Potentially the single most important piece of equipment in the average users' computer is their hard drive.

It stores all of your important data.  The operating system, music, videos, documents, browser bookmarks and everything else that is too important to lose.

While the inner workings of a hard drive are complicated, there really are only 3 parts the average user needs to be aware of in order to understand how they function, and how they break. (If you think of a hard drive like a small record player it'll help.)

1) Platters- The platters inside a hard drive are very much like the surface of a record.  They spin very quickly (sometimes up to 12,000 times a minute) and store data.  They are generally made out of ceramic or glass and have very delicate surfaces.

2) Actuator arm- The actuator arm holds tiny devices (read/write heads) that read and write the data onto the platters.  The read/write heads sit just above the platters and write data without actually touching it.  The arm moves along the platters to access the information on the disc.

3) Hard drive actuator- The actuator can be thought of like a motor that moves the actuator arm into the proper position so that the read/write heads can access data on the platters.

Now that we have a basic understanding of how hard drives work, we can look into what causes them to fail and how to best avoid accidental damage.

As mentioned before, the read/write heads should never actually touch the surface of the platters.  When this does happen however, a head crash occurs.  A head crash scratches the delicate outer layer of the platter causing the scratch to worsen each time it hits the crash site. With the hard drive spinning between 5,400 and 12,000 times each minute, that's a lot of damage done with each pass.  The biggest cause of head crashes in today's computer is the simple power flicker.  When the power in your home flickers, it jars the actuator arm and forces the head to crash into the hard drive platter.  Another common cause of this damage is when the user improperly turns off their computer.  When a computer  is properly shut down a signal is sent to the hard drive telling it to move the actuator arm away from the platter, forcing it to park in a safe position.  When the computer is shut down incorrectly the signal is  not passed along to the drive and the actuator arm runs the risk of jumping onto the platter.

The easiest way to protect yourself from head crashes is to be sure to properly shut down your computer and to use a quality battery backup system.

These two simple steps can dramatically decrease your chances of causing permanent damage to your hard drive or losing your data.

Wave Front Computers

@WavefrontPCMAC

http://www.wavefrontcomputers.com/blog/computing/how-does-a-hard-drive-work