Home-Excel-What to do if the computer does not start. The computer does not boot when I turn it on, what should I do? High degree of dust

What to do if the computer does not start. The computer does not boot when I turn it on, what should I do? High degree of dust

The situation when the computer does not turn on is, of course, not pleasant. Sooner or later this can happen to any PC. But if you want, you can find a way out of any situation, the main thing is not to panic, soberly assess the situation and begin to act.

Let's figure out how the problem of the computer not turning on can manifest itself, what the reasons may be, and how to find a way out of this situation.

She can manifest herself in different ways:

  1. When you click on the “Start” button, the computer is completely silent;
  2. It starts up, but it doesn’t go beyond the black screen and a beep is heard;
  3. After a seemingly successful switch-on, it turns off after a few seconds;
  4. Everything seems to be working, but only a black screen is visible;
  5. At the stage of a seemingly successful download, a blue screen suddenly appears with many incomprehensible codes, and the situation is not corrected.

The causes of these problems may be:

  1. Lack of 220V voltage in the network;
  2. Power surges;
  3. The power button is out of order;
  4. Problems with the power supply;
  5. Problems with hardware devices (faulty, device conflicts);
  6. The CMOS battery of the BIOS memory is dead;
  7. Incorrect BIOS settings;
  8. Overheating of the processor and video card;
  9. The system board has failed;
  10. Problems with cables;
  11. Windows has crashed or there is a conflict at the software level with device drivers;

Now let's look at each situation in more detail.

The computer is completely silent

When the computer does not react at all to the power button, and yesterday it was still working, then you need to go from simple to complex. And you need to start from the outlet.

Make sure that it is 220 V, and not 360 or 150, there have already been precedents, so don’t laugh.

The computer may not start even at a voltage of 210V, it all depends on the quality of the power supply.

There are power supplies (PSUs) that have a special switch on the back side.

Check if it is enabled.

There are also models where you can switch the input voltage level - 127 and 220 V.

127 V, this is for countries where such a voltage is provided in the network, for example the USA. These types of devices are typically used by people who frequently change jobs while moving around the world.

If everything is fine and 220 V is suitable for the computer, then the latter will have to be disassembled.

Power button

Button task START - POWER Briefly short-circuit the wires coming from the system board.

View of the button with the front cover removed.

At the end of the wires there is a chip that fits onto the contacts. Find these contacts along the wires, see.

Check that the chip is tightly put on and well fixed on the contacts.

Take it off and put it back on. If this does not give any results, carefully close the contacts together with a screwdriver. Don't be afraid, there is no 220V, but the screwdriver should still have an insulator. God protects those who are careful.

Watch the video at the end of the article.

If the computer starts up, then check the wires going from the system board to the button and if everything is fine with the wires, then change the button.

If you have a tester to check the Power button, you can take an even simpler route.

Set the tester settings as shown below.

And press the START button – POWER. If everything is normal, then you will hear a characteristic sound from the tester, which means the circuit is closed; if there is no sound, then there is a break somewhere.

power unit

If the computer does not turn on, then one of the main reasons for this may be a faulty power supply.

The main sign that the power supply is producing at least some voltage is the glow of the indicator lamp, which is located on the system board.

Modern power supplies are connected to the motherboard via 20 or 24-pin ATX connectors.

In our case, the connector is 24 pin.

And the plug is 20-pin - it would be correct to say an ATX connector.

There's nothing wrong with that. Simply, such a plug is connected to a 24-pin connector with an offset to the extreme left position. In this case, 4 contacts remain unused.

When the computer is connected to the network, a voltage of 5 V is supplied to the system board through the auxiliary power supply converter. The indicator lamp on the motherboard “tells” us this.

But it happens that there is no such indicator, so you need to check whether at least some voltage reaches the system board.

Take a tester and set it to the settings shown below.

Disconnect the ATX connector from the system board and connect power to the computer.

Using the diagram indicated above, we are looking for a voltage of 5 V that should reach the system board.

We also find out whether 5 V voltage is supplied to the PS_ON contact.

Again, using a tester, we check if there is voltage at certain contacts of the ATX connector.

If in at least one of the cases there is no voltage, or it is not significant, then the problem is in the power supply.

If you want to figure it out yourself, then look for the reason in the resistor of the unit itself. It has a resistance of about 1 kOhm and the so-called standby voltage of 5 V passes through it.

Power supply resistors are different. Replacement must be carried out only with an identical brand. Some characteristics of resistors can be seen below.

To avoid any doubts, if possible, install a different power supply on the computer, in 99% of cases this clears up the situation.

What is PS_ON

PS_ON is a signal that unlocks the start of the main power supply converter to turn on the computer.

When the computer is turned off, as we already found out above, there is a voltage of five volts at the PS_ON contact.

When you press the START - POWER button, a signal of the same name is sent from the system board to the PS_ON pin.

This signal resets the voltage at the PS_ON pin to zero (0 V) by shorting it to ground, thereby signaling to the power supply to turn on the main converters.

The power supply begins to produce current of the specified parameters, powering all computer systems with it.

If the specified voltage parameters for some reason exceed the permissible ones, for example, as a result of a short circuit, then the main converter stops working and the computer turns off.

It is worth mentioning the PW_OK signal, without which the computer cannot operate. When the computer is turned off, the voltage at the PW_OK contact is 0.

The power supply receives the PS_ON signal from the motherboard to start the main converters.

At this moment, two voltages 3 and 5 V are formed in it, which, in turn, begin to increasingly form a signal PW_OK having a final voltage of 5 V + - 0.5 V.

Signal formation time is from 0.2 to 0.5 seconds. This is the time during which a stable voltage will be generated in the power supply to start the processor and other devices.

After the required voltage indicators have been generated, the PW_OK signal is sent to the contact of the same name and then to the motherboard, where signals are already generated to set the initial parameters of the processor, and then the computer is completely turned on.

The 5 volt PW_OK signal always exists as long as the PC is running. It seems to tell the system that the voltage is “OK” and you can work.

If the network voltage drops or rises and the power supply cannot cope with these surges, the PW_OK signal changes its performance.

Usually the voltage decreases to 3 volts or less, making it clear to the system that the voltage is not stable and operation is not possible.

Then starting the computer will not be possible or it will safely turn off due to the fact that the signal to stop the processor will arrive before the main voltage is lost.

How important is the PW_OK signal?

The first attempt to turn on the computer was unsuccessful, what is the reason?

First, let's figure out how the PW_OK signal can affect freezes and errors when turning on the computer?

What do you think when a car has high fuel consumption, when it is just starting to drive or when driving on the highway at the recommended speed?

The answer is obvious, of course at the start.

The same thing happens when you start the computer. In the first seconds, the starting current is much greater than that consumed during its further operation.

For example, at startup a computer can consume up to 300 W, and in operating mode 150 - 200.

At the moment of start, all transistors, capacitors, chokes are switched on, and the process of filling the circuit with energy is underway.

In this situation, the power supply tries to stabilize the voltage as best as possible and reduce the current ripple, which is very large.

If at this moment you apply the PW_OK signal to turn on the processor, then malfunctions may occur in its operation, and therefore in the memory CMOS BIOS.

For this purpose, a delay is provided in the formation of the signal (command) PW_OK.

The first sign that this command is being generated very early is when the first attempt to turn on the computer fails, and when it is restarted with the Reset button, the boot process returns to normal.

You can also use hotkeys Ctrl+Alt+Del.

There are several results:

  1. A low-quality power supply unit is installed on the computer;
  2. It needs to be repaired or replaced.

Restarting the computer

Let's say an attempt to turn on the computer is successful, but after a while it starts to reboot.

What could be the reason?

As we said above, the PW_OK signal is constant when the PC is running. It is equal to 5 V, provided that the network voltage is standard, for our country it is 220V.

If the mains voltage drops, the PW_OK signal may disappear or decrease. This stops the PC before its systems notice any problems on the network.

When the voltage in the network normalizes, this problem will go away by itself. Therefore, it is recommended to use uninterruptible power supplies for PCs to stabilize the voltage.

Let's check the power supply further

In this situation, it is necessary to check whether voltage is supplied to other PC devices, in addition to the motherboard, through the ATX connector.

Common types of connectors on the power supply, in addition to the ATX connector.

We check the presence of power at the connectors, starting with the most important ones.

With the computer de-energized, disconnect the processor power cable from the system board and connect the tester probes to its connectors.

Connect your PC to the network and press the START – POWER button.

In both cases, the DC voltage should be within 12 V.

If there is no voltage, or it is significantly less (5.7V), then you should think about the health of the power supply.

Using the same method, we check the power connectors of the motors of hard drives, disk drives, etc.

If the voltage is below standard, then the power supply is clearly faulty.

The computer turns on but there is a beep

If you hear that the computer is working, but the system does not boot, and beeps are heard, then there are problems with the hardware devices.

If there are no signals, then check whether there is a special speaker on the motherboard.

If it is not there, then try to get one and connect it to the Speaker connectors on the system board.

There are situations when the speaker burns out, then you just need to replace it.

The signals emitted from the computer may vary. It all depends on the BIOS version that is flashed into the CMOS memory.

It is advisable to have such data at hand, or look it up in the documentation for the motherboard.

You can also, if your computer is still working, go into the BIOS and write out its version from there.

Common BIOS versions:

  1. Phoenix;
  2. Award;
  3. Compaq;
  4. Dell;
  5. Quadtel.



For example, when you turn on the computer, you hear 1 short and 1 long signal. BIOS version Award.

We look at the table and see that there is a RAM error.

We open the computer, pay attention to the RAM strips and see.

One strip is installed incorrectly.

We are correcting the error.

The bracket is inserted correctly, and as a result, the computer starts without problems.

There are situations when one of the RAM strips fails. It will not be possible to detect it by sight. It is necessary to remove each strip in turn and try to start the PC.

If there is only one strip, then it must be replaced with a similar one (DDR, DDR2, DDR3, DDR4), don't get confused. It is advisable that all RAM sticks be from the same manufacturer.

Incorrect BIOS settings

BIOS settings are a separate, very extensive topic. If the computer has stopped loading and some message appears on the black screen, then it does not just appear.

Study it, then the picture will become more or less clear.

A common problem when turning on a computer is that the operating system boot source is incorrectly set in the BIOS.

There can be several of them: from a hard drive (HDD), from a DVD, from a USB source and from the network.

Check how these settings are configured. If the system, for example, is not installed from scratch, then the first boot source should be the HDD.

This often happens when a USB drive is set as the primary boot source, and a regular, non-bootable flash drive is inserted into the computer. This may cause an error.

Many PC users do not even know that there is a battery on the motherboard, due to which the computer may not start due to its low state.

The CMOS memory in which the BIOS resides is not non-volatile. For its stable operation, a 3-volt battery is provided. It is easy to find on the system board.

Its working time is up to 5 years. The first sign that the battery is running low is that the time on the computer constantly lags for no reason.

Typically, the battery model CR2032, it costs a penny and changes in a few seconds.

But the problem may be different. If the CMOS memory in the BIOS is de-energized, even for a short time, all BIOS settings may be reset.

Therefore, you will have to set them again. If you don’t understand, then just set the factory default settings.

To do this, depending on the BIOS version, look for “Load Optimized Defaults” or Load Default Settings. Keywords "Load Defaults".

Overheating of the processor and video card

The importance of a computer's cooling system can hardly be overestimated, especially when it comes to cooling the processor, video card, and north and south bridges of the motherboard.

The processor is protected from overheating by a special cooler, which you need to know how to use.

But as a result of incorrect selection of the latter, its failure or heavy dust, the processor may overheat.

To prevent the CPU from burning out, it is protected, which turns off the computer when this danger occurs.

Therefore, if you notice that a few seconds or even minutes after turning on the PC, it turns itself off, look into the system unit.

Most likely you will see a picture like this there.

After cleaning the system unit from dust, the situation can be corrected, but not always.

If the computer shuts down continues, you will have to remove the cooler and get to the processor.

Remove the latter and look at the condition of the thermal paste.

Over time, it dries out and does not perform the function of improving heat transfer between the CPU and the cooler radiator.

Using alcohol or cologne, remove the old layer of thermal paste and replace it with new one.

In the case of a video card, the PC will not restart. Most likely you will only see a black screen or hear beeps.

If you are sure that the monitor is working properly, remove the video card and clean it from dust.

Don't forget to remove the old thermal paste and apply new one. She's there too.

Also, the failure of the video card is the reason that the monitor screen is black and the boot process can only be seen at the BIOS boot stage. But we'll talk about the monitor next.

Other devices

We have already briefly touched on problems with RAM sticks. All copper contacts of any devices tend to oxidize, especially if the room has high humidity.

Therefore, they need to be cleaned periodically. To do this, you can use a regular hard eraser.

Also, don’t forget about network cards, TV tuner, WI-FI adapter and other devices, if your computer has them.

If after cleaning the contacts the computer still does not turn on, then remember what device was recently installed on the system board. Dismantle it.

If this does not help, then use the method of elimination. Starting with the least significant devices, remove them from their slots and try to turn on the computer. If this does not help, move on to the next subsection.

System board

The presence of dust on the motherboard can lead to overheating of the north and south bridges, as well as other microchips.

Therefore, you need to clean your computer from dust at least once every 4-6 months.

The culprit for the failure of the motherboard may also be a poor-quality power supply.

Conclusion, you shouldn’t skimp on the power supply.

It is difficult to visually determine that the motherboard has failed. Although if you look closely, you can find the reason.

Replacing the motherboard can lead to a complete upgrade of the computer, and that's not cheap. It is worth repairing only when its repair does not exceed 50% of the cost of a new one. But everyone makes the decision themselves.

Loops

Loops rarely fail and, as a rule, the problem lies not in them, but in the places where they are connected.

It is especially worth paying attention to the cables: a seven-pin data cable and a fifteen-pin additional voltage cable.

Their disadvantage is weak fastening. Have you moved the system unit? Did you hit him with your foot or cleaning equipment? After this your computer won't boot?

Check the SATA cables to see if they have come loose from the hard drive and motherboard. Disconnect and reconnect them. As a rule, this solves the problem.

Blue screen

The topic of the blue screen when loading Windows is very extensive and it is impossible to cover it in this, and so not small, article.

The problem with this may lie in the plane of both hardware and software failure.

As a rule, it is solved by dismantling some hardware devices. For example, you have a motherboard from MSI and a video card from ASUS.

But incompatibility between devices from different manufacturers, although it does occur, has recently become extremely rare.

Also, the latest installed drivers may cause the system to crash, etc.

This problem is solved by rolling back the system, through safe boot mode, restoring the system from a boot disk or a specially created Windows recovery disk.

But we will definitely talk about this in another article.

Of course, the monitor cannot directly affect the problem with turning on the computer. But when a black screen appears, it is still worth paying attention to.

Its unexpected failure can mislead you and, against the backdrop of a general problem, there is a high probability that you will take a different path to find its causes.

The classic operating voltage for monitors is 12V. If the device’s power supply is external, then checking the output voltage with a tester is not difficult.

There were cases when the monitor showed signs of its operation (LEDs of the connected network), but when checking the power supply with a tester, the latter produced only 7 volts.

As a result, the problem was solved by replacing the monitor's power supply.

Bottom line

We looked at the main reasons why the computer refuses to turn on and the operating system refuses to boot.

You need to understand that the main problem is not how to eliminate them, but how to identify them.

In fact, there can be many reasons why your computer stopped turning on. We have prepared for you comprehensive material that describes the main reasons why the computer does not turn on, their descriptions and possible actions to correct them.

We hope that this instruction will be useful to you. You can ask all questions in the comments on this page and we will try to answer them. If you cannot identify and fix the problem yourself, you can always contact us for free* diagnostics and computer repair services.

We do not bear any responsibility for any manipulations you have made with the software or hardware of your computer in accordance with these instructions and do not guarantee the restoration of the computer’s functionality. Remember that this material was prepared by specialists and computer repair work should be carried out by professionals.

The main symptoms of a computer not turning on

This part contains the main, often common symptoms of a computer not turning on, actions and the sequence of their implementation, by taking which you can bring the computer into working condition.

Basic procedure when the computer does not turn on:Check:

  • Is there voltage in the socket, connecting, for example, a kettle?
  • Is the power cord connecting the power supply and the outlet faulty?
  • Is the power button on the power supply turned on?
  • Is the computer power button pressed correctly?
  • Correct power supply to the computer monitor
  • Are the system unit and monitor connected with a connecting cord?
  • Open the system unit and conduct a visual inspection
  • Correct connection of wires inside the system unit
  • Disconnect all peripheral equipment and try turning it on
  • Install a new BIOS battery or disable it temporarily
  • Disconnect the video card and all other cards from the PCI slots
  • Reconnect the RAM sticks one by one
  • Leave only the motherboard, processor and power supply

Following these recommended steps may get your computer back into working order. If the above recommendations did not lead to the desired result, then a detailed clarification of the reasons for the computer’s refusal to turn on is required.

Let's look at the main reasons and symptoms why your computer won't turn on.

  • No voltage at the socket
    Use a tester to check that the voltage in the outlet is correct or connect some other device to the outlet and check whether it will work from it.
  • The power cord is faulty
    It's quite easy to check if your computer's power cord is faulty. You need to measure the correctness of voltage transmission on both sides with a tester or take another power cord, for example, from a monitor.
  • The power supply is switched off
    There is a switch on the outside of the power supply. Try switching it to a different position and see if the switch is broken. On most power supplies, this switch should make a mechanical switching sound (click) when switched to another position.
  • BIOS battery is dead
    Each motherboard has a separate firmware (BIOS) that is supported by a coin cell battery. If this battery is completely discharged, the computer may not turn on in some cases. We recommend replacing the battery with a new one.
  • RAM strips have moved
    If there is an external impact on the system unit (shock, movement, vibration), the RAM strips may move and the computer will not turn on. We recommend disconnecting the RAM and trying to turn it on. Then connect the RAM and try to turn it on again.
  • Connecting cables are disconnected
    Open the cover of the system unit and visually inspect for any disconnected wires. Check that the wires are securely fastened.
  • The component part has failed
    Disconnect all additional cards from the motherboard: sound card, TV tuner, video card, Wi-Fi adapters, controllers, etc. Here you need to use the method of elimination - take out one board, try to turn it on, if when you disconnect one board the computer turns on, then that means it’s the problem.
  • There is a lot of dust in the computer
    When a lot of dust accumulates in the system unit, this can lead to serious consequences, including failure of all components with the prospect of purchasing a new computer. If there is a lot of dust, then your computer needs cleaning.
  • Severe overheating of the processor and/or video card
    The processor can heat up to hundreds of degrees in a few seconds. If the computer does not turn on due to the processor heating up quickly, then you need to replace the thermal paste. Also, dust could get under the processor or it could “move out” (you need to remove the dust and check that the processor is installed correctly in the socket).
  • The power button is broken
    If the reason the computer does not turn on is a broken power button, then you can check this quite simply. Open the system unit and identify two wires running from the power button to the motherboard. These two wires will be connected with plastic connectors to the motherboard. Disconnect them and short the two contacts with something metal that allows current to pass through. Remember to take precautions when working with voltage.
  • It smelled like something was burning
    If you smell a burning smell, immediately turn off the power to the computer and call a specialist. Most often, power supplies burn out. If you are confident and sure that the power supply has burned out, buy a new one and connect it.
  • The computer beeps and won't turn on
    If a squeak is heard from the depths of the system unit, these are the so-called BIOS sound signals about the state of the computer. But what do they mean? - you ask. You can find information about what this or that signal means on our website in the section on signals and BIOS codes. By deciphering the BIOS signal, you can understand what the problem is. Detailed information about BIOS beeps and signals.
  • Some numbers light up on the motherboard
    If the computer does not turn on, but the motherboard has BIOS status indicators in the form of a digital-alphabetic display, then from the codes issued by these displays you can find out at what stage the computer stops turning on/booting and take certain actions in accordance with this.
  • Peripherals are not connected correctly
    There are cases when people, out of ignorance, connect peripheral equipment to the wrong connectors to which it should be connected. Because of this, the computer may not turn on. Disconnect absolutely all external devices (cameras, mice, keyboards, etc.) from the computer and try to start it.
  • There are smudges and swelling on the motherboard
    If you measure that some part (capacitor) is swollen on the motherboard or notice strange leaks of an unknown substance, then most likely, at a minimum, you will have to replace the motherboard with a new one.
  • All or some fans do not turn on
    Most likely the power supply or motherboard has failed. They need to be repaired or replaced with new ones. We recommend checking the connections of the wires coming from the fans to the motherboard.
  • The computer turns on and then turns off immediately
    There are several reasons for this:
    • The power supply has failed and needs to be replaced
    • The processor overheats (the thermal paste needs to be replaced)
    • Motherboard malfunction (repair or replace)
    • Other components are faulty (diagnostics required)
  • The lights are on, the coolers are spinning, the computer does not turn on
    Possible options for not turning on the computer in descending order of probability:
    • BIOS settings are lost or the chip is faulty
    • RAM fault
    • Motherboard is faulty
  • Everything works, there is sound, but there is no image on the monitor
    Check the connecting cable between the video card and the monitor, this may be the only problem. The second option is that the video card has failed. If the video card is separate, then you can try installing another video card and check. If there is also no signal with the new video card, then the monitor is most likely broken.
  • The computer does not turn on and a blue screen appears
    The so-called blue screen of death appears due to problems in the operation of components, their malfunctions, incompatibility, dirt and problems in the operation of the Windows operating system. A blue screen appears and displays an error code by which you can determine the malfunction and, if possible, fix it.
  • The computer does not turn on and a black screen appears
    In most cases, a black screen is evidence of a component failure. Often, when the hard drive malfunctions, this same black screen appears; it also appears when the RAM is not working correctly and a number of system files are missing from the hard drive. In this case, diagnostics are required, as a result of which the cause of the malfunction will become clear.
  • The computer keeps rebooting and cannot turn on
    If at some stage of loading the operating system the computer starts to reboot and the whole process repeats all over again, this may be the result of a malfunction in the operating system or a malfunction of the hard drive. You can try to restore the operating system to an earlier date. A hard drive can have two problems - physical and logical. The logical problem can be eliminated using software, while the physical problem can only be eliminated using mechanical repairs. If the hard drive is physically faulty and there is really valuable information on it, then you can restore it, but we do not recommend using such a hard drive later.
  • The computer does not boot and some clicking noises are heard
    If you turn on the computer and the operating system does not load and you hear quiet or loud clicks inside the system unit, then the hard drive is most likely broken. As a rule, physically broken hard drives are not used after repair, since the reliability of their operation may be extremely low.
  • The computer does not turn on for a long time (boots)
    If the computer still turns on, but the operating system takes a very long time to load, then most likely this may be evidence of logical or physical malfunctions of the hard drive, as well as evidence of a large number of errors in the operation of the operating system. In case of errors in the operation of the OS, software prevention of its operation is required. Sometimes the computer slows down due to overheating of components.

Laptop system failure? Computer won't boot? What should you do if your computer beeps when you turn it on? We will look at the answers to these questions in our article.

Let’s immediately try to sort everything out and understand whether the personal computer (hereinafter referred to as PC) and/or monitor does not turn on? Is there a beep when you turn it on or not? There are situations when the PC is absolutely working, i.e. The computer turns on, but there is no picture on the monitor.

There are not many problems with the monitor, so we suggest starting with them.

What to do if the monitor does not turn on?

Pay attention to the monitor's power button. If it does not light up, there is a problem with the screen power supply. However, you should remember that not all monitors have a backlit power button; for example, the Samsung SyncMaster SA10 does not have it.

Here is an algorithm of actions for diagnosing a malfunction:

  • Press the power button on the monitor; it may be turned off.
  • Make sure the outlet to which the monitor is connected is working properly. This can be done with an indicator screwdriver, a multimeter, or using any portable electrical device, for example, a charger for a mobile phone, tablet, radio, lamp, etc. Try turning on the monitor from a different outlet.
  • Check the power cable, there may be a problem with static charge at the ends of the cable or with the cable itself. Pull out the cable and insert it back. Try a different cable.
  • The problem is in the power supply unit (hereinafter referred to as PSU) of the monitor. Repair (resoldering of capacitors) or replacement of the power supply is required.
  • The problem is with the power button. The button needs to be replaced.
  • Swollen capacitors on the monitor board. Resoldering of capacitors is required.

If the monitor's power button blinks, but there is no image, there is a problem with the VGA (DVI) signal cable or the PC video card.

  • Check the monitor signal cable (VGA or DVI), the cable may not fit tightly into the socket. Tighten the cable fixing screws. Try this cable on another screen or install another tested cable on the existing one. Some screens have both VGA and DVI inputs; if one does not work, you need to try another, of course, if you have the appropriate connector on your PC video card.
  • The problem is with the video card. If the system unit has 2 or more video cards, try moving the VGA or DVI cable to another video card. Move the video card to another slot. Replace the video card with a proven one. Test your video card on another PC.

