- Make sure all the wires are properly attached, as a loose connection can affect the picture
- Look at the device’s picture settings by pressing the menu button on its remote control. Adjust the brightness to see if this helps, and check any input modes to ensure the projector is looking for the type of cable you have connected to it
- Some projectors have a "shutter" feature. This can cover up the projecting lens. The user guide will tell you how to turn this off
Sorted. Now you can get back to that movie.
Always refer to the manufacturer’s manual for specific details.