2. When operating and writing on the whiteboard, the position of pen or finger doesn’t match the position of cursor. 1) The relevant location of projector and white has been changed. Please re-orient the whiteboard. 2) The projection area has trapezoid distortion, please adjust the projection area, and re-orient the whiteboard. 3) When orienting the whiteboard, the pen or finger is not perpendicular to the surface, please re-orient with correct posture. 4) When orienting the whiteboard, the pen or finger tip missed the green center of the red orienting cross, please re-orient the whiteboard. 5) The filters around whiteboard have been shaded by other objects, such as dust or chalk dust and so on. Please keep filters clean. 3. When I operate and write on the whiteboard, the system response is slow, or the stroke is intermittent. The computer is not under normal running or the memory is occupied too much. Please close some applications or restart the computer. The operating or writing force is uneven. Sometimes the force is too light to be sensed. Initializing hardware failed. Please reconnect the cable with the board to initialize the hardware again.