Printing quality problems2846. TroubleshootingCurl If the printed paper is curled or paper does not feed into the machine:• Turn the stack of paper over in the tray. Also try rotating the paper 180° in the tray.• Change the printer’s paper option and try again. Go to Printing Preferences, click the Paper tab, and set type to Thin (see"Opening printing preferences" on page 56).• An unknown imagerepetitively appears on a fewsheets• Loose toner• Light print or contaminationoccursYour machine is probably being used at an altitude of 1,000 m (3,281 ft) or above.The high altitude may affect the print quality, such as loose toner or light imaging. Change the altitude setting for your machine (see"Altitude adjustment" on page 213).Condition Suggested solutions