Hi, I'm guessing your fan might be broken/damaged. 
Hey guys, I have a Poweredge R240 and unfortunately, one day, the fans randomly ramped up to 100% speed and never went back down. I also noticed a dialog that stated "Ubuntu noticed a problem with a fwupd." A couple of dialogs came up that said there were some problems. These seem to be software or firmware related.  I attempted to set the fan control to low from IDRAC settings to no aveil. My next idea was to run the hardware diagnostics tool, I expected it to be like the Windows troubleshooter, but to my surprise it actually found some problems with the fans! I believe it might be a faulty temperature sensor causing the issue because I used lmsensors to get some temps, and everything was normal (32-34C). I attempted to disconnect the problem fan, but the fan speed stayed on 100%. I opened the case to see all 3 fans operating at 100% properly. From the pictures below, you can see that the server believes that the fans in slot 1 and 2 are not connected, but they are connected and running at 100% speed, it seems that it only detects fan 3. My question is: is there a temperature sensor embedded in the fan or is it seperate? How can I fix this issue?    Any help is greatly appreciated!   Thanks for reading.   Ubuntu 20 LTS  Dell Poweredge R240 Bios 1.2.0 (old)   [IMAGE][IMAGE][IMAGE]
Dell Poweredge R240 Fan at Max Speed Randomly