If you are experiencing problems with print quality, the following lists may help identify the cause of the problem.

Print quality problems associated with paper

Some print quality problems arise from use of inappropriate paper.

• Use paper that meets HP paper specifications. See Supported paper weights and sizes .
• The surface of the paper is too smooth. Use paper that meets HP paper specifications. See Supported paper weights and sizes .
• The driver setting is incorrect. To change the paper type setting, see Type and Size .
• The paper you are using is too heavy for the paper type setting you selected, and the toner is not fusing to the paper.
• The moisture content of the paper is uneven, too high, or too low. Use paper from a different source or from an unopened ream of paper.
• Some areas of the paper reject toner. Use paper from a different source or from an unopened ream of paper.
• The letterhead you are using is printed on rough paper. Use a smoother, xerographic paper. If this solves your problem, consult with the printer of your letterhead to verify that the paper used meets the specifications for this printer. See Supported paper weights and sizes .
• The paper is excessively rough. Use a smoother, xerographic paper.
• The transparencies you are using are not designed for proper toner adhesion. Use only transparencies designed for HP Color LaserJet printers.

Overhead transparency defects

Overhead transparencies may display any of the image quality problems that any other type of paper will cause, as well as defects specific to printing on transparencies. In addition, because transparencies are pliable while in the print path, they are subject to being marked by the paper-handling components.

• In the printer driver Paper tab, select Transparency as the paper type. Also, make sure that the tray is correctly configured for transparencies.
• Check that the transparencies meet the specifications for this printer. See Supported paper weights and sizes . For more information, consult the HP LaserJet Printer Family Print Media Guide . See http://www.hp.com/support/clj5550 for HP LaserJet Printer Family Print Media Guide ordering information. For downloadable manuals, go to http://www.hp.com/support/clj5550 . When you connect, select Manuals .
• The transparencies you are using are not designed for proper toner adhesion. Use only transparencies designed for HP Color LaserJet printers.
• If the color is off and the printer control panel displays the 41.5 UNEXPECTED TYPE IN TRAY X LOAD TRAY X error, the OHT sensor might be dirty. See Periodic cleaning for OHT cleaning instructions.
• Handle transparencies by the edges. Skin oil on the surface of transparencies can cause spots and smudges.
• Small, random dark areas on the trailing edge of solid fill pages may be caused by transparencies sticking together in the output bin. Try printing the job in smaller batches.
• The selected colors are undesirable when printed. Select different colors in the software application or printer driver.
• If you are using a reflective overhead projector, use a standard overhead projector instead.

Print quality problems associated with the environment

Print quality problems can occur if the printer is operating in an environment outside of the printer specifications (see Printer specifications ).

Print quality problems associated with jams

Make sure that all paper is cleared from the paper path. See Paper jam recovery .

• If the printer recently jammed, print two to three pages to clean the printer.
• If the paper does not pass through the fuser, which causes image defects to appear on subsequent documents, print two to three pages to clean the printer. However, if the problem persists see the next section.

Print quality problems associated with maintenance

Some print quality problems might occur when the printer needs cleaning. See Periodic cleaning for more information.

Print quality troubleshooting pages

The print quality troubleshooting pages provide information on aspects of the printer that affect print quality.

1. 1. Press Menu to enter the MENUS .
   2. Press down button to highlight DIAGNOSTICS .
   3. Press checkmark to select DIAGNOSTICS .
   4. Press down button to highlight PQ TROUBLESHOOTING .
   5. Press checkmark to select PQ TROUBLESHOOTING .

The message Printing... PQ troubleshooting appears on the display until the printer finishes printing the print quality troubleshooting information. The printer returns to the Ready state after printing the print quality troubleshooting information.

The print quality troubleshooting information includes one page for each color (cyan, magenta, yellow, and black), printer statistics related to print quality, instructions on interpreting the information, and procedures to solve print quality problems.

If following the procedures recommended by the print quality troubleshooting pages do not improve print quality, go to http://www.hp.com/support/clj5550 .

Calibrating the printer

The HP Color LaserJet 5550 printer automatically calibrates and cleans at various times to maintain the highest level of print quality. The user may also request the printer to calibrate via the printer's control panel, using QUICK CALIBRATE NOW or FULL CALIBRATE NOW located in the CALIBRATION and PRINT QUALITY menu. QUICK CALIBRATE NOW is used for color tone calibration and takes about 90 seconds. If color density or tone seems wrong, Quick Calibration can be run. Full Calibration includes the Quick Calibrate routines and adds Drum Phase Calibration and Color Plane Registration (CPR). This takes about 3 minutes and 30 seconds. If color layers (cyan, magenta, yellow, black) on the printed page seem to be shifted from one another, Full Calibration should be run.

The HP Color LaserJet 5550 printer incorporates a new feature to skip calibration when appropriate, making the printer available more quickly. For example, when the power switch is turned off, then on again quickly, calibration is not needed and will be skipped. This saves approximately one minute in time to be ready.

The printer may pause printing while it is calibrating or cleaning. When possible, the printer will wait for the job to complete before calibrating or cleaning.

1. 1. Press Menu to enter the MENUS .
   2. Press down button to highlight CONFIGURE DEVICE .
   3. Press checkmark to select CONFIGURE DEVICE .
   4. Press down button to highlight PRINT QUALITY .
   5. Press checkmark to select PRINT QUALITY .
   6. Press down button to highlight QUICK CALIBRATE NOW .
   7. Press checkmark to select QUICK CALIBRATE NOW .

OR

To perform a full calibration, use FULL CALIBRATE NOW instead of QUICK CALIBRATE NOW in Steps 6 and 7.

Print quality defect chart

Use the examples in the print quality defect chart to determine which print-quality problem you are experiencing, and then see the corresponding pages to find information that can help you troubleshoot the problem. For the latest information and problem-solving procedures, go to http://www.hp.com/support/clj5550 .

An image with no defects

	Horizontal lines or streaks		Misaligned colors
	Vertical lines		Repetitive defects
	Color fade in all colors		Color fade in one color
	Fingerprints and media dents		Loose toner
	Smeared toner		White areas (dropouts) on page
	Media damage (wrinkles, curl, creases, tears)		Specks or stray toner
	Skewed, stretched, or off-center page