Lexmark Optra C710 Service Manual - Page 149

5016-001 Black, Color Lines or Bands Service Check Banding is difficult to detect except on a page with a uniform gray, color or a large amount of graphics printed on the page. Banding is primarily due to a variation in the speed of the paper as it feeds through the printer, especially in the development and transfer process. FRU 1 Toner Cartridge 2 Intermediate Transfer Unit (ITM) 3 Transfer Roller 4 High Voltage Contacts Grid Block 1 Grid Block 2 5 HVPS 6 Printhead Action Try a new toner cartridge, as the present cartridge may be defective, replace the cartridge corresponding to the color of the line or band. An ITM may cause banding or lines on the printed page. Try a new ITM. Note: The transfer roll is spring loaded against the inner cover so that it properly contacts the transfer belt in the ITM unit. Check the transfer roll for correct installation. Be sure the transfer roll rotates freely. Check the left and right side transfer roll springs and bushings for signs of binding or damage. Replace parts as necessary. Check the high voltage contacts in grid block 1 and 2 to ensure they are clean, not bent, deformed or pitted. If incorrect, replace the failing grid block assembly. Be sure the HVPS is correctly installed and securely mounted to the HVPS mounting bracket and Grid Block assemblies. If correct, remove the HVPS and be sure the high voltage contacts align with the contacts on the HVPS. Also look for signs of pitting or damage. The printhead can cause this problem, but should only be replaced after a new toner cartridge(s) or ITM has been replaced. Diagnostic Information 2-83