Head faults - Recovering data from
noisy / clicking / ticking hard disk drives
Symptoms: When the computer is powered
on, the hard disk -
(1) Will not be recognised by the computer and
(2) A ticking or knocking sound will be heard coming from the hard
disk at regular intervals (often about 1 / second).
An error message similar to "Hard Disk not found" or "No
system disk present" will be displayed, and the system will then
halt.
Hard drives with these failure symptoms are often indicative
of an internal failure of one or more of the read / write heads in
the hard disk assembly. This type of failure is found with both desktop
and laptop hard drives. Fortunately, if the correct recovery processes
are applied, data from hard disks with these failure symptoms is often
recoverable.
What is happening when the hard disk makes a
ticking sound ?
Data is written to / read from the hard disk platter surface by a
read / write head which is located at the end of an arm that moves
across the hard disk platter surface when the disk spins. A faulty
hard disk that produces a knocking sound is likely to have a fault
on it's read / write head. The knocking sound you can hear is caused
by the arm of the hard disk knocking against other components in the
hard drive.
Example:
The movie below shows a laptop hard disk with a head failure. We have
removed the cover of the hard disk so you can see what is happening
internally.
(1) First of all, the disk powers up and the platter begins to spin
until the correct rpm is reached
(2) The arm containing the read / write head then moves out onto the
platter surface and attempts to read some basic information from the
hard disk. However, because of the faulty head the disk is unable
to read the data correctly.
(3) The disk then resets itself and attempts to re-read the data.
This stage is repeated a number of times and is what produces the
knocking noise.
> Sometimes
a ticking hard disk is not caused by head problems,
read about NV-RAM
corruption on Deskstar hard drives, and data
corruption in the 25P05AVG flash ROM chip which
is often used in hard disk drives
If your drive is making a beeping sound it may well
be suffering from a hard
disk motor failure.
>> Visit
our laptop
data recovery section
>> Visit our general
types hard disk failure section
>> Visit our main
data recovery section
Please note that all modern hard
disk drives are manufactured to very high standards, fail infrequently
and have very similar rates of reliability
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