The essence of the problem: when you press the power button, the computer turns on. Works from a few seconds (1-5 seconds) and spontaneously turns off. Sometimes the cooler starts making noise. It is possible that the cooler only rotates a few times and freezes.
To restart, you need to press the power button again.
The reasons why the computer turns off most often are two:
- Short circuit (short circuit) in the power circuit(not necessarily in the power supply).
- CPU overheating due to malfunction of the cooling system.
It is not difficult to distinguish these breakdowns:
- If the computer works and turns off within 1-3 seconds, there are no signs of system start on the screen. There is a power problem (short circuit in the circuit).
- If the computer works for five or more seconds and turns off, you can see signs of the system starting (UEFI, Bios screen). The conclusion is a problem with the CPU cooling system.
With such a breakdown, it is aimed at finding the module that led to the failure. The part is subsequently either repaired in the workshop or replaced with a new one.
What can cause a short circuit in a desktop computer?
The most common causes of short circuits are:
- Incorrect installation of computer modules. For example: they bought a memory bar or a processor and inserted it incorrectly - the computer will start for a couple of seconds and turn off.
- Somewhere in the computer, the contact in the connectors is broken, the polarity of the connection is broken, or the insulation in the wiring is destroyed. This happens if the user often connects and disconnects the hard drive, power supply, plays with coolers.
- or computer conducted in violation of the rules. Conductive thermal paste gets on the processor socket or contact pad, after which the PC does not start.
- Failure of the computer motherboard due to poor cooling and violation of operating rules. In this case, the binding of the central processor most often fails, which leads to a short circuit on the motherboard.
- Inappropriate power and / or low-quality power supply. Such a power supply with a constant excessive load quickly fails. The computer may turn on, but not the first time, freeze during games and watching videos.
It can also intermittently shut down under load.
For a better understanding of the problem associated with spontaneous computer shutdowns within a few seconds after turning it on, it is necessary to understand how modern desktop computers function.
How does the system unit start, and what can cause a computer to turn off during the first seconds?
I must say that it is the power supply that turns off the computer in case of any short circuit or excessive load.
Through the presence of a feedback system, it controls the voltage in all circuits of a stationary computer, reacts to an increasing load, the presence of a short circuit.
All devices with a modern ATX switching power supply have this function - it works in the same way:
- The power supply turns on when you press the power button on the computer and passes self-diagnosis.
- The power supply supplies 5 volts to the motherboard.
- Receives a PG (Power Good) signal.
- Continues to work.
If any step fails. The computer will not start.
How to localize the problem?
If there is a power problem, the result is:
- Lack of response to the computer power button (power supply). Short circuit or hardware failure of the power supply.
- The cooler on the power supply can make several rotations. Short circuit or failure of the power supply or motherboard.
- The CPU cooler may start spinning and turn off after a second or two. Short circuit, failure on the motherboard or other module.
Common breakdowns in which the computer turns off immediately after being turned on.
Turning off the computer is just a consequence. The source of the problem could be:
- In the power supply itself. Dusty. Swollen capacitors. Destroyed transistors. Disassemble - check - replace.
- In violation of the contact of connectors and plugs of a laptop, computer. Oxides on the wires, loose plugs, poor soldering - all this can provoke turning on for a few seconds, triggering the protection and turning off. This process is cyclic; if you disconnect the device and then turn it back on, the same thing happens - turn on, 3 seconds, protect, turn off.
- In powered devices and modules - the computer motherboard, laptop power circuit, etc. Evaluate visually - especially the binding of the central processor. Carry out diagnostics. Ring out the chains.
In which computer modules do such breakdowns occur most often? Where directly to look for a problem?
- Most often, the PWM power supply of the central processor in stationary computers fails. It is located on the motherboard near the CPU cooler. Look for where the 4-6-8 pin 12v connector is connected. The circuit serves to power the central processor, improving the quality characteristics of the input voltage.
Failure can sometimes be identified by swollen capacitors and burnt out mosfets on the board.
