The system unit starts but the monitor does not. Why doesn't the screen on my laptop turn on? Other computer hardware problems

Twitter

Detailed description of the problem:

FLATRON monitor does not turn on

I can't wake up the computer. The longer the computer runs, the longer it takes to wake up from sleep mode, and only the blue light is on or blinking. The computer gradually, day by day, began to increase the loading time of the desktop (it did not turn on for a long time, did not display the desktop picture, shortcuts) and the time it took to exit the energy-saving mode (hibernation) and the time it took to turn off the computer (it turned off for a long time). The monitor could start working 12 minutes after turning it on, or it could not boot up or work after 30 - 40 minutes, depending on how long it was in operating mode before I turned it off and then turned it on again... If I was holding the computer turned on for a day, then it (after disconnecting and resting) turned on earlier than when it worked without a break for 1.5 days or 2 days, or more. Therefore, it was possible to turn it on: wait for the monitor to turn on and, without waiting for it to turn on, turn it off, and do this 2-3 times in a row. As a result, I didn’t wait to turn it on; the monitor remained black all the time. It didn’t glow at all, even in short flashes, and only one blue indicator light was on or blinking. But on another day, after 3 attempts to turn on and turn off the computer, you might finally get lucky and the monitor would wake up, the desktop would appear, and the computer would work perfectly..., it worked like that for all the hours - until it turned off, and it worked for 10 hours and 20 hours and 48 hours... – uninterruptedly. Then, the next day (after switching on again) everything started again (in a cycle). Question: Why does the time for waking up from sleep mode and (or) from completely resting the computer gradually increase, and the time to turn off the computer lengthens (I couldn’t turn off right away, I had to wait)? Every day (for two months) the computer took longer and longer to boot and turned off longer and longer, but depending on the duration of the previous period of work, how long I did not turn off the computer... What is this violation connected with? The monitor was in good working order and all the components of the unit were good, because after a long awakening everything functioned perfectly, but the time of waking up and loading the desktop only lengthened. Therefore, nothing was clear what was happening... Computer parts cannot alternately be faulty, and then work, and then break down and then work, as if nothing had happened, and - again - on their own, for no reason at all. out of order, work and then remain idle. This means: The Beast acts remotely on the contacts, because the Beast usually always sends waves to chips (including airplane black boxes) and to contacts when it wants to disrupt the operation of electrical equipment. Therefore, some users MISTAKENLY think that they use the computer too much (without turning it off), which causes it to break down. The Beast may or may not harm... it all depends on the rules of the Beast... and (in this case) on the picture of the logo... Because all the sabotage (secretly) orchestrated by the Beast begins with a picture - a smiley, which (in the prototype) is like this , is displayed on the monitor as the letter “G”. There, next to the “LG” logo, there is also a “smiley” formed by these two letters. At first, after the computer was running for a long time, turning it off and resting, as soon as I pressed the start button again to turn on the computer, the monitor turned on after 2-3 minutes - I had to wait so long. Then (another time) after 5 minutes the monitor turned on, and so - every day more and more time passed until the pictures appeared on the monitor. t of the unit is normal, the unit did not overheat, and the monitor is working properly, but the feeling was created that the system was slowing down, as if it was freezing at the moment of loading the desktop, waking up; there is a long “freeze” of waking up and a long “freeze” of turning on the monitor, and not a freeze of the working (awakened) system or computer program. What really happened? Here's what: Two monitor plateau capacitors failed due to overvoltage, power surges in the network. The capacitors gradually burn out (failure), turn after turn... and therefore: the monitor gradually becomes covered, and may or may not turn on. These capacitors have 4 silver petals at the top, and these petals are swollen - barely noticeable, on one of the capacitors it is almost impossible to see the swelling, they look quite even (flat) because they have just begun to deteriorate. For the Beast, there are Signs in the capacitors: the number 4 and “flower” (petals). But what does the “smiley” have to do with it? Here's the thing: the monitor started to malfunction after I looked (with a special glance) at the image of a smiley - downloaded from the Internet. The beast does not like My gaze, and it begins to harm. The Beast from time to time sends waves into the computer and freezes - very often (by the way, it is also the Beast - “other” and the computer, sometimes, suddenly turns off or reboots), and now, it has begun to harm the monitor specifically. The Beast, acting on the capacitors with waves, stops their operation, because the Beast creates increased pressure (voltage) of the electric current. And also - in the monitor power connector... there are contacts and they need to be updated: that is: with a soldering iron, heat the solder to a liquid state - melt it and immediately let the molten solder harden, without changing the contacts themselves, without touching them. When a relative did everything like this for Me, at My request, the monitor started working again. It turned on at lightning speed without any problems, the yellow indicator light came on again, and everything loaded as it should and started working. And before this, the indicator was always on, only blue, or the blue light was constantly blinking. At first, a relative recommended that I take the monitor to a service center, and then he concluded: “The monitor is dead (the service won’t help)!”, and we also started looking for advertisements on the Internet for the sale of used monitors. After everything, in the end, it turned out that damaged capacitors and contacts of the power socket (connector) were to blame. Currently, when I write all this to you, the computer is working perfectly, the monitor has been successfully repaired!

