The computer does not turn on after. What to do if the assembled computer does not turn on

Once I was given a young man as a trainee who was very fond of computers, but absolutely did not understand them. At first I tried to find out his skill level required for system administration. Faced with deathly silence, I had to ask him questions about the hardware. The result was the same. Then I could not stand it any longer and asked a question about what he would do if the computer did not start. The answer still makes me laugh. “To do this, you need to call a computer engineer,” my intern answered.

Despite the abundance of information on the Internet, I am increasingly bombarded with questions from both novice computer assemblers and those who already have solid experience. Alas, low-quality components are often imported to Russia, which affects the assembly results. However, let's take a look at the main causes of PC inoperability. By the way, this algorithm suitable for detecting computer malfunctions.

So you have assembled computer and you, fading with delight, press the Power button. And look disappointedly at the empty screen. This situation is quite common, although I personally encountered it only once. Let's now see how we can launch an iron friend:

1. If the computer starts up (the fans make noise or the speaker beeps), then proceed to the next steps. If not, please read this section carefully. There can be only a few reasons for a launch failure. Either the computer's power supply is defective, or you just plugged in the power button terminals incorrectly. IN individual cases the motherboard may be faulty. I do not think that you are experts in the field of electronics, otherwise you simply would not read this article. Therefore, I will leave questions about repairing motherboards (and there can be a lot of reasons, ranging from swollen capacitors, faulty transistors, etc. to dead chipsets). However, the factor of a faulty motherboard should not be overlooked. If you have a normal motherboard, then there is always a power indicator. It perfectly allows you to exclude a malfunction of the power supply. The latter can be checked either on another computer, or using a multimeter (tester). However, personally, I myself acquired a tester relatively recently, but with additional computers I have no problems. Power supply defective? Change everything. If the power supply is OK, then try to start your computer by jumpering the PWD SW pins on motherboard with a flathead screwdriver, having previously disconnected the button connector. The PWD SW pins are located in a group of pins at the front (often on the left) of the motherboard. Often, contacts are color-coded, in which case look for a green (light green) color. This will make it run. If this fails, then remove the battery from the motherboard and put a coin in its place. So you remove the residual charge and bring down the BIOS settings to the factory ones. If this does not work, then remove the motherboard from the case and run your stuffing on the table. I came across cases that closed the motherboard. Well, if this did not help, then you will have to accept your fate and pay a fee to the service center. At home, you can't do anything with it.

2. However, the computer most often still starts up, but the monitor screen remains blank. And here there can be a lot of reasons. It could also be a faulty processor. It may even be incorrectly inserted into the socket. The RAM may not be fully inserted into the slot, or it may be defective. All of these issues are easy to spot on your own. Professionals for these purposes have special devices called POST cards. They read data from the BIOS and issue signal information by which a malfunction can be determined. A good thing, but if you do not assemble computers on an industrial scale, then you will not need it. Often your assistant is a speaker on the case or motherboard. I'll tell you a little secret - the computer diagnoses itself already at the startup stage, reporting the signals of this diagnostic to the speaker. Having beeped once, the BIOS reports that the system is working normally and there are no problems. But multiple signals indicate various problems. However, the speaker may be completely silent. Sometimes this is due to the fact that it is simply not connected, but more often it is something with the iron. In this case, remove the cooler on the processor, start the computer and turn it off after a couple of minutes. Place your fingers on the processor. If its surface is warm, then everything is in order with it. If not, then make sure you remember to connect the four-pin 12 volt connector from the power supply to the motherboard. It is easy to distinguish it - four wires on it will have a black and yellow marking. If it is connected, then remove the processor and reinstall it in the socket. Try to run. In any case, it is important for us that it be warm.

And if the processor is warm, the speaker does not beep, and the fans are spinning. Then you need to bring down the BIOS in the way described in paragraph 1. Be sure to bring down the charge with a coin!

I always tell my clients that if the computer "beeps", then this is very good. Despite the variety of bios (and now UEFI), they still have some common features. So, for example, I always came across motherboards that reported problems with RAM with two signals. If this happens to you, then pull the memory sticks out of the slots and wipe their contacts with an eraser, and then insert them back. If the signals persist, then the memory is faulty. Will have to change.

