ActivManager is a utility loaded on all school Macs. It is accessible via the top toolbar.
Click on the Whiteboard icon. A red X indicates a missing connection. If this appears, check connections to projector and computer.
ActivManager provides access to Control Panel and Calibration.
Calibration can be used to recalibrate pens.
Control Panel provides various details concerning hardware, connections, pens and projector status helpful in diagnosing problems.