Solving the problem with monitor not detecting pc via HDMI, DVI, or VGA is usually required at the most inopportune time. You press the power button, and the PC starts to hum like always – but instead of the welcome window that you just saw on the display yesterday, only blackness.
Restarts do not help and you, being the owner of a working computer, cannot print anything, run an application or watch a movie simply because the monitor is not visible. At best, instead of complete emptiness, you have the pleasure of seeing the inscription “No signal” or similar, reporting an error. Nothing else and after a few seconds, the screen backlight goes out, and the problem remains unresolved.
The causes of the problem that we will discuss in this article are quite diverse. In the vast majority of cases, they are of a hardware nature, that is, they are not related to the settings of the operating system, but to the operation of the hardware; in our case, the monitor itself, which the computer does not see. Everyone can find themselves in such an unpleasant situation: owners of inexpensive and prestigious monitors experienced and novice users. Below we will explain what happens when the monitor is not connected to the computer: “No signal”. Follow our step-by-step troubleshooting guide and you’ll be sure to get your display back up and running! Check out the Difference Between 1600 X 900 Vs 1920 X 1080 Resolution.
Table of Contents
why does Monitor Not Detecting Pc? Reasons and Causes
In almost 99.9% of situations with the inability for the computer to see the monitor, the matter lies in the PC itself, for some reason refusing to transmit the video signal to the display. The latter, which is quite logical, notifies you that the signal cannot be displayed, after which it goes into standby mode.
As you may have noticed, after pressing the power button in the system unit, first of all, the coolers begin to buzz. This is good because it means that the power supply is properly energized but one rotation of the fans cannot be used to conclude that, for example, the motherboard or video card is working. And since the device from which the video signal is sent to the monitor is not working, instead of the expected picture, you see only the notification “No signal” on the computer screen. The display itself usually remains perfectly functional – you can easily verify this by connecting the device to another PC or laptop.
So, you notice that there is no video signal on the computer monitor. The reason for “No signal” can be eliminated in several ways, the easiest of which is to check whether the wire plugs are tightly connected to the computer and display contacts. Quite often, the problem is caused precisely by an incorrect connection – and there is nothing easier than fixing it: just connect the cable as needed.
Other possible reasons for Monitor Not Detecting Pc include:
- Damage to the power supply. Maybe the power of the device is only enough to spin up the very coolers that you hear so well, and the rest of the components have a minimum voltage that does not allow the motherboard or graphics adapter to turn on.
- Failure of RAM. The bar may get dusty, the contacts may oxidize, or simply come out of the socket – and as a result, your monitor is completely invisible to the computer.
- Failure of the graphics adapter. A video card is a complex device that can fail for almost any reason: from overheating to a power surge on the contacts.
- Failure of the entire motherboard. Fortunately, this rarely happens – but if it happens, you will most likely have to purchase a new motherboard.
Finally, if there is no signal on the monitor after assembling the PC, the problem may indeed be in the display. Do not rush to worry and, moreover, run for a new device: first go through the instructions we offer step by step the problem is almost certainly solved easier than you think. Here is Shortcuts Not Working In Windows 10 fix.
How to fix Monitor Not Detecting Pc?
Despite the above considerations, we will start with a software problem. No operating system is immune to accidental failures – and fortunately, such problems are usually fixed by the OS itself, without user intervention.
But such a decision takes quite a lot of time, up to several minutes. As a result of this delay, the signal from the computer does not reach the monitor – this is the reason that you see a notification on the screen that there is no signal. As a rule, the malfunction is eliminated by the operating system – and, after 2–5 minutes, you can still see the picture on the display.
So, advice: before proceeding to decisive action, wait at least ten minutes without rebooting and without disconnecting the computer that does not see the monitor from the mains.
After the specified time has elapsed, determine what exactly could be the reason for the lack of a signal. Follow a simple algorithm:
- If the new computer does not see the monitor, connect the device to any other available. Use an old PC, ask family or friends for help – you just need to see that the display is basically functional.
- Turn off the power to the computer, and then turn it back on in the usual way. Do you hear the familiar squeak that accompanies the start of the fans? Then everything is fine – you can proceed to the next paragraph. Are there no sounds? Well, it’s almost certainly a motherboard failure, RAM or video card failure. However, if the computer does not beep, it may simply not have a speaker.
- Make sure the system hard drive is securely connected to the motherboard. The cable connecting the HDD and the board should be firmly attached to both connectors – in addition, you can try replacing the cable with a new one.
- Listen to see if coolers rotate inside the system unit. Do you hear a characteristic hum? Great, you can move on to the next step. No sounds? This means that the power supply is inoperative and is not able to supply voltage even to the fans, not to mention other components. One possible solution is to make sure that the power supply is in principle connected to the mains: the power cable is inserted into the connector, and the toggle switch on the rear panel is turned to the “ On ” position.