Three beeps may indicate a problem with the graphics system. Most modern motherboards come with a built-in video output (or graphics integrated into the board or processor, for example, from Intel). If you have an external video card, then remove it and connect the monitor to the integrated video. The problem is resolved? Great, throw away your video card. But what about those who do not have a built-in video core? Pull out the video card and wipe the contacts with an eraser and reinsert. Did an image appear? If not, then you need to go to the service and check the video card there. Sometimes the problem may not be in the video card. So, for example, I came across the mother asus motherboard, where the PCI-Express bus failed due to a burned-out transistor. However, this case is rather exceptional.

Well, if everything starts up for you, but the BIOS does not see HDD, check that all loops are connected to it correctly.

Troubleshooting a computer is very easy. Thanks to the block architecture, repairs can be carried out even by a schoolboy. I hope this article helped you.

Hello dear readers of my blog site! In this article, we will try to figure out in detail what can be done if the computer does not turn on, we will analyze common errors. But first, you should make a remark, the computer may not turn on for two main reasons: due to problems with hardware and problems with programs. As they say, there is no third!

If, when you turn on the computer, all the lights come on (which have lit up before), the coolers are noisy, the screen passes bios loading, and starts Windows boot, but then a crash occurs: errors, the computer starts to hang, all kinds of bugs - then go to the article - ““. Let's try to figure out the most common hardware failures further.

1. If the computer does not turn on - what to do at the very beginning ...

First what you need to do is make sure you don't have a power outage. Check the outlet, cords, adapters, extension cords, etc. No matter how silly it may sound, but in more than a third of cases, the “wiring” is to blame ...

An easy way to verify that the outlet is working is to remove the plug from the PC and connect another electrical appliance to it.

It should be noted here that in general, in general, if it does not work for you: printer, scanner, speakers - check the power!

And one more important point! On the back of the system unit there is additional switch. Be sure to check if someone turned it off!

Switch to ON mode (enabled)

Secondly if there are no problems with the power supply to the PC, you can go in order and find the culprit on your own.

If the warranty period has not yet expired, it is best to take the PC to a service center. Everything that will be written below - you do at your own peril and risk ...

Electricity is supplied to the computer by the power supply. Most often it is located on the left side of the system unit, at the top. First, open the side cover of the system unit, and turn on the computer. Many system boards have indicator lights that indicate if power is being supplied. electricity. If such a light is on, then everything is in order with the power supply.

In addition, it should be noisy, as a rule, it has a cooler, the performance of which is easy to determine by raising your hand to it. If you don’t feel the “breeze”, then things are bad with the power supply ...

Thirdly, the computer may not turn on if the processor is burned out. If you see melted wiring, you feel a pungent smell of burning, then without service center no longer manageable. If all this is not present, the computer may not turn on due to processor overheating, especially if you have overclocked it before. First, vacuum and brush off the dust (it interferes with normal air exchange). Next, reset the bios settings.

To reset all bios settings, you need to remove the round battery from system board and wait about 1-2 minutes. After the time has elapsed, replace the battery.

If the reason was precisely the overclocking of the processor and incorrect bios settings, the computer will probably work ...

Let's summarize. If the computer does not turn on, you should:
1. Check the power, plugs and sockets.
2. Pay attention to the power supply.
3. Reset the bios settings to the standard ones (especially if you climbed into them, and after that the computer stopped working).
4. Clean regularly system unit from dust.

2. Frequent errors due to which the computer does not turn on

When you turn on the PC, the first thing that starts working is Bios (a kind of small OS). It first checks the performance of the video card, tk. further, the user will see all other errors already on the screen.

However, many motherboards have small speakers that can beep to notify the user of a particular malfunction. For example, a small table:

If no problems are found, bios starts loading the system. At first, it often happens that the logo of the video card flashes on the screen, then you see the greeting of the bios itself and you can enter its settings (for this you need to press Del or F2).

After the bios greeting, according to the boot priority, devices begin to be checked for the presence of boot entries in them. So, let's say, if you changed the bios settings and accidentally removed the HDD from the boot order, then bios will not give the command to boot your OS from hard drive! Yes, it happens with inexperienced users.

In order to exclude this moment, just in case, go to the boot section in your bios. And see what the order of loading is.

IN this case it will boot from USB, if there are no flash drives with boot records, it will try to boot from CD / DVD, if it is empty, the command will be given to boot from the hard disk. Sometimes the hard disk (HDD) is removed from the queue - and, accordingly, the computer does not turn on!

By the way! Important point. On computers that have a floppy drive, there may also be a problem that you left a floppy disk and the computer looks for boot information on it when it boots. Naturally, he does not find them there and refuses to work. Always remove the floppy disk after work!

That's all for now. We hope that the information in the article will help you figure out if your computer does not turn on. Happy parsing!

10.08.2016

The causes of failures when starting a computer can be divided into groups: related to hardware problems, with errors in software and related to the human factor. All these errors are subject to diagnosis and correction.

Computer won't start at all

In this case, we consider the "dead" state of the computer: when you press the power button, nothing happens. In this case, the probability of a human factor is high. Therefore, you need to check whether the PC is connected to the mains and if connected, then check the contact density. It is possible that the contact has come off somewhere, and therefore no electric current is supplied to the power supply. Also, the button behind the computer's power supply may be disabled. You need to turn it on.

The computer will not start if there is a loosely fitted memory strip in one of the slots or the processor is installed incorrectly, so you should check the tightness of connecting PC components in their sockets. So, you can exclude the human factor in the diagnosis of your PC. If the check determined that everything is fine, then you should look for the hardware cause of the problem.

The most obvious reasons leading to the fact that the computer does not start are malfunctions in the power supply, motherboard. If there is a known working power supply, then it must be connected to the motherboard. A good power supply will allow the computer to start. In addition, even if the computer is turned off, standby power is supplied to its components from the PSU.

If the standby LEDs installed on the motherboard are on, then power is being supplied, and therefore the PSU can start the computer. Also, to check the operability of the unit, you can connect a CD-ROM to it and if problems are found, then it is the PSU that is faulty. It is very rare for a motherboard problem to cause a computer to start up.

Sometimes the problem computer starts up, but the boot itself does not occur. The coolers start up and work, but the computer does not beep and the HDD activity indicator does not light up. In this case, you need to simplify the configuration as much as possible by disabling all possible components. Then gradually add one component at a time, checking which one is causing the failure.

After the PSU sends a command to the chipset that everything is fine with the power supply, the system logic starts the processor, which, having done the self-test procedure, launches the PC component check and initialization procedure (POST) - it is a subroutine of the input / output system (BIOS) program . Therefore, if the computer starts, but the download does not start, then this means that the failure occurs precisely during the initialization of the components.

In this case, the motherboard usually emits sound signals when initialization errors are found. These signals for each BIOS different, however, the successful completion of the initialization of components, as a rule, is the same for all these programs - one short signal.

The minimum configuration of the processor, power supply and motherboard, which does not issue a single signal, is evidence of a malfunction of one of these components. If, when turned on in this configuration, the PC starts to reboot immediately, then there is a high probability of power failures, and therefore the PSU may be the culprit of what is happening, since the chipset resets the voltage at the Reset pin only after receiving a signal from the PSU that everything is in order with the power supply. Also, faulty motherboard capacitors can be the cause.

The result of the self-test procedure is a table in which all found devices are recorded. The creation of the table is accompanied by the entry "Verifying DMI pool data". If, after the creation of the DMI table, the loading has not occurred, then there are a number of reasons why this can happen.

The computer configuration has been changed and the BIOS routines are not interpreting it correctly.
A faulty device has been found.
The data in the DMI table in CMOS is corrupted and cannot be written further.
Problems in the BIOS itself.

To resolve these issues, reset the CMOS settings to default, or have the POST routine recreate the table.

Why does the computer not start when loading the operating system

After completing the POST procedure, testing the memory modules and initializing some other components, the boot record is searched for on those devices and in the order in which they are specified in the BIOS. The I/O system looks for the 55AA signature to identify boot sector disk. The detected MBR boot record on Windows systems consists of two parts: the boot loader code and the partition table. The bootloader starts looking for the active system partition, trying to identify its boot entry.

The bootloader of the active partition, in turn, starts the bootmgr boot manager, which is located as a system file in the root directory of this partition. The boot manager, after reading the system configuration data from the BCD store, transfers boot control to the winload. At the new stage, the system kernel is loaded and initialized, and then drivers, services, user session data, and the desktop are loaded.

Problems during the boot phase of the operating environment can be caused by existing problems in the boot phase chain: problems in the MBR search phase, problems in the partition boot record search phase, problems with the boot manager and with reading configuration data from the BCD store. Also, loading can be disrupted by problems at the stage of loading the system kernel and its initialization.

If the computer does not start with problems at the stage of loading the operating system, then in this case the system recovery disc can help. It is easy to create using the tools of Windows itself. At the same time, the user can use the operating environment startup repair tool. If necessary, a boot failure can be overcome by rolling back the system to the time it was imaged.

For example, in order to use the Startup Repair tool, the user must navigate to the boot selection menu using the F8 key. There you need to select the item "Troubleshoot your computer", as shown in the figure below.

Parameters Windows localization 7

The operating environment will open the recovery utility window with a suggestion to configure its localization settings. The user must select a language convenient for him and click the "Next" button.

At the next step, the system will prompt you to log in, and if the user enters the system with a password, and not automatically, then he must enter his real password in the "Password" field. So, he will have access to the recovery tool. If the login is automatic, then just click "OK".

The recovery utility offers a number of options to choose from. However, in our case, the computer does not start due to failures in loading the environment, and therefore our choice is "Startup Repair".

Selecting a tool by the user will allow the system to run it and start looking for problems. If the problems are related specifically to problems at the boot stage, the system will detect and fix them. If no problems are found, the environment will notify the user.

The computer does not start - this is a sign of significant problems

Problems with starting a computer can usually be caused by a whole group of reasons. This can be the fault of both individual PC hardware components, software problems, and a person who forgot to plug the plug into a socket or loosely installed a component in its slot.

To correctly diagnose problems, the user must correctly understand the process of starting the computer and loading its operating system. Only understanding at which stage the failure occurs will allow you to localize the cause of the failure, which will later allow you to accurately determine what the problem is, with which of the PC components.

What to do if WINDOWS does not boot

A quick guide on what to do if the computer does not turn on or boot.

1. Problem: when you press the power button, nothing happens, the computer does not make any sounds, there is no image on the monitor.
Recommendations: Check if the computer is connected to the outlet, if there is electricity in this outlet, check the switch located on the back of the system unit on the power supply, check that the power cable for the computer is working (for example, connect a monitor with it). If everything is checked and everything is in order and the computer does not start, the hardware of the computer is most likely faulty. Most often, the power supply fails (usually not the entire unit fails, but only the fuse, which is quite simple to change) or the motherboard, in which case we recommend contacting the service.

2. Problem: when you press the power button, the computer makes normal sounds, there is no image on the monitor.
Recommendations: It is possible that the computer does not turn on due to incorrect BIOS settings (for example, the processor bus frequency is higher than necessary for normal computer operation). In this case, try to boot with the Insert key held down (on different motherboards in different ways, the instructions describe which key resets the settings), if it doesn’t help, try resetting the BIOS settings in a different way: remove the cover from the system unit, find the Clear CMOS jumper on the board (in the instructions for the motherboard it is written where it is located) and for how many seconds, move the jumper to the adjacent contacts, or find the battery and remove it for a few minutes.

3. Problem: The computer turns on and immediately turns off.
Remove the cover from the system unit, make sure that the cooler (fan) on the processor rotates normally and fits snugly against it.

4. Problem: the computer turns on, but stops on the first page, some kind of inscription is written below.
Recommendations: Check if the keyboard is connected correctly and if it works, if any key is pressed. Try resetting the BIOS settings, as indicated in paragraph 2. Check the connection and performance hard drives and drives. Check if the BIOS settings are correct.

