Lexmark Optra C Service Manual - Page 100

5045-001 Light Image Service Check Be sure the printer is not installed in an unusually hot or cold environment, see the User's Reference. If the problem is with one color, try a new toner cartridge of that color. FRU 1 Density sensor unit 2 High-voltage cable resistors (approximately 9K Ohms) 3 High-voltage power supply PCB, Mechanical controller PCB 4 High-voltage power supply PCB, Mechanical controller PCB Action Operate the density adjustment panel to adjust the density. Clean the density sensor lens, if the problem remains perform the remaining checks before replacing the density sensor unit. Check the continuity between the transfer drum contacts and the high-voltage PCB. Replace the high-voltage cable or the contact if necessary. Clean the developer bias contact and the toner cartridge contact. If the problem remains, continue with this service check. Check and replace as necessary the high-voltage power supply PCB or the mechanical controller PCB. If the problem remains, replace the transfer sheet. 2-68