use the following procedure to remove the mainboard tray:
step 1 power off the router. however, to channel esd voltages to ground, do not unplug the power cable.
before opening the chassis, disconnect the telephone-network cables to avoid contact with telephone-network voltages. to see translations of the warnings that appear in this publication, refer to the regulatory compliance and safety information document that accompanied this device.
step 2 remove all network interface cables from the mainboard tray's rear panel.
step 3 place the router so that the rear panel is facing you.
there are two sets of screws on the mainboard rear panel: one set of captive screws, and one set of torx screws. (see figure 5-4.)
do not remove or loosen the torx screws.
step 4 loosen the two captive screws located in the upper corners. (see part 1, figure 5-4.)
step 5 swing the two tray levers out, and slide the mainboard tray out of the chassis. (see parts 2 and 3, figure 5-4.)
the mainboard is an esd-sensitive component. to avoid damage, observe all esd precautions.
when you are ready to replace the mainboard tray, see the "replacing the cisco 3660 mainboard tray" section on page 5-33.