HP 4300 Service Manual - Page 336

Table 59. Lines Possible cause Recommended action(s) Vertical lines (in the paper path direction) The print cartridge is not seated correctly. q Remove the print cartridge and the reinstall it. The top cover should be able to completely close when the print cartridge is fully seated. Defective print cartridge. q Perform the half self-test functional check. See "Half self-test functional check" on page 310. If the defect developed on the drum, replace the print cartridge. Worn or dirty fuser roller. q Process a printer cleaning page. See "Running the cleaning page manually" on page 56. Several pages might be required if the fuser is very dirty. If the problem persists, replace the fuser. See "Fuser" on page 162. Static eliminator teeth (just beyond the q Clean the teeth with a small brush or compressed air. Replace transfer roller) are contaminated or the assembly if it is damaged. defective. Light is leaking into the printer. q Make sure that all of the covers are in place. Move the printer away from outside facing windows. Horizontal lines (opposite the paper path direction) Repetitive defect. If the lines are repeated at a consistent interval down the page, this is a repetitive defect. q Use the repetitive defect ruler to determine the cause of this defect. See "Repetitive defects troubleshooting" on page 325. Sharp random lines indicate a problem with the laser/scanner control circuitry. q Replace the following in order: 1. Laser/scanner assembly. See "Laser/scanner assembly" on page 173. 2. DC controller PCA. See "DC controller PCA" on page 181. 3. Cables between the DC controller and the laser/scanner assembly. 4. Formatter assembly. See "Formatter assembly" on page 161. 316 Troubleshooting Q2431-90912