Image defects The quality of the MFP output is subject to user judgment. This section of the manual helps to define print-quality defects and the factors that affect print quality. The print samples shown in the following table illustrate some print-quality defects. Keep copies of print-quality defects you encounter in the field and an explanation of their causes to use for future reference. Note Verify that the image defect is only on scanned images. If an image defect is on printed pages, see the HP LaserJet 9000 series printer service manual.
Note For blank pages, vertical lines, and horizontal lines defects, verify whether the image defect occurs on scanned pages from the glass, the ADF, or both. Table 31. Image defects C8523-90921 Image-formation troubleshooting 229 Problem Condition Solution Blank page Dirty white calibration strips. Clean the white calibration strips on the back of the glass. If the problem persists, replace the glass. Defective flatbed inverter PCB. Replace the flatbed inverter PCB. Defective flatbed scanning lamp. Replace the flatbed scanning lamp assembly. Defective flatbed CCD driver. Replace the flatbed optical assembly. Dirty white calibration strips.
Clean the white calibration strip on the delivery roller cover. If the problem persists, replace the delivery roller cover. Defective ADF inverter PCB. Replace the ADF inverter PCB. Defective ADF scanning lamp. Replace the ADF scanning lamp assembly. Defective ADF analog processor PCB. Replace the ADF analog processor PCB. Defective ADF CCD driver. Replace the ADF optical assembly.