These messages are seen on the console or in the router log. They can be caused by any of these:
A dirty filter.
A bad fan assembly.
A mis-seated fan assembly.
A failed Chassis Interface (CI).
These are example error messages:
%CI-3-BLOWER #[x] fan failure
%CI-1-BLOWSHUT Blower failure, shutdown in [x] seconds
%CI-3-BLOWER: main fan failure
These error messages is recorded by the router.
The fan assambly or system blower draws cool air through the chassis interior to maintain an acceptable operating temperature for the internal components. If the filter is blocked or if the fan assembly or system blower has failed, the router will overheat.
To resolve the issue, perfrom these steps:
Check and clean the filter.
If the problem continues, re-seat the fan assembly or system blower.
If the error message continues, replace the fan assembly or system blower.
In order to have the fan tray or blower system replaced, perform the replacement instructions in these documents: