Re: Cisco 2911 Router Fan Issue

Ryan10122 · ‎06-11-2023

Hello,

I am running into an issue with my 2911 router. When I power on the router all 4 fans spin up, shortly after turning it on fans 1 and 2 will stop spinning and a few seconds later fan 3 will go to 100%. The two fans don't seem to spin back up.

Due to this issue the router prints an error message in the CLI and due to the third fan spinning up to 100% roughly every 5 seconds, it is almost impossible to do anything in the CLI. The specific error is "%EVMON-4-MULTI_FAN_LOW_RPM: Critical Warning: More than two fans are running at low RPM. Rotation speed is now high for all other fans. Please replace fan tray to prevent system from over heating.

Has anyone run into this issue and if so how did you fix it?

As a troubleshooting note:

I have removed and reinstalled the fan tray which did not seem to make a difference.
There is no dust filter installed, and the fans and internals have no visible build-up of dust
The router itself seems to have no other issues and functions normally other than this fan issue

Any help is appreciated!

Leo Laohoo · ‎06-11-2023

Go to used market and buy an old 2911.

Ryan10122 · ‎06-11-2023

I just bought this one on the used market.

Also I was messing with it a little more after posting originally and it seems that if I take to top cover off all the fans spin as normal. As soon as I put the cover back on the issue starts up again.

Leo Laohoo · ‎06-11-2023

There is a toggle switch? I must confess, I have never opened an ISR G2 before.

Ryan10122 · ‎06-11-2023

I am not sure... I will do some searching to see if I can find anything. It almost seems like that might be it but I can figure out why toggle the fans off when the top is closed. I had the top off this afternoon and was able to work in the CLI without issues for about 45 minutes. All the fans ran as normal so as far as I can tell this is the only issue. I am still very new to Cisco so there is virtually nothing on the router and it is just being used for home lab type work so I doubt it is anything along the lines of a load issue.