The monitor keeps turning off. The monitor screen goes blank while the computer is running - why does this happen? Unstable operation of the monitor power supply

Does your monitor go blank when loading Windows? Or does your laptop screen go dark? Does it turn on first and then turn off after 1, 2 or 3 seconds? At the same time, the computer itself (the system unit) works, right?

There can be many reasons why the monitor turns off. And it doesn’t depend on what your price is operating system: Windows XP, 7, 8 or 10. And it doesn’t even depend on what monitor you have: Samsung, LG, Asus, Acer or Philips. Anyone can have this problem.

I would like to note right away that all malfunctions on PCs and laptops come in two types – hardware and software. Below we will only consider software problems, which are caused by Windows errors or wrong installed programs(+ a few problems general). Hardware faults are a breakdown of equipment (monitor, video card, etc.). It is better to contact a service center for this.

Since you don't know why the screen goes blank, you first need to make sure that it's not a hardware error. Below are 10 ways to solve this problem, and you can check them all one by one.

To fix the problem you will need to turn on the computer. You can do this by downloading it to safe mode. To do this, when you turn on the screen, press the F8 button repeatedly until a menu appears (in it you need to select the “Safe Mode” item). If the Windows logo appears, it means you didn’t have time. Restart your computer and try again.

Turn off the display

Let's start with the simplest. Your monitor turns on, works great, but goes out after 10, 15 or 30 minutes. What is the problem?

By default, Windows is set to “turn off display after N minutes.” It's all about her.

“This can’t be true!” – you say. Maybe. But it's worth checking out. It would be stupid if, because of such a trifle, you spend a lot of time and nerves trying to figure out why the monitor goes out. In addition, the check will only take 2 minutes.

Instructions for Windows 7 users:

On Windows 8 and 10 the procedure is approximately the same.

Instructions for Windows XP users:

1. Right-click on the desktop and select “Properties”.
2. Go to the "Screensaver" tab and click the "Power" button (bottom right).
3. See the familiar “Display off” field and select “Never” (or any other value).

It's all about humidity

Another popular reason is humidity. You may not believe it, but if a PC or laptop is left in a room with humid air for a long time, this causes malfunctions in its operation. As a result, the monitor turns on and immediately turns off. And all because condensation can accumulate in it, which, naturally, will not do anything good.

What to do in such a situation? Just leave your computer off for a while and let the water evaporate. This will solve the problem (if, of course, that is the problem).

How long have you cleaned your system unit or laptop?

The problem is as old as the world, but still. How long has it been since you cleaned your computer? If it's been a long time, then that could be the problem. And now you are trying to understand why the monitor lights up and goes out immediately after Windows boot….

Dust can interfere with the operation of the video card or random access memory, therefore it is recommended to clean the system unit as soon as possible. Or take it to a service center and have them clean it. And in the future, do not run your computer to this state.

Poorly connected wires

The next reason the monitor turns off is poorly connected wires. We are talking about a cord from the monitor to the system unit (more precisely, to the video card). Perhaps you accidentally caught it or pulled it. Perhaps one of your family members did this, or maybe even your favorite cat or dog.

In any case, this should be checked first. To do this, simply disconnect the wire on both sides, wipe (blow), and then connect it again. May I help.

To begin with, it is recommended to unplug the cord only from the monitor side. If the message “No signal” appears on it, then I have 2 news for you. The good one is that everything is fine with it, it is not broken, but the bad one is that you still don’t know why the screen immediately turns off when you turn it on.

Another common problem is cable damage. To check this, you need to find a similar cord and connect it.

Malfunction of random access memory (RAM)

For this reason, the monitor goes out quite less often, but it still happens sometimes. Perhaps you recently bought new RAM. Or maybe she just had time.

If you have several sticks of RAM, you can disable one. Or swap them. You can also check your RAM from a friend or take his RAM and connect it at your place. If this is the problem, you will immediately understand it.

Video card malfunction

Most often, the monitor turns on for 2 seconds and goes off due to a faulty video card. After all, it is she who is responsible for displaying the image on the screen. And the cord from the monitor is connected just to it.

