There could be various factors why your MacBook won’t detect an external display. It can be due to wrong port selection, faulty cable, macOS glitches, wrong resolution setting, and more. We will discuss every scenario and potential solutions.
1. Check the Cable
First of all, you should confirm if you’re using a correct HDMI cable with your external monitor. If you are using new 2021 MacBook Pro models or pre-2016 MacBook models, chances are, you are trying to use HDMI to HDMI cable along with an HDMI to Type-C adapter to connect MacBook to a display. Closely inspect both the ends of the HDMI cable. Make sure there isn’t any heavy wear and tear on either side. Some might be using Type-C to HDMI cable to connect MacBook to a display. And here’s where things get interesting. You should also check the display resolution and FPS the cable supports from the product page. Some cables are limited to 4K at 30fps only while your monitor can go up to 4K at 60fps.
2. Remove Dust from Ports
Exposed ports on your Mac often attract dust particles and that might cause the cable port to not fit properly. The Mac won’t detect the display even with the right high-quality cable. You should clean mini-Display port or Type-C port, depending on your Mac model. You can use compressed air to clean out the dusty ports. While you are at it, do take a close look at the external display’s HDMI ports too.
3. Select the Correct HDMI Port on Display
Most modern monitors come with multiple HDMI ports to use. You may have connected the cable to the first port and used HDMI 2 as the output screen. Use the remote (if it comes with a monitor like Samsung M7) or use the on-device buttons to change the HDMI selection. Select the right HDMI port on the monitor and check the Mac output.
4. Restart Mac and External Monitor
Sometimes a simple trick such as rebooting the Mac can fix the device not detecting the display issue. Click on the Apple icon in the menu bar and select Restart. Upon reboot, macOS will ask for authentication (Touch ID won’t work here, enter Mac password). You should also completely power off the external monitor and disconnect your Mac from it. Apparently, this trick has worked for many as per the Apple forums. Reconnect Mac with the display using the preferred cable and it should work now.
5. Keep Your MacBook in Charge
You might be planning to use macOS on the external display only. To continue working on the big screen, by keeping the MacBook lid closed, you need to keep the device in charge all the time. This prevents the MacBook from going into sleep mode when the device lid is closed. Try using the default adapter that came with your MacBook. Don’t go with third-party adapters or the ones with less capacity. Those adapters might not be suitable to deliver enough power to keep the MacBook running with the external display.
6. Change Display Resolution
If you are dealing with incorrect display settings on Mac, the scaled-up version on the monitor might look tiny or blurry and give unnecessary strain to your eyes. macOS offers scaled settings from the System Preferences menu to make changes. Step 1: Click on the little Apple icon at the top and open the System Preferences menu. Step 2: Select Display. Step 3: Click on Scaled and select relevant resolution settings with text size. Select the text size that you are comfortable using on a big screen. Don’t worry about the low resolution here. macOS will scale it up to match your display’s highest resolution capacity (2K or 4K). For example, if you select something like Full HD (1920 x 1080) in the scaling menu, the monitor receives a 4K quality signal. With larger text, you may take a hit on MacBook performance. It won’t be visible on MacBook Pro models, but it’s quite evident on MacBook Air devices running Intel CPUs.
7. Update macOS
Normally we don’t advise readers to update their main Mac machine to the latest OS immediately. On the release date, you shouldn’t be upgrading from macOS Big Sur to macOS Monterey. However, If you already upgraded to the latest macOS, and now you are facing problems detecting display. You should wait for Apple to release another OS patch and install it. Open the System Preferences menu and go to Software Update. Install the newest macOS build and try detecting the display again.
Enjoy macOS on a Big Screen
Using macOS on a big screen lets you get work done more quickly. It lets you play with multiple windows offers a large canvas to fly through tasks. How did you manage to fix Mac not detecting display issue? Share your experience with our readers in the comments below. The above article may contain affiliate links which help support Guiding Tech. However, it does not affect our editorial integrity. The content remains unbiased and authentic.
