One of the main components of any computer is the hard drive. This device is also known under the slang names "screw", "broom", hard drive "," hard drive "," hard ". The latter owes its origin to the English name - Hard Drive Disc (HDD), in Russian use reduced to “hard”.
Winchester is a kind of information storage, data on which, unlike RAM, is stored even when the power is completely disconnected. To a certain extent, old video and audio cassettes, in which magnetic tape performed the same function as disks in hard drives, can serve as an analogue.
There is no doubt that many computer owners would like to know the hard drive device. What clicks inside when turned on, why there is a rattling sound when the information is read / written actively, etc. Yes, and there are windows of an unknown destination on the case. There are many questions, but the hard disk device remains a mystery.
With this article we want to shed light on some key points. In addition, perhaps an inquisitive user who decides to independently start repairing hard drives with disassembling the case, will think about the feasibility of this ten times and contact a service center.
The enclosures of all existing hard drives are made of metal. The control electronics board is located on the bottom side. Microcircuits can be soldered both from the outside (old models), and from the inside. This does not affect the performance in any way, unless it is accidentally possible to touch the protruding microcircuit with an internal arrangement.
A hard disk device involves placing on this controller board (MCU), a buffer memory chip (familiar DDR), a read-write head control module - VCM, ROM memory with control firmware and a protection diode (TVS). The board is connected to the internal elements of the case (pressure zone) by copper clamping contacts.
Of course, the hard disk device cannot be understood without removing (real or mental) the upper case cover. Inside, on a single spindle of an electric motor (from 5400 to 15000 rpm, depending on the model), several disks of non-conductive material are placed. A magnetizing layer is applied to their surface: recall the cassettes - there the basis was a polymer tape.
Each disk is placed in a special aerodynamic arc, forming the necessary air flow. The frame, at the ends of which the heads are placed, is locked off in a special parking zone outside the surface of the discs using a latch and (or) a magnet. After spinning up the spindle, air flow is created, the VCM board unlocks the frame and puts it into working position. The heads do not touch the surface of the disks, but fly over them on an
air cushion. By the way, when the power is turned off, the rotation energy is enough to generate enough current to bring the heads to the parking zone (20-30 years ago it was necessary to run a high-level parking program).
Thus, there is no vacuum inside the hard drive, and the “windows” in the case are needed to equalize the pressure inside and out. Of course, the air inside is virtually dust free. Chirping with the active use of the hard drive occurs due to the frequent positioning of the heads on the desired section of the disk (track). Well, a quiet click when turned on can be caused by unlocking the parking zone or the frame self-test.
By the way, the device of the external hard drive is exactly the same. Exception: solid-state memory-based models that are gaining popularity operate on completely different principles.