HP LaserJet Pro 4001dw Monochrome Wireless Printer - Manual (Page 102)

7. Open the front door.
8. Close the front door.
Resolving print quality problems
Review the following information about resolving print quality problems.
Introduction
Use the information below to troubleshoot print-quality problems, including issues with image quality.
The troubleshooting steps can help resolve the following defects:
● Blank pages
● Black pages
● Curled paper
● Dark or light bands
● Dark or light streaks
● Fuzzy print
● Gray background or dark print
Resolving print quality problems 93