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Third Monitor Not Working

Gamers, graphic designers, day traders, and engineers are amongst the many users who rely on multi-monitor setups.

Despite a variety of ultra-wide monitors on offer, there are many reasons why users prefer two or even three screens connected to their PC or laptop.

But problems often arise when trying to connect to the third monitor due to configuration or setup errors.

There are some common reasons why your third monitor’s not working. It may not be detected by your operating system or it may be detected but not displayed. The failure could be incorrect display settings, a faulty display adapter, a missing graphics driver update, or a power cable fault.

black monitor on the table

While it may be frustrating to find that your third monitor is not displaying correctly, most of these problems can be fixed fairly quickly.

You just need to follow the steps I lay out below and you could be enjoying your new monitor in a matter of minutes.

Third Monitor Not Detected / No Signal

black monitor on the table

Once you’ve connected the monitor to your PC or laptop, it is quite common to find that your monitor either won’t turn on or doesn’t show up as an available option.

So, rather than pulling your hair out, follow along as I show you step by step how to fix this monitor problem.

If you get a third monitor not detected or no signal error, check that the power cable is plugged in and that the monitor is receiving power. In Windows settings, Project Mode, select PC screen only, switch off the PC and disconnect the monitors. Then reconnect the monitors and turn the computer on.

How to Detect Your Monitor By Changing Project Mode:

  • Press the Start button and then select the Control Panel.
  • Select Display followed by Change Display Settings.
  • Select PC screen only.
  • Disconnect your external monitors, unplug power and display cables.
  • Switch your computer off.
  • Plug all your monitors back in.
  • Switch your computer on.
  • Select the Windows logo key and “P” simultaneously.
  • Click on the “Extend Desktop to this Display” option.

You can then check to see if your monitor is working.

If, after following the steps above, you are still experiencing a problem, keep reading to discover other possible solutions.

Consider the follow articles to help you diagnose monitor signal problems.

No DisplayPort Signal from Your Device Error

No HDMI signal from your device

Windows Not Detecting Third Monitor

Frustrated woman looking at the monitor

If you find that Windows is still not detecting your third monitor after resetting project mode, then you may need to check your Windows updates.

If Windows is not detecting the third monitor, then it may need an update. In settings, select Update & Security. Click the Check for Updates button and wait for Windows to automatically check for the latest update. If necessary, it will download the update and install it on your computer.  

Once the update has been installed, you can check settings to see if the monitor is detected. If not, press the detect button and wait for Windows to detect the monitor.

How to Configure Your Display Adapters

Frustrated man looking at the monitor

Another possibility is that the display adapters are not correctly configured.

To check them, follow these steps:

  • Step 1 – Go to your device manager by clicking on the start button and start typing “device”. A popup will appear with the Device Manager link.
  • Step 2 – Click the link and then select display adapters in the menu (you may have more than one).
  • Step 3 – Click the display adapter and select “enable the device”. Do this with all the adapters you see.
  • Step 4 – Return to the device manager and select the monitor option and double-click on the Generic PnP monitor options to see that the display adapters that you selected above are visible in the general tab under location.

Your display adapters are now correctly configured and the monitors should be detected by Windows.

Copyright protected content owner: and was initially posted on February 17, 2022.

How to Configure Your Display Drivers

black monitor on the table

If Windows is still detecting your third monitor, then you may need to update your display drivers.

To update your display drivers, follow the steps above to access your device manager. Then expand the display adapters and right-click your specific display adapter. Select “properties” on the available menu and then go to the Driver tab.

In the popup, click on update driver, and select “Search automatically for driver software”. Windows will search for the updates you require and then install them automatically.

You can also search for updated drivers on the Windows Update link at the bottom of the popup screen. This will require that you search for Windows updates first and then install the updates that Windows has available for your display.

Once the updates are completed, reboot your PC or laptop and check that your monitors are working correctly.

Macbook Not Detecting Third Monitor

black monitor on the table

Normally, a Macbook will automatically detect any displays connected to it and start working on the extended desktop.

But this is not always the case and you will then have to manually set up your monitors.

If a Macbook is not detecting the third monitor, then go to the Apple menu and click on system preferences. Choose Displays, then press and hold the option key while selecting the Detect Displays button. Click the button and watch as the dual regime activates. If this fails, then check your cables.

Should the external monitors still not display, then there are potentially greater problems with the monitors or with your MacBook which may require a visit to the Apple store.

Third Monitor Detected But Not Displaying

black monitor on the table

If Windows has detected your monitor but the display is still not working, you can rule out problems related to cables or the various connections.

Copyright article owner is for this article. This post was first published on February 17, 2022.

In this instance, it is most likely the configuration or the display adapter that is causing your problem.

If a third monitor is detected but not displaying, right-click the desktop to access Settings. Click Display Settings to see which displays are connected. Click the Identify button to see which monitor is not working. Select that monitor and scroll to Multiple Displays to select the required option.

Within the “multiple displays” option, you can select various options that allow you to display either an “extended desktop”, “duplicate your desktop” or “disconnect your display” completely.

It is usually the last option that requires adjustment for the monitor to display your desktop.

Once you have completed your selection, click on the “keep changes” popup that appears to ensure that your display options are saved.

You will notice that the monitor will immediately display your desktop or an extended desktop once you have saved your options.

While there are several reasons why one or more of your monitors won’t display despite being detected by Windows, the most common occurrence is when you have disconnected a display and then reconnected it.

This commonly happens with laptops making use of a display docking unit that is either intentionally disconnected or unintentionally bumped or moved.

Related Articles

Second Monitor Not Working

Monitor Not Turning On

ReadyToDIY is the owner of this article. This post was published on February 17, 2022.

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