The most reliable way to make sure that the monitor is going dark because of the video card is to connect another one and try to turn on the computer. You can take it from your friends or acquaintances (if you have any).

As an alternative, you can connect another monitor (again, you need to borrow one from friends). If you do not have this option, then skip this step and move on to the next one.

The problem may be due to overheating of the video card. The cooler (fan) is broken, the cooling system is not doing its job, etc. To make sure of this, turn off your computer and wait 20-30 minutes (more is possible). If the problem was overheating, then it should turn on normally. In this case, you will need to resolve the issue of cooling the video card or replacing it.

Video card driver conflict

Another reason is a video card driver conflict. To check this, do the following:

1. Start – Control Panel – Device Manager (for convenience, you can select the “Large icons” view mode in the upper right corner).

   
   How to open Device Manager

2. In the new window, click on the “Video adapters” item, after which the name of your video card will be displayed.
   
3. Right-click on it, select “Properties” and look at the status. If the video card is functioning normally, then this will be written in the new window.
4. Next, select the “Resources” tab and read if there are any conflicting devices.
5. If everything is in order, then hide all windows. Next, right-click on the desktop, select “Screen Resolution” and select the minimum - for example, 800x600 pixels. Click “Apply” and restart your PC. If it turns on, congratulations, the problem is fixed.

The video card driver is not working correctly

If the device is NOT functioning normally, some conflicts have been detected or previous method If it didn’t help you, then we’ll act more aggressively:

1. Boot your PC again into safe mode and go to Device Manager.
2. Open the “Video adapters” item and find your video card.
3. Right-click on it and select “Delete” (don’t worry, this is the usual driver removal procedure).
4. Confirm the deletion and restart your PC - it should start in normal mode.
5. Install the driver on the video card from the disk included in the kit, or download it from the official website.
6. Reboot your computer again to make sure the monitor no longer goes blank.

It is recommended to install drivers only from the disk! There was a case when downloaded from the office. For some reason the sites were installed crookedly. The problem was solved by installing the drivers from the disk (then you can install a new, more current version on top of them).

Motherboard or processor malfunction

This is probably the worst of all possible options. It is a breakdown of the processor or a short circuit in the motherboard that causes the screen to go dark a second after turning it on, but the computer continues to work.

By the way, yes - the system unit can still function. In particular, the coolers will spin, creating the illusion that everything is normal. But in such situations, it may be necessary to replace the processor or motherboard(or, at a minimum, their repair) - and this will already cost you money.

However, problems with the monitor could have occurred for other reasons, but in this particular case it is best to entrust computer diagnostics to specialists.

Why does my monitor turn off during a game?

And finally, one more problem that every gamer has probably encountered while playing. Moreover, such a malfunction can occur only when starting some toys. Quite a sticky situation, right?

In 90% of cases this happens because you have set your monitor settings too high. The fact is that each model only supports a certain resolution and refresh rate. And if you select parameters that exceed its capabilities, then when you start the game the monitor goes blank (the message “Out of range” appears or the screen simply turns black).

But there is one more nuance. And most often it occurs among owners of old monitors - for example, square ones (with a resolution of 1024x768 or 1280x1024 pixels).

The fact is that developers prescribe a certain resolution in games by default. And usually it is much higher than 1280x1024 pixels. He doesn't support this high resolution(or refresh rate). This problem was observed in Far Cry 3, S.T.A.L.K.E.R, etc. Then many players complained that the monitor went blank during the game.

Solving this problem is very simple. You just need to find the configuration file. It can be called differently, but is always in the .ini format. And it is located either in the game folder or in “My Documents”. More precisely, you can find out in Google or Yandex by the name of a specific game.

In that file you need to find the line where the resolution is indicated, change it to your own, save - and you can play.

Instead of a conclusion

Well, I hope one of these methods helped you solve your annoying problem. If your monitor screen still turns on and off, then it may be a faulty hardware issue. In this case, you can look for other ways to solve this problem or immediately contact the service center. But this is up to you to decide.

Connecting the system unit to the monitor is quite simple; to do this, you need to connect them with a cable through the appropriate port, after which the image will be broadcast on the screen. Despite the relative simplicity of the procedure, a number of problems may arise immediately, even after a successful connection. If the monitor goes off while the computer is running, many users may complain that this is due to its malfunction. In fact, this is not always the case, and below we will look at the main reasons why the monitor turns off during operation system unit.

Signal loss due to faulty cable or connector

The most common reason why the monitor turns off for a while while the computer is running is faulty cable. In this case, you need to check the condition of the cable itself, which transmits information from the computer to the monitor. Most often, a DVI or HDMI connector in the computer case is used to output images. Make sure that the cable is inserted firmly into it; if we are talking about DVI, it must be tightened, otherwise the connection will not be reliable.

If damage or a poor cable connection cannot be identified, it is recommended to try using another port for connection in the system unit; most often there are several such ports. Also try to get a cable that is definitely not a problem, and connect the monitor to the system unit through it.

The monitor turns off due to problems with the video card

In a computer, the video card is responsible for displaying images on the monitor. Its malfunction can cause the monitor screen to go dark while the system unit is running. You can make sure that the problem is not related to the video card by connecting the computer to another monitor or, for example, to a TV. If the image is displayed on it without problems, then the option with a faulty video card can be dismissed.

Most often, a video card malfunction, which can lead to temporary interruptions in the output signal, is associated with overheating. The base cooler of a video card is not always enough to cool the chip on it, especially if the video accelerator is . Check the temperature of the video card using special applications, making sure that it does not go beyond.

It is worth noting: If the problem with the monitor turning off when the system unit is running is due to overheating of the video card, it may appear, for example, only when running resource-intensive games or programs.

Monitor turns off due to bad memory modules

Another common problem that can cause a monitor to temporarily turn off is the failure of the RAM or its operation with errors. To make sure that this problem does not exist or does not exist, it is recommended using Windows or third party applications. Even if one of several RAM modules is faulty, this can cause the monitor to spontaneously turn off while the system unit is operating.

RAM modules cannot be repaired, and if the test reveals problems in the operation of one or more of them, you will need to purchase new RAM sticks in their place.

Monitor malfunction

If the monitor goes out while the system unit is running, it cannot be ruled out that there are some problems with it. Most monitors have protection that automatically turns off the screen if there is a risk of overheating. It is not possible to check the temperature of the monitor using diagnostic tools, so the only option is to “touch” to determine whether it is too hot. If your monitor is overheating, you may need to place it in a more ventilated place in the room or, for example, move it further away from the wall.

The monitor can also turn off automatically if it is working in a room with high humidity. In such a situation, you need to move the monitor to a room with normal humidity and let it stand for some time without connecting to the network. During this time, the settled moisture should evaporate, and when working in a normal environment, the monitor will no longer go out if corrosion has not yet formed.

The monitor screen goes blank, but the computer continues to work? Almost every user has encountered a similar situation, regardless of their level of computer literacy. Let's consider all the factors that can lead to such a situation, and also consider how this or that situation can be resolved.

Why does my monitor screen go blank?

In some situations, a similar problem may arise due to simple user errors, for example, accidentally turning off the monitor's power button. Everything is much more complicated and unpleasant when the computer hardware fails or the monitor itself breaks down, because in this case you will either need to completely replace the component part or contact a service center. Let's consider various reasons separately and ways to solve them.

1. Monitor failure.

To understand the reason, it is always necessary to go through a certain screen test procedure. Turn off the computer completely, and then turn it on again and monitor its behavior:

• if the monitor shows the image, but after 2-3 seconds. the picture disappears, most likely the reason for this is the failure of one of the incandescent lamps and it needs to be changed.
• in case the monitor screen does not light up, but when an external LED lamp it lights up and shows some kind of image, which means the problem is in the voltage inverter, which needs to be replaced.

If, when the system unit starts, nothing is displayed on the monitor, disconnect it from the SB by pulling out the cable. The operating monitor should display a “No Signal” message, or something similar, depending on the model and manufacturer. If this does not happen, then we can clearly say that the output device has failed without service center There is no way around this, since there can be many reasons for the malfunction and this cannot be checked at home.

1. Video card malfunction.

The display of the image on the monitor screen directly depends on the health of the video card, which can also break at some point. If you have a discrete one, unwind the system unit, take it out and reconnect it to the motherboard. If nothing has changed, additionally try inserting it into another system unit to fully verify that the graphics adapter is working.

If you are using an integrated video card, try to get a discrete one and connect it. If the computer starts normally, the problem lies precisely in the failure of the built-in adapter.

1. Presence of dust.

If your PC has not been cleaned of dust for a long time, then try. The fact is that dust is electrically conductive and, if it gets on components, it can make work difficult. Clean the computer with brushes and a vacuum cleaner, and then reassemble it and try turning it on again.

1. Damaged cable.

This reason is one of the most common, but it is quite difficult to recognize and for some reason users always pay attention to it last. Even if the connection cord has no visible damage and has not been subjected to any mechanical stress, it can also break on its own.

Try using a different connecting cord, and if the display is normal, the reason will be clear. You just need to be absolutely sure that the other cable is probably working.

1. Incorrect connection.

If several people have access to the PC, then it is possible that when reconnecting, the connecting cable was inserted into the wrong connector and nothing will actually be displayed on the monitor. Modern motherboards have video connectors, although there may not be an integrated graphics adapter on the processor or motherboard, and accordingly, nothing will be shown on the screen when connected. And even if there is integrated graphics, it will only recognize the preinstalled discrete one, which is usually more powerful, and accordingly no image will appear on the screen.

1. Failure of the processor or motherboard.

Sometimes, when you turn on the computer, only the appearance of correct operation system unit (the power supply is working, the coolers are spinning, etc.). In fact, this does not always indicate serviceability. When you turn on the system unit, listen to see if there is an intermittent sound signal, whether the mouse and keyboard turn on (do the indicators light up), whether power is supplied to the flash drive (the LED should light up, although some models do not have it).

1. Life situations.

There are times when the user may accidentally pull the power cord, after which the monitor simply theoretically cannot turn on. Incorrect settings may be set.

My monitor, LG Flatron L1917S, began to go dark during operation and immediately after turning it on. I will give the schedule in more detail. Two monitors are connected to my system unit: ASUS PA248QJ and LG Flatron L1917S. Monitors are connected via Asus video card AMD Radeon HD7770, which allows you to connect up to 4 monitors simultaneously. One fine day, the second monitor, LG Flatron L1917S, went out while working. What was most interesting was that the green light remained on, indicating that the monitor was working. In the device manager it was listed that the monitor was working normally, but at the same time, the monitor screen was blacker than black.

I tried turning off the monitor with the Power button and turning it on immediately. At first, after turning the power off and on, the monitor started working, but then went out again. A day or two later, the situation looked like this: The monitor turns on for about a second and goes off again.

Initially, I thought that the problem was related to the video card, but when I disconnected the VGA cable from the system unit, the standard “Check cable” message did not appear on the LG monitor. Just in case of emergency, I connected the monitor to the laptop - the laptop determined that the monitor was connected and the monitor was working, but the monitor did not light up. After checking the VGA cable one last time, I finally concluded that the monitor was faulty. I have already repaired it before, but last time, i.e. The power light didn't even light up. Although the problem looked completely different this time, I ventured the assumption that the problems were again related to the monitor's power supply.

Disassembling the monitor

If you know how to disassemble LCD monitors, you can safely skip this part. If you don't know, it's better to read. We will disassemble the LG Flatron L1917S, but many other models are opened using the same principle.

Take a shaped screwdriver and unscrew the six screws.

Next you need to act carefully. The connections of the cases of many monitors and laptops are secured with latches, so the case must be opened carefully, otherwise you can break not only the latches, but also the case itself. According to the LG Flatron L1917S service manual (I managed to find it on the Internet), the case can be opened “with your bare hands.” It really opens, but you can break your fingers, so it’s better to carefully pry off the front frame with a flat-head screwdriver.

