When you move your laptop, the display appears to flicker on and off. What is going on?

When the laptop is moved, a loose video cable may be okay while stationary, but it will wiggle enough to break connection between the motherboard and display. Fortunately, this is a simple repair. A laptop's video cable is a very thin and sensitive ribbon cable. Disassemble the laptop according to the manufacturer's instructions until you can reseat the video cable, then gently reseat it.