Drive repair. Typical faults

Introduction

optical drive interface

Drive failure is a common occurrence, and its repair turns out to be quite problematic for the owner. A typical situation is when service center specialists offer either a replacement of the electronics board or a replacement of the laser reading head (Fig. 1).

Figure 1. CD-ROM drive

The actual repair in this case turns out to be little cheaper than a new device and becomes impractical. What to do in such a situation? Malfunctions of optical drives are eliminated mainly by completely replacing “optics” or “electronics”, which is quite expensive. A structured approach and some knowledge of the device will help you isolate the problem and find the faulty part.

Quite if you apply a certain systematic approach and localize the fault. All that is necessary for this is to classify the fault according to its characteristic features. It sounds simple, but it requires an understanding of the operation of all drive elements and actual knowledge of the characteristic signs of malfunctions. To do this, let's look at how exactly the interaction of various drive elements occurs, and at the same time we will highlight them. Typical faults: experience shows that most of the OP faults are associated with the incorrect operation of mechanical elements. The mechanical elements of the drive perform two main functions: loading and unloading the disc from the disc receptacle and moving the pickup along the disc field. The implementation of these functions is ensured by appropriate motors and their drive circuits. In accordance with the structure of this rather complex device, three main groups of its “diseases” can be named: mechanical malfunctions; malfunction of the optical system; malfunction of electronic components. This course work provides methods for typical maintenance of a CD-ROM drive, maintenance, testing of optical drives, and typical malfunctions of optical drives. Many serious optical drive problems can be fixed with your own hands. The main thing is to want it and not be afraid to experiment.

The relevance of the topic under study lies in the fact that today the development of computer technology has led to the need not only to transfer a large load of documentation and performing mathematical calculations to computer equipment, but also to develop methods for maintaining this equipment in working condition.

The goal of the project is to explore technology for diagnosing faults and restoring the functionality of optical drives after a failure.

The object of the project is methods for carrying out maintenance of optical drives.

The subject of the project is the technology for repairing optical drives.

To achieve the goal, it is necessary to solve the following tasks:

)Consider the design of optical drives.

)Describe the operating principle of optical drives

)The causes of problems should be considered and analyzed.

)Describe the use of diagnostic programs.

1. Main part

.1 Connecting optical drives

Today, there are several ways to connect optical drives. The first method is based on the fact that one IDE interface channel (Fig. 2) can support two built-in devices.

Figure 2 - Drive with IDE interface

The optical drive is connected to the I/O board via the IDE interface along with the hard drive according to the master/slave principle. However, in this case, the speed of data exchange with the hard drive is reduced. One way to solve this problem is to connect CD/DVD ROM devices to different channels of the same EIDE interface or to two different IDE controllers. If the drive has a SCSI interface (Fig. 3), then it is connected to the SCSI controller accordingly. Another approach is to use 32-bit drive drivers instead of the currently used 16-bit ones.

Figure 3 - Connecting the SCSI interface

It is also possible to connect disk drives via a sound card controller. Also, we should not forget that modern motherboards can contain built-in SCSI and IDE controllers, which generally eliminates the need for an additional I/O card to connect CD-ROM drives. It is also possible to connect drives via the SATA interface (Fig. 4). Due to its shape, the SATA cable is more resistant to multiple connections, which allows for multiple connections. The SATA interface has greater bandwidth than IDE and SCSI, which allowed SATA to gain popularity and become the main interface for computer components.

Figure 4. Drive with SATA interface

1.2 Installing the optical drive driver

A driver is a mandatory component of the software of any device that can be installed or connected to a personal computer in one way or another. The main task of the driver is to provide standard access to the device to other programs and the operating system. Once the download is complete, the operating system will detect a new device installed on the computer. In the Found New Hardware Wizard dialog box that appears, click Next. In the next window, select “Search for a suitable driver for your device (recommended)” and click “Next”. In the window asking you to specify additional sources for your search, click “Next.” After the installation wizard finds the required driver on the disk, in the window confirming this, click “Next”. The installation wizard will begin copying and installing the driver components. After copying is complete, in the window that appears notifying you that the driver has been installed successfully, click “Finish.” Choosing an optical drive is not difficult if you rely on a few basic characteristics.

1.3 Selecting an optical drive

It's hard to imagine a modern desktop computer or laptop without an optical drive. After all, it is on CDs and DVDs that distribution kits, music collections and new films are usually located. The presence of a drive is especially important in the event of a PC failure (Fig. 5). Restoring the system on a machine completely killed by viruses or crooked hands without a CD/DVD reader will be extremely difficult.

Figure 5 - CD/DVD drive

For an ordinary PC, the choice of an internal optical drive is optimal - convenient and profitable in all respects. If your computer has a compact case, such as a barebone format, a standard internal drive may not fit there. Some manufacturers, in particular Lite-On, produce shortened and lightweight drives. Moreover, the length of the device is 170 mm (versus the standard 198 mm), and the weight is 750 g (versus 900-1000 g of the standard weight). Laptop owners definitely shouldn't buy a regular internal drive. Ultra-thin (slim) drives are produced especially for them (Fig. 6), but installing them on your own is quite a responsible task. It is better to use the services of a service center from the manufacturer of your mobile PC. The length of such a flat drive is 130 mm, weight is slightly less than 120 g, and the price is high.

Figure 6 - Ultra-thin (slim) drive

With interfaces everything is quite simple. The vast majority of drives have an IDE (parallel ATA) connector. For connection, 40- or 80-wire cables are used. Recently, models with a SATA interface have begun to appear (instead of a cable - a compact cable (Fig. 7). You should buy them only if you have a modern motherboard in your computer. Theoretically, SATA is faster than PATA, but in practice the speeds of the drives are absolutely the same .

Figure 7 - SATA cable

There are not so many companies producing external optical drives. An external drive is more expensive, but in terms of functionality it is often inferior to an internal one. But an economical option is to buy one drive for several PCs or for an office. In this case, mobility and connection speed justify the high price. Owners of laptops are another matter. The built-in drive may either be missing or not perform the required functions. Purchasing and installing a thin internal drive will be expensive. In this case, an external drive is recommended (Fig. 8).

Figure 8 - External drive

The most budget options are very similar to their domestic brothers, especially with their angular design. More expensive drives can boast a stylish case and the presence of several interfaces for connecting to a computer. Finally, among external drives there are slim models. They are positioned as stylish accessories for laptops and sometimes have a stunning appearance and price. Today, the most widespread models are those connected to a PC via a USB bus. Sometimes there are drivers with a wireless FireWire (IEEE1394) connector, as well as combined USB+FireWire. The maximum data transfer speed via USB is 480 Mbit/s, via FireWire - 400 Mbit/s. Even the fastest drives load the channel at no more than 200 Mbit/s. The peculiarity of external optical drives is that they require additional power.