In a particular monitor model, the power supply is located in metal case(circled in red).

For ease of operation, disconnect the plugs with wires. Just in case of emergency, mark where and what you turned off from. As a rule, plugs are made in such a way that they cannot be connected to a “non-native” connector. However, “God protects the careful” - take a marker and make marks on the body.

Checking electrolytic capacitors

After opening the case, first of all we pay attention to the filter capacitors of the secondary circuits.

A visual inspection showed that one of the capacitors was slightly swollen.

I unsoldered the capacitor and checked its capacity using a Victor 205 multimeter, which can measure capacitance. The actual capacitor turned out to be significantly less than the nominal one.

I was almost 100% sure that after replacing this capacitor the monitor would start working, but I was wrong. The situation has not changed. Then I didn’t think much about it and began to desolder and check the remaining electrolytic capacitors one by one (it was not possible to check the capacitances without desoldering, since the capacitors are shunted by other elements). I give the breakdown for all six capacitors at the time of the malfunction:

1. C202 (1000 µF x 25V) - actual capacity 857 µF;
2. C203 (680 µF x 25V) - actual capacity 403 µF;
3. C204 (1000 µF x 16V) - actual capacity 1002 µF (changed during a previous repair 3 years ago);
4. C205 (1000 µF x 16V) - real capacity 256 µF;
5. S206 (1000 µF x 25V) - actual capacity 834 µF;
6. S207 (470 µF x 25V) - real capacity 409 µF.

Please note that all capacitors, except one (I changed it earlier when the monitor did not turn on at all), have capacities less than the nominal ones. During the repair, the problem was that from the spare parts I could only find two 2200 uF 16 volt capacitors. I was too lazy to run to the TV experts, so I did the following:

1. The first capacitor was installed instead of C205 (1000 µF x 16V). Those. the voltage of the capacitor coincided with the “native” one, but its capacity was twice as large;
2. I installed the second capacitor instead of C202 (1000 µF x 25V). Not the best solution, since I replaced the 25 volt capacitor with a 16 volt capacitor.
3. Native C202 (1000 µF x 25V), installed instead of C207 (470 µF x 25V).

On good terms, we had to look into the TV workshop and buy new capacitors. Anyway. The malfunction was eliminated after replacing capacitor C207 (470 µF x 25V), which was replaced by a capacitor with an actual capacity of 857 µF.

“Sweet couple” - monitors ASUS PA248QJ (left) and LG Flatron L1917S

In such cases, if the monitor is 5-6 years old, there is no need to buy a multimeter with a capacitance meter and check all capacitors. It is safer to replace all the “kanders” with new ones.

Mini-instructions for soldering radioelements

For those who have not previously soldered radio components, I will give a few simple tips. For repairs you will need a soldering iron, solder, rosin and... a wooden toothpick. Instead of a toothpick, you can use a needle or pin.

After you have soldered the capacitor, you need to remove the solder from the holes for its terminals. To do this, heat the soldering area and insert a toothpick or needle into the hole.

Please note that the toothpick or needle must be inserted from the soldering side, otherwise you can tear the printed conductors from the board. Now you can insert a new electrolytic capacitor, remembering to check the polarity.

Everything is ready to install a new capacitor - the main thing is not to confuse the polarity of the connection

Important! For electrolytic capacitors, the connection polarity cannot be changed. We connect plus to plus, minus to minus. Otherwise, the capacitor will fail.

If for some reason the polarity of the capacitors is not indicated on the printed circuit board side of your monitor, then look at the markings on the radio components side. In this case, the light stripe of the capacitor is aligned with the light mark on the printed circuit board.

It is no coincidence that he said a lot about maintaining polarity. One of the site users, when repairing a monitor, soldered in an electrolytic capacitor incorrectly and for a long time could not understand why the monitor stubbornly did not want to work.

conclusions

A power supply unit (PSU) is found in any monitor and computer. As a rule, it is problems with the power supply that cause the failure of many electronic devices. Failure of various power supply elements can be accompanied by different symptoms. If you remember the previous breakdown of my monitor, when the monitor did not turn on at all, the reason was the loss of capacitance by capacitor C204. This time, it was his neighbor, capacitor C207, who failed. Visually the capacitor looked normal, i.e. the notches did not swell; in fact, its capacity turned out to be significantly less than the nominal one.

