Q: hi I just recently bought an iphone 5s and the fingerprint sensor didn't work can anyone help?  thx

Hi. I just recently bought an iphone 5s and the fingerprint sensors didn't work.. ive try to turn on and off but it doesn't seems to work.. I try almost everything non have work.. some say is the I os 7.1.1 have some problems with it.. is it true? And can anyone help me with this issue?  Thx a lot..