Lexmark C520 Service Manual - Page 40

5022-xxx User status and attendance messages (continued) Error code 84 PC Unit missing Action • Scroll down the operator panel to see if the printer is showing that all four of the PC units are missing. If so, check the HVPS cable between the system card and the HVPS. Ensure that the cable is not plugged in backwards on the HVPS. Disconnect and reconnect the cable to make sure there is good contact. • Insert or reinstall the specified photoconductor unit and see if problem clears. See "Photoconductor unit removal" on page 4-70. • Remove the top access cover assembly (see "Top access cover assembly removal- model C52x only" on page 4-28 or "Top access cover assembly removal-model C53x only" on page 4-32), and confirm that the camshaft follower (A) on the left side is not out of the groove (B). If the camshaft follower is out of the groove, raise the arm, use a screwdriver to ease the camshaft follower back into the groove. You need to press down to snap it into position. BA • Check the high voltage contacts path, especially the "finger" on the specified photoconductor unit (printer is shown with components removed for clarity). High voltage power supply High voltage contact path Finger • If the contacts are good, replace the HVPS. See "High voltage power supply (HVPS) removal" on page 4-62. • If the problem persists, replace the system card. See "System card removal" on page 4-79. Diagnostic information 2-25