HP 4700n Service Manual - Page 473

Table 7-30 Causes for distortion or blurring Cause The color-plane registration is out of specification. The cartridge OPC drum is slipping. The ETB is defective. The ETB motor drive gear is worn or damaged. The drum motor drive gear is worn or damaged. The color misregistration detection unit is defective. The laser/scanner unit is defective. The DC controller PCB may require a firmware upgrade or the connectors to the high-voltage PCB (J1002 Yellow, J1003 Cyan, J1004 Magenta, and J1005 Black) are disconnected or not seated properly. Solution Calibrate the printer from the PRINT QUALITY menu. See Full Calibrate Now on page 539. 1. Set the pre-rotation optimize mode to on. 2. Replace the cartridge. If the ETB belt does not rotate smoothly, replace the ETB. Calibrate the printer after replacing the ETB. See Full Calibrate Now on page 539. Replace the ETB. Replace the drum motor for the affected color. See Remove main drive assembly on page 256. Replace the paper feed assembly. See Paper feed assembly on page 283. Replace the laser/scanner for the affected color. See Laser/ scanner assembly on page 287. Calibrate the printer after replacing the laser/scanner. See Full Calibrate Now on page 539. 1. Upgrade formatter and DC Controller firmware, which can be found in a single .rfu file from http://www.hp.com/ support/clj4700 or http://www.hp.com/support/cp4005. 2. Check the connectors (J1002 Yellow, J1003 Cyan, J1004 Magenta, and J1005 Black) on the DC controller PCB to make sure they are seated correctly. Smearing This table contains information about the causes of and solutions for smearing. Table 7-31 Causes for smearing Cause A poor contact exists in the printer ground and cartridge ground contacts. Solution Clean each print-cartridge ground contact and the printer ground contact. If they are still dirty after cleaning, or if they ENWW Image defects 453