Board edge detection failure (Normal) This error is shown when STOP is pressed after the “Clear Board Sensor” message is displayed. See the “Clear Board Sensor” troubleshooting section for more details. The “Clear Board Sensor” error occurs during the length (or X) edge find. After the roller releases the board sensor was not able to find the edge within approximately 4″. Can also occur when the board sensor did not detect a large enough transition to define an edge (usually happens when the material is very dark or there is dust on the sliding plate).