Check the toner cartridge:

1. Check if the toner cartridge needs replacing
2. If toner is low, refill or replace the cartridge as needed
3. If the cartridge is not empty, clean the toner cartridges contact area on the printer
4. Reinstall the toner cartridge and print a sample page to see if the smudges have gone

1. Clean the drum unit according to manufacturer’s instructions
2. Reinstall the drum unit in the printer and print a sample page
3. If the smudges remain, replace the drum unit and try printing a sample page again