This means you’ve probably got an issue with the drum in your printer, the mark being in the same part of every page is because the drum has wear-and-tear and the damaged section of it keeps marking the same part of the page.
If you recently replaced a cartridge or drum unit
That unit has a defect and will likely need replacing. Let us know your details and we'll have a replacement sent out for you and get you printing as quickly as possible.
If you only replaced a toner and you have a separate drum unit
Check the remaining life of your drum unit, it is likely running low on life and will need replacing. Once a new drum is installed your print quality will return to normal.
If you have faded lines on different parts of the page then you likely have an ink cartridge printer with one cartridge having an issue - check troubleshooting for that here.
