Even the most accurate user is faced with a situation where his computer suddenly stops turning on. This can be due to a variety of reasons - hardware, software, or due to the complex effects of both. How can they be detected? What are the available ways to fix breakdowns that prevent my PC from booting?
Interpretation of breakdowns
Strictly speaking, a situation in which the computer does not turn on at all, that is, when there is no reaction to pressing the power button, is rare. It is due to a number of reasons, for example, simply because the electricity is turned off in the apartment.
Many users understand the state when the computer does not turn on at all, the absence of an image on the screen, while the system unit is habitually buzzing, the lights on it are on. There is another interpretation of the problem - there is an image, but Windows is not loading. In this sense, the user identifies this state of affairs with the fact that the computer does not turn on at all, since the result is the same: you cannot work on a PC. We will consider several scenarios taking into account the difference in user views on the essence of the problem in question.
The situation when the computer does not turn on at all when turned on , as we noted above, is quite rare. Most often, certain mechanisms on the system unit still begin to work, but for a number of reasons, further loading of the PC becomes impossible. The architecture of modern PCs provides a mechanism that assumes that in the event of such breakdowns, the I / O system - the BIOS - signals them through sounds similar to a squeak. They can be heard in speakers or in a small speaker built into the motherboard. Consider their features.
Sound signals about breakdowns
The sounds in question are divided into two types - long and short. If the computer does not turn on and squeaks, then you need to determine what the sequence of signals is. Modern motherboard manufacturers most often program the corresponding function of microcircuits in relation to such combinations of sounds:
- if 1 long signal and 3 short signals are heard, then this indicates that the computer cannot find the video card;
- if the user hears long identical and repeating sounds, then this means that there are problems with RAM;
- if the speaker makes 5 short sounds, then this may indicate a processor failure;
- Problems with the video card can also be voiced by 1 long signal and 3 short ones.
Note that the use of various signal formats depends on the BIOS version. How is it shown? For example, in some BIOS versions, problems with the video card are signaled by 2, 3, or 4 consecutive short signals. If the computer does not turn on and squeaks in a certain way, then in the BIOS type Award the interpretation of sounds may differ from that set for the input / output system in the Phoenix modification.
Power problems
Consider the case in which the computer does not turn on due to power problems. If the PC does not respond to the press button, then the first thing to check is whether there is electricity in the apartment. If it is, then you need to check if the protection on the surge protector has worked. This happens when you connect to it a large number of devices - especially those that require significant power. There may well be problems with the PC power cable - you need to check whether it is connected correctly to the corresponding jack in the system unit, as well as to the outlet.
If the computer does not turn on at startup, this may be due to a user oversight regarding the activation of the switch in the back of the system unit. It is located next to the socket where the power cable is inserted. The corresponding element must be in the on position. Also on some PCs there is support for several types of alternating current, for example, 110 and 220 volts. To work in each of them, you must translate the corresponding switch to the correct position.
Power supply problems
Another possible reason that the computer does not turn on at all is a power supply failure. In this case, electricity is supplied to the PC normally, but the corresponding component responsible for its distribution does not work. It is not recommended to diagnose the functionality of the power supply without the appropriate equipment - it is better to immediately contact specialists.
But it may well be that the system unit of the computer does not turn on due to a failure in the power supply, which the user can completely eliminate by himself. The fact is that the internal protection mechanism from voltage changes sometimes works on the power supply. If a jump occurs in the electric network, the corresponding elements in the PC system unit are triggered and do not allow power to the microcircuits. This lock will remain in effect until the user discharges the capacitor responsible for the operation of the protection system. To do this is simple - you need to unplug the power cord from the socket on the system unit, wait a few seconds and put it back. If the problem was protection triggering, the PC will start to boot normally.
