The router has two separate cooling subsystems, one for the power supplies and one for the other router components. Each subsystem maintains a separate air flow and is monitored independently. For a graphic depiction of the airflow, see Figure 19.
For the cooling system to function properly, the clearance around the chassis must be sufficient for unobstructed airflow. See Clearance Requirements for Airflow and Hardware Maintenance.
To troubleshoot the cooling subsystems, follow these guidelines: