1. Check your display has power, is connected and switched on.
2. Check the correct source input is selected. Most displays (projectors, TVs) have input selection buttons either on the display, or on the remote. Check all inputs one at a time in case this has been changed. Note, a display can have multiple HDMI inputs.
3. Check the cables are all connected and nothing has been moved or bumped.
4. Check HDCP (High-bandwidth Digital Copy Protection) is turned off on the projector
See below for must have devices and equipment: