Interesting

Why the computer does not turn on: reasons and solution

Good day!

Well, right off the bat ?! 👌

In general, today's problem can be globally divided into two components:

  • hardware malfunctions (i.e., for example, your power supply has become unusable);
  • software errors (for example, something happened to the Windows system files, and now it does not load).

Because many users often confuse these "subtle" points, I will start this article with the symptoms (just like a doctor 😉).

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Symptoms of iron (nutritional) problems:

  1. when you press the power button, absolutely nothing happens (that is, "dead" silence, nothing makes noise in the PC, does not blink, there is nothing on the screen, etc.);
  2. after turning on the PC, it turns off at once (after 2-3 seconds);
  3. some squeaks from the system unit are heard, nothing is shown on the screen;
  4. the computer seems to be buzzing with coolers, but only "No Signal" is lit on the screen.

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If your computer starts up, and then an error appears when Windows boots (or immediately after it), then, most likely, the problem is of a software nature.

Try in this case, for a start, 👉 restore the Windows bootloader (often helps to solve the problem) Also, pay attention to the most popular reasons for which 👉 Windows won't boot.

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In this article I will try to give "step-by-step" recommendations for diagnosing and fixing hardware problems (ie the first component ...).

And so, now more to the point ...

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👉 Remark!

If you have a problem not with a classic PC, but with a laptop, then I would also recommend this article.

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What to do if the computer does not turn on (main reasons)

STEP 1: checking power, switches

The first recommendation is pretty standard: check if the electricity has been cut off, if the surge protector is on (if the LED on it is on, see the photo below), if the cables are tightly connected, etc.

Surge protector included

Besides, also check the toggle switch (switch) on the computer's power supply (for many users, its presence is a whole discovery!). It is usually located on the back of the system unit, next to the socket for connecting the power cable.

By the way, it can often be accidentally switched when moving the system unit.

Switch on the PC power supply

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STEP 2: check the monitor connection

Next, check if the cable for connecting the monitor is tightly visible in the socket (especially if the PC itself seems to be noisy after turning on, but there is nothing on the screen, or the message "No Signal" appears).

Monitor with VGA and DVI interfaces

I also highly recommend doing the following:

  1. if you have 2 video cards on your computer, connect the monitor to another card;
  2. if it is possible to connect a monitor to an excellent interface - try it! (for example, you have a monitor connected via DVI, but it is also possible to use HDMI; in more detail about connectors for connecting monitors)
  3. check the performance of the monitor itself. To do this, just connect it, for example, to a laptop (how to do it).

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STEP 3: if you hear some squeaks from the system unit

Almost every system unit has a small speaker ... It is designed to reproduce the simplest sounds (old games, by the way, the sound was fed to it).

Now it is used solely to inform the user about any malfunction (you must admit that not all errors can be displayed on the screen).

Options "beeping" quite a lot: starting with a simple long squeak, and ending with combinations of long and short. Moreover, depending on the BIOS version, they can mean different things.

👉 Help!

"1 long, 2 short" - what sounds from the computer when you turn it on? BIOS Signals: Tables

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Of course, these signals cannot help us directly, but a diagnosis can be made with them (at least it will be clear where to look for a malfunction!). It can be very helpful if you have any spare parts in stock that you can install on your PC yourself.

Examples (for Award BIOS):

  1. continuous signal (just a long squeak without pauses) - a problem with the power supply;
  2. 1 long and 1 short beeps - RAM problem;
  3. 1 long and 2 short beeps - a problem with the video card;
  4. 3 long beeps - keyboard controller malfunction, etc.

You can find out your BIOS version in the documentation that came with the PC (however, there should also be a decryption of the "squeaks").

Award BIOS

Important!

If you have a new computer and it is still under warranty - do nothing further!

If you open the lid of the system unit, you may receive a denial of warranty service ...

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STEP 4: cleaning the PC from dust, checking the RAM strips

Next, I would recommend opening the system unit and cleaning it from dust (👉 on how to do this).

By the way, if your PC turns off abruptly after a long time (and then after turning it on again turns off) - this is a symptom of overheating.

The fact is that modern computers have a dual-circuit overheating protection system: when the processor temperature reaches a critical level, it turns off (and until it cools down, you will not turn it on). Intel processors overheating

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After that, pay attention to the ramps. It is advisable to remove them from the slots and clean the contacts with an elastic band (see the photo below. It is best to brush away the villi with a brush).

Cleaning the RAM strips

Then try to take only one stick of RAM and insert it into the slot (advice for those with 2 or more sticks of RAM). If you have one bar, insert it into another slot.

Try turning on your PC and check it works. If the computer has booted, it is quite possible that you have a problem with one of the RAM sticks, I recommend that you drive their specials. utility (👉 i.e. run a test).

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STEP 5: reset BIOS settings

In some cases, the computer may not boot due to lost BIOS settings (although if the reason is related to this, then after turning on the PC, it should still show some "signs" of life).

If you are unable to reset the BIOS using the classic methods, try disconnecting the PC completely from electricity and finding a small battery on the motherboard (in the form of a pill, see the photo below 👇). It must be removed for 10-15 minutes. (for reliability, wait a little longer).

Battery on motherboard

Then put it in place and try to turn on the computer. BIOS settings must be reset.

👉 Supplement!

On some motherboards, the battery may not be removable. In this case, see if there is a reset jumper next to it (example in the photo below).

jumper for BIOS reset

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STEP 6: try disconnecting all peripheral equipment

In general, only a motherboard, RAM, processor, video card, power supply are needed to boot and operate a computer. Try to disconnect everything that is possible from the motherboard: printers, scanners, mice, tuners, audio card, etc., leaving only the basics ...

If the computer turns on, then try connecting one card at a time, rechecking each time (whether the PC will turn on after connecting the next device). By this method of elimination, you can find the reason ...

From experience, I can advise you to first of all pay attention to various media devices: tuners, audio cards, USB hubs, modems.

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STEP 7: check the condition of the capacitors

Inspect the capacitors on the motherboard, video card, power supply (how they look - see the photo below, in the form of a small barrel 👇).

Pay particular attention to the top of the capacitor: ideally, it should be flat. But over time, some capacitors may swell (the top will become convex, see capacitors marked in red in the photo below).

Swollen capacitors

If such capacitors are found, you should:

  1. or replace the board with a new one;
  2. either hand over the computer for repair;
  3. or try to find the same capacitor (see the marking on it), and solder a new one yourself (if you have experience in soldering, this is done quite simply).

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STEP 8: if your self-assembled PC does not turn on

  1. check how the power cable is connected to the mat. board (24 pin). Often, many when assembling a system unit for the first time, do not fully fix it.

    Fixed 24 pin connector (power supply to the motherboard)

  2. After that, also pay attention to the processor power connection cable (it goes either 4-pin or 8-pin);

    4pin connector

  3. It is also not superfluous to check the "Power SW" connection (PC power button); "Reset SW" (reset button); "Power LED" (LEDs on the PC case, signaling that it is on); "D.D.LED" (hard disk loading indicator).

    reset sw

  4. make sure the CPU matches the motherboard, RAM. Often, many "get confused" and pick up the wrong components (for example, not matching in frequency). By the way, now it is quite easy to assemble a system unit according to your requirements with the help of specials. constructors (they evaluate compatibility on their own!);
  5. if you chose too high-performance components, but saved on the power supply, then it is possible that it simply cannot cope with the current load;
  6. It will also not be superfluous to remove the processor and check the condition of its legs (very often novice users bend them if handled carelessly).

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STEP 9: hike service or replacement of components

If you find the cause of the malfunction (for example, the computer gave you a beep that there is a problem with the RAM), then you can try to replace the memory stick with another one (if you have them, or order it from the 👉 Chinese online store).

In general, the sequence for replacing components is as follows:

  • RAM and power supply;
  • video card;
  • CPU (processor);
  • motherboard;

Those. to start troubleshooting and replacing components (for similar workers) for diagnostics, they begin with RAM, then go to the power supply, etc.

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If the components you do not have (or the cause of the malfunction is unclear) - it is better to take the PC to the service ...

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Additions on the topic are welcome!

Happy work!

👣

First published: 30.10.2018

Correction: 10/10/2020

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