It is not easy to earn fame and trust from users, and when buying a product, people are increasingly paying attention to the brand. All brands can be divided into cult, mainstream and little-known. Plextor is primarily among the cult ones. It is he who has been considered the king of recording for several years. This affects primarily the prices - they are relatively high. But in return, Plextor guarantees maximum operating speeds with high reliability and durability. A fresh contender for the championship is NEC. The last few models of this company turned out to be very successful and gained great popularity among Russian users. Their main strong point is reliability. The main brands of optical drive manufacturers after the above, which it makes sense to focus on today: BenQ, TSST, Toshiba, HP.

1.4 Purpose, design and operating principle of CD-ROM

The drive's operating principle is similar to that of conventional floppy disk drives. The surface of the optical disk (CD-ROM) moves relative to the laser head at a constant linear speed, and the angular speed varies depending on the radial position of the head. The laser beam is directed onto the track and focused using a coil. The beam penetrates the protective layer of plastic and hits the reflective layer of aluminum on the surface of the disk. When it hits the protrusion, it is reflected onto the detector and passes through a prism, which deflects it onto a light-sensitive diode. If the beam hits the hole, it is scattered and only a small part of the radiation is reflected back and reaches the photosensitive diode. On the diode, light pulses are converted into electrical ones, bright radiation is converted into zeros, and weak radiation into units. Thus, the pits are perceived by the drive as logical zeros, and the smooth surface as logical ones. The performance of a CD-ROM is usually determined by its speed characteristics during continuous data transfer over a certain period of time and the average data access time, measured in KB/s and ms, respectively. There are one-, two-, three-, four-, five, six and eight-speed drives that provide data reading at speeds of 150, 300, 450, 600, 750, 900, 1200 KB/s, respectively. Currently, two- and four-speed drives are common.

In general, 4x-speed drives provide better performance, but the net benefit of a 4x-speed drive over a 2x-speed drive can be difficult to assess. First of all, it depends on what operating system and what type of application you are working with. With a high intensity of repeated access to a CD-ROM and reading a small amount of data (for example, when working with databases), the “pulse” speed of reading information becomes important. For example, according to InfoWorld, 4x-speed drives perform on average twice as fast as 2x-speed drives on database accesses. In the case of simple data copying, the gain ranges from 10 to 30%. However, the greatest benefit will come when working with full-length video. To increase the performance of disk drives, they are equipped with buffer memory (standard cache sizes: 64, 128, 256, 512, 1024 KB). The drive buffer is a memory for short-term storage of data after it is read from the CD-ROM, but before it is sent to the controller board and then to the CPU.

This buffering allows the disk device to transfer data to the processor in small chunks, rather than taking up its time by slowly sending a constant stream of data. For example, MPC Level 2 requires that a 2x speed CD-ROM drive consume no more than 60% of the CPU resources.

An important characteristic of the drive is the buffer fill level, which affects the quality of playback of animated images and videos. This value is defined as the ratio of the number of data blocks transferred to the buffer from the drive and stored in it

before the start of their output to the system bus, to the total number of blocks that the buffer can accommodate. Too much fill may cause delays in output from the buffer to the bus; On the other hand, a buffer that is too low will require more attention from the processor. Both of these situations lead to jumps and stuttering during playback.

1.5 Diagnostics of CD-rom performance and fault detection

Scheme.

1.6 Troubleshooting optical drives

DVD drives and CD-ROM drives are no fundamentally different from each other. Therefore, the problems and malfunctions of these devices are almost the same.

Over the long history of the CD/DVD, many computers suddenly displayed unpleasant messages on the screen such as “disc missing” or “no connection to the device,” but it was impossible to obtain more specific information from the PC.

Such malfunctions can be associated either with a complete loss of functionality of the devices themselves, or with a refusal to read certain disks (while reading others normally). So-called conditional failures (floating faults) also cause a lot of trouble, when disk reading either suddenly stops and then resumes, or is carried out with errors.

Of course, many failures are associated with cheap pirated disks, the use of which can interfere with the smooth operation of the device. Moreover, in addition to the fact that the information on such a disk may not be readable, the use of unbalanced disks in high-speed drives often leads to the destruction of both the disk itself (it literally shatters into small fragments) and the structural elements of the reading device.

When purchasing a disc, pay attention to its workmanship. The disk should not have nicks, sagging or damage, and its working surface should be free of scratches and foreign inclusions (bubbles, visible irregularities, etc.). Check the discs both inside and outside, since the information layer is located just under the colorful CD/DVD label.

However, “pirates” are not always to blame for failures of optical drives. As practice has shown, failures of CD/DVD devices are quite frequent.

1.7 Basic malfunctions of CD/DVD drives

It is not difficult to classify optical drive malfunctions based on their external manifestations, but the reasons that caused them may be different.

The following manifestations of malfunctions can be distinguished:

)The CD/DVD drive is not detected by the computer;

)the drive is detected, but the disk does not spin up;

)the tray is thrown away and immediately put back;

)the disc is accepted and immediately thrown back;

)The drive reads discs poorly or does not read them at all.

If the drive is not detected by the computer at all, then the reason may not be there, but in the operating system settings, BIOS settings, or a malfunction of the motherboard IDE controller.

Therefore, you first need to check the reliability of the connection between the power wires and the IDE cable suitable for the device. After this, check that the MASTER/SLAVE jumpers are installed correctly on all devices connected to this cable. The optical drive should not conflict with a hard drive connected to the same IDE interface cable. Then you should make sure that the BIOS settings are correct and see if it detects this optical drive and other devices connected to the same IDE cable. If the device is not detected, then you need to try disconnecting other devices from the IDE cable and connecting the cable itself to another controller. In the case of a CD-ROM with a SCSI interface, check that the address is set correctly (other SCSI devices should not have this address) and see if the device appears in the BIOS of the SCSI controller.

If all else fails, then you may need to check whether the firmware in the ROM memory of the optical drive (most often it is Flash memory) is damaged, whether the secondary voltage source (3.3 V) or fuses (resistors) are burned out. To protect the power supply, an optical drive always has an additional filter, and sometimes additional 5 V stabilizers are installed, the failure of which usually leads to the same effect.

All other malfunctions can be divided into three types:

1)mechanical failures;

2)malfunction of the optical system;

)malfunction of electronic components.

Prevention and treatment

The main causes of malfunctions of optical drives are, of course, mechanical failures. They make up about 75-80% of the total number of faults. Moreover, most often the reasons for the failure of CD/DVD drives (both computer and household, intended for listening to music and watching movies) are contamination of the moving parts of the disc transport mechanism and dust accumulated on the optical parts (Fig. 9)

Figure 9 - dust accumulation in the drive

In order to clean the drive from dust, you can first limit it to partial disassembly (pull out the tray and remove the front panel), and then blow out the insides of the drive with a vacuum cleaner set to blow out an air stream.

Most drives operating under normal conditions do not reach the stage where increased dust levels can cause failures. Most often, the plastic of the lens simply becomes cloudy from time to time and/or from overheating of the drive in the system unit. Such a malfunction can only be eliminated by an expensive replacement of the laser read head. However, such a malfunction accounts for no more than 10% of cases.

Characteristic signs of a malfunction are either the lack of rotation of the disk, or, conversely, its constant acceleration to maximum rotation speed. When you try to remove a disk from a faulty drive using the controls, the carriage opens with the disk rotating on it.

In the operation of a working system, the following phases should be clearly visible:

)start and smooth acceleration of the disk;

)steady state of rotation;

)braking interval to a complete stop;

)removing the disk from the motor spindle using the carriage tray and moving it out of the drive.

You can check whether the optical drive system is working properly by opening the device and observing its operation. You can verify whether the disk spins up after installation by connecting only the power cord to the drive (the data cable is not connected). If the disk does not rotate after installation, then check whether the laser lights up when the carriage is installed in the working position, but without the disk. Sometimes the laser glow is not visible in daylight, so the room needs to be darkened. Observation of the laser lens should be carried out from different angles.

In modern optical devices, the presence of a disk is monitored by the laser itself. If a photosensor installed in a laser carriage receives a reflected signal from a disk, then the electronic circuit perceives this signal as “the presence of a disk” and only after that generates a command to turn on the main rotation motor. Consequently, if the intensity of the laser light is insufficient, the disk will not spin.

Optical drives also have many mechanical components that require lubrication of rubbing parts. Lack of lubrication leads to the fact that the drive has difficulty pushing out the carriage with the disk, and the carriage lock may even jam, and then using the disk drive will become impossible at all. Lubricant must be applied carefully, after completely disassembling the device (the places where it is required are usually clearly visible). Before lubrication, it is a good idea to clean the lubrication points from dust and dirt. The fact is that if you miss the moment when it is necessary to apply lubricant, then the difficulty in sliding will lead to mechanical breakdowns of the parts of the transport mechanism or disruption of its adjustments, which, in turn, will entail either stopping the carriage mechanism in an intermediate position, or slipping the disk in rotation time.

A similar situation can also arise due to clogging of the friction surfaces of the disc holder due to the frequent use of dirty CD/DVD discs, which ultimately leads to unreliable operation of the drive, even to its complete stop.

Contamination of the disk drive seat and weak pressing of the disk to the seat can be eliminated by cleaning the disk seat with any woven material soaked in alcohol.

Other mechanical failures include jamming of the disk on the transport carriage (in this case, the disk does not unwind at all). Sometimes this happens because the disk seat spontaneously lowers along the motor shaft and the disk touches the elements of the transport carriage. To eliminate this defect, the seat is moved upward along the shaft and its height is selected “at random” so that the disk rotates without touching the structural elements, and also so that the drive ensures stable reading of all disks. After this, the position of the disk seat is carefully fixed on the shaft.

Finally, electronic components may malfunction. However, their share hardly exceeds 5-6% of all breakdowns (Fig. 10). Unfortunately, modern optical drives are very complex electronic systems, and a faulty microcircuit is no different in appearance from a working one.

Figure 10 - faulty electronic components

In short, if after cleaning, checking all wires and connections, as well as system settings, your CD/DVD drive does not work, and its warranty has already expired, then simply throw it away and buy a new one.

2. Special part

.1 Cleaning optics in optical drives

The laser beam is reflected from the prism, passes through the focusing lens and falls on the disk. Having reflected from the disk, the beam returns, passes through the prism and falls on the reading photodetector (Fig. 11).

Figure 11 - CD-ROM device diagram

As you can see, contamination of a lens or prism doubly impairs the passage of the beam, since it ends up in its path twice. Dirt getting on the laser optics is the most common reason for the drive to stop working normally: the device “stutters”, does not “recognize” or does not spin the disks (Fig. 12).

Figure 12 - CD-ROM optics: a) dusty lens, b) clean lens

Contamination of the objective lens is the most common and simplest malfunction. It is best to blow off dust from the surface of the lens using an aerosol can. A thin plastic tube extends from the head of the can, allowing you to direct the air to the desired location. To clean the laser, point the tube at the lens and “blow” on the laser for 1-2 seconds. You can also use a CD cleaning disc; you just need to apply one drop of cleaning liquid to a special brush on the CD and install it in the household CD player or computer CD/DVD drive that you want to clean. The surface of the lens can also be cleaned with a cotton swab. If the contamination is severe, you can use ethyl alcohol. Do not press hard - this will erase the special anti-reflective layer on the surface of the lens. And the lens suspension mechanism is very delicate; pressing it can damage it (Fig. 13). Attention: do not use acetone under any circumstances - the lens is made of plastic and you will hopelessly ruin it. If cleaning the surface of the lens did not help, then dust probably got inside the laser, onto the surface of the prism. This is a more complex contamination, but it can be dealt with. But to do this you will have to disassemble the laser.

Figure 13 - CD-ROM disassembled

Having pressed out the tucks, remove the safety cap and you will see the following: A complex structure near the lens is a special electromagnetic suspension. It is part of the automatic beam focusing system. During playback, the electromagnet continuously adjusts the position of the lens, maintaining a constant distance between the lens and the disk. This is necessary because, when rotating, the disk undergoes significant oscillations in the vertical plane, and without an automatic focusing system, normal operation of the optical drive would simply be impossible. The first way to clean the prism is simple. Bring the tube to the gap between the lens and the body and blow through the prism several times in short bursts (Fig. 14)

Figure 14 - Can of compressed air

You cannot blow for a long time, since the compressed air leaving the cylinder is cooled and, thereby, the prism is also cooled. In this case, condensation of moisture from air at room temperature on the surface of the prism is possible. After the water droplets dry, dirt stains form, which will be very difficult to wash off. This method allows you to clean the dust that has settled on the prism, but for more serious contamination, use the second method. The second method: requires accuracy. Just like in the first method, remove the plastic cover. Underneath you can see two small screws. Apply thin marks to the metal frame where the screws go through and to the metal base on the laser body. This will allow you to correctly install the lens in place during reassembly. And this is very important, otherwise the optical axis will be damaged. Unscrew the screws and remove the focusing lens. There may be droplets of glue near the screws - carefully cut them off with a sharp scalpel. There is a prism in the shaft under the lens. You need to carefully wipe its surface. There is a slight difficulty here. The prism, as you remember, is tilted at 45 degrees, and a regular cotton swab is too thick. It can only clean the center of the prism. To remove dust from the corners of the prism, a thinner tool is needed. Aiwa supplies service centers with special, smaller sticks. At home, you can take a match, sharpen it and wrap a little cotton wool around the tip.

The main thing is not to scratch the surface of the prism and make sure that there is no cotton wool left inside the laser. Wipe the prism with a few movements. Reassemble the laser, precisely aligning the previously applied marks. Avoid sudden movements. The connecting cable between the lens electromagnets and the laser can be broken by careless movement. If after carrying out these operations the drive does not start working, then you can slightly add current. If nothing helps this time, then most likely either the laser can no longer be restored, or the fault lies elsewhere.

2.2 Checking the optical unit

It is advisable to use a magnifying glass and a bright light source to view the surface of the lens. The lens must be clean, transparent, without scratches, otherwise the power of the read beam decreases and the effect of a “hooked laser” is observed. The surface of the lens is covered with a special photosensitive layer, which gives it a bluish tint. To clean the lens, cans of special liquid are available. You can also use matches with cotton wool and alcohol. Wipe the lens with a cotton swab soaked in alcohol and immediately remove traces of alcohol with a dry swab. This must be done very carefully so as not to damage the suspension or disrupt the alignment of the focusing lens. Due to the use of active substances for cleaning, the lens may become cloudy over time. In practice, small scratches are allowed, but with large damage, reading the information becomes impossible. The laser head needs to be replaced or restored.

2.3 Checking the tilt of the lens

Lens tilt is the deviation from parallelism of the lens plane relative to the disk plane. This value should be minimal (Fig. 15).

Figure 15 - Lens tilt

Due to an increase in the tilt of the lens, the amplitude of useful rays decreases, track tracking deteriorates, so discs are difficult to read. Over time, due to changes in the characteristics of the coil suspension material (internal stress, etc.), the tilt of the lens may increase. Adjustment: Lens tilt adjustment can be carried out in one or two planes, depending on the LG model, or it is not provided at all (Fig. 16, where 1 - adjusting screws; 2 - spring; 3 - screw with spring; 4 - fixing screw ; 5 - hole for the adjusting key).

Figure 16 - Adjusting the tilt of the lens

Adjustment is carried out using screws 1. In most cases, tilt adjustment can only be done with the mechanics disassembled, “in the air”. The precise slope is adjusted based on the maximum amplitude of the EFM signal. If this signal is absent or weak, a rough adjustment may need to be made by eye first. To do this, apply a voltage of 1...2 V to the focusing coil so that the lens rises up to the disk without touching it. This makes it easier to see the tilt error (Fig. 2.1). The lens will not be able to rise above a certain level, so you need to be careful not to burn the coil. Then you need to adjust the tilt of the lens for maximum parallelism. After a rough adjustment at startup, the lens should focus and the dial should rotate.

2.4 Typical faults and methods for their elimination

.4.1 The operating system does not detect the optical drive

If the disk boots normally, the transport mechanism is working properly. Next, we check the connection of external connectors to the drive to eliminate the influence of bad contacts. Then, if possible, change its connection, i.e. change the port on the system board (IDE0 or IDE1). Next, check that the MASTER-SLAVE switch is installed correctly. If the device has a SCSI interface, you should change its address. If all this does not lead to a positive result, open the device and make sure that the connections of the information connector, power connector and device activity (address) switch are secure. Then we check whether the drive motor shaft rotates along with the disk. If it does not rotate, check the serviceability of the engine. Having disconnected both of its wires from the printed circuit board, we apply a constant voltage 5 to them from an external source in accordance with the color of the wires ("+" - red, "-" - black).

Rotation of the motor shaft indicates that the fault should be sought in the motor control circuits. Which of the microcircuits (there are only two or three of them on the printed circuit board) controls the electric motor is determined by the printed conductors going to it, to which the wires from the motor are soldered. In addition, several pins of this microcircuit (most often two or three middle ones) are connected to the common wire bus. It is also necessary to check the supply voltage of the control chip. Visually inspect the printed circuit board for darkening; if there is darkening on the board, check the parts located on the board near the darkening for serviceability. If you cannot find the faulty element, then you need to try replacing the control chip. Measure the speed stabilization voltage in the electric motor housing. I advise you to immediately replace the zener diode, and if that fails, then replace the entire motor assembly.

2.4.2 When you press the eject button, the disc does not open

In the event of such a malfunction, it is necessary to ensure that voltage is supplied from the input connector of the drive to its electronic elements. Then, in accordance with the above algorithm, the serviceability of the button, the electric motor of the transport mechanism and its control microcircuit are checked. In some devices, you also need to ensure the integrity of the rubber belt that transmits rotation from the electric motor to the driving gear of the transport mechanism

2.4.3 The drive is unstable and the information is read with errors

We check whether the laser glow (red) appears for 2...10 s when the transport mechanism is installed in the working position. The glow can only be seen from a certain viewing angle in a darkened room (under no circumstances should you look into its lens - this is dangerous for the eyes!). At this moment, the carriage with the laser should move back and forth, and the drive motor should turn on for a short time. After making sure that everything is working properly, lift the upper disc clamp and manually move the transport mechanism to the CD-ROM installation position, thereby opening access to the laser lens. Use a soft brush to carefully clean the lens of dust. This must be done with great care so as not to damage the laser suspension. Next, by moving the transport mechanism or disassembling it, the seat of the laser disk on the drive motor (drive gear) is freed. After this, first the landing disk (rubber ring) is cleaned of dust with alcohol, and then the upper pressure ring (if, of course, there is one). Finally, clean the rest of the mechanical part of the device from dust, check the movement of the laser carriage and, if necessary, lubricate its guide with technical petroleum jelly.

First, they check whether the OS is installed correctly in the system (whether the driver or the program that ensures “docking” of the operating system with the device is correctly selected and installed). Then check the correct installation of the MASTER-SLAVE jumpers on the device itself. The OP should not conflict with a hard drive connected to the same IDE interface cable. As for drives with a SCSI interface, check that the device address is set correctly (other SCSI devices should not have this address). Then open the case of the optical drive device and check whether the disk spins up after its installation. This operation can be carried out by connecting only the power connector to the OP; the information cable does not need to be connected. If the disk does not rotate after its installation, check whether the laser lights up when the OP carriage is installed in the working position, but without the disk.

Sometimes the laser glow is not visible. Then you need to check the glow again, but in a darkened room, and the laser lens should be observed from different angles. The fact is that in modern OP devices, the presence of a disk is monitored by the laser itself. If the photosensor installed in the laser carriage receives a reflected signal from the disk, the OP logic circuit perceives this as “the disk is installed” and only after that generates a command to turn on the disk rotation motor. If the laser glow is visible, but the drive motor with the disk does not start, increase the intensity of the laser glow. To do this, first find a variable resistor installed on the carriage with the laser. Usually it is very small in size (5...7 x 2...5 mm). Turn the slider of this variable resistor clockwise by 20...30°. Check the rotation of the drive motor when installing the disk. If the disk does not begin to rotate, turn the variable resistor slider another 20...30° and continue until the engine starts (the engine should start and rotate at a constant speed for some time, about 10...20 s speed). The need to rotate the variable resistor that regulates the intensity of the laser glow is due to the fact that over time the power of the laser light flux decreases (aging of elements, clouding of the lens, etc.), so this needs to be compensated.

2.4.5 Frequent device failures when reading disks

Possible causes of this malfunction may be: a decrease in the intensity of the laser glow, clouding or contamination of the laser lens, contamination of the disk drive seat, weak pressure of the disk to the seat. The decrease in laser light intensity is compensated as described in paragraph 1. Contamination of the laser lens is removed with a soft (for example, squirrel) brush. This operation is carried out extremely carefully, since the suspension of the laser itself can be damaged. Contamination of the disk drive seat can be cleaned with any woven material soaked in alcohol. You can check whether the disc is pressed against the seat if you first read a regular audio disc. If there are no errors or failures in this case, to ensure stable reading of computer disks, measures are taken to increase the pressure on the disk from above (bend the springs or increase the load).

2.5 Mechanical faults

.5.1 The drive tray closes and then opens immediately

The reason for this malfunction lies in a small switch, the lever of which, when closing the tray, is pressed and signals to the drive that the drive is closed. In this case, for some reason this switch does not work, so the drive, after closing the tray, immediately opens it again. You should find this switch and eliminate the reason for its inoperability. Most likely, the reason is purely mechanical, for example, the switch lever is bent, or oxidation of the contacts is also possible.

2.5.2 The tray closes, but the disc does not lock, or the tray does not close completely or hesitantly, with a loud grinding noise

2.5.3 No reading, disk does not spin up

The cause of this malfunction, unlike those given above, may be a jammed disk on the transport carriage. Often in this case, the disk seat spontaneously lowers along the motor shaft and the disk touches the elements of the transport carriage. To eliminate this defect, move the seat up along the shaft and experimentally select the height of the seat so that the disk rotates without touching the structural elements, and also to ensure stable reading of all disks. Then carefully (by punching) fix the position of the disk seat on the motor shaft.

3. Labor protection and safety requirements

TURNING ON THE COMPUTER

To turn on your computer, do the following:

)turn on the voltage stabilizer if the computer is connected through a voltage stabilizer;

)turn on the printer (if needed);

)turn on the computer monitor;

)turn on the computer.

TURNING OFF THE COMPUTER

)To turn off your computer you need to do the following:

)end running programs;

)turn off the computer (using the switch on the computer case);

)turn off the printer (if it is turned on);

)turn off the computer monitor;

3.1 Safety requirements during operation

After turning on the computer, the PC operator must monitor the results of automatic test programs that check the serviceability of individual computer units immediately after turning it on. Be sure to run antivirus programs daily.

During operation, the monitor screen should be no closer than 0.5 meters from the user’s eyes. It is forbidden to compensate for the lack of contrast and brightness of the screen or lighting by reducing the distance between eye level and the surface of the screen.

)To ensure optimal performance and maintain health throughout the work shift, regulated breaks should be established:

)with an 8-hour shift, 2 hours from the start of the shift and 1.5-2 hours after the lunch break, lasting 15 minutes each or 10 minutes after every hour of work;

The duration of continuous work with a PC without a regulated break should not exceed 2 hours.

If an emergency occurs or a situation that could lead to an accident, the signs of which are: the appearance of a smell of burning insulation, random spontaneous actions on the part of the software and other deviations, the operator must take measures to turn off the computer.

If necessary, the operator must be able to provide first aid.

On labor protection during electrical soldering:

1.Persons who have passed a medical examination and

.occupational safety briefing.

.Dangerous and harmful production factors:

Burns from a hot electric soldering iron or splashes of molten solder

Poisoning, eye and skin damage when working with fluxes and tin-lead solders.

Electric shock due to a faulty soldering iron.

.When performing electrical soldering work, special clothing is used: a cotton robe, beret, and safety glasses.

.If a student receives an injury, provide first aid to the victim, inform the administration of the institution, the victim’s parents, and, if necessary, send the victim to the nearest medical facility.

.After performing electrical installation work, wash your hands thoroughly with soap.

3.2 Safety requirements before starting work

.Wear protective clothing.

.Prepare and check the serviceability of the tool, accessories and electric soldering iron, make sure that the handle of the electric soldering iron and the power cord are intact.

.Check the reliability of the workbench grounding.

.Make sure that there are no flammable materials or flammable liquids near the workplace.

.Turn on exhaust ventilation.

3.3 Safety requirements during operation

.Handle the electric soldering iron with care, do not drop it or hit it with any objects.

.Do not touch the hot spots of the electric soldering iron with unprotected hands, be careful when soldering molten solder

.During short breaks in work, place the heated electric soldering iron on a special heat-resistant stand.

.Do not determine the degree of heating of the electric soldering iron by touching its heated parts with your hands.

.When soldering, use only rosin as a flux, do not use acid for this purpose.

.Do not leave an electric soldering iron plugged in unattended.

3.4 Safety requirements after completion of work

.Disconnect the electrical circuit from the power source.

.Clean up your work area and tools, turn off the exhaust ventilation.

.Shine your overalls and wash your hands thoroughly with soap.

Conclusion

The reliability of many drives deteriorates over time. This is mainly caused by two reasons: contamination of the focusing lens and degradation of the laser emitter (LED). The lens most often becomes dirty as a result of exposure to dust and tobacco smoke. You can use special cleaning discs to clean lenses, but some of them have hard brushes that can scratch the plastic of the lens. The lens can be cleaned more accurately by disassembling the drive and washing with a natural cotton wool swab moistened with warm water and soap, followed by wiping with the same dry swab. The lens must be handled with extreme care so as not to damage its soft plastic and suspension parts. Degradation (decrease in luminosity) of the laser emitter occurs in cases where the drive uses a low-quality LED, or it operates in the maximum mode for it. In some cases, the situation can be improved by increasing the radiation power with a subline resistor, which is found on the heads of most drives, but after some time the power will again drop below normal. An excessive increase in power also reduces the reliability of disk reading, and also accelerates the degradation of the emitter. Another possible reason is wear of the mechanical parts of the drive and deterioration in positioning accuracy, but this occurs mainly only in very simple and cheap drives, where measures have not been taken to eliminate backlash in the transmission mechanism.

List of sources used

Hacker magazines, founder and publisher of Game Land CJSC, 1999-2004.

Magazines “Game World Navigator”, founder of “Biblion” LLC, 1999-2003.