Replace battery
Among the possible reasons that the PC refuses to respond to the power button is a failed CMOS battery, which is located on the motherboard. Shelf life is about 5 years. Therefore, it is perfectly normal that after this period it may cease to function. Note that this problem does not appear immediately: it, as a rule, is preceded by certain problems with starting the PC, spontaneous failures in the system time settings, and computer boot up after a while.
Replacing the CMOS battery is quite easy - it makes sense for professionals to contact completely inexperienced users, those who do not want to accidentally harm their computer due to the lack of significant skills in working with hardware. The item in question looks, in fact, like a battery, but very flat, like a small coin. It can be located in different places on the motherboard. An example is in the photo below.
You can remove the battery with a thin screwdriver. It is better to take it with you to the store as a sample and ask the seller to give exactly the same, but recently released.
When the "iron" loses momentum
If the computer’s power does not turn on, then there may also be problems in other hardware components of the system unit. For example, it often happens that the design of the launch button of the system unit itself is deformed. As a result of this, the corresponding element simply cannot close the necessary contacts on the motherboard so that the computer starts to boot. You can also help the system start manually by finding the Power connector on the motherboard and gently closing the contacts on it with a screwdriver. Of course, it is better if a specialist does it.
A large number of capacitors, transistors, and other elements are located on the PC motherboard, each of which is important for the stable operation of the PC. If the computer does not turn on at all, the reasons may be that one of the corresponding components has failed. It is clear that only an experienced specialist can detect it. But by elimination it is quite possible to try to calculate this problem, making sure that it is not a matter of power supply, not of a power supply unit, and not of a power button.
We examined the main reasons why a PC may not respond to the power button at all. We will now study situations in which the computer turns on but does not start, that is, there is no picture on the screen or it is there, but it does not give anything from the point of view of the prospects of PC operation.
Noise without result
Consider the first option, when the system unit is working, but the image does not appear on the screen - it blinks. This situation may be due to several reasons.
The most common factor why a computer monitor does not turn on is problems with the video card. This is a rather sensitive component, mainly due to exposure to overheating. Video cards usually have factory coolers, but the increased load on the corresponding PC component may require significantly more powerful cooling systems.
If the computer screen does not turn on, then checking what type of device has stopped functioning is quite simple. You need to connect another monitor to the PC, or, conversely, connect the current display to any third-party device. It happens that there are problems in ensuring contact between the monitor and the system unit - the cable is twisted or, for example, the connector is clogged. And in this case, an interesting effect can be observed - another monitor on the computer being tested does not work due to dust clogging the video connector on the system unit, and the current display does not work on a third-party device due to clogging in its elements.
Another reason for this situation, when the computer does not turn on (coolers work, but nothing is displayed on the screen), is a problem at the motherboard level. As we noted above, a large number of components are present on it. Many of them are responsible for the processing of video signals.
Why Windows does not boot?
What can the situation mean when there is a picture on the screen? The fact that, at a minimum, the PC has a processor, RAM, video card and main chips. That is, technically the computer is ready to work, but for some reason it cannot start the operating system. Failure scenarios may then be as follows.
Suppose, before the eyes of the user, the following picture: the computer does not turn on (the screen works), and this is expressed in the fact that instead of loading Windows, there are inscriptions on the screen. In this case, it is extremely important what type of messages pop up, what are they about. There may be several basic options.
There may be problems with the hard drive. In this case, an inscription like Reboot and Select Proper Boot Device (“reboot and select the correct device to boot the system”) or Disk Boot Failure (“disk boot error”) will appear on the screen.
It is possible that Windows OS files are damaged for some reason, for example, due to a computer virus. In this case, the command line may appear on the screen, but the graphical components of the OS will not load. Note that sometimes on the monitor in the case of a failure in Windows, the same labels appear as in the case of difficulties with the disk.
In both scenarios, the problem is quite serious, and you may need to reinstall the OS or replace the hard drive. But it happens that this is a very small glitch, for example, due to the unstable contact of the hard drive connectors on the motherboard. It is easy to eliminate by checking the relevant items.
