I tried selling the HDD to the second hand computer parts vendors lining the pavements of lamington road.None of these computer vendors seemed interested in my HDD.I guess that's because home pcs seldom use scsi drive al though its widely used in servers.I came back home with a cheap chinese made torx srewdriver set which i got for cheap there.
I had no option but to throw away the hdd since nobody would buy it. I thought of opening the hdd before i could let the hdd rest in peace.
The hdd was an old 18.64 Gb seagate barracuda.
The LCT spindle chip burnt out when i was fiddling with the hdd.i tried powering it directly from a laptop charger,an old power supply of a lexmark printer!!! notice the dent on the chip!!
I started by removing the pcb mounting screws.to unmount the pcb from the hdd body.
The various components on the pcb of the Hdd are as follows.Notice that the only contact between the hdd and the pcb is made by spring contacts there are no soldered contacts asone might have guessed!!
These are all the components i could identify since i'm just a newbie.
Data contacts connect the main unit to the pcb all the data transfer takes place through these pins. The spindle motor is a special type of a stepper motor . Unlike steppers wich has 2 coils its actually a"brushless" three-phase motor driven by three phase current.The lct spindle chip drives the motor.The motor has 3 coils .Each driven by 3 sine waves 120 degrees out of phase.thus the motor runs on analog waveform rather than digital steps as in stepper motors.
Now for the label side of the HDD
The head movement assembly moves the head to the position where the data is stored this is a stepper motor.The motor is made up of a coil attached to the arm.this coil lies between the extremly strong magnets.when current is applied to the coil the coil moves causing the arm to move. the movement of the arm is proportional to the signal applied hence it forms a stepper.By applying the right amount of current the arm movement can be controlled very accurately so as to move the head to the appropriate position where the data is stored.
The metal supports carrying the head are very flexible and delicate. here's a closeup of the head
the head assembly has of an ic on board.sorry for the blurry image i will upload a better image as soon as possible