Why is a laser printer printing all gray?

Printing with a laser printer?

• Everytime i use my laser printer there seems to be lines in the print like "little wheels" it happens mostly when printing graphics in color such as black.this printer im using is a brother-4070cdw it is fantastic it does everything else except for that small little defect.i owned aHP colorsphere 1600 and got that same issue.anyone else out there have this same problem?

• Answer:

  After a period of use, the photosynthetic drum that transfers the toner from the hopper to the paper can become worn. When this happens, often toner will stick to non-charged areas. There is also the possibility of toner dust being stuck to the feed wheels, but this would only be a temporary issue/ Find out how often you are supposed to replace the drum on that model, if it is outside that timeframe replace the drum.