How old is your HD?
Have you installed new hardware in your PC lately?

Maybe the belt from the board(or the power cord) to your HD disconnected, I will recommend cleaning your pc with a air blower and reattach the belt from your board to your HD. If that dosen't work, test your HD in someone else PC, there you can see if your HD suffered a electric overload or not.

I hope your HD is fine

2 years old. The slave doesn't work either. Tried can of air, disconnect reconnect first. Changed boot order, and reserved BIOS. It's looking like a short circuit.