- In second place - problems with the video card. The additional power circuit of a powerful video card often fails, the failure leads to a short circuit. The localization of the failure is indicated in the figure by the number 3.
- The circuits on the motherboard are powering the chipset, RAM.
Here, as a rule, mosfets burn out, or electrolytic capacitors “swell” from overheating, lose their capacity greatly or “short”.
- Damaged USB ports with mechanical damage can also cause the computer to turn off.
One of the common problems with a computer is that it turns on and then immediately turns off (after a second or two). Usually it looks like this: pressing the power button, the power-on process begins, all the fans start up and after a short period of time the computer turns off completely (and often the second press of the power button does not turn on the computer at all). There are other options: for example, the computer turns off immediately after turning it on, but when it is turned on again, everything works fine.
If any work related to opening the case and disconnecting or connecting the equipment was not carried out, the problem may be caused by the following points:
- If the computer is old enough - dust (and short circuits), problems with contacts.
- A failing power supply (one of the signs that this is the case - earlier the computer turned on not from the first, but from the second or third, etc. time, the absence of BIOS signals about problems, if any, see).
- Problems with RAM, contacts on it.
- BIOS problems (especially if updated), try .
- Less often - problems with the motherboard itself or with the video card (in the latter case, I recommend, if you have an integrated video chip, remove the discrete video card and connect the monitor to the built-in output).
Additionally, you can try this option: turn off all equipment except for the processor and cooler (i.e., remove the RAM, discrete video card, disconnect disks) and try turning on the computer: if it turns on and does not turn off (and, for example, beeps - in this case this is normal), then you can then install the components one at a time (each time turning off the computer before) in order to find out which one fails.
However, in the case of a problematic power supply, the approach described above may not work and the best way, if possible, is to try turning on the computer with a different, guaranteed working power supply.
Additional Information
In another situation - if the computer turns on and immediately turns off after the previous shutdown of Windows 10 or 8 (8.1), and turning it back on works without problems, you can try, and if it works, then take care of installing all the original drivers from the motherboard manufacturer's website.
The problem discussed in this article is very common. A similar situation usually occurs with computers that are 3-5 years old or more. There are a number of reasons why it can turn on and off after 2 seconds and then turn on again and now we will talk about them.
Checking the power supply
With these symptoms, the power supply is one of the prime suspects. The most correct option would be to install another, obviously working unit, taken, for example, from a friend's or neighbor's computer.
Replacing the power supply
Special attention should be paid to the four-pin processor power connector. Isn't he melted?
4 pin CPU power connector
Also, last but not least, you should pay attention to the motherboard capacitors. Weren't they pissed off? Otherwise, swollen capacitors will need to be soldered.
One of the reasons for turning off the computer is a swollen capacitor.
Stuck power button
If everything is in order with the power supply and its replacement did not correct the problem, then it is worth checking the power button on the case. It often happens that it wedges in a certain position, thereby automatically turning the computer on and off. The fastest and most effective way is to disable the button and by closing the corresponding pins on the board.
If it turns out that the problem is in the button, then you can turn on the power button by rearranging RST in place of PWR_SW.
Reset BIOS
Often the problem lies in the BIOS settings or in the battery. Therefore, in a situation where the computer turns on and off after 2 seconds, then it turns on, it will not be superfluous to reset the BIOS settings for a few minutes. It is also better to change the battery itself, as there are motherboards that do not work with a dead battery.
Cleaning the contacts of the video card and RAM
Further, to solve this problem, it is worth removing the motherboard and all the RAM sticks, wiping the contact tracks on them with alcohol, putting everything back together and starting it up. If there are several RAM sticks, then it is better to insert them one by one, changing the slots.
One of the most common problems with a computer is turning it off immediately after turning it on. It looks like this: the user presses the power button, the standard boot process seems to start (fans start spinning, a characteristic beep sounds), and literally after a couple of seconds the computer turns off completely.
When you press the power button again, the PC may not start at all, although sometimes a normal boot occurs after a second press. What can cause such trouble?
