1, check whether the paper is normal, and replace the printing paper with better quality;
2. Check whether there are black spots on the drum core of the toner cartridge. If there are black spots, replace the drum core;
3. Check that there are black spots on the platen glass, and clean the platen glass with a paper towel;
4. Check whether there is a powder block on the fixing component, resulting in black spots when printing out;
5, check the laser for foreign bodies, clean the laser.