Hello,
If you are getting blue smudges/streaks on the page when you are printing in black and white, it looks like there is loose toner power in the printer or there is something wrong with the hardware. In this situation, you can try reseating the color toner cartridges. While the toner is out of the printer, you can inspect the cartridges to see if they are leaking. You can also inspect the inside of the printer for any loose toner powder that can be wiped up with a damp cloth.
Once the toner has been resat and the printer has been checked for loose toner powder, you can clean the fixing assembly. If you continue to have issues after that, it looks like there is something wrong with the hardware or the toner needs to be replaced. At that point, I would suggest contacting support over the phone at 1-800-652-2666 to check your available service options
