Computer Turns On But the Screen is Black [Fixed]

When your computer displays a black screen, it means that the data it is trying to display is not being received. To fix your displays, you must first identify the source of the problem.

Computer Displaying Black Screen

Once you’ve ruled out a broken monitor or faulty cable, you’ll have to look deeper into the computer to figure out what’s preventing it from working.

Here are a few common causes of a screen staying black even when the computer is on.

• Faulty PSU
• GPU issues
• BIOS settings

How to Fix a Computer that Turns On But the Screen is Black

The best way to troubleshoot a computer is to start with easy fixes that only take a few moments. If these fixes don’t help restore the picture to your display, you might have to test some of your computer’s components. 

Restart the Computer

One of the first things you should do is make sure your computer is completely restarted. Sometimes when you think your computer is off, it is actually still on in a low-power state to speed up startups. Powering the computer down all the way ensures that when you restart it, it’s a truly fresh start.

To restart your computer completely, press down on the computer’s power button. Hold it down for five seconds before releasing it. Let the computer fully startup before you continue troubleshooting. 

Check the Connections

Make sure your monitor is plugged into your video output device. Some motherboards have onboard graphics and can work without a GPU. Others don’t have graphics built into them and require a GPU to display anything.

If you have a GPU, make sure the monitor is plugged directly into it. If you don’t, make sure it’s plugged into the motherboard. 

You should also ensure that all power cables required by the computer are plugged in. If your GPU needs a supplemental connection, it might prevent the computer from sending video to your display. 

Check for Brightness

Sometimes the brightness on your system is so low that you think nothing is displayed on the screen because it’s not visible.

Look at your keyboard for a brightness hotkey you might have adjusted without meaning to. Press the keys to turn up the brightness while the computer is connected to a display you think is working. 

Reset your Monitor

Resetting the monitor will ensure that you don’t have strange settings incompatible with the computer selected. The method will vary depending on what monitor you have. 

Make sure the input is selected for the computer. If you’ve changed what wires you’re using to connect the monitor to the computer, you might also need to change the input settings. 

When the monitor is set to default, restart your computer and see whether it grabs a connection. 

Check your Peripheral Devices

Unplug anything unnecessary from the computer, like extra monitors, external drives, or USB hubs. 

Restart the computer with a single monitor plugged in. If the screen is still black, try switching the cable that connects the monitor to another one. Try plugging it in with a different cable type or to a different port in your computer.

Once you know the monitor is working, the cable is suitable, and your computer doesn’t have one flawed connector, it’s time to start thinking about what else might have failed for the monitor to display a black screen. 

Change the RAM

Try removing all the RAM from your computer, inserting one stick into a slot, and booting with that single stick inserted. If that doesn’t work, try another stick in the same slot. 

Try one stick in a different slot if it still doesn’t work. With this method, you’re trying to find damaged slots or damaged RAM sticks. If it starts and works with a single RAM stick in a specific place, you might have damaged RAM, or your slots are damaged. 

Make sure you place the RAM in the slot with firm pressure until it clicks into place. RAM that isn’t seated correctly can prevent the computer from working. 

Test Your Power Supply

Even when the power supply appears to be working, it can fall victim to errors that prevent all computer parts from receiving sufficient power.

Consider getting a power supply tester if you frequently work with computers. It’s a safer and easier way to test a PSU than using a multimeter.

1. Unplug and open your computer.
2. Remove any power cables going from the PSU into other components. It shouldn’t be connected to anything when you’re done.
3. Check the voltage switch on the PSU to make sure it’s correct. The setting for US computers is 110V/115V.
4. Plugin the larger power connector and one of the smaller ones, depending on the model you’re using.
5. Plug your PSU into a wall outlet. Turn the power on if it’s a model with a switch.
6. Turn the power supply tester on and refer to the screen on the device. If the screen isn’t turning on, the power supply is bad.
7. Check to make sure none of the numbers say LL or HH. That means the power supply is bad and needs to be replaced. 
8. Check your power supply tester manual against the voltages reported on the screen. Make sure they’re within the correct limits for your PSU. If the numbers are out of the acceptable range or the delay value is not 100-500ms, you should replace the power supply.
9. Check the other cables, if necessary. It depends on what model PSU you’re using and what power cables extend from it. 

If you have to replace your PSU, make sure you get a model rated to handle the power loads of all the components in your PC. 

Listen for Beep Codes

Some computers make sounds when something is wrong with the system. These beep codes help you troubleshoot and fix any problems preventing it from working correctly.

