Fujitsu MHY2040BH, Product/Maintenance Manual, Page: 64 / 322

Theory of Device Operation
4-6 C141-E262
4.4 Power-on Sequence
Figure 4.3 describes the operation sequence of the disk drive at power-on. The
outline is described below.
a) After the power is turned on, the disk drive initializes its SATA interface
block.
b) The disk drive executes the MPU bus test, internal register read/write test,
and work RAM read/write test. When the self-diagnosis terminates
successfully, the disk drive starts the spindle motor.
c) The disk drive executes self-diagnosis (data buffer read/write test).
d) After confirming that the spindle motor has reached rated speed, the head
assembly is loaded on the disk.
e) The disk drive positions the heads onto the SA area and reads out the system
information.
f) The drive becomes ready. The host can issue commands.
g) The disk drive executes self -calibration. This collects data for VCM torque
and mechanical external forces applied to the actuator, and updates the
calibrating value.