HP LaserJet 4250 Service Manual - Page 414
Repetitive-defects troubleshooting, Table, Repetitive, defects - image defect ruler
View all HP LaserJet 4250 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 414 highlights
Table 7-39 Dark print Possible cause Recommended action(s) The toner-density setting is incorrect. Open the print-quality menu at the control panel and adjust the tonerdensity setting. See Print-quality submenu. The print cartridge drum is close to the Replace the print cartridge. end of its expected life. 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 for type and quality. Replace the media, and advise the customer to use the HPrecommended media and to store it correctly. See Media specifications. The high-voltage contact to the power supply is poor. The laser/scanner assembly is defective. The high-voltage circuit is defective. Clean the contacts if they are dirty. If the problem persists after cleaning, or if the contacts are damaged or deformed, replace the contacts. Replace the laser/scanner assembly. See Laser/scanner assembly. Replace the power-supply assembly. See Power supply. Repetitive-defects troubleshooting Defects on printer rollers can cause image defects to appear at regular intervals on the page, corresponding to the circumference of the roller that is causing the defect. Measure the distance between defects that recur on a page. Use the following table or the repetitive-defect ruler to determine which roller is causing the defect. To resolve the problem, try cleaning the roller first. If the roller remains dirty after cleaning or if it is damaged, replace the part that is indicated in Table 7-40 Repetitive defects. CAUTION Do not use solvents or oils to clean rollers. Instead, rub the roller with lint-free paper. If dirt is difficult to remove, rub the roller with lint-free paper that has been dampened with water. Table 7-40 Repetitive defects Roller Primary charging roller Developer roller* Fuser Distance between defects 37.7 mm (1.5 inches) 62.8 mm (2.5 inches) 75.0 mm (2.95 inches) 94.0 mm (3.75 inches) Replacement part Print cartridge Print cartridge Fuser 400 7 Troubleshooting