Poor printing quality in laser printers can be caused by a variety of factors. You can check the following:
Image and Printer Resolution
Use the highest resolution of your file to improve image quality. The best one would be your original file. Avoid using screenshots or compressed copies.
Next go to your printer settings and adjust it to its highest possible resolution.
Printer Speed
If the color saturation of your print is too high, simply increase your printer's printing speed in the printer settings. This will prevent your printer from printing too much per line. If the color saturation of your print is too low, slow down your printer's printing speed.
Toner Save Mode Activated
If Toner Save Mode is activated, the printer will use less toner to prolong the cartridge. Please check your printer's manual on how to deactivate Toner Save Mode.
Printer Environment
Extreme printer environment can cause faint printing, gray backgrounds and spotty printing.
High humidity, high temperatures and other extreme elements can affect the printer's mechanism such as its fuser that melts the toner powder. Extreme element can also affect toner powder to clump.
To resolve the issue, please relocate the laser printer away from direct sunlight in a well-ventilated room with a temperature of 50-90⁰ F and humidity levels of 20-80%.
Faulty Toner Cartridge
Faulty cartridges that hinder toner flow can cause faint printing or vertical blank lines. While faulty cartridges with loose parts can cause unwanted toner marks, vertical black lines or gray backgrounds.
Please replace the toner cartridge with a new one to confirm.
Faulty Drum Unit
A faulty drum unit can cause a variety of poor printing. This is because the laser printer forms the images into the drum unit with a positive charged laser. The toner powder will then be attracted to the positive charge to form the intended print.
Worn drum units are not as effective at attracting toner powder. This can cause:
- Interval blank marks
- Faint printing
- Spotty printing
- Blank lines across the page
- Gradually fading printing
Overused drum units that have stuck toner powder can cause:
- Interval toner marks
- Toner specks
- Lines across the page
- Gray background
- Black pages
Therefore, the drum unit will need to be replaced.
Paper Specifications
Paper with rough surfaces can cause uneven toner powder distribution. This causes blank lines, toner specks or gradually fading printing. Please check if your printing paper is compatible with your laser printer.
You can also check if the type of paper you're using matches the paper type in your printer's settings. Incompatible paper can cause poor printing quality such as gray backgrounds, gradually fading printing, spotty printing, toner specks, toner marks or blank lines.
When your paper doesn't match the paper type in the printer's settings, it can cause blank lines and gradually fading printing.
Contaminated Fuser Unit
The fuser unit is the part of the printer that fuses toner powder into the paper with heat.
A contaminated fuser unit will not be able to fuse toner the longer it's used. A contaminated fuser can be clogged, causing gradually fading print.
A contaminated fuser can also smudge the paper with toner specks, black lines or black pages.
Please contact your printer manufacturer's customer service to know how to clean the fuser unit of your printer model.