Main reasons
To understand what exactly the problem lies in, you need to remember after which it appeared. Loading problems may be due to:
If you can't remember any previous events (in other words, problems appeared suddenly), but the computer turns on and off by itself endlessly, the reasons must be looked for in the hardware itself. Most likely, you have problems with RAM, power supply, video card or motherboard.
The causes of problems with turning on the PC can be divided into two categories: those that are immediately visible, and those that have to be tinkered to detect.
Visible problems
So, let's start with a visual inspection of the computer:
If none of the above is observed, remove the cooling system from the processor. Inspect the heat sink sole and the chip itself - if they are completely dry, it's time for you to replace the thermal paste, since its absence causes the processor to overheat sharply when turned on.
The same must be done if you see an excess amount of thermal paste that has spread even beyond the chip - in this case, when the system unit is turned on, the processor contacts close.
All of the problems described interfere with heat dissipation from large chips and CPUs, so the hardware monitoring firmware turns off power to the computer to prevent thermal damage to components. Once the problems are fixed, the computer will start up normally.
Component problems
If the problem is not visually visible, most likely it lies in the iron itself. In other words, one of the components is out of order.
In addition to the above, you can try the following option: remove all boards from the system unit, leaving only the motherboard with the processor and cooler, and try to start. If the computer beeps but does not turn off, try installing one component at a time (of course, de-energizing the PC each time) to find out which one fails. If the computer still turns off immediately after startup, and at the same time a known working power supply is installed on it, there are two options: the processor or the motherboard itself has failed.
OS issues
If the computer starts up after disconnecting the HDD with the system, the problem is either in the system or in the drive itself. To clarify this point, leave the drive connected to the power supply by disconnecting the interface cable. If P.K. does not start, the cause of the problem lies in the HDD. If the start was successful, the operating system is to blame.
In cases where the OS is the culprit, there may be several solutions. The algorithm of actions largely depends on whether the computer starts at all. If on the first attempt the PC immediately turns off, and on the second it starts to boot normally (that is, you can still log into the system), try doing the following:
If you cannot log in, try checking the disk for unreadable sectors or reinstalling the operating system.
If no action helps, and the computer still refuses to turn on normally, there is only one way out - take the system unit to a specialized center.
No computer is immune to hardware problems. Many components deteriorate and become dirty over time, which then affects the entire operation of the computer as a whole. Some factors speed up these processes, for example, running through extremely hot conditions, not cleaning internal components for a long time, etc. However, even if a computer (PC) has been well looked after, it is in any case not immune to the influence of time. After a certain period of time, malfunctions will inevitably begin to arise, and after that they will have to be eliminated, spending a certain number of minutes and seconds on this. But in any case, it can be restored later.
Very often, with technical problems with a PC, the same situation occurs - it starts to spontaneously turn off by itself a few seconds / minutes after it starts. In this article, we will look at why this happens and tell you what needs to be done in such cases, what problems are solved through, how it is repaired later in case of any trouble - sometimes the same few minutes are enough (seconds, however, much less often).
The simplest reasons for disconnection
There are a couple of common culprits for why a computer randomly turns on and off within minutes/seconds. So why might this be with PC:
- Pollution of the internal space of the system unit - it can be the reason for the shutdown. As trivial as it may sound, this is probably the most common root cause of most problems. If the computer is not cleaned for years, then the dust will settle in a huge layer on all its components: coolers, microcircuits, boards, etc. So the first thing to do if there are problems with turning on the computer is then it must be well cleaned from the inside. This will take not a few minutes and seconds, but a little more, but it will greatly increase productivity. In general, preventive cleaning of the insides is recommended to be done about once every six months.
- Another reason for shutting down the computer can be RAM. Its slats, the slots themselves for their connection may fail. Also, if the computer was subjected to some kind of transportation or carrying, the RAM bar could simply detach from the input. So the first thing to do is check if they are well connected to the motherboard. If no violations were noticed, you can insert a RAM stick into another slot or, if you have several sticks, stick out one of them and try turning on the computer without it. Perhaps the answer to the question of why troubles arise lies in only one bar of RAM, without which the computer will start normally.
- Also, the computer can spontaneously turn off when it swells, and, accordingly, fails, its capacitors. Even an inexperienced user will be able to notice their physical deformation, but he will not be able to fix it himself. If such a deformation was detected, then it is better to do nothing with your own hands. The best option here would then be to deliver the computer to a service center or to the appropriate master, it will not be difficult for them to make corrections.
Reset BIOS settings
In some cases, restoring the default BIOS settings can then help. For example, if you yourself accidentally changed the configuration of the computer (after which problems with turning on began) or this happened due to some other reasons. This can be done in several ways, the first of which is much easier than the second. But it will be realistic to use it only if it is possible to call the BIOS menu. Therefore, if your computer does not turn off spontaneously immediately, but a few minutes after turning it on, then during the last one press the F2 or Del key (most often), which will turn on the BIOS. Then on the last tab "Exit" there should be a line "Load Setup Defaults" (the name may vary slightly depending on the BIOS model). We click on it, confirm the application of the command and select "Exit & Save Changes". Then we wait for the computer to be turned on for verification.
If the computer turns on and immediately turns off when it starts up, without giving you the opportunity to enter the BIOS menu, then resetting will have to be done manually. It is worth noting right away that for inexperienced users this method can be difficult, so if you are not sure, it is better to ask one of your friends to do this or contact a professional.
So, you can manually reset through a special jumper on the motherboard. The latter is usually located next to the CMOS battery. This battery looks just like an ordinary round battery, and CMOS is a special computer chip that contains the keys to start the PC and data about its components. It is the CMOS memory that goes through the reset when the BIOS returns to the standard settings. The jumper is made in the form of 3 small plugs, the first two of which are put on a special “cap”. To reset the BIOS to factory settings, you need to remove this cap from the first two plugs and put it on the "second - third" for about 10 - 15 seconds. Then again put it on the first two. This must be done very carefully so that after this you do not damage the plugs themselves, do not rush to do this in a few seconds, it is better to spend a certain number of minutes. Also next to the plug is usually the inscription "Clear", "Clear CMOS", "CLRTC", etc.
If you have an expensive and high-quality motherboard, then it will most likely have a special button with similar inscriptions, after pressing which the settings will be automatically reset.
Malfunctions of individual components
Another reason why the computer turns off after a few minutes / seconds may be the unstable operation of one of its components. The first suspect is the power supply. If it cannot withstand the voltage through itself, then after such a constant shutdown of the computer it will be quite a natural phenomenon - that's why troubles occur. You can ask friends or acquaintances to give you a power supply from your computer for a while and turn on your own car after that with it. If it starts normally, then this will only confirm the suspect's guilt, explain why there is a problem with the computer.
Overheating of the processor or video card is also a common reason for shutting down the computer. Switching off in such cases does not occur after a few seconds, but after 5 - 10 minutes after switching on. You can check the temperature of computer parts using the AIDA64 program in the "Sensor" section. The normal temperature for a modern processor should not exceed 65 - 70 degrees (Why? Because this is already a critical maximum). If the temperature of your processor is higher, then the problem is clearly with it. For video cards, a temperature of 65 degrees is quite a normal phenomenon, temperatures of 90 - 100 degrees and above will be evidence of overheating.
Overheating problems
If the processor or video card overheats, the first thing you should do is clean them. If this does not help, then you can replace the thermal paste on the chip. Thermal paste is a special substance. You can buy it at any specialized store, it is usually supplied inside ordinary syringes. Before applying the paste to the chip, you need to carefully clean it from traces of the previous one in itself and only then apply a thin layer of a new one, completing the procedure by installing the remaining elements of the component. It won't take too many minutes and seconds. The logic "the more thermal paste, the better" does not work here. Too thick a layer of this substance will only make it difficult to conduct heat later, so you don’t need to pour liters of it yourself.
If this does not correct the situation and the problem with overheating remains, then the component should be taken to a service center.