1. Power on the computer.
2. Listen for the beep codes.
3. Write down how many beeps there were, whether they were fast or slow and whether the code repeated. It’s okay if you have to turn on the computer a few times to catch the code perfectly.
4. Refer to a manual or reference for your BIOS model to determine what is causing the beep code.

Recognizing the cause of a beep code isn’t the end of the problem because you still have to fix whatever caused it. However, it’s a great starting point for finding the source of the problem.

Clear your CMOS

Clearing your CMOS battery on your motherboard will reset BIOS to default. If a problem with your BIOS settings prevents your computer from displaying an image on your monitor, clearing the CMOS should fix it.

1. Shut down the computer and disconnect the power.
2. Press the power button on the computer three times.
3. Locate the CMOS battery on the motherboard.
4. Remove it from the socket.
5. Wait five minutes.
6. Place it back into the socket and restart your computer.

Your BIOS will be back to the way it was when your first turned on your computer. If you ever flashed the BIOS to upgrade it, you may need to repeat the process. 

Test your GPU

Your GPU could experience a problem that prevents it from displaying on the screen. However, it’s not as easy to test as some other parts.

The standard way to test a GPU is to run a series of benchmark programs to see what it can handle. That’s not possible when you can’t see your screen.

The best way to check your GPU is to hook it into another computer to which you have access. See whether that computer boots. If it does, run a stress test on the GPU.

Download a program like 3dMark, Unigine Heaven, or FurMark and use it to make sure your GPU is working as intended.

If the GPU isn’t working right, you can try disassembling it, cleaning it, putting on a new thermal paste, and then reassembling it. Sometimes that can help manage the temperatures and keep the GPU more stable. 

Reseat Your Cpu and Reapply Thermal Paste

If your CPU isn’t seated perfectly or isn’t as cool as it should be, it might cause errors that prevent your computer from displaying an image. 

1. Make sure all power to the computer is turned off. Disconnect the motherboard and remove it to a safe, static-free workspace.
2. Remove the CPU cooler.
   
3. Loosen the clamp holding the CPU down.
4. Lift the CPU straight out of its seat. 
5. Wash off the remaining thermal paste with a soft, lint-free cloth dampened with 99 percent isopropyl alcohol.
6. Allow the CPU to dry for an hour.
7. Reapply a sufficient amount of thermal paste to the CPU.
8. Place it straight into its socket on the motherboard. Remember that it’s imperative not to bend pins.
9. Put the clamp into place.
10. Reattach the motherboard and all the internal components.
11. Restart the computer.

You should also take a closer look at your CPU cooler. If that isn’t functioning correctly, it can cause your CPU to overheat and prevent your computer from working. 

Clean and Reseat Your Components

It’s surprising how often a thorough cleaning and reseating of all your components can fix errors for a computer. Take your time and be gentle as you work through each part.

1. Turn off the computer, unplug it from its power source, and press the power button a few times once the power is off.
2. Remove the motherboard, GPU, and drives. Disconnect everything.
3. Pull the RAM from its slots.
4. Use compressed air to blow dust from the inside of the case.
5. Clean any removable filters and the blades on your fans.
6. Use compressed air again to remove any dust that has fallen during the rest of the cleaning.
7. Reseat the ram into its slots.
8. Replace the fans and coolers.
9. Replace the PSU, GPU, and any AIO coolers for the GPU.
10. Plug everything back in properly.
11. Reconnect the power.
12. Restart the computer.

If the computer starts normally, it may be that something simply needs to be adjusted a bit. 

Look for Damage on the Computer Hardware

Look for things like blown capacitors and electrical shorts on your motherboard. You might notice burned areas, bulging pieces, or exposed wiring.

If something is damaged on your motherboard, you might have to replace it entirely to make your computer work again. Unfortunately, replacing aspects of your motherboard is pretty complicated, and most of the time, it makes more sense to get a new one.

Frequently Asked Questions

Why Does My Computer Screen Go Black Randomly?

It’s possible that your display is not working. However, if your screen is going black randomly at different times, one of your computer components might also fail. Stress-test your components to see whether the CPU or GPU are close to dying, experiencing high heat, or having other problems. 

Why Is My Computer Screen Black With a Cursor?

This can be caused by many different issues, including outdated drivers or BIOS issues. Try restarting your computer, using Windows key + R to access Device Manager to update your drivers, and booting the computer into safe mode to run System File Checker. 

How to Stop a Computer Screen From Going Black?

Check your settings to see whether you’re on a power plan that turns off the display. When the computer doesn’t sense movement or use for a while, it will shut down the displays even if it leaves the hard drives on. You can adjust your power plan’s settings not to turn off the display or select another power plan without that feature.