Lines or streaks on printed pages
First see whether the lines also appear on a page printed by the printer itself. That tells you whether to check the printer or the computer next.
1. Print a test page from the printer
If the lines appear there too: the problem is in the printer. Start with clean paper, then use the normal cleaning or supply checks for your exact model.
If the printer's page looks clean: try the same job from another program before cleaning or replacing anything.
2. Try clean, dry paper
Reload a small stack of flat, dry paper and make sure the paper type selected on the printer matches what you loaded. Damp or damaged paper can cause smears and uneven printing.
3. If you have an inkjet printer
Use the printer maker's normal nozzle check, printhead cleaning, or alignment. Test after each step instead of running cleaning again and again.
4. If you have a laser printer
Follow the exact model's normal toner and maintenance instructions. Do not touch covered or hot parts inside the printer.
5. If only computer print jobs have lines
Check the paper type and print-quality settings. If only one program or file has the problem, use the one-program guide.