When your Mac fails to detect an external display, it can disrupt your workflow and productivity. Here are some steps you can take to troubleshoot and resolve this issue:

Steps to Fix External Display Detection Issue:

1. Check Physical Connections:

Ensure that the cables connecting your Mac and the external display are firmly plugged in at both ends. Try reseating the cables to ensure a secure connection.

2. Restart Your Mac and the External Display:

Turn off both your Mac and the external display. Then, power them back on, allowing both devices to establish a fresh connection.

3. Press the Detect Displays Shortcut:

On your Mac keyboard, press Command (⌘) + F2 or Command (⌘) + F1 to trigger the “Detect Displays” function. This key combination can sometimes force the Mac to recognize the external display.

4. Check Display Preferences:

Go to System Preferences > Displays on your Mac. Ensure that the external display is recognized and configured correctly in the display settings.

5. Try Different Ports or Adapters:

If possible, connect the external display to different ports on your Mac or use a different adapter. Sometimes, a faulty port or adapter can cause detection issues.

6. Update macOS and Drivers:

Make sure your Mac is running the latest version of macOS. Check for software updates in System Preferences > Software Update. Also, ensure that display drivers are up to date.

7. Reset NVRAM or PRAM:

Restart your Mac and immediately press and hold Option + Command (⌘) + P + R to reset the NVRAM or PRAM. This can resolve various hardware-related issues.

8. Check Power Saving Settings:

In System Preferences > Energy Saver, disable power-saving features like “Automatic graphics switching” that may interfere with external display detection.

9. Use Safe Mode:

Boot your Mac into Safe Mode by restarting and holding the Shift key. Safe Mode helps diagnose and fix various issues, including external display problems.

10. Consult Apple Support:

If the issue persists, contact Apple Support or visit an Apple Authorized Service Provider for more advanced troubleshooting and potential hardware diagnostics.

In Conclusion, By following these troubleshooting steps, you can address the issue of a Mac not detecting an external display and potentially restore your external monitor functionality. Ensuring proper connections, software updates, and configuration settings can help resolve common display detection issues.