Book of the series “What is What”, “Multimedia and Virtual Worlds”, Andreas Schmenk, Arno Wetjen, Rainer Köthe, publishing house “Slovo”, 1998.

“Physics reference book for schoolchildren and students,” edited by prof. Rudolf Goebel, Bustard publishing house, 1999

.#"justify">Article “Laser discs and drives”, site “Computer from Scratch”

.#"justify">.#"justify">.#"justify">.#"justify">.Repair and service magazine - Repair and maintenance of CD drives Author Rodin A.

.#"justify">.Book “Personal Computer Hardware. Self-instruction manual" Author - Valentina Solomenchuk, publishing house "BHV-St. Petersburg" in 2003.

. #"justify">. Book "Hi-Tech"

Http://cxem.net/comp/comp23.php article “Repair and maintenance of CD-ROM drives” site “soldering iron site”.

Drive repair. Prevention and treatment.

The main causes of drive malfunctions are mechanical failures. They make up about 75-80% of the total number of malfunctions and repairs associated with it. Moreover, most often the reasons for the failure of DVD drives (any kind, not just computer ones) are contamination of the moving parts of the disc transport mechanism and dust accumulated on the optics. Repairing a disk drive is almost guaranteed to be equivalent to the cost of a new one, so we read carefully and weigh whether the skin is worth the candle.

Is the disc still in the drive? Emergency holes for a thin screwdriver blade will force the tray to open.

Repairing a disk drive is not a trivial task.

The presence of dust and dirt on the moving parts of the mechanism, especially on the edges of the moving carriage slides, makes it impossible to lock the drive mechanism that holds the disk, as a result of which the device does not lock the disk and constantly throws it out. If, on the contrary, the drive ejects the tray and immediately takes it back, then most likely the cause of the defect is a failure of the tray position sensor. The drive detects that the tray has been ejected using a contact sensor, which you should find and try to correct its position, repair or replace. Repairing the drive as such is not necessary here; from time to time, just check to ensure that dirt does not accumulate in the places where the slide moves.

In order to clean the drive's disk drive from dust, you can first limit it to partial disassembly (pull out the tray and remove the front panel), and then blow out the insides of the drive with a vacuum cleaner configured to blow out an air stream. This is not yet about repairing the disk drive.

The optical drive system often fails due to dust accumulated on the focal lens or prism. If blowing through the device does not help, you can try to wipe off dust from the lens with a soft flannel or a brush/stick, as in the picture.

Remember that under no circumstances should you use alcohol or solvents for cleaning!

The focal lenses of most modern optical drives are made of organic plastic, and solvent will irreversibly damage their surface. It is best to wipe a heavily soiled lens with a piece of hard paper (at worst, with a cotton swab, being careful not to leave any lint). This operation is carried out extremely carefully, since the suspension of the laser itself can be damaged. Repairing the drive in this case will be expensive, almost equal to the cost of the drive itself.

The situation is more complicated with the prism that stands behind the lens - it is extremely difficult to get to it. Moreover, the head, as a rule, is not dismountable, but even if it is disassembled, its settings can be lost. Therefore, for most drives, contamination of the lens means its complete unsuitability. Sometimes the optical system fails even because of an ordinary hair caught on the prism - in this case, again, you can try to blow through the system with a powerful stream of air. Otherwise, repairing the drive (its cost) will be unreasonably high.

By the way, it is not recommended to use special discs supposedly designed specifically for this purpose to clean optics. Most of them will not only fail to clean your drive, but may even seriously damage it. After all, modern optical drives spin the disk to a very high speed and at the same time have a very delicate read head, so if you value your device, then do not clean it using such devices. This will no longer be repairing the drive, but almost deliberately disabling the drive.

However, most drives operating under normal conditions do not reach the stage where increased dust levels can cause failures. Most often, the plastic of the lens simply becomes cloudy from time to time and/or from overheating of the drive in the system unit. Repairing a disk drive involves an expensive replacement of the laser read head. However, such a malfunction accounts for no more than 10% of cases. Here we can, of course, advise increasing the intensity of the laser glow. To do this, adjust the variable resistor installed on the carriage with the laser. Turn the slider of this variable resistor clockwise by 20-30°, and then check the rotation of the drive motor when installing the disk. If the disk does not begin to rotate, then turn the variable resistor slider another 20-30°, and continue this until the engine starts (it should start and rotate at a constant speed for some time - about 10-20 seconds) .

The need to rotate the variable resistor that regulates the intensity of the laser glow is due to the fact that over time the power of the laser light flux decreases (aging of elements, clouding of the lens, etc.), however, after such adjustment, the optical system usually still does not last long. This kind of alleged disk drive repair is no longer practiced.

You are unlikely to be able to fix other malfunctions of the optical-electronic information reading system on your own. Despite its small size, the optical system of a DVD drive is a very complex and precise optical device, including servo systems for platter rotation control, laser reader positioning, autofocus, radial tracking, and laser diode sensing and control systems. Repairing the drive in this case is not worth it.

Until the disk drive repair began...

In the operation of a working system, the following phases should be clearly visible:

Start and smooth acceleration of the disk;

Steady rotation mode;

Braking interval to a complete stop;

Using the carriage tray, remove the disk from the motor spindle and take it out of the drive.

The servo system for positioning the information reading head ensures a smooth approach of the head to a given recording track with an error not exceeding half the track width in the search modes for the required piece of information and normal playback. The reading head, and with it the laser beam, moves across the disk field by the head motor. Engine operation is controlled by forward and reverse motion signals from the control processor, as well as signals generated by the radial error processor. Characteristic signs of a malfunction are both erratic movement of the head along the guides and its immobility.

Drive repair. Before the malfunction...

You can visually check the correct operation of the focusing system. At the moment the disk starts, the control processor generates correction signals that provide multiple (two or three attempts) vertical movement of the focal lens necessary to accurately focus the beam on the disk track. When a focus is detected, a signal is generated that allows information to be read. If after two or three attempts this signal does not appear, the control processor turns off all systems and the disk stops. Thus, the performance of the focusing system can be judged both by the characteristic movements of the focal lens at the moment the disk starts, and by the signal that starts the disk acceleration mode when the laser beam is successfully focused. Other parameters for the correct operation of the optical system are not visually determined.

A similar situation can also arise due to clogging of the friction surfaces of the disc holder due to the frequent use of dirty DVDs, which ultimately leads to unreliable operation of the drive, even to its complete stop.

Contamination of the disk drive seat and weak pressing of the disk to the seat can be eliminated by cleaning the disk seat with any woven material soaked in alcohol.

You can check whether the pressing force of the disc to the seat is sufficient when trying to play a regular disc. If there are no errors or glitches when playing the disc, but the disc with computer data is still readable unstable, you can take additional measures - bend the springs or increase the weight to increase the pressure on the disc from above.

However, the listed mechanical faults relate mainly to simple mechanisms of relatively cheap drives. Expensive models, as a rule, have complex mechanisms, for which the main type of mechanical failure is irreparable breakdown of mechanism parts. Most often this happens because the user, instead of using the control buttons, pushes the carriage with the disk inside the drive with his hand. The consequences of such actions can be the most unpleasant. If a dirty and neglected mechanism is sufficiently cleaned, wiped and lubricated for it to perform its functions properly again, then haste and excessive force applied to the disk tray can cause breakdowns, which will lead to expensive and time-consuming repairs of the disk drive.

Finally, electronic components may malfunction. However, their share is unlikely to exceed even a small fraction of all breakdowns. Unfortunately, modern optical drives are very complex electronic systems, and a faulty microcircuit is no different in appearance from a working one. Accordingly, repairing a disk drive at home without preparation is impossible.

Now drives may cost less than some network card or video card, but this does not mean that they are just as simple in design. The optical drive has a rather complex design and, in addition to the mechanical part, contains at least two microcontrollers, a signal processor (DSP), a secondary voltage source, circuits for controlling the mechanics, etc. Moreover, most of the microcircuits used in modern drives are specialized, and therefore, repairing the drive in its electronic part is hardly advisable.

Note that it is quite difficult to diagnose electronic failures in an optical drive, even with a sufficient degree of reliability. Indeed, depending on the error correction strategy chosen by the manufacturer for a particular model and, accordingly, on the complexity of the processor and the device as a whole, in practice a particular drive can work with different disks in different ways. This, by the way, explains the often encountered situation when your disk can be easily read on a colleague’s machine, but your own PC does not even see it. In cheap models, the correction system can correct only one or two minor errors in the information frame, but a complex, expensive system can restore even serious and extensive destruction of information, and it does this in several stages using a complex algorithm. So repairing the drive in this case will not work due to the absence of a malfunction as such.

Each manufacturer uses its own set of chips or completes it with products from different manufacturers, and, of course, does not provide descriptions. Due to the fact that for each specific device it is necessary to look for specifications for almost each microcircuit separately, often even service center specialists cannot always restore the functionality of your device. If only because repairing the drive will not be economically justified.

In short, if after cleaning, checking all wires and connections, as well as system settings, your DVD drive does not work, and its warranty has already expired, in the end you may be faced with a situation where you simply have to throw out the old one and buy a new one.

Modern laptops are characterized by a set of various functions, but at the same time, their components are very fragile. The slightest damage is enough for one or another part of the device to stop functioning.

Today we will talk about disk drive malfunctions and consider possible ways to eliminate them. This device is extremely necessary, especially during a trip to nature, when you would like to watch movies or show memorable videos to friends. If you experience any signs of disk drive problems, contact BSL service. Our employees will help to implement high-quality.

Causes of drive failures

One of the main factors of failure is dust getting into the drive. In this case, the laser stops working. There is only one way out - replacing the DVD ROM. If the laser cannot work, the computer does not read information from any disk.

Also, the laser malfunction may be due to a long service life. During frequent use of the drive, the strength of the laser beam is weakened, and it also loses its ability to read information.

Among the causes of drive malfunctions are mechanical damage, as a result of which the drive may not engage or not fully open. In this case, the rollers have worn out and need to be re-lubricated. Also, the drive may begin to work incorrectly or even fail due to an impact or liquid entering the laptop. In this case, the drive becomes displaced or its contacts become oxidized.

One of the common causes of breakdowns is software glitches. The system may simply stop seeing your drive, or obvious software errors will begin to appear in its operation. In this case, you can reinstall the drivers on the DVD drive or perform a system update, which may require rearranging the PC software. To carry out the last steps, it is better to contact specialists.

Another cause of the malfunction is loss of contact between the drive and the motherboard. In this case, the problem may also be with the motherboard. Also, the problem of lack of contacts may be a breakdown of the south bridge.

The disk in the drive may spin up, but the computer will not record any changes. In this case, you most likely have a broken microcircuit that is responsible for the operation of the drive.

There are many reasons for drive failure in laptop computers. We hope that knowledge about them will help you keep your equipment in working condition for a long time.

Many years of service to your laptop!

DVD player disk drive

Laser disk drives have become widespread in electronics. Any DVD player, CD/MP3 radio, or stereo system includes a laser drive.

In most cases, such devices need to be repaired precisely because the laser drives break down.

The malfunctions caused by a breakdown of the laser drive are quite similar and boil down to one thing - the laser disc is either unreadable, or music (CD/MP3) or video (DVD) playback fails.

It should be noted that the service life of the laser diode, which is included in any disk device, is on average 3-5 years. It would be naive to think that a DVD player will last 10 years or more! Check your DVD player's manual...

In general, the first thing you need to ask when they bring any disk drive to you for repair is how old the device is and how intensively it was used. If the answer is 3 or more years, then the likelihood that the optical unit is faulty increases sharply. How often the device was used is also important, because a laser drive is an electronic-mechanical device. The number of miniature motors in one laser drive is unlikely to be less than 2-3.

First of three– spindle drive. He is responsible for promoting the laser disc. A very large number of malfunctions are associated with it. Here's an example.

Second– drive of the optical unit. This drive is responsible for positioning the laser head along the disk. Quite rarely it fails.

Third– loading/unloading drive ( LOAD ). Unloading and loading a disc into the drive. Malfunctions of this engine are quite rare, and are usually easy to repair.

In practice, such a malfunction occurs. Mostly CD/MP3 car radio .

The sound often disappears during playback. It suddenly appears and also disappears. There is “stuttering”.

U DVD players The malfunction manifests itself as follows.

It takes a very long time to read the disc, after which the message ( ERROR or NO DISK ). It is possible that the disk may randomly freeze. Reinstalling the disc solves the problem and the recorded disc plays normally.

The reason for this “incomprehensible” behavior is not due to a malfunction of the optical laser unit, but to a malfunction of the spindle drive.

The fact is that the spindle motor must spin up at a certain speed. The speed is adjusted by the feedback system. So you don’t have to think that the disk is spinning on its own. I applied 3 volts to the engine and that’s it! No! The disc rotation speed is regulated by a complex adjustment system. If the spindle motor is faulty, then even the correction system does not cope well and failures occur. The engine does not produce the required speed, “fails”.

Therefore, if the malfunction described below occurs, do not rush to replace the optical laser unit!

Replacing the spindle drive is cheaper than buying an optical laser unit. You can temporarily replace the drive with a motor from another device or find a suitable one in the storage room.

A very common problem is with CD/MP3 radios with vertical disc installation.

The disk spins up, but the disk does not boot. Writes ERROR or NO DISK .

