Cisco Gigabit Switch Router 12008 Installation And Configuration Manual page 283

Step 2 Inspect the condition of the air filter and decide if it should be removed and
cleaned.
Step 3 To remove the filter, slide it off the two panel fasteners (see Figure 7-1).
Exercise care to prevent damage to the honeycomb screen in the EMI frame.
Caution
Damage to the honeycomb screen might reduce its EMI suppression characteristics and
restrict the flow of cooling air through the router.
Step 4 Vacuum both sides of the filter thoroughly.
Do not vacuum the filter without removing it from the EMI frame; also,
Note
do not vacuum a removed filter in the proximity of the lower card cage. Either
action might dislodge particulate matter that could be drawn into the interior of
the router.
If the filter is damaged or cannot be adequately cleaned, discard it and replace it
with a new one.
As appropriate, reinstall the old filter or install the new filter in the EMI frame;
Step 5
grasp the filter by its sides, position it for insertion over the two panel fasteners,
and seat it against the EMI frame.
Grasp the plastic bezel by its sides; position the two slots in the lower surface of
Step 6
the bezel over the two lower spring clips of the EMI frame.
Rotate the bezel upward, making sure that the two slots in the upper surface of
Step 7
the bezel are properly aligned with the two spring clips at the top of the EMI
frame.
Step 8 Exert inward pressure on the bezel to snap it firmly into place.
Cleaning the Air Filter
Maintaining the Cisco 12008 7-3