We work on a fair number of Fujitsu's and I see nothing in their logs about a BIOS issue, but of course, we do not know your model.
You can try these two sites for more assistance from Fujitsu. You will need the model number and other details from the bottom of your notebook:
http://support.fujitsupc.com/CS/Portal/support.do?srch=DOWNLOADS
For telephone assistance, please contact their technical support staff at 1-800-8FUJITSU.
If there is a known issue with the fan, they will help.
The fan does shut down or slow down when not needed on many models... Do you get any indication that it is running too hot or operating intermittently? Does it report that it is shutting down due to heat? What is the error message.
On some models , it is just quietly but running. The error message is the clue
Otherwise, Fujitsu will fix it quickly and have it back to you within a week if still in warranty, and any good repair shop can get a replacement fan installed quickly and relatively cheaply... usually under $50 including shop time and replacement. But for some, the part number takes two to three weeks to arrive.
We have never seen one go bad... but of course, any laptop fan is fragile and subject to sudden failure.