Wrong Paper

• Using paper that's too smooth for your printer could cause the toner not to stick. Use only recommended papers, and set the printer properly for the paper you're using. Most programs allow you to set paper type from the print menu.
  
  

Double-Sided Smears

• If you re-feed a freshly printed page back into the printer for double-sided printing, the rubber rollers that feed the paper could pick up toner from the initial printing. The result is an unattractive, smeared print. Always allow pages to cool completely before re-feeding. Clean the printer rollers, and then try printing again.
  
  

Printer Contamination

• Dust or debris inside the printer can prevent toner from fusing to the paper correctly, resulting in a smear. Print one or two more pages to see if the problem fixes itself. If it persists, clean the printer, or use the cleaning page for your printer to remove the debris.
  
  

Defective Cartridge

• Defective toner cartridges may leak or release too much toner at once, causing free-floating black or colored dust inside the printer. This results in smearing. Replace the toner cartridge, and then clean the printer to reduce page smears.
  
  

Dirty Roller

• If the fusing roller inside the printer becomes dirty or scratched, it may leave deposits on the page, which smear when the printer ejects the paper. Remove the roller and inspect it closely for damage or built-up toner. Clean it using isopropyl alcohol and a soft cloth, but only after the roller has cooled completely.
  
  

Poor Bonding

• If the fusing assembly stops heating, or heats to a lower temperature than required to melt the toner, the page may smear easily. Check the fuser after printing. If it's not hot, you may need a new one. Have a qualified technician replace this part to avoid future problems.
  
  

Dirty Corona Wires

• If the main or transfer corona develop toner deposits or other debris, they can leave vertical white lines or a dingy gray mist on the paper. Fix this quickly by replacing the toner cartridge. If you have the time for a more detailed repair, use a cotton swab dipped in alcohol or a felt-lined printer cleaning tool to wipe the exposed wires on the cartridge. Work carefully; these wires are delicate and easily break.