The most common hardware problems are a bad controller, a bad
drive motor, or a bad head mechanism.
1. Can the BIOS see and identify the hard drive correctly? If
it can’t, then the hard drives on board controller is bad.
2. Does the drive spin and maintain a constant velocity? If it
does, that’s good news. The motor is functioning.
3. If the drive surges and dies, the most likely cause is a
bad controller (assuming the drive is cool). A gate allowing
the current to drive the motor may not be staying open. The
drive needs a new controller.
4. Do you hear a lot of head clatter when the machine is
turned on and initialized (but before the system attempts to
access the hard drive). Head clatter would indicate that the
spindle bearings are sloppy or worn badly. Maybe even lose and
flopping around inside.