If Connected to the Document Camera, is the Doc Camera On? The power light for the doc camera will show as yellow when its plugged in, once turned on it shows as Blue.
If using Doc Camera/Laptop or Desktop: There are two VGA cables that go into the Doc camera. The black VGA is the cord to the projector and this goes in the Blue port on Doc Camera. The Blue VGA runs from the Doc camera to either your desktop or to your laptop. This Blue VGA goes in the Black port on the Doc Camera
Check power light on mounted Epson projector - if its not blue make sure that projector cord is still plugged in or power strip is turned on (red light is on)
Double check projector settings from your device:
For Laptop, hold down Windows Key (to the left of your space bar next to the ALT key) and the letter P at the same time. This brings up a side bar of Display choices, choose "Duplicate"
For Chromebook, the setting should be on "Mirror". To double check this go to Chromebooks settings (the three dots at top right, click settings and type in "Display" in the search box). If "Mirror" is not on, turn it on by clicking on it. NOTE: You will only see these choices if there is a HDMI cord plugged into the Chromebook.
Sometimes turning off the Projector and turning it back on AFTER the document camera is turned on will resolve the issue
There is switch on the side of the Doc Camera that should always be set to RGB.