Sometimes users encounter a situation where, after turning on the computer, a “no signal” message appears on the monitor. Such a message on the monitor can be caused by various problems with the computer, so without proper experience it is unlikely that you will be able to quickly find the cause of the problem.

If you are faced with the same problem, we suggest you familiarize yourself with our list of the most likely reasons that could lead to this.

Problems connecting the monitor to the computer.

If, when you turn on the computer, a message appears on the monitor stating that there is no signal, then the first thing you should check is the cable that is used to connect the monitor to the computer. There are usually two problems with the cable: the cable may lose contact where it connects to the computer or monitor, or the cable may be faulty and need to be replaced.

First of all, you need to check the contact at the cable connection points. To do this, disconnect the cable from the monitor and computer and reconnect it. If this is a VGA cable, be sure to tighten the two screws that secure the cable in the connector.

Screw for fixing the cable in the connector.

Breakage of a cable that previously worked normally is quite rare. But, if you have another cable on hand, or you can remove such a cable from another computer, then you can check how the monitor will work with another cable. Perhaps after replacing the cable the problem will be solved.

The wrong source is selected on the monitor.

On those that have multiple video inputs, there is a button to switch between the signals from these video inputs. Typically, this button is called “Source” or “Input”. If the buttons on your monitor are not labeled, then read the instructions.

Source button on a computer monitor.

Try pressing this button several times to switch to another video input. If the wrong video input was selected on the monitor, this should solve the problem and the “No Signal” message will disappear.

Video card malfunction.

If you have checked everything described above, but there is still no signal on the monitor, this may indicate a serious computer problem. The first suspect is the video card. If the video card is faulty, then when you turn on the computer, the message “No signal” may appear on the monitor.

There are two ways to check a video card for malfunction: install a known working video card into the computer, or remove the video card and start the computer with integrated graphics (if it has one).

In the event of a video card failure, it is also possible that there is no signal at only one of the video outputs of the video card. Therefore, it makes sense to try connecting the monitor to a different video output.

Video outputs VGA, HDMI and DVI on the video card.

For example, if you previously used DVI for connection, then you can try connecting the monitor to the VGA output of the video card.

Monitor malfunction.

Monitor failure is less common than video card failure, but it can also lead to the “No Signal” message appearing when you turn on the computer. Therefore, this option cannot be ruled out either. Luckily, you don't even need another monitor to test this option. All you need is any modern TV. Look at what video inputs (DVI, VGA, HDMI) your TV has and determine the easiest way to connect to your computer.

Video inputs VGA and HDMI on TV.

And change the signal source using the "Source" button on the remote control. If the TV displays a picture from the computer, then the problem is either in the monitor or in the cable that was used to connect the monitor to the computer.

The other day my sister came to me and asked me to pick up a new monitor. I was surprised - why? Two years ago there was an excellent 24-inch Samsung. The answer was that it was broken. The symptom is that the monitor does not turn on when you turn on the computer. Buying a new display is quite expensive given today's salaries, so I decided to first conduct independent diagnostics and make a short instruction on what to do if there is no image on the screen when starting the computer. I hope that it will be useful to many.

1. Does the monitor work?!

The first thing to do is to find out whether the display itself works at all or not. You can, of course, take it to your friends or neighbors and connect it to their computer. But there is an easier way and it is relevant in almost 99% of cases. Its meaning is as follows. We take and disconnect the monitor from the computer, and then turn it on. The message “Check the signal cable”, or “No signal”, or something else should appear on the screen, but the main thing is that at least some information message should appear.

