If there is a memory card fitted in the camera, try removing it and let me know if the camera turns on and off normally again. If it does, then the memory card is corrupt and will need to be reformatted or replaced.
If the camera still won't operate normally without a memory card fitted then the lens mechanism may be jammed - this can happen if something like a small grain of sand gets into it. It will need to be sent for repair if this has happened (a local camera repair tech could also clean it out for you).
Let me know how you make out...
Hi, just checking in on your question, do you need any further assistance?