Using two monitors for computers is wonderful. You can have an application, clip, or a game open on one monitor and do something completely unrelated on the other one. However, sometimes it’s tricky to get both monitors working simultaneously.
That’s why I’ve listed 11 fixes for when only one of two monitors is working, with the goal being to help you get back to working with two monitors. Before you start reading this list, make sure you’ve done all the basic stuff first.
Restart your computer using only one of the two monitors, connect the other one when you get into Windows, and ensure all cables are connected properly.
1. Try a different video transmission cable
A potential issue that can make one of your monitors not work is a cable being broken. Whether you have HDMI or DP, try another cable for the monitor that isn’t working. It’s fairly common that video transmission cables get stretched or otherwise worn out to the point where they don’t work anymore.
That way, we can also rule out cables as the faulty party and progress with the issue at hand.
2. Make sure you pick the correct output
On most screens, there is a settings menu button on the monitor where you can choose what input the monitor should use to find the connection to your computer. For example, my monitor has a button at the bottom where I had to turn on the DP option before it started transmitting a signal.
Where this button is located depends on what brand you have, but it can probably be accessed somewhere next to the power button on your screen.
3. Update firmware
Firmware provides basic tasks to devices, and it’s important that it’s updated, especially if you’re running a dual monitor setup. Firmware is usually available from manufacturers’ websites.
How you apply these firmware updates differ somewhat depending on what screen you have but it shouldn’t be all that complicated. Find firmware from your manufacturer’s website.
4. Check the ports on your devices
If possible, try to switch which ports you are using on both your computer and monitor to see if the fault lies with either of them. This way, you can exclude the screen or computer as the faulty party.
A lot of computers have only one DP port, so if you’re using that, use another HDMI instead to see if that fixes the issue.
5. Manually update your graphics drivers
You should make sure that your GPU drivers are up to date as well. I would not recommend you let Windows automatically look for them in the device manager, it’s better to download drivers yourself from your GPU manufacturer.
Most people have Nvidia graphics cards, and their various drivers are available to download here. Make sure you choose the correct graphics cards for your computer in the menu, otherwise your computer won’t be able to install them.
6. Remove other peripheral devices
If you have an abundance of different devices connected to your monitor, it can be a good idea to disconnect a bunch of them to see if your screens begin to work. Sometimes, having a lot of peripherals can cause different errors and interference between your devices.
If possible, don’t use your screen(s) as the main connector for things as USB devices, it’s better to use your computer.
7. Make sure your monitors are connected to GPU
Your computer probably runs on a dedicated graphics card. That means your computer isn’t using the integrated graphics card within your motherboard. Therefore, connecting your transmission cables to your motherboard rather than GPU will cause your screen to not display anything.
Make sure you have both cables connected to the GPU and not the motherboard. If one is working, then that’s the one that’s connected to your GPU. The ports next to it are the ones you should connect the other monitor to as well.
8. Check your display settings
If you haven’t tried experimenting with your display settings in Windows, this is something you should do. Right-click the background of your desktop screen and click on “Display settings”.
Here you can see if your computer has detected both of your screens or not, detect other screens connected to your computer, and more.
If your computer can detect both of your screens and furthermore lets you arrange different settings for the dual screen setup such as mirroring or extending your screens. Try all of these options to see if any one of them works.
9. Set the correct refresh rate for both monitors
If your monitors for some reason are set at the wrong refresh rate, namely a refresh rate that it can’t handle, then it won’t work. Therefore, you should make sure that your monitors are configured to the refresh rate that they can handle. To do this, follow the steps below.
- Right-click on your Windows desktop background and select “Display settings”
- In the menu that pops up, scroll down to “Advanced display settings” and click it
- In the new menu that pops up, click on “Display adapter properties for Display”
- In this final window, click on the “Monitor” tab
- Under “Screen refresh rate”, select the proper refresh rate for your monitor
10. Rollback Any New Changes
Sometimes, new updates to your system can bring bugs and other errors. For example, Windows released an infamously bad patch in 2018 that destroyed users’ data and made keyboard drivers crash Windows.
The point is if you have recently installed new patches or updates to Windows, consider rolling them back to your previous version. This also goes for graphics drivers and new software. To rollback updates in Windows, follow the steps below.
- Press the Windows key + I
- Click on “Update & Security”
- Click on “View update history”
- At the top of the new Window, select “Uninstall updates”
To install a previous version of your GPU drivers, go here and fill in the details of your graphics card, then download older drivers and do a clean install of them.
11. Reinstall Windows
Some users have reported that reinstalling Windows has worked for them. This is hardly a surprise seeing as your computer gets completely reset, deleting any potential issues on your system that was the reason for the monitors not working.
I know that this probably is the most cumbersome option, which is why I’ve put it as the last option on this list. Only do this if you’ve run out of solutions to your problem, and you’re sure that the problem isn’t because of cables or any other external reason.