HP LaserJet 4250 Service Manual - Page 402

Table 7-24 Lines (continued) AaBbCc AaBbCc AaBbCc AaBbCc AaBbCc (Continued) Possible cause Recommended action(s) Horizontal lines (parallel to the paper-path direction) If the lines are repeated at a consistent interval down the page, a repetitive defect exists. Use the repetitive defect ruler to determine the cause of this defect. See Repetitive-defects troubleshooting. Sharp, random lines indicate a problem 1 Check the cables between the with the laser/scanner control circuitry. dc controller and the laser/scanner assembly. 2 If the cables are not connected, connect the cables. 3 If, after checking the cables between the dc controller and the laser/scanner, the problem persists, replace the laser/scanner assembly. See Laser/scanner assembly. 4 If, after replacing the laser/ scanner, the problem persists, replace the dc controller PCA. See Dc controller PCA. 5 If, after replacing the dc controller PCA, the problem persists, replace the Formatter assembly. See Formatter assembly . Horizontal scars on the photosensitive drum. Defective fuser film. Replace the print cartridge. Replace the fuser. Table 7-25 Grey background Possible cause Recommended action(s) The media does not meet 1 Turn over the stack of media in the specifications or is not stored correctly. tray. Also try rotating the media 180°. 2 Check the media type and quality. Replace the media if it does not meet specifications, and advise the customer to use the HPrecommended media and to store it correctly. See Media specifications. The inside of the printer is dirty (toner leaked out of the print cartridge). The operating environment does not meet specifications. Clean the inside of the printer (see chapter 3), and install a new print cartridge. Make sure that the printer is installed in an area that meets the environmental specifications. See Operating environment. 388 7 Troubleshooting