A user reports that they cannot get their laptop to work with a video projector...

Comprehensive and Detailed Explanation

CompTIA troubleshooting procedures emphasize confirming input source settings on the external display device.

Even if the HDMI cable is connected properly:

The projector must be set to the correct input source (HDMI 1, HDMI 2, etc.).

If the source is incorrect, the laptop will not display, even though the laptop output is functioning normally.

Since the projector is powered on, and the laptop is already set to “Duplicate,” and cables are good, the most likely cause is:

✔ The projector is set to the wrong input source.

This is a common real-world issue covered under "video and projector troubleshooting."

Why the other answers are incorrect

A. Projector may support HDMI; this is not the “most likely.”

B. “Extend” is not required — “Duplicate” works for projectors.

C. A failed HDMI port is possible but not the most likely scenario.

Final Answer: D