Causes: 1. No Developer Unit. 2. No Toner Waste Container.
Code: U20
Description: CLOSE ADF COVER
Causes: 1. ADF Cover is open. 2. ADF is not installed correctly. 3. ADF Cover Sensor is disconnected. 4. ADF Cover Sensor is defective. 5. LVPS connector is disconnected. 6. LVPS is defective.
Code: U21
Description: CLOSE PLATEN COVER
Causes: While the copier is initializing, the ADF Cover was opened. (Optional ADF installed)