Laser failure detection The DC controller determines an optical unit failure and notifies the formatter, if the laser/scanner encounters the following conditions: ● The scanner motor does not reach a specified rotation within a specified period of the scanner motor start up. ● The rotation of the scanner motor is out of specified range for a specified period during the scanner motor drive. ● The BD interval is out of a specified value during a print operation. ENWW Engine-control system 23