chassis.
(See Figure 1.)