Samsung ML-4551ND, ML-4550 manual Solving print quality problems

Solving print quality problems

Dirt inside of the printer or improper paper loading may reduce print quality. See the table below to troubleshoot problems.

Condition	Suggested solutions
Light or faded	If a vertical white streak or faded area appears
print	on the page:

AaBbCc	•	The toner supply is low. You may be able to
		temporarily extend the toner cartridge life. See
AaBbCc		page 8.4. If this does not improve print quality,
AaBbCc	•	install a new toner cartridge.
AaBbCc		The paper may not meet paper specifications
		(for example, the paper is too moist or too
AaBbCc
		rough). See page 5.3.
	•	If the entire page is light, the print resolution
		setting is too light or toner save mode is on.
		Adjust the print resolution and toner save
		mode in the printer properties. See the
		Software Section.
	•	If the entire page is faded with "Toner Low
		Replace Toner" message on LCD,
		set "CLR Empty Msg." to "On" referring to
		page 8.7. In this case, you can keep printing
		but the quality cannot be guaranteed, and the
		product support is no longer provided.
	•	A combination of faded or smeared defects
		may indicate that the printer needs cleaning.
		See page 8.1.
	•	The surface of LSU may be dirty. Clean the
		LSU. See page 8.2.

Toner spots	• The paper may not meet specifications (for
AaBbCc	example, the paper is too moist or too rough).
	See page 5.3.
AaBbCc	• The transfer roller or paper path may be dirty.
AaBbCc	See page 8.1.
AaBbCc
AaBbCc

Condition		Suggested solutions
Dropouts	If generally rounded, faded areas occur
	randomly on the page:
AaBbCc	•	A single sheet of paper may be defective. Try
AaBbCc		reprinting the job.
AaBbCc	•	The moisture content of the paper is uneven
AaBbCc		or the paper has moist spots on its surface.
		Try a different brand of paper. See page 5.3.
AaBbCc
	•	The paper lot is bad. The manufacturing
		processes can cause some areas to reject
		toner. Try a different kind or brand of paper.

•The toner cartridge may be defective. See “Vertical repetitive defects” on the next page.

•If these steps do not correct the problems, contact a service representative.

Vertical lines If black vertical streaks appear on the page:

AaBbCc	• The drum inside the toner cartridge has
	probably been scratched. Install a new toner
AaBbCc	cartridge. See page 8.5.
AaBbCc	If white vertical streaks appear on the page:
AaBbCc	• The surface of the LSU part inside the printer
AaBbCc	may be dirty. Clean the LSU. See page 8.2.

Gray	If the amount of background shading becomes
background	unacceptable, the procedures below may fix the
	problem.

AaBbCc	• Change to lighter weight pages. See page 5.3.
AaBbCc	• Check the printer’s environment; very dry (low
AaBbCc	humidity) or high humidity (higher than 80%
AaBbCc	RH) conditions can increase the amount of
AaBbCc	background shading.
	• Remove the old toner cartridge and install a
	new one. See page 8.5.

Toner smear	•	Clean the inside of the printer. See page 8.1.
	•	Check the type and quality. See page 5.2.
	•	Remove the toner cartridge and install a new
		one. See page 8.5.

9.11 <Troubleshooting>