This indicates that the device is working properly and is operational. The reason for the lack of image on the screen is something else.

2. Check the cable

You have to deal with cheap, low-quality DVI and HDMI cables. First, try simply disconnecting it from both devices and connecting again. Did not help?

Check the plugs themselves to see if they are damaged or if the contacts are bent by accident. Carefully inspect the cable itself to see if it is damaged.

Try switching video inputs through the display menu. Sometimes it may happen that due to a malfunction, it will default to a different connector. You can also try resetting it to factory settings.

For example, in our case it was pinched by the table. As a result, instead of buying a new monitor, we bought a new HDMI cable for 300 rubles and solved the problem!

3. The reason is the computer!

After we have checked and ruled out the monitor and cable as serviceable, we need to move on to diagnosing the system unit. You may ask - how to do this if there is no image on the monitor when you turn on the computer? The easiest way, of course, is to pick up the system unit and go with it to visit friends. Connect everything there and check it. But we are not looking for easy ways and will test everything on the spot!

We need to understand whether the computer starts up fully and whether the operating system has loaded onto the PC or not. We do this because sometimes, if the power supply or motherboard breaks down, the computer seems to turn on, hum, fans spin, but that’s all. Personally, I do this: I wait about 2-3 minutes until Windows has finally loaded and just briefly press the power button once. After this, the computer should turn off within a couple of minutes. This is normal operation of the operating system. If this does not happen, you need to carefully check the system unit.

The most difficult thing is when the computer turns on normally and the operating system starts, but the monitor does not turn on. Try pressing the WIN+P key combination. It changes the image projection modes on the second monitor. Even if you have only one, you should never forget that the OS could simply be buggy.

Video card problem

Turn off the PC, remove the cover and find the video card (the monitor cable is included in it). Carefully remove it from the connector. Don't forget about the lock, which needs to be moved to the side. Otherwise, you will not be able to remove the adapter. After that we stick it back. Why did we do this? The fact is that now Windows must re-identify it and install the driver. This will prevent the video adapter software from malfunctioning. The OS will first start with a universal driver and only then install the one that is most suitable.

If the motherboard has an integrated video card, then you can try switching the monitor to it. I once encountered the fact that the motherboard itself switched to the integrated adapter and began to completely ignore the discrete one.

P.S.: If none of my advice helped you, then most likely the monitor does not turn on due to a more complex and insidious problem. This will become clear after a thorough diagnosis, which is best done by a specialist.

How to calibrate a laptop or computer monitor in...

Today, most people use a computer for both work and leisure. But, like any other type of equipment, a PC can fail. Most often, the failure is only partial and affects only one of the devices. One of the most popular situations is when the monitor is silent when you turn on the computer. This problem is often discussed on computer forums. The first thing you need to understand is that either the monitor itself is broken, or the system unit may be the cause of the malfunction.

The block consists of many devices that are responsible for displaying the image on the monitor. And when a breakdown occurs with these components, the image quality will deteriorate or will not be displayed on the monitor at all. The user in such a situation will immediately think that the problem is in the screen, and perhaps even buy a new one, and this will be a waste of money. First you need to figure out the reason for the loss of the image, find out why the screen is not showing, and only then take action. Most of these problems can be solved with your own hands and even without specific knowledge.

The most common reasons why the monitor does not turn on are:

Lack of electrical power;
Problems with the connecting cord;
Incorrect image settings;
Problems with video adapter drivers;
Video card failure;
Motherboard malfunction;
Unstable operation of the operating system;
Incorrect BIOS settings;
Monitor failure;

Despite its simplicity, this is a very common problem. An unconnected cable may not be noticed, especially if a person is in a hurry and panicking. You can also accidentally touch the plug and disconnect the cord from the outlet or monitor. Children and even pets can do this.

Such a funny problem is very easy to solve and identify. If the power is connected, you can see a glowing indicator of a certain color on the monitor (depending on the type of screen). If it does not light, then check the connection. You need to remove the plug from the socket, see if there is any dust or other debris on it, and insert it back. The same manipulation must be performed with the cord on the side connecting to the display.