The simplest case is that a floppy disk is located in the reader for flexible magnetic media (although they are considered obsolete, but are sometimes used). In many PCs, in the system settings, no matter how surprising it may sound, an option has been activated, according to which the OS boot should start from a floppy disk. Not finding the operating system on it, the computer decides that it is not installed at all, and displays a message on the screen. The diskette needs to be removed and try loading again.
A similar situation is when a user recently reinstalled Windows or supplemented it with some software samples from a boot disk and forgot it in the corresponding reader. The system, quite possibly, will also be configured to start booting from a CD or DVD drive, and it will carry it out each time until a person removes the disk from there. Usually, if there are no system files on the DVD, then the download then continues from the hard drive. But they can be on the media in a form hidden to the user, and he may not even suspect what is the matter when Windows does not boot. Therefore, when starting the PC, in any case, make sure that no media - neither flexible nor laser - is placed in the readers.
If Windows does not boot, then this may also be due to problems in the hardware of the hard drive. To do this, connect the hard drive to another PC as an additional one, and check whether files are read from it. By the way, it will be useful to make copies of the most valuable data on another computer.
Another option is that Windows may start to boot, but instead of the “Desktop”, other pictures or, again, the command line will be displayed on the screen. This means that everything is fine with the disk, but there are problems with the operating system itself. In this case, it is highly likely that you will need to reinstall the OS.
In case of possible problems with starting Windows, the user should always have a boot disk on hand. This may be a proprietary installation media from Microsoft or, for example, formed by the manufacturer of the computer. In the second case, useful system programs may also be located on the disk . This type of media can be made independently, for example, based on free Linux distributions.
Incorrect BIOS settings
It happens that the computer turns on, but does not start due to incorrect settings in the I / O system. This may be due, for example, to the fact that the user installed some new hardware component in the PC, for example, the additional RAM module updated the video card or even the processor, and the BIOS settings remained the same.
In this case, the most correct option is to set the options in the input / output system by default. To do this, go to the BIOS interface - most often you need to press DEL at the very beginning of the PC boot, and then find the Set Default Settings item or a consonant with it. Then you should select the Save and Exit Setup option or that sounds similarly. After that, the I / O system will record the changes consisting in setting the default settings and restart the PC. If the problem persists, then the reason that the download does not go is in something else. Subsequently, the most optimal BIOS settings can be set by consulting with experienced specialists.
By the way, in the BIOS, you can also fix the sequence of system requests to boot the OS. Above, we examined a scenario in which a floppy disk inside an appropriate reader might prevent Windows from starting. The settings responsible for accessing it are also written in the BIOS. They are located in the Boot Sequence section or in tune with it. As a rule, these settings assume a vertical ranking of the media from which the download will take place. If the Floppy disk is located above the others, then it can be replaced with an HDD - hard disk.
The working PC is turned off
What should I do if the following situation occurs: the computer shuts down and does not turn on? The simplest option here is, of course, power outages. But quite often the reason is different - overheating of various hardware components. Most often - the processor. When it overheats, a protection algorithm is triggered in the system. Moreover, it is usually hardware, that is, included in the architecture of the processor itself. If the temperature of the main PC chip is higher than the critical point programmed in it, the computer will not turn on.
There are two reasons for the occurrence of such a problem - a faulty or insufficiently powerful cooler, as well as dried thermal grease - a substance that enhances the effect of the fan. It happens that the user overdid it with overclocking the processor - as a rule, this procedure involves a significant increase in the clock frequency of the microcircuit, which leads to its noticeable overheating, which the cooler may not be designed for.
In order for a computer with a processor, whose temperature is above normal, to boot, you need to wait a bit. To avoid this problem later, replace the thermal grease, and also improve the cooler. The fact may also be that the fan simply became dusty. In this case, you need to clean it. By the way, the hygiene aspect is important for most PC components - not only the cooler, but also the video card, motherboard, disks, the main fan on the system unit.