A wrong move can never be corrected.Many of us know one or more person who has attempted data recovery from crashed computers.
Within a majority of the events where the users have tried to recover lost data on their own, it has only ended in conditions that even an authority can't fix and irreversible loss of data!Allow us to hark back to reason number 1 - a tough drive is delicate delicate delicate!
The disk platters are finicky about what comes into exposure to them and can react adversely to dust, fingerprints and any other debris.These platters are moved with the spindle which moves according to the speed based on an electric motor.
The valuable data held within the folds with the platters is accessed by the actuator arm.
So when an untrained hand dives into this balanced mechanism, it may set into motion all kinds of disturbances which may cause an irretrievable loss of data.For example one of several elements of today's hard drive technology - mechanical precision.
Just how much this precision brings about the truth that the top assembly of the hard drive can be so finely tuned that any contact or operation about it needs specialized tools.