When you turn on your computer and nothing appears on the screen, it can be a tricky problem to diagnose, as there can be many reasons for this. The entire computer might be malfunctioning, or the issue could be with the screen itself. You may see a message like “No Signal” or “Cable Not Connected,” or you may not see any message at all. Let’s explore some steps to troubleshoot the issue so you can get back to working hard (or wasting time) on the Internet.
1. Check Power
There should be lights on the front of the computer screen and the computer itself when receiving power. Ensure that your computer is receiving adequate power, whether it’s on battery or plugged in. If you’re using an external monitor, it should be connected to a power source to operate, so make sure it’s getting power as well.
It’s possible that you may have accidentally pressed the monitor’s power button or perhaps kicked the cable with your feet without realizing. This could be why your laptop isn’t charging even though it’s plugged in.
2. Check Cable Connections
While checking this, make sure that the cable connecting the screen and the computer is securely plugged in at both ends. Even if everything looks correct, there may be an issue with the connection between the computer and the screen. If you have any spare cables available, try using another cable—perhaps the one you were using is damaged. It could also be an issue with a USB port, so try another port as well.
3. Have You Tried Restarting?
If the computer is powered on, try restarting it to see if the problem persists. You should be able to press the power button on the computer until the light goes off. Leave the device for a few seconds, then press the button again to turn it back on.
4. Increase Screen Brightness
There may not be anything wrong with your computer’s screen. The brightness might simply be set too low. Many laptops allow for dimming the screen until it completely turns off. Your keyboard should have brightness buttons at the top, so increase the screen brightness and see if that resolves the issue. If you have a cat that likes to sit on your keyboard, this might be the reason for it.
5. Try Another Cable
If your computer has multiple connection options, you might try a different type of cable—e.g., an HDMI cable instead of a DisplayPort cable—to see if that fixes the issue. If you have a separate graphics card, the monitor should be connected to that card, not to the HDMI port on the motherboard.
Also, if you are using an adapter, the problem might lie there. You could have a faulty adapter or be using it in a way it wasn’t designed for. For instance, HDMI to VGA adapters only work in that direction—if you are trying to connect a VGA computer to a DVI screen, you’ll need a different type of active adapter.
Additionally, ensure that your cable meets the correct specifications for the required task. If you are using DisplayPort, make sure it is VESA certified; for HDMI, there might be a certification label on the packaging you can scan using an HDMI Cable Certification app on iPhone or Android.
Remember
not all cables are created equal. If you’re trying to run a 4K display at a high refresh rate, you’ll need a premium high-speed HDMI cable rather than the older high-speed model.
6. Try Another Display
If you’re not currently using an external display, you may want to connect an additional monitor to see if the problem lies with the laptop’s display or the internal components of the device. You can also use your TV for this purpose. If an image is displayed on the second screen, it may mean that the computer is capable of outputting the image, but there is a fault with the built-in display itself.
The defective display will need to be replaced. You might be able to change the panel yourself if you’re skilled with a screwdriver. Otherwise, it might be time to call in the professionals – hopefully, you have a good backup in case they need to wipe the drive.
7. Change the Input
Ensure that your display is set to the correct input. Most displays should be able to auto-detect the correct input, but it doesn’t hurt to double-check. You may even need to completely disconnect the display. I had one display that refused to show an image until I unplugged it.
If the display is stuck on an input without anything connected to it, you may need to connect something to that port before you’re able to switch the input to the correct one. This is rare, but it can happen.
8. Check Power Settings
If the display turns off randomly, it might be due to the laptop’s battery or sleep settings, rather than an issue with the display itself. Make sure your power settings aren’t set to turn off the screen before expected. Go to Settings > System > Power & Sleep (in Windows 10) or Settings > System > Power & Battery > Screen & Sleep (in Windows 11) and ensure nothing is set to turn off your computer’s display prematurely.
Next, type “power plan” into the Windows search and open the control panel. Navigate to Change advanced power settings and open the battery entry. Open Critical battery level and make sure it’s not set to a value that’s too high so that the display doesn’t turn off at unexpected times. Open Low battery actions and ensure your computer isn’t shutting off things when the battery hits 20%.
On macOS Ventura or later, go to System Settings > Lock Screen and make sure the options that dictate when the display will turn off aren’t set too low. Those using macOS Monterey or earlier can open System Preferences > Battery > Battery and adjust the slider to set how long before the display turns off.
9. Disconnect Peripherals
Does your computer only sometimes refuse to display an image? It’s possible that one of your peripherals is causing a problem that prevents the computer from starting. I’ve encountered situations where a particular USB port prevented the computer from booting if something was plugged into it. Disconnect any non-essential devices from your computer (like the mouse, keyboard, printer, or display), then try to start again.