What is the reason for the failure of electrolytic capacitors? In this specific case I have two versions:

1. Low quality capacitors from SAMXON. I had a little argument about this with my TV technician friend. He claimed that since the monitor was already 9 years old (I bought it in 2006), the service life of the capacitors had expired. To this I noticed that I have a JVC TV (bought in 1996) and which has been working for almost 20 years without repair. Let me also remind you of the fact that the HEC capacitor, which I soldered instead of SAMXON three years ago, did not lose capacity.
2. Severe thermal conditions. In this particular case, in my opinion, the ventilation of the power supplies leaves much to be desired. Poor ventilation and close proximity to cooling radiators leads to the fact that capacitor housings heat up to temperatures above 50 degrees Celsius.

That's all for now. If you have any questions, ask them in the comments.

Updated: 01/06/2020 Published: 04/25/2019

Description

The monitor turns off by itself while the computer is running. At the same time, the computer continues to work - sounds are heard. After rebooting, the screen works for a while, then goes blank again. Most often this happens during:

1. Games.
2. Watching the video.
3. Working with any program.
4. Using scrolling on a laptop.

• The video card may start to make a lot of noise.
• The monitor may go dark on both a desktop computer and a laptop/monoblock.
• The time that the computer works after loading Windows varies - from a few seconds to several hours.
• The longer the monitor runs, the more often it turns off.
• The monitor may turn off and on, or it may turn off with the message “no signal”.
• It can be permanently turned off. But when you turn it on, you can see the loaded operating system desktop.

Cause

There may be several reasons:

1. Monitor malfunction.
2. Problems with wires or connectors.
3. Video card failure.
4. Overheat.
5. Incorrect operation software.
6. Poor power supply.
7. RAM malfunctions.

Solution

1. Video card malfunction

If the video card malfunctions, the problems can be of various types, in particular, the monitor may turn off.

To check the functionality of the video card, you can run it in the AIDA64 program. You can also try replacing it temporarily or using an integrated video card (if available).

2. Video card overheating

When overheating occurs, the problem usually occurs under high loads - while working with demanding programs or while playing games. In this case, the fans may begin to make a lot of noise. And the longer the computer works, the more often the monitor turns off.

6. Power problems

With this problem, not only the monitor, but also the computer itself may periodically turn off. This can happen more often under load, for example, when running games or demanding programs.

To check you need:

a) Temporarily change the power supply of the computer itself.

b) Test the socket with a multimeter. It should show a voltage close to 220. The minimum threshold is 190. If it shows lower, the socket needs to be repaired.

In the same way, we check the voltage at the surge protector, if one is used.

c) If a UPS is used, and the multimeter shows that the outlet is working, we try to connect the computer directly to the power source.

d) We change all power cables - both for the computer and the monitor itself.

e) Check the tightness of the cables for supplying additional power to the video card (if any).

7. Software errors

In this case, the problem occurs when entering the game, while playing or watching a video. In some cases, the problem can be solved using software methods.

a) Reinstall the video card driver. The best thing . You can also use a specialized program, for example, DriverHub, to update the driver in a semi-automatic mode.

b) Update DirectX.

c) Update or install codecs, for example, K-Lite Code pack.

8. Bad contacts (wires, connectors, adapters)

This reason is characterized by the disappearance of the image without any pattern - at any time. This can also happen when your foot touches the system unit or when the side cover of the case moves. In this case, the screen can turn off and on by itself.

a) First, you should try to tightly secure the cable from the monitor to the video card.

b) Then we try to connect the wire to another connector on the video card, if there are several of them:

* in this image the connectors are different - in this case you will have to use different wires or adapters.

c) If an adapter is used to connect the monitor to the video card, try replacing it.

d) On laptops there may be problems with the contact connectors that connect the monitor to the case. In some cases, this can be repaired by disassembling - cleaning contacts - reassembling.