There are many benefits to using an external monitor with your Mac. Perhaps the most obvious benefit is that it can give you more screen real estate. This can be especially helpful if you are working on a project and need more room to spread out your work. Additionally, using an external monitor can improve your productivity by allowing you to keep multiple applications open at the same time.
Unfortunately, there are also some downsides to using an external monitor. One of the most common problems is that the external monitor may not work correctly with your Mac. This can be especially frustrating if you rely on your external monitor for work or other important tasks.
In this article, we will discuss some of the common issues that can cause your Mac to not recognize an external monitor. We will also provide some tips on how to fix this issue.
3 Common Reasons Why Your External Monitor Isn’t Working On Mac
1. Damaged Cable
If you are still having problems with your external monitor not working, it is possible that the cable is damaged. If the cable is damaged, it is likely that your Mac will not be able to detect the external monitor. To fix this problem, you will need to replace the damaged cable.
2. Upgrade to new macOS
There are many Mac users who have reported that their external monitors stopped working after upgrading from Big Sur to macOS Monterey. One or more external monitors is suddenly not recognized by a Mac running macOS Monterey.
The problem is being caused by an incompatibility between macOS Monterey and the external monitors or the outdated driver of the dock that your Mac is connected to.
3. Your Mac supports one external monitor only
Some Macs do not support more than one external monitor. If you are trying to connect two or more external monitors to your Mac, it is possible that your Mac will only detect one of the monitors. In this case, you will need to purchase a dock that supports multiple monitors or use a new Mac that supports multiple monitors.
A newest Apple Silicon M1/M2 is one of the Macs that support one external monitor only.
Now we know the reasons that can cause external monitors not working on Mac, it’s time to fix them. Of course, there is no single solution that can fix all the problems. You need to try different solutions to see which one works for you.
9 Solutions to Fix External Monitors Not Working On Mac
Solution 1: Restart Your Mac and External Monitor
If your external monitor is not working, the first thing you should try is to restart both your Mac and the external monitor. This may seem like a simple solution, but it can often fix many problems.
To restart your Mac, click on the Apple icon in the upper left corner of your screen and select “Restart.” Once your Mac has restarted, turn on your external monitor and see if it is working correctly.
Solution 2: Check the Connection Between Your Mac and External Monitor
If your Mac is not recognizing your external monitor, it is possible that the cable connection between your Mac and the external monitor is loose or damaged.
To fix this problem, unplug the cable from your Mac and then plug it back in. Make sure that the connection is tight and that there are no loose wires. You can use a new cable to test if the old one is damaged. If the new cable works, then you know that the old one was the problem.
If the cable is not the problem, it is possible that there is an issue with the port on your Mac. To fix this problem, you will need to try another port.
Last update on 2023-09-21 | Details
For example:
- Buy a new DisplayPort/HDMI to USB-C cable to connect your Mac to an external monitor. (Recommend)
- Connect the HDMI end of the adapter to the HDMI port on your monitor.
- If you are using a VGA/DVI monitor, connect the VGA/DVI end of the adapter to the VGA/DVI port on your monitor.
Solution 3: Update the Software on Your Mac
If you are using a USB-C or Thunderbolt hub/dock to connect multiple monitors to your Mac, it is possible that the problem is caused by an outdated driver. To fix this problem, you will need to update the driver for your dock.
There are many docks/hubs that support DisplayLink, you can check your device online or in the box to see if it is compatible with DisplayLink.
Some popular docks that use DisplayLink technology include the Plugable 4K USB C Docking Station and the Sonnet DisplayLink USB.
To update the driver for your dock, you will need to visit the DisplayLink Manager website and download the latest driver for your dock. Once you have downloaded the new driver, install it on your Mac and restart your computer.
Although DisplayLink Manager can be found on many devices, some docks have driver-based firmware that are not DisplayLink Manager. In this case, you should check for firmware updates on the manufacturer’s website or contact their customer support.
For example, TOBENONE Driver-based USB C Docking Station requires an InstantView driver to extend a dual or triple display.
