HP 2700n Service Manual - Page 228

Completely blank image Table 6-8 Causes for a completely blank image Cause Solution High-voltage PCB is defective (no developing-bias output) Replace the high-voltage PCB. DC controller PCB is defective Replace the DC controller PCB. Calibrate the printer after replacing the DC controller. All black or solid color Table 6-9 Causes for an all black or solid colored image Cause Poor contacts with the primary-charging bias, developing bias, or drum grounding Cartridge (primary-charging roller) is defective High-voltage PCB is defective DC controller PCB is defective Solution On the cartridge that is producing the solid color, check the primary-charging bias and developing-bias contacts to the high-voltage PCB, or the drum-grounding contacts. Clean the contacts as necessary. Replace any deformed or damaged contacts. Replace the cartridge that is producing the solid color. Replace the high-voltage PCB. Replace the DC controller PCB. Calibrate the printer after replacing the DC controller. Dots in vertical lines Table 6-10 Causes for vertical lines of white dots Cause Solution Transfer unit or primary-transfer charging roller is deformed Replace the transfer unit. or deteriorated Secondary-transfer charging roller is deformed or deteriorated Replace the secondary-transfer charging roller. High-voltage PCB is defective Replace the high-voltage PCB. DC controller PCB is defective Replace the DC controller PCB. Calibrate the printer after replacing the DC controller. Dirt on back of paper If the defect is repetitive dirt, go to step A; if not, go to step B. Table 6-11 Causes for dirt on the back of the paper Cause Solution A Repetitive dirt (dirty registration roller, pressure roller, See Table 6-26 Causes of repetitive defects feed roller, fuser delivery roller, or face-down delivery on page 216 to identify the roller with which the problem is sub-roller) 210 Chapter 6 Troubleshooting ENWW