I have a new S5500BC in a new SC5650DP chassis.
I am running Win 2008 Server R2.
No matter what, the fans run at full speed.
How do I control the fan speeds?
you've connected the fans (possibly the pci and hdd cage fan) the wrong way. check the motherboard/chasis quick install to check proper connections.
I updated the FRU etc but it did not make any difference.
BUT, it made me re-check a few things and I eventually noticed that I had plugged a chassis fan into the empty CPU2 fan plug.
I fixed that and now it works as it should.
Even though I had checked the fan connections previously, I still missed it....