The optical laser unit is protected from dust and dirt. A thin, fine dust deposit on the top lens is enough to make the disc unreadable. Radios with vertical disk installation are more vulnerable to dust; the disk is loaded from above and the amount of dust entering increases.

In this case, disc car radios are more protected; they have slot loading of the disc.

Fine dust deposits can be removed from the surface of the laser unit lens with a regular cotton swab or just a piece of cotton wool. Wet cotton wool with cleaning agents No need, you can ruin the lens! We rub a cotton swab over the surface of the lens in a circular motion 3-4 times. We make sure that there are no large dust residues on the lens and that’s it!

You should not press on the lens; it is attached to spring wires! They supply power to the focusing electromagnet. They are quite strong, but with excessive force they can be damaged.

It is not uncommon that after such simple cleaning, the operation of the device is completely restored.

The main difficulty in this operation is to properly disassemble the device and get to the laser head. This is most difficult to do on music centers with a 3-disc loading unit or changer (when the discs are placed in a box - like plates in a dryer), as well as on car CD/MP3 players and DVD players with slot-loading discs.

Therefore, on the pages of the site I also posted information on disassembling various CD drives.

Optical CD and DVD drives are one of the last components of modern computers that contain structural mechanical elements and, as a result, have an increased accident rate.

With the spread of data storage devices on Flash memory chips, the constant reduction in their prices while simultaneously increasing the amount of memory, the relevance and popularity of optical media is gradually falling.

However, new films, music albums, software products are released on DVD? and CD, so it is premature to abandon use (see).

If an optical disc reader fails, you should first determine the cause, which lies in low-quality or damaged media.

Over time, problems with reading CDs and DVDs occur more often. This is accumulating surface damage and contamination. If the drive reads some discs well, but others much worse, then this is the problem.

It happens that the drive reads DVDs, but when working with CDs, frequent errors occur, this indicates that the reading device has been misaligned or that the laser is aging.

When starting to troubleshoot a DVD drive, you need to carefully study the background:

Initially, the drive worked normally, and reading errors appeared occasionally, but over time the number gradually increased - aging of the drive.

The problem arose suddenly - often this happens after installing new software or updating existing software (see).

The newly installed drive immediately refused to work, while the old one was functioning normally - the installation was carried out incorrectly.

The drive reads some discs normally, others with errors or refuses altogether - low-quality or damaged discs.

DVD drive problems

Mechanical

Failure of the mechanical components of a DVD device due to wear and tear over time is the number one cause of failure.

Tip: Do not forcefully push the retractable carriage, use the button to do this, this will extend the life of the mechanisms.

During intensive use backlash appears in the mechanical drive of the reading head, the adjustment of the positioning device is disrupted. Such DVD drives must be replaced.

Repair and adjustment are complex operations and have no practical meaning for older devices due to the accumulation of wear and subsequent increase in the number of reading errors. Modern high-speed drives often refuse to read old CDs, accompanied by a sharp, unpleasant noise.

Reducing the drive speed can help in this situation, for which special programs are used, the simplest and most common of which is CDSlow.

Windows doesn't see the drive

A common reason for a DVD device to refuse to read discs is invisibility from the operating system. This malfunction is most often due to the following reasons: incorrect connection.

When replacing an old device or installing a new one, it happens that the user, when connecting signal cables, forgets to pay attention to the settings of the jumpers that select the MASTER/SLAVE connection of the ATA/IDE bus.

In this case, a conflict occurs between the DVD device and the HDD disk. This malfunction is typical for devices on the ATA/IDE bus. If the built-in hard drive is SATA standard (see), installing a jumper on the rear wall of the DVD does not matter.

Windows requires driver

At 7 or 8, the installation program often displays the message: “The required optical disk driver was not found,” regardless of the data source: DVD, USB or HDD.

The reason for this may be either the low quality of the blank or ISO file, or reading errors during installation. Even the writing speed of the installation DVD can affect the occurrence of this problem.

This problem can be resolved in several steps:

FCIV.exe program check the SHA1 checksum of the downloaded ISO file by comparing it with that indicated on the Microsoft Download Center website. If both values match, the original file?source is not damaged.

To make an installation DVD, you must choose a clean, high-quality blank. The recording speed should be set to minimum. To control the recording quality, you can re-check and compare the checksums of the source and the recorded disc.

DVD drive recovery

Self-repairing an optical disc reader at home requires at least minimal knowledge of radio engineering.

Performing complex operations such as replacing a control controller board or laser reader is hardly advisable at current prices for DVD drives. Such repairs may be more expensive than purchasing a new device.

Often the cause of the malfunction is so commonplace that the simplest troubleshooting operations can be done by a user who knows how to use a screwdriver.

Restoring a DVD drive at home

A common cause of failure is dust accumulation on the laser read/write head. And when starting the simplest repairs, you should first address this problem.

If in the future it turns out that it was not the main reason for the refusal, such a preventive measure will not hurt, helping to prolong the life of the dividiroma.

For such an operation, the DVD device of a desktop computer will have to be disassembled to gain access to the laser head. For laptops it is located on a retractable platform.

The positioning mechanism of the reading laser is precise and therefore gentle. Cleaning the laser head from dust should be done without any effort, very carefully with a soft brush or a stream of air. It is strictly not recommended to use any liquids.

DVD-ROM failure occurs due to loss of contact in signal and current-carrying wires and cables. In most cases this can be resolved by replacement. It’s worse when the fault lies in a bad connector.

Sometimes it is possible to “cure” by cleaning and rinsing the contacts with alcohol.

Structural faults in connectors can only be eliminated by replacement.

Programs for reading bad disks

If a problem that arises when reading a disc is caused by contamination of its surface, it can be eliminated by simply cleaning it with a dry soft cloth. Heavy dirt can be removed by rinsing the disc with warm water or medical alcohol. Under no circumstances should any other solvents be used for these purposes.

Typically, users clean the surface of optical discs in a circular motion, “along the tracks.”

Practice shows that radial movements from the center to the edges are more effective.

When there are scratches on the surface, the problem becomes much more complicated. In these cases, many experienced users suggest polishing the disk with a hard cloth, such as denim, filling scratches with viscous liquids, such as glycerin, and then polishing the surface for a one-time backup read/copy.

There is no universal way to deal with scratches. What helps in one case will be useless in another.

Reading can be affected by scratches not only on the working surface, but also on the front surface when the reflective mirror layer is damaged.

As a rule, the operating system, having detected a fatal read error on a damaged disk, mercilessly interrupts work with it, trying to ensure the reliability of the data being read. To help the user save at least part of the recorded information, there are programs that read despite errors.

The most popular of them: Any Reader, Super Copy, Iso Buster, Recovery ToolBox for CD Free, CD Chek.

The basic algorithm is quite simple: they either read the content “as is” or fill problem areas with zeros.