- Despite your best efforts, you are still convinced that the computer does not see the monitor. What to do next? Try connecting the display not to a discrete (separate) video card, but to an integrated one on the motherboard. Perhaps, immediately after launch, you will see the long-awaited picture on the screen – which means that the answer, how to fix the problem, has been found. Connect the graphics adapter to the contacts more tightly, try to clean the connectors, and if you see burn marks on the board, replace the device with a working one.
- Make sure that the RAM sticks are not the source of the problem. As practice shows, they sometimes fail due to overheating. Regularly clean the RAM from accumulated dust, do not allow dirt to stick or increase the humidity inside the system unit. We recommend that you start the inspection by examining the contacts: you should clean them, try to swap them, insert one bar at a time – of course, not forgetting to turn off the computer before each new operation, which does not yet see the monitor.
Perhaps, already at the verification stage, you will find a way to fix the problem. If not, we advise you to come to grips with a monitor that is not visible to the PC. This makes the most sense if nothing is visible on the screen, not even any warning notifications:
- If there is no signal on the monitor when you turn on the computer, first unplug the device from both the mains and the PC. Then plug it back into the outlet. See the notice “Cable not connected”? Great, then your display is in working condition, and you just need to carefully connect the cable coming from the PC to the monitor.
- Using a suitable wire, try connecting the display to any other working computer or laptop. In addition, it makes sense to perform the opposite action: connect the system unit or laptop to another monitor.
An unpleasant, but relatively harmless breakdown is the failure of the screen backlight system. Take a sufficiently powerful flashlight in your hand and shine it on the seemingly black screen: if you see a dim, but still familiar picture on it, it’s the backlight. You can replace it with a serviceable one at any service center – quickly and quite inexpensively.
8 ways to fix Monitor Not Detecting Pc
Tip #1: Check your monitor’s power cable
The display, like any other computer hardware, only works (and can be seen by the computer) when sufficient voltage is applied to it. In the vast majority of cases, the monitor is powered by a separate cable connected to a household outlet. Here is the first of the possible answers why the new PC does not see the monitor: the matter may lie in the banal disconnection of the power cord. Connect it more tightly to the contact on the display housing, check that the plug is inserted into the socket, and also make sure that the socket itself is in working condition. If necessary, you can tape the cable to the device with electrical tape, but you need to remember that this is only a temporary measure – until the first opportunity to carry out a normal full repair.
Pay attention to the cord itself. Clean the contacts using an alcohol-based technical solvent, check if the cable is damaged: if there are any frays, cuts, breaks on the outer layer. If such problems are found, the best solution is to immediately replace the cord with a new one. And in principle, try connecting the monitor to the network using another, obviously working cable – not all possible problems can be identified by eye.
Tip #2: Check cord from video card to monitor
The second wire, which necessarily extends from the PC towards the display, also needs to be carefully checked. During the inspection, you can detect damage to the cord insulation, outgoing contacts, and other problems. If the monitor shows “No signal” when you turn on the computer, try connecting the cable more tightly to the appropriate pins or replace it with a new one that is not in doubt. As in the previous case, you can use electrical tape or tape for temporary fixation; it is strictly forbidden to fill the contacts with adhesives.
You may have connected a monitor that is not yet visible to the computer to the video card using an adapter. In this case, it is necessary to check the serviceability of this equipment as well: as a rule, cheap adapters quickly fail. If possible, connect the display directly to the same or another computer.
If you see an image on the screen as a result of the steps you took, you can stop reading this article and move on to troubleshooting the problem that caused the computer to be unable to see the monitor. Nothing succeeded? So it’s time to move on to the next section!
Tip #3: Check if your video card is working
It is from this device that the video signal is fed to the screen. Accordingly, if the graphics adapter fails, you simply cannot find pictures on the display – even if all other components are in perfect order.
So, there is no signal on the monitor. The causes of PC failure, the most common, we have already listed above, now – to the details.
To make sure it’s not the graphics card, turn off the computer and, after removing the side panel, carefully disconnect the graphics adapter from the motherboard. After that, carefully, using a cotton swab with a degreasing solution, clean the contacts, removing traces of dust and oxidation from them. If instead of an oxide film you see signs of burning on the surface, you can immediately proceed to replacing the video card and repairing the contacts – nothing more can be done in this situation.
Most likely, your motherboard has its own integrated video card – low-performance, but still capable of transmitting a video signal to a monitor. Try to connect the display to this connector, not forgetting to turn off the PC again. If, after turning on, you see an image on the monitor, you still have to change the discrete graphics adapter – but for now, you can use the built-in one. Another common problem is the incompatibility of simultaneously working video cards; to fix it, disable in the BIOS the one that you are not currently using.
And, of course, the card must stand straight in the slots, without distortions, without falling out of the slot – all these factors can lead to the fact that after assembling the computer there is no signal to the monitor. Carefully adjust the position of the video card, make sure that it is connected to all the required connectors – and if you still can’t fix the problem, go to the next step.
