If you don't give any information as to why your drive might not function anymore there's little we can do to help.
When asking for help, be sure to provide the information necessary for others to provide that help:
1) post what product you are having problems with
2) post what hardware you connected it to (motherboard/chipset)
3) post what you have tried to identify the problem
4) post the diagnostic information provided by the harddrive itself (SMART information)
etc. without any of this any reply you will get will be useless and unhelpful.