Below is a list of potential action items to troubleshoot the issue with displaying an external monitor on your laptop:

1. Check if the external monitor is powered on.
2. Check the laptop’s display settings, and update it to the recommended one.
3. Ensure that the external monitor is compatible with the laptop’s video output.
4. Check all of the physical connections of the device, ensuring that everything is secure.
5. Restart the computer.
6. Update or reinstall the laptop’s audio, video, and chipset drivers.