At this point, 90% of all monitor malfunctions are exhausted, and we move on to PC malfunctions.

Computer won't turn on or won't boot?

Before we begin describing PC malfunctions, we should understand the terminology, since seemingly identical words used to describe a malfunction have different meanings. So, the machine does not turn on when, after pressing the computer's power button:

  • indicator lights do not light up;
  • You can’t hear the noise of operating cooling coolers (fans);
  • There is no single sound signal from the built-in speaker, which usually accompanies normal PC startup. Please note that a series of several beeps of varying duration (short/long), on the contrary, indicate a computer malfunction.

The PC does not boot when, after pressing the computer's power button:

  • indicator lights are constantly on or flashing;
  • the noise of operating cooling coolers (fans) is heard;
  • there is a single sound signal from the built-in speaker after the PC starts; The operating system (hereinafter referred to as OS) of the computer does not load, black screen, blue screen of death (BSoD).

What to do if the computer beeps?

When you turn on the PC, if the result is positive for errors, the built-in speaker emits one short beep. If there is a series of beeps when loading (the computer beeps), then the PC has problems. The correspondence of the number of signals, their duration, system errors are different and differ depending on the BIOS manufacturers. When you turn on your PC, pay attention to the BIOS developer (information is indicated on the monitor during boot, and can also be found in the instructions for the motherboard). The most popular BIOS manufacturers are: Asus, Award, AMI, AST, Phoenix, Compaq, DELL.

Interesting! Tables for decoding sound signals can be found in the corresponding section of Wikipedia.

If the computer does not turn on, you need to follow a number of recommendations below:

  • Make sure that the system unit's power supply is turned on. On the back of the system unit there is a power supply button.
  • Make sure that the outlet to which the PC is connected is working properly (see the solution to a similar problem for a monitor).
  • Make sure the PC power cable is in good condition; there may be a problem with static charge at the ends of the cable or with the cable itself. Pull out the cable and insert it back. Try a different cable (for example, from a monitor).
  • Make sure there is no large amount of dust on the computer boards. Try cleaning your computer using a brush and a vacuum cleaner.
  • Make sure the computer's power supply is working properly. Measure the voltage at the output of the power supply with a multimeter. Between the black and yellow wires the voltage should be 12V, between the black and red - 5V. Try another power supply of similar power.
  • Make sure the PC power button is working properly. If necessary, replace the button.
  • Make sure there are no swollen capacitors on the computer motherboard. If there are any, it is necessary to resolder the capacitors.
  • BIOS battery problem. Pull out the battery and check the voltage at its contacts, it should be 3V. Deviations to the smaller side lead to unstable PC operation. Try inserting another battery.
  • Make sure the hard drive is working properly. Check if all connectors (power/SATA/IDE) are installed properly. When using a PC, incl. and when loading it, if you put your hand on the hard drive, you can feel a slight vibration, if this does not happen, there is a high probability of problems with the hard drive connection cables or its malfunction.
  • Make sure that the RAM (hereinafter referred to as RAM) is in good working order. Try inserting the RAM module into a different slot on the motherboard. If there are several modules, you need to remove them, after which you need to try to insert them into the slots one by one and after each attempt try to turn on the PC. Try replacing the RAM module with a tested, working module.

What to do if the computer does not boot?

As a rule, the computer does not boot due to failures in the operating system or problems with the hard drive. To troubleshoot you need to:

  • Make sure the hard drive is working properly. Check the hard drive for bad sectors.
  • Make sure there is no BSoD message on the screen. BSoD or blue screen of death (from English Blue Screen of Death) is the name of a critical error in Microsoft Windows operating systems. If you encounter this type of error, you need to write down the error code and use the search to find the cause of its occurrence.
  • If everything is fine with the hard drive and there are no BSoD errors on the monitor, then there is a very high probability that there is a problem with the operating system and it will need to be reinstalled.

Hello friends! I have already written many articles about what to do if Windows 7 does not boot. But I haven’t written yet about what you need to do first if your computer refuses to start, or maybe I did :). Well, it’s okay, twice is better than never :).

