The user should check the display settings on the computer and set them to extend/duplicate. This will allow the computer to send the video signal to both the laptop screen and the projector. If the display settings are set to only show on one screen, then the projector may not detect any source. According to the CompTIA Core1 objectives, one of the common display issues is no image on screen. A troubleshooting guide for projectors also suggests checking the display settings as a possible solution for no source found error.