Dell 5100cn Color Laser Printer - Manual (Page 57)

Maintenance 57
4. Gently wipe the automatic density control (ADC) sensor window with a clean dry cloth or
cotton swab.
NOTE: Do not allow anything hard to come in contact with the automatic density control (ADC) sensor
window. Do not use excessive force to clean the window.
5. Replace the transfer roller. Grip the tabs as shown.