Calibrate the scanner in a well-lit bright room using these steps.       

• Place the scanner on a white paper.
•  Press the Power button to set the scanner to ON.
•  Press the JPG/PDF button, then immediately press the Scan button. This action starts the calibration mode.
•  "start cal" will appear on the Home screen.
• Wait until "scroll scanner" is shown on the Home screen. This can take several seconds.
• Move the scanner up and down on the white paper. Move the scanner at a steady speed. Do not move the scanner fast.
• Continue until the Home screen turns OFF.
• The calibration is complete.