Thank you , actually I just found the solution ! under the motherboard there was a 0X7C1K GPU Power Supply Module  , I removed the module and server's all good now , very quiet and healthy in IDRAC9So even without GPU if the module is present it will need external R fanThanks for the help !
Hello,We have a PowerEdge T640 with a fan blowing full speed all the time because of a cooling alert on sensor "Fan Ext R" saying it's running a 0RPMThe thing is there's nothing plugged on those pins and there's no external fan at allAll 6 internal fans are OK but running at full speedI tried reseting IDRAC/BIOS and everything to default and nothing's helping , Lifecycle inventory is enabled and everytime I boot the server it seems to be running the inventory but does not remove the sensor the non existant fan !if anyone have ideas I could try... all I want is the sensor for "Fan Ext R" to be "disabled" instead of reading 0RPMUpdated BIOS and IDRAC9 to latest version already too
PowerEdge T640 : Fan Ext R