Trouble Shooting
| Step | Cause | Solution | Parts |
| 1 | Dirt on the drum unit charger. | Clean the charger of the drum unit (see below). | |
| 2 | Device and the drum unit not conducting. | Replace the drum unit. | Drum (015-0289-21) |
| 3 | LSU defective. | Replace LSU. | LSU (002-B097-0-SP) |
| 4 | Main board defective. | Replace the main board MBA890. | Main board: AM7630i (004-3479A-9-SP) AM7640i (004-3479B-9-SP) AM5630i (004-3479C-9-SP) AM5640i (004-3479D-9-SP) |
Clean the charger of the drum unit.
Slide the corona wire to the end and then back to the original place. Repeat this for at least 3 times.