This will be some kind of advice on how to give first aid to the system in case of its failure. I usually write similar tips and describe in them how to restore Windows 7 if a specific error occurs. But today I will write how to try to cure the system from various errors and problems when loading.

If you turn on the computer, but it frankly does not turn on. Well, you know how it happens, a certain error appears, a blue screen appears, or the computer simply reboots itself, then you need to try to start the computer with the last successful configuration with working parameters.

If we talk about what can cause Windows to stop booting, there are a lot of options. For example, a failure may occur after installing some program or driver. After cleaning your computer from viruses. After incorrect completion of work (when, for example, there was a power outage). I had a problem where I normally turned off my computer in the evening, but in the morning it wouldn’t start, and it seemed like I hadn’t installed anything, but then this happened.

In such cases, the first thing we do is try to start the computer with the last known successful configuration. If this does not help, then you need to look for other ways to solve the problem, for example, searching by error. But as my practice shows, it very often helps to bring the computer back to life. Moreover, all these actions can be done in a few minutes. Now more details.

How to start Windows 7 with Last Known Known Configuration?

It's very simple. Reboot the computer and immediately actively press the key F8.

A black window will appear with additional download options to choose from. Choose “Last Known Good Configuration (Advanced)” and press “Enter”.

The first step is to establish the cause of the malfunction. If the situation is such that the computer turns on, but then the operating system (OS) itself does not load, then naturally you need to dig towards the same OS.

And if the situation is that the computer does not even turn on at all, that is, it shows absolutely no signs of life, then the situation can be much worse.

A few recommendations on what to do if your computer won’t boot!

For the first case (when the computer turns on, but the OS itself does not boot).

Here, as a rule, there is a problem with system files, either they are damaged or completely lost. Try the tips below, all tips are for Windows XP:

  1. Use the “Load last known known configuration (with working parameters)” option. You can use it as follows: after turning on the computer, press the F8 key, a window will appear, and in it select the above-mentioned menu item.
  2. Enter safe mode and try to restore the computer to its previous state. To do this, when booting the computer, press the F8 key (as in the previous paragraph), select “Safe Mode”, if the system boots, go to the following path: Start -> All Programs -> Accessories -> System Tools -> System Restore. And following the wizard's prompts, try to restore an earlier working system.
  3. If the previous methods did not help, then I suggest you familiarize yourself with another option. This option will return your computer to working order with a 99% probability. What should I do? You just need to update the old system. To do this, you will need a boot disk with Windows XP. Insert the disc into the DVD-ROM, reboot, it should boot from the CD, for this you need to set the appropriate item in the BIOS, or you can call up the boot option menu with the F12 key when booting the PC and select boot from CD/DVD-ROM, but This method may not be suitable for everyone.
    After booting from the CD, select "Install Windows XP" following the prompts. When a window appears notifying you that a previously installed OS has been found, press the R key. This way, the Windows installer will update the existing copy. Wait until it finishes and try to boot normally.
For the second case (when the computer does not turn on at all).

In fact, there can be a lot of reasons for this, and it can sometimes be very difficult to help in absentia in this case. And, as a rule, the reason is a malfunction of some device (motherboard, power supply, RAM, etc.). At home, especially for an inexperienced user, there is simply no way to check the functionality of a device by replacing it with a known working one. But there is a way out, although not 100%.

First, try resetting the BIOS. To do this, you need to remove the battery for a few minutes. Or close the jumper contacts to reset the BIOS. Look for a jumper next to the battery labeled Clear CMOS (possible designations: CCMOS, CL_CMOS, Clear RTC, CRTC, CLRTC, CL_RTC). If it doesn't help, read on.

Second. It is necessary to disconnect ALL devices on the computer, leaving only the motherboard connected. That is, we take out the video card, all RAM slots, disconnect the hard drive and DVD-ROM from the power supply, if there are additional devices (internal modem, sound card, etc.) we take them out, leaving only the motherboard connected to the power supply.

And now we try to turn on the computer, if it turns on, then the problem is in one of the disabled devices. Turn off the computer and try ALTERNATELY connect devices, checking the computer for functionality. First, connect the most important devices (video card, hard drive, RAM), and then the secondary ones.

Thus, if, when installing a device, the computer stops turning on, you can independently determine the faulty device. If the computer does not turn on with one motherboard, then the problem is either with the motherboard itself or with the power supply.



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