Below is a picture of a typical black box:
Make sure the equipment is powered on in this order:
Pull down the projector screen mounted above the dry erase board.
Check if the computer's turned on; it's power button will light up blue.
Make sure the projector is set to Computer 2 input. If it's not, press the COMPUTER button on the remote to cycle between the Computer 1 and Computer 2 inputs.
Check if the DVD/VCR player is turned on.
Choose DVD or VCR for the appropriate video source.
Insert your DVD or VHS cassette.
Press the VIDEO button on the projector remote
Depending on your laptop's ports, you will connect the VGA adapter or the Mini-Displayport adapter.
When you are finished with the classroom, please turn the projector off using its remote control. Do not turn off the computer. Do not turn off the black box's master power switch.