Please try the following steps to find the possible root cause:
- Change the HDMI cable and try again.
- Change the external monitor or projector and try again. Some old display devices may not be able to receive the projection.
- If the external monitor or projector is connected with a long cable (over 5 meters), replace it with a shorter cable (less than 5 meters) and try again.
- If the external monitor or projector is connected through an HDMI extender (convert between HDMI signal and wireless signal), please remove the extender to connect with the display device directly and try again.