Image-defect tables

 

 

 

 

 

Hint

 

The image defects described in this section are associated with the ADF unit and the scan unit.

 

 

For more information about image defects and their causes, see the HP LaserJet 4100 series

 

 

printer service manual.

 

 

 

 

 

 

The MFP output quality is subject to user judgment. This section of the manual helps define

 

print-quality defects and the factors that affect print quality.

 

The print samples shown in the following figures illustrate some print-quality defects. To use for

 

future reference, HP suggests that you keep copies of print-quality defects you encounter in the

 

field and an explanation of their causes.

 

 

 

 

 

Hint

 

When troubleshooting image defects, try scanning a test page through the ADF and from the

 

 

glass to help isolate the cause of the image defect to the ADF unit, scan unit or the print unit.

 

 

 

 

 

 

Table 23. Image defects

 

 

 

 

 

 

 

 

 

ProblemCondition

Solution

 

 

 

 

 

 

 

 

Distorted images

Improper optical-unit drive-belt

● Adjust the belt tension for the pickup

 

 

 

 

tension.

motor. See “Optical unit” on page 95.

 

 

 

 

 

● If the problem persists, replace the

 

 

 

 

 

 

 

 

 

 

belt. See “Optical unit” on page 95.

 

 

 

 

 

 

Blank page (when

The source document was not

● Verify that the source document is

using the ADF)

placed in the ADF input tray face-up.

face-up in the ADF input tray.

 

 

 

 

 

 

 

 

The source document was not

● Remove and then reinsert the source

 

 

 

 

 

 

detected in the ADF input tray.

document into the ADF input tray.

 

 

 

 

● Verify that the document-detect-sensor

 

 

 

 

(PS2) flag freely moves See “ADF

 

 

 

 

components” on page 56.

 

 

 

 

● Use the control-panel diagnostic test

 

 

 

 

 

 

 

 

to verify that the sensor, ADF motor,

 

 

 

 

and pickup solenoid are fuctional. See

 

 

 

 

“Diagnostic tests” on page 126.

 

 

 

 

 

 

 

 

A source document was not picked

● Inspect the ADF pickup and separation

 

 

 

up when attempting to feed multiple

rollers for damage. See “ADF

 

 

 

documents.

components” on page 56. Clean the

 

 

 

 

rollers if dirty. See “Cleaning the

 

 

 

 

product” on page 36.

 

 

 

 

 

Horizontal lines

Dirty glass, whiteboard cover, ADF

● Clean the glass, whiteboard cover,

 

 

 

delivery guide (clear mylar strip).

and/or ADF delivery guide. See

 

 

 

 

“Cleaning the product” on page 36.

 

 

 

 

 

 

 

 

 

 

 

 

ADF unit and/or scan unit is

● Calibrate the scan unit. See

 

 

 

improperly calibrated.

“Calibration” on page 47 and/or

 

 

 

 

 

 

 

“Performing manual calibration” on

 

 

 

 

 

 

 

 

page 48.

 

 

 

 

 

138 Troubleshooting

C9148-90909