Lexmark C720 Service Manual - Page 243

5024-001 High Voltage Power Supply Unit (HVU) Removal 1. Remove the upper side cover (L). See "Upper Side Cover (L) Removal" on page 4-7, for more information. 2. Remove the side cover (L). See "Side Cover (L) Removal" on page 4-10, for more information. 3. Remove the controller board. 4. Remove the shield cover B. 5. Remove the shield cover A. 6. Disconnect all harness connectors (8) to the main engine (MCTL P.W.B.) board. 7. Remove the screw F3X6 (1) from the controller fan assembly, and the case. See "Side Cover (L) Removal" on page 4-10, for more information. 8. Remove the set screws ST3X6 (4) from the shield case A assembly and remove shield case A assembly. 9. Remove rear screw from base cover (L). 10. Disconnect all harness connectors (3) to the high voltage unit. 11. Remove the set screws ST3X6 (1) and BT3X8 (8) from the high voltage unit. 12. Remove the high voltage unit. Power supply installation: 1. To install a new high voltage unit: a. Put each electrode terminal through the holes of the P.W.B. from the back. b. Having the set holes for the electrode meet the installation hole of the P.W.B., replace the screws. 2. Perform the reverse removal steps. 3. Connect the power supply cable. 4. Turn the power On. 5. Execute the test print in service mode. See "Diagnostic Mode" on page 3-5, for more information. 6. Confirm printer operation and print quality. Repair Information 4-33