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Visual chart of HP LaserJet print defects

Visual chart of HP LaserJet print defects

This is a useful reference chart of images, showing a picture of each of the most common print defects found in laser printers. Use this guide to identify your print defect, and read more about the print defect with potential causes and solutions.

Below is a chart of common print defects found in laser printers. It is not a complete list but should cover 90% or more of the most common image defects. Click on the defect for more info on potential causes and solutions:

Background scatter

Possible Cause -Solution

  • Toner cartridge is defective - Install a new toner cartridge

  • Fuser assembly is bad - Do a half-way test to determine if it is the fuser

  • Transfer Roller is dirty or worn. A worn Transfer Roller can cause background scatter due to improper bias voltages. - Replace the transfer roller.

Black lines - parallel or perpendicular

Possible Cause -Solution

  • parallel or perpendicular If the lines are repeated at a consistent interval down the page, this is a repetitive defect.--See the Repetitive Image Defect Ruler in the service manual to measure and determine source of lines.

Black page

Possible Cause -Solution

  • Defective toner cartridge --Install a new toner cartridgeblack pages

  • High voltage power supply circuit is defective (not supplying the correct negative voltage)--Replace the High Voltage Power Supply PCA

  • DC controller PCA is defective. If the DC Controller turns on the laser beam continuously, the entire surface of the Photosensitive drum is neutralized causing a completely black page.--Replace the DC Controller PCA

Blank page

Possible Cause -Solution

Occasional Pages

  • Multiple feeds--The printer may be feeding two or more pages at once because the paper is difficult to separate. Flex the paper a bit to help separate before installing in printer.

  • Software configuration ,. network configuration--Re-install