How To Fix a MacBook Not Detecting External Display

Most MacBooks come with a handy external display port to help you connect an external monitor. External monitors can be used to extend your desktop, create more visual space for more applications, or minimize distractions when in public spaces.

There’s only one problem: MacBooks don’t always detect when external displays are connected. If you try to connect one, sometimes, all you get is a dead, blank screen. The monitor might even light up for a few seconds, only to turn black a few moments later. This can be frustrating, especially if you’ve got something urgent to work on.

But don’t fret. There are several troubleshooting methods that can help you resolve the issue.

In this article, we’ll go over each possible fix to help you get back on track.

How To Fix When a MacBook is Not Detecting External Display

Most MacBook owners love the idea of an external monitor because of the many benefits it provides:

• It can help you lock in a more immersive gaming experience by enlarging your play area.
• If you’re an artist or video editor, you could display your results on one monitor while using the other screen as your work area.
• Amenities like multitasking and resizing screens can be done more efficiently on a large external monitor than on a small built-in screen.
• If you plan to use multiple applications simultaneously, the increased screen space will help you stay organized. You won’t have your windows bumping all over the place – something that can save you valuable time.

But for all their benefits, external monitors don’t always sync up perfectly with MacBooks. Your Mac might even detect the monitor for a while but then lose the connection after a reboot.

If this has happened to you, there’s no need to panic. The situation can arise for several reasons, and in this entry, we’ll go over some of the most common ones.

We’ll also provide tips on how to fix these issues so that you can get back to work without any delay.

Check Your Cable Connection

Before trying anything complex, make sure that both ends of the cord connecting the two devices are securely plugged in and that they’re plugged into compatible ports (such as HDMI or Mini DisplayPort). If the connection seems okay, but your MacBook still can’t detect the external display, you may try switching the connection ports.

Restart Your Computer

If your computer still can’t detect the external monitor, even after confirming that all cables are connected correctly and securely, you should try restarting your Mac. A reboot is one of the oldest troubleshooting methods that can resolve a myriad of connectivity issues, including external monitor detection problems.

While restarting your computer, you shouldn’t unplug the external monitor. Simply click on the Apple logo in the top left of the screen and select Restart.

If restarting doesn’t work, you could try putting your MacBook to sleep. To do so, click on the Apple logo and select Sleep. Then wait for a minute or two before waking up your MacBook.

You can also activate sleep mode by simply closing your MacBook.

Check Your Display Preferences

If you’re having problems connecting an external monitor to your MacBook, one possibility is that your display settings aren’t configured correctly. To be specific, an external monitor may not work if your Mac’s brightness and resolution settings aren’t right.

Luckily, it’s easy to tweak your display preferences. Here’s how:

1. Click on your Apple logo and select System Preferences.
   
2. Click on Display.
   
3. Click on Gather displays in the bottom right corner of your screen. This will allow you to view the display settings for all the monitors connected to your system.
4. Try adjusting your external monitor’s brightness and color options. To undo any changes, simply click on the Escape key.
5. To adjust the picture size on your monitor, click on the Overscan or Underscan slider menus.
   

Apart from the display settings on your system, you might also want to consider checking your external monitor’s display preferences. Some models need specific display settings to work.

Connect a Test Monitor

Sometimes the problem may boil down to a faulty monitor. If the external monitor you’re trying to connect is faulty, then settings adjustments won’t resolve the issue. You’ll have to get yourself a new monitor.

To find out if your monitor is faulty, disconnect it and then connect a second external display. If the second monitor works just fine, it means the first one is either broken or incompatible with your MacBook.

Update Your Operating System

Updating your computer’s software and firmware can be a great way to solve many display issues that crop up on MacBooks.

Here’s how to perform a software update:

1. Connect your computer to the internet.
2. Click the Apple logo in the upper left corner of your screen.
   
3. Select Software Updates from the resulting menu.
   
4. Follow the on-screen prompts to download and install any available software and firmware upgrades.

Turn Your MacBook Into a Workhorse

With an external monitor, you can turn an already productive MacBook into a workhorse. Besides creating space for more applications, you’re able to avoid clutter or even lock in a more immersive gaming experience.

That said, external display connection problems are relatively common. If your MacBook isn’t detecting an external display, we have outlined multiple troubleshooting methods. Any of them can resolve the issue and set you up nicely with a more productive computing environment.

Have you encountered any problems while connecting an external display to your MacBook? How did you get around them? Let us know in the comments section below.