If everything works normally after removing the peripherals, one of those items is the cause. You can narrow it down by restarting again with one USB device connected at a time to see how the computer responds upon booting. Once you find the culprit, you’ll need to remove the problematic drivers and reinstall them to see if the issue has been resolved.
In
Windows system, right-click on the Start button and select “Device Manager”, then look for the suspected peripheral device. Right-click on the entry and choose “Uninstall device”. You can then reinstall the driver from the manufacturer and see if the problem is resolved.
10. Multiple Displays
If you are trying to connect a second monitor, you may encounter an issue where only one screen works properly. First, make sure that your computer is capable of running two or more displays at the same time – some devices may not support all the monitors you want to connect. For example, MacBook Pro devices only support one external display at a time, and the specific model and external monitors you have will determine how many displays can be connected.
If the second display is recognized by the system but shows a black screen, you may have the settings configured to display the image only on the laptop screen. On Windows, open Settings > System > Display and ensure that the multiple displays dropdown is set to extend the desktop across both screens or duplicate the desktop on both screens. Mac users can go to System Preferences > Displays to access a similar menu. Open the display settings and select “Extend Display”.
11. Listen for Sound
When your computer starts up, you will usually hear a small sound coming from a speaker inside the device. This speaker is there to give you error codes when something goes wrong. If you don’t have one, you can order one from Amazon and connect it to the speaker header on your motherboard.
If your computer makes a quick sound upon startup, it isn’t registering any hardware issues. But if it emits a specific series of sounds – for example, one long beep followed by two short beeps – it is trying to tell you something. This could be due to a malfunctioning RAM stick, a processor overheating beyond acceptable limits, or a video card that is not seated properly. (Some devices may instead have a digital display showing error codes or a series of lights that light up in a specific order to indicate a problem.)
There are web pages that contain information about these sounds, but your best option is to check your computer or motherboard manual, where you will find the most accurate information. Once you identify the issue, fixing it should be straightforward.
12. Reseat the Graphics Card, Memory, and Other Devices
If you recently built your computer, upgraded it, or moved it, it’s possible that a piece of hardware has shifted inside the case, preventing the computer from starting. Remove the side panel of your computer and take a look inside. If you have a dedicated graphics card, try removing it and reinserting it into its PCIe slot until you hear a click, or try moving it to a completely different slot. Also, ensure that the power cables are securely connected.
If the problem isn’t resolved by this step, you may need to perform deeper tests using spare hardware if you can get hold of it. Look for a cheap video card on Craigslist and see if it works instead of the current card – if it does, the issue may lie with your graphics card, and it might be time to upgrade.
While you’re inside, also reseat the memory sticks. Press down on the sticks near the edges to release them from their slots, and then press them back in until you hear a click. Ensure that all cables connected to the motherboard are securely plugged in, and that the hard drive is connected.
13.
Booting into Safe Mode
If you’re unable to see a picture when booting your computer, you may have a driver issue or another problem. You might be able to get a picture by booting into Safe Mode. But without a picture, how can you navigate to such a screen?
On a Windows PC, you can interrupt the boot process three times (by pressing the restart button when Windows starts booting, for example). You will then enter the Automatic Repair menu, where you can access Advanced options to find Safe Mode. If that doesn’t work, you can create a Windows installation media using another computer, boot from that media, and then go to “Repair your computer” > “Troubleshoot” > “Startup Settings” > “Safe Mode with Networking”.
macOS has its own safe mode feature, but how to access it depends on whether you have a Mac with Apple Silicon or an Intel-based Mac.
If your computer boots into Safe Mode, there’s a chance to fix things. Try uninstalling any new software that may be causing the problem. Make sure that the resolution and refresh rate are set correctly (if set to a value that is too high, the screen may not be able to display a picture). You can also try reinstalling graphics card drivers by downloading them from the manufacturer’s website. You may also want to run a malware scan, use system restore, or – if you have one – rely on your backup media (for either Windows or Mac) to revert to a known working configuration. Once that’s done, check if your computer can restart normally. If not, you can return to that menu to perform startup repair. You may also want to head to the command prompt and run sfc /scannow or chkdsk C: /r to check for disk errors.
Conclusion
When you encounter a black screen on your computer, there can be many possible causes. Follow these steps to diagnose and fix the issue yourself. If you can’t resolve the problem, you may need to contact maintenance professionals for assistance. Enjoy browsing the internet and working hard after fixing your computer’s black screen!
Source: https://me.pcmag.com/en/how-to/13073/what-to-do-when-your-computer-screen-wont-show-a-picture
Leave a Reply