If the indicator starts to light up and the screen works, then the problem is solved and you can start using the computer with relief. If the light appears, but the screen does not turn on, or even the light does not appear, then the problem is different, and it is worth looking for its cause further.

Incorrect connection or faulty cable

You need to check whether the cable is connected to exactly the input that is required. This is true if you have an integrated and floppy video card. The monitor, in this case, is connected to a discrete one, the connector of which is located below.

You also need to check whether the cable is inserted correctly, both into the monitor and into the system unit. It needs to be removed and inserted back with the correct side. It may also be that the cable is simply faulty. You can check this using a working cord. If this is really the reason, then you need to go shopping. The cable is inexpensive, and there is no point in repairing it.

Problems with settings

If the system unit turns on but the screen does not, then the settings may also become a problem. This happens when the user configures a monitor resolution that is not supported. The refresh rate can also cause problems. Some monitors reset such incorrect settings on their own, and some simply refuse to work after this.

You can fix this yourself without spending a lot of time. You need to start your PC in safe mode. If in this mode the monitor shows, then we begin system recovery or reset.
To do this, go to the “Start” menu and click on “System Restore”.

Driver problems

Here, again you need to go through safe mode and reset the faulty driver. You need to go to the “Task Manager” menu and look at the properties of the video card driver.

There, click on the “Driver” tab and the “Roll Back” button. If this is not possible, then you just need to delete it.

If after this the monitor turns on, and the user sees a low-quality picture, then the problem can be solved by installing the latest driver for the video card.

Broken or incorrectly connected video card

The video card may be responsible for the fact that the system unit starts, but there is no image on the screen. And the reason may lie not only in the drivers. It is possible that the video card itself was touched during cleaning, or was placed back incorrectly after removal. You need to remove it and put it back in, but first turn off the PC.

If this does not help, then you need to open the unit and try connecting the video adapter to another connector on the motherboard. If you have an integrated video card, you need to try connecting the screen to it, but removing the discrete one. There is a possibility that the video card is broken. This is very unpleasant and will cost a lot of money, but what can you do?

Motherboard failure

The next probable cause is a malfunction of the motherboard. The computer can start and even work, but the screen does not show any pictures. To check this yourself, you need to open the computer unit and carefully examine the motherboard.

The video card connector may be damaged. To check, you will need another video card with which to turn on the monitor.

If there is no picture through the motherboard, then there is no need to rush to buy a new one, this thing costs a lot, first it is better to call a specialist.

Problems with the operating system

If the cause of the malfunction has not yet been determined, then you need to check the operating system. It happens that when the unit turns on, something about BIOS is written on the screen, but after that there is nothing except a black screen. During this entire process, you can even hear the sound of the operating system starting up.

All this happens due to a system failure after installing strange programs that change the design and functionality of the OS. We should not forget about viruses, which have been fought for a long time, but cannot be defeated.

To make the problem go away, we again go into safe mode and restore the system to its earlier state. If everything worked out, then be sure to launch the antivirus and look for the pest.

If the problem is in the operating system, but safe mode does not start, then you will need to reinstall the operating system.

BIOS Settings

If two video cards are installed in a computer unit at once, then one of them is integrated into the motherboard, and the second is not, and the wrong device may be selected in the BIOS. The computer sometimes automatically detects the video adapter that is needed, but there are exceptions.

You will need to reset the settings and return them to default. To do this, you just need to remove the battery from the motherboard and wait a few seconds. The settings will return to standard and everything will work.

Monitor failure

If the screen stops working unexpectedly and all possible reasons are not confirmed, then the problem may be in the monitor. Power surges, mechanical damage and other causes of failure lead to the user not seeing the image.

Determining which part of the screen is not working is very difficult. Only people who are familiar with electronics can handle this. If you are sure that the cause of the breakdown is the monitor, then you need to contact the service center.

But checking whether the problem is really in the monitor is quite simple:

You need to check the functionality of the old power cable and test the new one;
Do the same with the connecting cable;
Connect the monitor to another device (TV, smartphone, laptop);

Other reasons

If the computer unit starts up and there is still no image, then the cord contacts may be oxidized. To fix this, you need to take alcohol and gently wipe the ends of the cable. Gold-plated contacts are more resistant to oxidation. Also, do not put pressure on the bayonets; they may bend or fly off. In the first case, they can still be aligned with a needle or a small screwdriver, but if they break, you will have to go get a new cable.