Tip #4: Check your RAM
You will, first of all, learn about the breakdown of RAM strips, of which there are usually several in modern computers, by the specific signal given by the speaker built into the motherboard. Of course, you can try to figure out all the possible beeping options – but we offer an easier troubleshooting option, especially since we already know the problem: your PC still cannot see the monitor.
Having again removed the sidewall of the system unit, remember in which slots there are RAM strips. You can even take a picture so as not to be mistaken in the future.
Now that the position of each unit of RAM has been fixed, you should remove the strips one by one, not forgetting to turn off the computer beforehand. Put the bars back one at a time, run the OS after each such manipulation – and watch the changes on the monitor.
As a result, you can find the reason that the monitor does not see the computer, writes no signal: perhaps one or more bars are out of order. Try to remove the damaged unit, install a working one in its place – and see if the display works. Given the versatility of modern motherboards, such rearrangements can be avoided: just leave workable boards in their places, and at the first opportunity, buy new modules to replace the broken ones.
Tip #5: Check your power supply to fix Monitor Not Detecting Pc
The main contact that supplies voltage from the power supply to the motherboard and other directly connected components has exactly 24 pins – and looks something like the photo below.
In addition, you will need to check the second contact, which has 4 or 8 pins.
Disconnect both pins from the motherboard and inspect them carefully. See signs of oxidation? Clean the metal parts using a technical grease-dissolving liquid. Do you see signs of burning instead of an oxide film? Then the best solution would be to immediately stop using a broken power supply and purchase a new one for a computer that does not yet see a monitor.
Tip #6: Check your hard drive connection
The system hard drive, which hosts the files needed to write the OS, can cause the monitor to stop seeing the computer. Having delved into the system unit again, check whether both cables are connected to the hard drive reliably enough: transmitting information and providing power. As additional measures, we can advise you to connect a new, obviously working cable to the disk, or connect to a free connector on the motherboard: usually there are at least four of them. Of course, before each such manipulation, it is necessary to turn off the computer, which cannot yet see the monitor: it is unacceptable to perform operations “for-profit”.
Tip #7: Check Your Monitor Mode
It may happen that there are no hardware faults at all, and the cause of all your troubles is downed or incorrectly set display settings. Remember if you pressed any buttons that are usually located on the bottom of the monitor. If so, find the instructions supplied by the manufacturer, and, having figured out the cause of the problem, set the correct operating parameters. If possible, just perform a hard reset – and, after turning it on again, the picture should finally appear on the screen.
Tip #8: Reset BIOS
We continue to tell why the new computer does not see the monitor. The next possible reason is an incorrect BIOS setting; and the answer to the question of how to make the PC see the display is extremely simple: reset the settings to the original ones set by the manufacturer.
To do this, follow the simple instructions:
- Turn off the computer, which cannot yet see the monitor, using the power button, then disconnect from the network. Instead of the last step, you can move the power supply toggle switch located on the back of the PC to the inactive position.
- Remove the side wall of the system unit. If necessary, clean up inside: remove dust particles, traces of dirt, extra items.
- To make it easier to access the motherboard, you may need to remove the processor, video card, and some other components from the power supply. Do this if necessary – don’t forget to remember the connection order.
- To make it more convenient to perform the following manipulations, lay the system unit on its side, working side up.
- Look for a relatively large, round, shiny battery on the motherboard. Usually, it is located in the center of the motherboard, but can be shifted to one of the corners.
- To solve the problem due to which the computer does not see the monitor, remove the battery. It is better to do this with fairly thin tweezers, a knife, a slotted screwdriver or even an awl; the main thing is not to damage either the battery or the board itself. In some cases, the battery is held by latches – they must first be bent.
- When you remove the battery, the CMOS module, which is responsible, in particular, for BIOS settings, will be de-energized, which will lead to a reset. As a rule, for a guaranteed reset, it is enough to keep the computer in this state for a couple of hours, up to a day. It makes no sense to insert the battery immediately after removing it: the settings will not have time to reset. If you do not want to wait, just connect the contacts in the battery connector: one is located on the side, the other at the bottom of the platform.
- After a certain time, insert the battery back, not forgetting to snap the latches. After that, you can assemble the system unit, apply voltage to it – and check if the monitor has become visible to the computer.
And most importantly – never perform manipulations related to connecting or disconnecting components without first de-energizing the PC. Otherwise, you run the risk of getting much more serious problems than a monitor that is not visible to the computer – up to the burnout of the hard drive and motherboard.
After assembly, do not be too lazy to check whether the power supply is connected correctly to all internal components – otherwise, even if the reset was completed successfully, you will again have to solve the riddle why the computer does not give a signal to the monitor.
If it is impossible to remove the battery, it remains either to reset it directly from the BIOS menu, or contact a professional – at home, you should not completely disassemble the motherboard.
If after checking the problem monitor not detecting pc, checking the PC components, and resetting the BIOS, the display is still not visible to the computer, then the monitor may be broken. This can be avoided by connecting the monitor to another PC or laptop. Got questions? Ask them in the comments, we will try to answer your problem most importantly, describe what you have already done to make the computer see the monitor.