How to Fix Mac not Displaying on Second Monitor?

Connecting your Mac to an external display sounds easy, but what if nothing shows up after connecting it through the cable?

Some people need that extra screen for their work. However, multiple screens have their own drawbacks.

Yes, not every time a second monitor display with Mac is fine and works smoothly. Sometimes you can encounter the Mac not displaying the second monitor issue.

If you too are facing an issue extending the external display or mirror the screen on a larger monitor, then this article is for you.

We did our little research to get you the tried and tested methods to fix Mac external monitors not working.

So without any further ado, let us begin.

How to Fix Mac not Displaying on Second Monitor?

When the external monitor connected to your Mac device fails to work, then these troubleshooting tips will help you and in no time your second monitor will multitask across the two screens.

Method 1 – Update All the Mac Software

For the second monitor to work with your Mac it is important for all the software to be updated and work fine.

The different software involved is the Mac operating system, the app you are working on, the firmware built into the Mac, and the external monitor and cables.

Start by checking all these software and ensuring they are all updated. To check for Mac operating system update –

Step 1 – Go to the Apple Menu. Click on System Preferences.

Step 2 – Then select System Update.

This will install the MacOS updates that might be pending.

Mac System Updates

Step 3 – Next to install firmware updates, open the App Store on your device.

Step 4 – From the menu on the left side, click on Updates and install the firmware and app updates.

To check for the firmware update of the external monitor, visit the manufacturer’s website. You can also check the same for display cables, extenders, hubs, or adapters that you are using.

Method 2 – Check the compatibility of your External Monitor

Compatibility between the two devices that we are trying to connect is important. Your Mac might not be displayed on the second monitor because the latter is not compatible with your Mac device.

You won’t be able to operate every feature of two devices that are connected through an adapter unless they run on software that is compatible.

To check the compatibility requirements of the second monitor, head to the manufacturer’s official website. And then go to Apple, and click on About this Mac.

About this Mac window

Here you can check the requirements of your Mac. Also for more information about the various ports on your device, you can click on the System Report button.

Pay attention to the Thunderbolt and USB-C ports, and connect it to the required port only.

Method 3 – Reconnect every Cable and try a Different Port

The next step to troubleshoot the issue is disconnecting all the cables that connect your Mac to the external monitor. Then inspect the cables and ports and look for any sort of damage. Also, check for dirt and clean all the ports.

If it is still not working, then try to reconnect the cable to a different port on your Mac. And if there are different inputs on the display device, then try to connect the cable to a different display input.

Reconnect different cable to Mac

You can even try a different cable if you have some spare one in your hand.

Tip – Do not use extension leads, adapters, or hubs. Instead, connect the two devices directly. If this works, then the issue was possible with your connecting accessory.

Method 4 – Restart Mac with External Monitor Connected

If the Mac is not displaying on the second monitor that is connected then another way to resolve it is by restarting your Mac.

However, we would suggest you not unplug your monitor while restarting your Mac. Simply go to the Apple menu, and click on Restart.

Another trick that worked for a few users is putting their Mac device to sleep. Open the Apple menu and click on Sleep. After waiting for 30 seconds, press any key or move the mouse.

Put Mac to Sleep

You can also try restarting your external monitor. But while you power off and on your monitor, make sure you disconnect it from Mac and reconnect it respectively.

Bonus Tips

  • Adjust the display brightness and resolution.
  • Go to the Support tab under About this Mac and check how many displays you can connect to the Mac.
  • Enable the Detect Displays option to ensure your Mac detects the new display.
  • Connect your Mac to an external power source to give it enough power for an external monitor.
  • Lastly, boot your Mac in safe mode.


Do not let errors like this discourage you from connecting your extra monitor to the Mac device.

There are various ideas and tricks that you can put to resolve the display issue with a second monitor connected to Mac.

Sometimes, connecting the two devices is quite easy; however, if you are stuck at such an issue, try out the aforementioned methods.

We hope that this guide will help troubleshoot connection issues with the second monitor easily.

What do you think of this feature of extending the display options? Let us know in the comment section.

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