Solution 4: Reset NVRAM/PRAM or SMC on Your Mac
Resetting NVRAM/PRAM or SMC can often fix many problems, including external monitors not working on a Mac. To reset NVRAM/PRAM or SMC, follow these steps in this post which covers how to reset NVRAM on a Mac.
NVRAM (non-volatile random-access memory) is a small amount of memory that your Mac uses to store certain settings and access them quickly.
PRAM (Parameter RAM) is similar to NVRAM, but it stores more settings.
SMC (System Management Controller) manages many low-level functions on your Mac.
Solution 5: Change a Refresh Rate on Your Mac
The best external monitor for Mac can have a refresh rate of 60Hz, 75Hz, 100Hz or even 144Hz. If the refresh rate on your Mac is not set to match the refresh rate of your external monitor, it is possible that this is causing the problem.
You can try different refresh rates to see which one works best for you. If you are not sure what refresh rate to choose, start with a lower refresh rate at 60Hz and then work your way up.
To change the refresh rate on your Mac, follow these steps:
- Click on the Apple icon in the upper left corner of your screen and select “System Preferences.”
- Click on “Displays.”
- Click on the “Display” tab.
- Click on the “Refresh Rate” drop-down menu and select the refresh rate that matches your external
Solution 6: Deactivate TrueTone and Night Shift on Your Device
Many Mac users have found that deactivating TrueTone or Night Shift can fix external monitors not working on Mac.
To deactivate TrueTone, follow these steps:
- Click on the Apple icon in the upper left corner of your screen and select “System Preferences.”
- Click on “Displays.”
- Click on the “Display” tab.
- Uncheck the box next to “True Tone.”
To deactivate Night Shift, follow these steps:
- Click on the Apple icon and select “System Preferences.”
- Click on “Displays.”
- Click on the “Night Shift” tab.
- Uncheck the box next to “Turn On Until Tomorrow.”
Solution 7: Adjusting Your Monitor Resolution
If you are still having problems with your external monitor not working on Mac, you may need to adjust the resolution of your monitor. The best way to do this is to use the “Scaled” option in the “Displays” preferences.
To adjust the resolution of your monitor, follow these steps:
- Click on the Apple icon, and click on “System Preferences.”
- Click on “Displays.”
- Click on the “Display” tab.
- Click on the “Scaled” radio button.
- Select the resolution that you want to use from the list of options.
Solution 8: Use Monitor With Another Mac/Laptop/PC
If you have another laptop or PC that you can connect your external monitor to, it is a good idea to do so. This will help you determine if the problem is with your Mac or with the external monitor.
- If the external monitor works fine with another PC, then the problem is most likely with your Mac. You should try one of the other solutions in this post.
- If the external monitor does not work with another laptop or PC, then the problem is most likely with the external monitor. You should contact the manufacturer for assistance. Or just buy a new one.
Solution 9: Update Your macOS or Go back to an Older macOS Version
As we mentioned before, many pepple have been having this problem after updating their macOS to macOS Monterey. If you are having this problem, you can try updating your macOS to the latest version or downgrading to an older macOS version.
To update your macOS, follow these steps:
- Click on the Apple icon in the upper left corner of your Mac and click “System Preferences.”
- Click on “Software Update.”
- Click Upgrade now and wait for the updates to install.
To downgrade to an older macOS version, follow these steps:
It’s more complicated to downgrade your macOS version. We suggest you create a USB installer for the older macOS version that you want to use.
1. Download the older macOS version (Big Sur) that you want to use from the App Store.
2. Follow this post to create a bootable USB installer for the older macOS version.
3. Boot your Mac from the bootable USB installer.
4. Follow the prompts to install the older macOS version.
5. Once the older macOS version is installed, you can try connecting your external monitor and see if it works.
Conclusion
There you have it. This is how to fix external monitors not working on Mac. We hope that one of the solutions in this post was able to fix your problem. If you have any questions or suggestions, feel free to leave a comment below. And don’t forget to share a new solution that you found if it is not listed in this post. Thanks for reading!
