Canon colour printer/scanner (black not working properly) (New Marston OX3)

Canon PIXMA MG4150. works perfectly for scanning/copying. Colour printer works fine, black appears fuzzy and haven't been able to fix this. Have shown a test sheet in photo to show quality of black/colour print. Includes manual, CD ROM set up and refillable colour cartridges/ink if wanted (just let me know if you'd rather not have these).