In contact with

If your laptop screen does not turn on, then the first thing you should try is to reset the hardware settings. If this does not help, then you will have to look for other causes of the problem, which may be so serious that you cannot do without a trip to the service center.

Reset

A hard reset helps in most situations where the screen does not work. To execute it:

Disconnect the charger from the laptop.
Remove the battery from the laptop.
Remove any residual charge and reset the hardware by holding down the power button for 20-25 seconds.
Place the battery back into the laptop and connect the charger.

If a window appears asking you to select a boot mode after an incorrect shutdown of the device, select the normal Windows startup.

Checking the laptop display

If after resetting the hardware settings there is still no image on the screen, then try to determine which component has failed: the video card, matrix or other part of the display. An external monitor will help you do this. For example, on the ASUS website in the support section it is recommended to do the following:

Connect an external monitor to your laptop using the existing interface - HDMI or VGA.
Turn on your laptop. Using the combination Fn+F8, select broadcasting the image through the connected monitor.

If no image appears on the external screen, then the problem lies in the operation of the video card. This is also true for laptops from Lenovo, Acer and other manufacturers. If the picture is displayed on the monitor, then you should further look for a problem in the laptop display. The check should be carried out if the laptop's fan is noisy, the indicator lights up, or there are other signs that the laptop is turning on. If there is nothing like that, then perhaps the problem is not in the display - the entire laptop is not working.

Resetting BIOS Settings

If the problem occurs after changing the BIOS settings, you can try rolling them back to the factory state. Using a keyboard to do this will be problematic, but possible. The BIOS has hotkeys that are responsible for performing certain functions. A factory reset is usually done using the F9 key.

In theory, you can enter the BIOS by pressing the Delete key, then reset the settings (F9) and save the configuration (F10). But in practice, there is a high probability of missing the right moment, so it would be wiser to reset the settings by removing the CMOS battery, which stores the BIOS settings.

The main disadvantage of this method is the need to disassemble the laptop. But you will be sure that the BIOS settings have been reset, and if the cause of the black screen was incorrectly set parameters, the problem will be fixed.

Reinstalling the RAM stick

If the problem occurs after cleaning the laptop, then you should disassemble the laptop again and make sure that you installed all the modules correctly and connected the necessary cables. Therefore, for proper disassembly/assembly of a laptop, it is recommended to use the manufacturer’s manual - then the likelihood of an error occurring is significantly reduced.

In some cases, reinstalling the RAM stick can help solve the problem of no image on the laptop screen. This is especially true if liquid was spilled on the laptop’s keyboard, or it was left in a damp room for a long time, after which malfunctions occurred.

After reassembling the laptop, try turning it on again. If the black screen remains, although the laptop turns on and continues to work without an image on the display, then contact a service center. Possible causes of the problem:

Damage to the display cable.
Keyboard short circuit.
Inverter failure.
Backlight lamp failure.

These faults are unlikely to be resolved on your own; qualified assistance using special tools is required. The worst thing that can happen to a laptop is the motherboard failure. But then he will not show any signs of life. In any case, diagnostics at a service center will reveal the exact cause.

Problems resuming from sleep mode

If the screen remains black when resuming from sleep mode, the first thing you should do is check your video card drivers. The software must be the latest version and suitable for the system. You can download the latest drivers on the laptop manufacturer's website.

In some cases, the problem is caused by input devices that do not support Windows sleep mode correctly. Exiting sleep is done using the touchpad (mouse) or keyboard. If an external device is connected, it may block the laptop from waking up. To fix this flaw:

Save the configuration by clicking "OK". Do not prevent the mouse and keyboard from waking up the laptop at the same time, otherwise you will not be able to wake the computer from sleep. Set the ban on both devices in turn, checking if there is a positive effect.

Laptop overheating

If the screen on your laptop goes blank during operation, then most likely you are faced with overheating of the equipment. First of all, you should check the temperature of the video card. Use the free Speccy utility for this.

If you see that the video card’s temperature is too high (you can see the maximum permissible value in the specifications on the manufacturer’s website), then you should check the laptop’s cooling system. Sometimes just cleaning the cooling system is enough, but if the installed coolers are not powerful enough, then try using a cooling pad or installing more powerful fans.