5. Problem: the computer starts, but instead of loading the operating system, some kind of inscription is displayed.
Recommendations: Check if there is a floppy disk in the drive, if there is a disk in the drive, check the boot order specified in the BIOS. If a message is displayed that there are no system files you will need to reinstall or repair the operating system.

6. Problem: Windows* starts to load and the computer freezes.
Recommendations: while the computer is booting, press the F8 key, in the menu that appears, select the SAFE MODE item, if in safe mode the system booted up, then most likely the problem is that the system is infected with viruses or malware. In safe mode, check your computer for viruses (not all antiviruses work in this mode, try using free utilities AVZ or DRWEB CureIT, do not forget about updating anti-virus databases) and disable all programs from startup, for which you need to click Start-Run-type msconfig and uncheck all the checkboxes in the startup item.

*) For Windows systems XP

IT option -

Windows 7 has become a classic for home use, it is it that is installed on every second computer, despite the development of new operating systems from Microsoft. Entering the market in 2009, the "seven" still does not get rid of the problems during the launch, which pretty much spoil the nerves of the multi-million user audience. To simplify the life of a user whose computer is running the "seven", this article was written. In it, we will look at how to perform Windows recovery 7 if it doesn't start.

BOOTMGR is missing

The most common problem that appears during the launch of the "seven".

The reasons for its appearance may be:

damaged hard disk or non-working cells SSD memory on which Windows 7 is installed (in most cases, you can restore them);
spontaneous power outage or reboot of the PC using the "Reset" key;
activity of viruses (very rarely);
inept user handling of hard disk partitioning utilities.

There are several ways to make the error disappear. We will consider how to restore a computer using the OS itself.

If problems occur during Windows startup 7 press F8 to bring up the combo menu additional options starting the computer.
Select the "Troubleshooting..." option.

Select the Russian language and click "Next".
Choose account with administrator rights.
Click on "Startup Repair" to operating system I tried to find and fix the problem myself.

If the error is not fixed, run command line from the OS Resume Options window.
We sequentially enter the commands:

"bootrec.exe /FixMbr" - write MBR to the system partition;

"bootrec.exe /FixBoot" - creates a boot entry on the system volume.

Reboot and start the computer.

If, after following the above steps, the PC still does not detect the installed Windows 7 during startup, run the bootrec.exe command through the command line with the "RebuildBcd" attribute.

It will scan all the devices installed on the computer long-term storage information on the presence of installed operating systems compatible with the "seven" on them, and will allow you to add them to the boot list.

And in the very last case, when nothing helps to restore the start of the "seven", reserve the old BCD folder responsible for starting the PC and create a new one. This is done using the following chain of commands:

"Disk boot failure" problem or "Insert system disk" message

The startup error is caused by one of several reasons, the essence of which is as follows: the computer is trying to find a boot record on a disk that is not bootable. Factors preventing Windows 7 from starting:

The device from which the computer starts to boot is not system drive- try turning off all flash drives, phone, camera, including external hard drives, and reboot the system.
Check BIOS settings, which are responsible for the priority of boot devices - there is a high probability that the computer starts to boot from a disk that is not a system disk. Also look in the BIOS or through one of the special utilities that has Windows 7 installed.
Reconnect the HDD to a different cable and cable, perhaps the problem lies in the unreliability of the connection or damage to one of the cables, for example, due to its considerable bending.

The list of reasons can safely include the absence installed Windows 7 due to the fact that the disk with it was formatted due to the inattention or inexperience of the novice user, and reinstalling it or restoring the deleted partition will help here.

If none of the options brought the desired result, try to restore the OS, as described in the previous paragraph, and also make sure that the hard drive is working.

Inability to start Windows due to corrupted registry files

Among other things, Windows 7 may not boot due to damaged files register.

As a result, the computer will inform the user about the problem and launch an application that allows you to restore the operating system to working order.

But the remedy automatic recovery Windows 7 is far from always effective and, for example, in the absence of backup damaged data, the user will have to manually perform an operating system recovery.